How To Cover NASA's Chandra X-ray Observatory

NASA Astrophysics Data System (ADS)

1999-07-01

NASA's newest space telescope, the Chandra X-ray Observatory, is scheduled for launch not earlier than July 20, 1999, aboard Space Shuttle mission STS-93. The world's most powerful X-ray observatory, Chandra will join the Hubble Space Telescope and NASA's other great observatories in an unprecedented study of our universe. With its capability to "see" an otherwise invisible but violent, vibrant and ever-changing universe, Chandra will provide insights into the universe's structure and evolution. The following information is designed to assist news media representatives cover launch and activation of the Chandra X-ray Observatory. Covering from the Chandra Control Center NASA will establish a news center at the Chandra X-ray Observatory Operations Control Center in Cambridge, Mass., during the critical period of launch and early activation. The news center will be open from approximately two days prior to launch until the observatory is established in its operating orbit approximately 11 days after launch. The telephone numbers for the news center are: (617) 496-4454 (617) 496-4462 (617) 496-4484 The news center will be staffed around the clock during the Shuttle mission by media relations officers knowledgeable about the Chandra mission and its status. Media covering from the news center will be provided work space and have opportunities for face-to-face interviews with Chandra management, control team members and Chandra scientists. They will be able to participate in daily Chandra status briefings and have access to a special control room viewing area. Additionally, media covering from Cambridge will receive periodic status reports on Chandra and the STS-93 mission, and will be able to participate in interactive televised briefings on the STS-93 mission originating from other NASA centers. While advance accreditation is not required, media interested in covering Chandra from the Operations Control Center should contact Dave Drachlis by telephone at (256) 544-0031 in advance of the mission to make arrangements for special support, such as telephone service, and uplink or remote truck parking. Covering from the Kennedy Space Center The Kennedy Space Center, Fla., news center is primarily responsible for disseminating information about the Shuttle countdown and launch. However, media relations officers knowledgeable about Chandra will be present at the Kennedy news center through launch. Additionally, some members of the Chandra management and science team will be at the Kennedy Space Center and available for interviews through launch. Media interested in covering the Chandra launch from the Kennedy Space Center should contact its Public Affairs Office at (407) 867-2468. Prior accreditation is required. Covering from the Johnson Space Center The Johnson Space Center, Houston, Texas, news center has responsibility for disseminating information about STS-93 flight operations. Media interested in covering the mission from the Johnson Space Center should contact its Public Affairs Office at (281) 483-5111. Prior accreditation is required. Status Reports During the STS-93 Space Shuttle mission to launch Chandra, NASA will issue twice-daily status reports from the Chandra Operations Control Center in Cambridge, Mass. Following the Shuttle mission, through Chandra's on-orbit checkout period, reports will be issued weekly. These reports are available via the Internet at: http://chandra.msfc.nasa.gov Press Briefings During the Space Shuttle mission to launch the observatory, NASA will conduct daily press briefings on the status of the observatory. These briefings will be conducted at the Chandra Operations Control Center in Cambridge, Mass. Media briefings will be broadcast on NASA Television (see below). Media without access to NASA Television may monitor the briefings by calling (256) 544-5300 and asking to be connected to the NASA Television audio feed. A briefing schedule will be released before launch and updated as appropriate during the mission. NASA Television The launch and early activation of the Chandra X-ray Observatory will be carried live on NASA Television, available through the GE2 satellite system, which is located on Transponder 9C, at 85 degrees west longitude, frequency 3880.0 MHz, audio 6.8 MHz. Around-the-clock, up-to-the minute commentary, television and daily briefings on Chandra's status will originate from the Chandra Operations Control Center in Cambridge, Mass., during Shuttle Mission STS-93. Internet Information Up-to-date, comprehensive information on the Chandra X-ray Observatory is available to news media on the Internet at: http://chandra.harvard.edu The latest status reports, news releases, photos, fact sheets and background archives, as well as links to other Chandra-related sites, are available at this address. Live Shots - Television Back-hauls Television station news departments may conduct live, or live-to-tape interviews via the NASA satellite with Chandra program managers, scientists and control team members prior to, during, and following the launch of Chandra. For additional information or to arrange interviews, broadcasters may contact Dave Drachlis at (256) 544-0031. Interviews Members of the Chandra development, operations, and science teams are available to the news media for interviews upon request. NASA TV on the web

Chandra Resolves Cosmic X-ray Glow and Finds Mysterious New Sources

NASA Astrophysics Data System (ADS)

2000-01-01

While taking a giant leap towards solving one of the greatest mysteries of X-ray astronomy, NASA's Chandra X-ray Observatory also may have revealed the most distant objects ever seen in the universe and discovered two puzzling new types of cosmic objects. Not bad for being on the job only five months. Chandra has resolved most of the X-ray background, a pervasive glow of X-rays throughout the universe, first discovered in the early days of space exploration. Before now, scientists have not been able to discern the background's origin, because no X-ray telescope until Chandra has had both the angular resolution and sensitivity to resolve it. "This is a major discovery," said Dr. Alan Bunner, Director of NASA's Structure andEvolution of the universe science theme. "Since it was first observed thirty-seven years ago, understanding the source of the X-ray background has been aHoly Grail of X-ray astronomy. Now, it is within reach." The results of the observation will be discussed today at the 195th national meeting of the American Astronomical Society in Atlanta, Georgia. An article describing this work has been submitted to the journal Nature by Dr. Richard Mushotzky, of NASA Goddard Space Flight Center, Greenbelt, Md., Drs. Lennox Cowie and Amy Barger at the University of Hawaii, Honolulu, and Dr. Keith Arnaud of the University of Maryland, College Park. "We are all very excited by this finding," said Mushotzky. "The resolution of most of the hard X-ray background during the first few months of the Chandra mission is a tribute to the power of this observatory and bodes extremely well for its scientific future," Scientists have known about the X-ray glow, called the X-ray background, since the dawn of X-ray astronomy in the early 1960s. They have been unable to discern its origin, however, for no X-ray telescope until Chandra has had both the angular resolution and sensitivity to resolve it. The German-led ROSAT mission, now completed, resolved much of the lower-energy X-ray background, showing that it arose in very faraway galaxies with extremely bright cores, called quasars or Active Galactic Nuclei (AGN). The Chandra team sampled a region of the sky about one-fifth the angular area of a full moon and resolved about 80 percent of the more-energetic X-ray background into discrete sources. Stretched across the entire sky, this would account for approximately 70 million sources, most of which would be identified with galaxies. Their analysis confirms that a significant fraction of the X-ray background cannot be due to diffuse radiation from hot, intergalactic gas. Combined X-ray and optical observations showed that nearly one third of the sources are galaxies whose cores are very bright in X rays yet emit virtually no optical light from the core. The observation suggests that these "veiled galactic nuclei" galaxies may number in the tens of millions over the whole sky. They almost certainly harbor a massive black hole at their core that produces X rays as the gas is pulled toward it at nearly the speed of light. Their bright X-ray cores place these galaxies in the AGN family. Because these numerous AGN are bright in X rays, but optically dim, the Chandra observation implies that optical surveys of AGN are very incomplete. A second new class of objects, comprising approximately one-third of the background, is assumed to be "ultra-faint galaxies." Mushotzky said that these sources may emit little or no optical light, either because the dust around the galaxy blocks the light totally or because the optical light is eventually absorbed by relatively cool gas during its long journey across the universe. In the latter scenario, Mushotzky said that these sources would have a redshift of 6 or higher, meaning that they are well over 14 billion light years away and thus the earliest, most distant objects ever identified. "This is a very exciting discovery," said Dr. Alan Bunner, Director of NASA's Structure and Evolution of the universe science theme. "Since it was first observedthirty-seven years ago, understanding the source of the X-ray background has been the Holy Grail of X-ray astronomy. Now, it is within reach." Drs. Cowie and Barger are searching for the optical counterparts to the newly discovered X-ray sources with the powerful Keck telescope atop Mauna Kea in hopes of determining their distance. However, these sources are very faint optically: They show up as a dim blue smudge or not at all. Further observations with the Hubble Space Telescope or Keck will be extremely difficult, and the power of the Next Generation Space Telescope and Constellation-X may be required to fully understand these sources. Resolution of the X-ray background relied on a 27.7-hour Chandra observation using the Advanced CCD Imaging Spectrometer (ACIS) in early December 1999, and also utilized data from the Japan-U.S. Advanced Satellite for Cosmology and Astrophysics (ASCA). The Chandra team has also reproduced the ROSAT lower-energy X-ray background observation with a factor of 2-5 times the resolution and sensitivity. For images connected to this release, and to follow Chandra's progress, visit the Chandra site at: http://chandra.harvard.edu/photo/2000/bg/index.html AND http://chandra.nasa.gov The ACIS instrument was built for NASA by the Massachusetts Institute of Technology, Cambridge, and Pennsylvania State University, University Park. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program. TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass.

NASA Satellites Find High-Energy Surprises in 'Constant' Crab Nebula

NASA Image and Video Library

2011-01-12

NASA image release January 12, 2010 NASA's Chandra X-ray Observatory reveals the complex X-ray-emitting central region of the Crab Nebula. This image is 9.8 light-years across. Chandra observations were not compatible with the study of the nebula's X-ray variations. To read more go to: geeked.gsfc.nasa.gov/?p=4945 Credit: NASA/CXC/SAO/F. Seward et al. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Join us on Facebook

Distant Supernova Remnant Imaged by Chandra's High Resolution Camera

NASA Astrophysics Data System (ADS)

1999-09-01

The High Resolution Camera (HRC), one of the two X-ray cameras on NASA's Chandra X-ray Observatory, was placed into the focus for the first time on Monday, August 30. The first target was LMC X-1, a point-like source of X rays in the Large Magellanic Cloud. The Large Magellanic Cloud, a companion galaxy to the Milky Way, is 160,000 light years from Earth. After checking the focus with LMC X-1, Chandra observed N132D, a remnant of an exploded star in the Large Magellanic Cloud. "These were preliminary test observations," emphasized Dr. Stephen Murray, of the Harvard-Smithsonian Center for Astrophysics, principal investigator for the High Resolution Camera. "But we are very pleased with the results. All indications are that the HRC will produce X-ray images of unprecedented clarity." The N132D image shows a highly structured remnant, or shell, of 10-million-degree gas that is 80 light years across. Such a shell in the vicinity of the Sun would encompass more than fifty nearby stars. The amount of material in the N132D hot gas remnant is equal to that of 600 suns. The N132D supernova remnant appears to be colliding with a giant molecular cloud, which produces the brightening on the southern rim of the remnant. The molecular cloud, visible with a radio telescope, has the mass of 300,000 suns. The relatively weak x-radiation on the upper left shows that the shock wave is expanding into a less dense region on the edge of the molecular cloud. A number of small circular structures are visible in the central regions and a hint of a large circular loop can be seen in the upper part of the remnant. Whether the peculiar shape of the supernova remnant can be fully explained in terms of these effects, or whether they point to a peculiar cylindrically shaped explosion remains to be seen. -more- "The image is so rich in structure that it will take a while to sort out what is really going on," Murray said. "It could be multiple supernovas, or absorbing clouds in the vicinity of the supernova." The unique capabilities of the HRC stem from the close match of its imaging capability to the focusing power of the mirrors. When used with the Chandra mirrors, the HRC will make images that reveal detail as small as one-half an arc second. This is equivalent to the ability to read a stop sign at a distance of twelve miles. The checkout period for the HRC will continue for the next few weeks, during which time the team expects to acquire images of other supernova remnants, star clusters, and starburst galaxies. To follow Chandra's progress, visit the Chandra News Web site at: http://chandra.harvard.edu AND http://chandra.nasa.gov NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra X-ray Observatory for NASA's Office of Space Science, NASA Headquarters, Washington, D.C. The Smithsonian Astrophysical Observatory's Chandra X-ray Center in Cambridge, Mass., manages the Chandra science program and controls the observatory for NASA. TRW Space and Electronics Group of Redondo Beach, Calif., leads the contractor team that built Chandra. High resolution digital versions of the X-ray image (300 dpi JPG, TIFF) and other information associated with this release are available on the Internet at: http://chandra.harvard.edu/photo/0050/ or via links in: http://chandra.harvard.edu

Deepest X-Rays Ever Reveal universe Teeming With Black Holes

NASA Astrophysics Data System (ADS)

2001-03-01

For the first time, astronomers believe they have proof black holes of all sizes once ruled the universe. NASA's Chandra X-ray Observatory provided the deepest X-ray images ever recorded, and those pictures deliver a novel look at the past 12 billion years of black holes. Two independent teams of astronomers today presented images that contain the faintest X-ray sources ever detected, which include an abundance of active super massive black holes. "The Chandra data show us that giant black holes were much more active in the past than at present," said Riccardo Giacconi, of Johns Hopkins University and Associated Universities, Inc., Washington, DC. The exposure is known as "Chandra Deep Field South" since it is located in the Southern Hemisphere constellation of Fornax. "In this million-second image, we also detect relatively faint X-ray emission from galaxies, groups, and clusters of galaxies". The images, known as Chandra Deep Fields, were obtained during many long exposures over the course of more than a year. Data from the Chandra Deep Field South will be placed in a public archive for scientists beginning today. "For the first time, we are able to use X-rays to look back to a time when normal galaxies were several billion years younger," said Ann Hornschemeier, Pennsylvania State University, University Park. The group’s 500,000-second exposure included the Hubble Deep Field North, allowing scientists the opportunity to combine the power of Chandra and the Hubble Space Telescope, two of NASA's Great Observatories. The Penn State team recently acquired an additional 500,000 seconds of data, creating another one-million-second Chandra Deep Field, located in the constellation of Ursa Major. Chandra Deep Field North/Hubble Deep Field North Press Image and Caption The images are called Chandra Deep Fields because they are comparable to the famous Hubble Deep Field in being able to see further and fainter objects than any image of the universe taken at X-ray wavelengths. Both Chandra Deep Fields are comparable in observation time to the Hubble Deep Fields, but cover a much larger area of the sky. "In essence, it is like seeing galaxies similar to our own Milky Way at much earlier times in their lives," Hornschemeier added. "These data will help scientists better understand star formation and how stellar-sized black holes evolve." Combining infrared and X-ray observations, the Penn State team also found veils of dust and gas are common around young black holes. Another discovery to emerge from the Chandra Deep Field South is the detection of an extremely distant X-ray quasar, shrouded in gas and dust. "The discovery of this object, some 12 billion light years away, is key to understanding how dense clouds of gas form galaxies, with massive black holes at their centers," said Colin Norman of Johns Hopkins University. The Chandra Deep Field South results were complemented by the extensive use of deep optical observations supplied by the Very Large Telescope of the European Southern Observatory in Garching, Germany. The Penn State team obtained optical spectroscopy and imaging using the Hobby-Eberly Telescope in Ft. Davis, TX, and the Keck Observatory atop Mauna Kea, HI. Chandra's Advanced CCD Imaging Spectrometer was developed for NASA by Penn State and Massachusetts Institute of Technology under the leadership of Penn State Professor Gordon Garmire. NASA's Marshall Space Flight Center, Huntsville, AL, manages the Chandra program for the Office of Space Science, Washington, DC. TRW, Inc., Redondo Beach, California, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, MA. More information is available on the Internet at: http://chandra.harvard.edu AND http://chandra.nasa.gov

History of Chandra X-Ray Observatory

NASA Image and Video Library

2002-01-23

Leon Van Speybroeck of the Harvard-Smithsonian Center for Astrophysics in Cambridge Massachusetts was awarded the 2002 Bruno Rossi Prize of the High-Energy Astrophysics Division of the American Astronomy Society. The Rossi Prize is an arnual recognition of significant contributions in high-energy astrophysics in honor of the Massachusetts Institute of Technology's late Professor Bruno Rossi, an authority on cosmic ray physics and a pioneer in the field of x-ray astronomy. Van Speybroeck, who led the effort to design and make the x-ray mirrors for NASA's premier Chandra X-Ray Observatory, was recognized for a career of stellar achievements in designing precision x-ray optics. As Telescope Scientist for Chandra, he has worked for more than 20 years with a team that includes scientists and engineers from the Harvard-Smithsonian, NASA's Marshall Space Flight Center, TRW, Inc., Huhes-Danbury (now B.F. Goodrich Aerospace), Optical Coating Laboratories, Inc., and Eastman-Kodak on all aspects of the x-ray mirror assembly that is the heart of the observatory.

Jupiter Hot Spot Makes Trouble For Theory

NASA Astrophysics Data System (ADS)

2002-02-01

A pulsating hot spot of X-rays has been discovered in the polar regions of Jupiter's upper atmosphere by NASA's Chandra X-ray Observatory. Previous theories cannot explain either the pulsations or the location of the hot spot, prompting scientists to search for a new process to produce Jupiter's X-rays. "The location of the X-ray hot spot effectively retires the existing explanation for Jupiter's X-ray emission, leaving us very unsure of its origin," said Randy Gladstone, of the Southwest Research Institute in San Antonio and lead author of a paper on the results in the Feb.28, 2002 issue of the journal Nature. "The source of ions that produce the X-rays must be a lot farther away from Jupiter than previously believed." Chandra observed Jupiter for 10 hours on Dec. 18, 2000, when NASA's Cassini spacecraft was flying by Jupiter on its way to Saturn. The X-ray observations revealed that most of the auroral X-rays come from a pulsating hot spot that appears at a fixed location near the north magnetic pole of Jupiter. Bright infrared and ultraviolet emissions have also been detected from this region in the past. The X-rays were observed to pulsate with a period of 45 minutes, similar to the period of high-latitude radio pulsations detected by NASA's Galileo and Cassini spacecraft. Jupiter X-ray/UV/Optical Composite Credit: X-ray: NASA/SWRI/R.Gladstone et al. UV: NASA/HST/J.Clarke et al. Optical: NASA/HST/R.Beebe et al. An aurora of X-ray light near Jupiter's polar regions had been detected by previous satellites. However, scientists were unable to determine the exact location of the X-rays. The accepted theory held that the X-rays were produced by energetic oxygen and sulfur ions that became excited as they ran into hydrogen and helium in Jupiter's atmosphere. Oxygen and sulfur ions (originally from Jupiter's moon Io) are energized while circulating around Jupiter's enormous magnetosphere. And, some - the purported X-ray producers - get dumped into Jupiter's atmosphere when they return to the region of Io's orbit. Chandra's ability to accurately determine the location of the X-rays proved this model incorrect, as ions from regions of Jupiter's magnetic field near Io cannot reach the high Jovian latitudes where most of the X-rays were observed. This result has its own problems. At the large distances required for the source of the ions - at least 30 times the radius of Jupiter - spacecraft measurements have shown that there are not nearly enough energetic oxygen and sulfur ions to account for the observed X-ray emission. One possibility is that heavy ions among the particles flowing out from the Sun as the solar wind are captured in the outer regions of Jupiter's magnetic field, then accelerated and directed toward its magnetic pole. Once captured, the ions would bounce back and forth in the magnetic field from pole to pole in an oscillating motion that might explain the pulsations. The High Resolution Camera used for the Chandra observations was built by the Smithsonian Astrophysical Observatory in Cambridge, Mass. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program, and TRW, Inc., Redondo Beach, Calif., is the prime contractor. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass.

Astronomers Find New Evidence for the Violent Demise of Sun-like Stars

NASA Astrophysics Data System (ADS)

2005-06-01

Two astronomers have used NASA's Chandra X-ray Observatory to discover a shell of superheated gas around a dying star in the Milky Way galaxy. Joel Kastner, professor of imaging science at the Rochester Institute of Technology, and Rodolpho Montez, a graduate student in physics and astronomy at the University of Rochester, will present their results today at the American Astronomical Society meeting in Minneapolis. Their discovery shows how material ejected at two million miles per hour during the final, dying stages of sun-like stars can heat previously ejected gas to the point where it will emit X-rays. The study also offers new insight into how long the ejected gas around dying stars can persist in such a superheated state. According to Kastner, the hot gas shows up in high-resolution Chandra X-ray images of the planetary nebula NGC 40, which is located about 3,000 light years away from Earth in the direction of the constellation Cepheus. Chandra X-ray & NOAO Optical Composite of NGC 40 Chandra X-ray & NOAO Optical Composite of NGC 40 "Planetary nebulae are shells of gas ejected by dying stars," Kastner explains. "They offer astronomers a 'forecast' of what could happen to our own sun about five billion years from now - when it finally exhausts the reservoir of hydrogen gas at its core that presently provides its source of nuclear power." In his research, Montez discovered the X-ray emitting shell in NGC 40 by generating an image that uses only specific energy-selected X-rays - revealing a ring of superheated gas that lies just within the portions of the nebula that appear in optical and infrared images. "This hot bubble of gas vividly demonstrates how, as a planetary nebula forms, the gas ejection process of the central, dying star becomes increasingly energetic," Kastner notes. "Mass ejection during stellar death can result in violent collisions that can heat the ejected gas up to temperatures of more than a million degrees." The detection of X-rays from NGC 40 adds to a growing list of such discoveries by Chandra and its European counterpart, the XMM-Newton X-ray satellite observatory. Kastner and Montez (along with collaborators Orsola de Marco, of the American Museum of Natural History in New York, and Noam Soker, of the Technion Institute in Haifa, Israel) have studied these previous X-ray observations of planetary nebulae, and find that the X-ray and infrared output of such objects is closely coupled. "The connection between X-ray and infrared emission seems to show that the hot bubble phase is restricted to early times in stellar death, when a planetary nebula is quite young and the dust within it is still relatively warm," says Montez about his observations. The correspondence indicates that the production of superheated gas is a short-lived phase in the life of a planetary nebula, although Kastner cautions that additional Chandra and XMM-Newton observations are required to test this idea. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate, Washington. Northrop Grumman of Redondo Beach, Calif., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Black Hole Jets Make Shock Waves

NASA Image and Video Library

2014-07-02

A composite image of the spiral galaxy NGC 4258 showing X-ray emission observed with NASA Chandra X-ray Observatory blue and infrared emission observed with NASA Spitzer Space Telescope red and green.

Kepler Supernova Remnant: A View from Chandra X-Ray Observatory

NASA Image and Video Library

2004-10-06

The images indicate that the bubble of gas that makes up the supernova remnant appears different in various types of light. Chandra reveals the hottest gas [colored blue and colored green], which radiates in X-rays. http://photojournal.jpl.nasa.gov/catalog/PIA06908

History of Chandra X-Ray Observatory

NASA Image and Video Library

2004-08-12

NASA’s Chandra X-Ray Observatory (CXO) was launched July 22, 1999 aboard the Space Shuttle Columbia, STS-93 mission. This image was produced by combining a dozen CXO observations made of a 130 light-year region in the center of the Milky Way over the last 5 years. The colors represent low (red), medium (green) and high (blue) energy x-rays. Thanks to Chandra's unique resolving power, astronomers have now been able to identify thousands of point-like x-ray sources due to neutron stars, black holes, white dwarfs, foreground stars, and background galaxies. What remains is a diffuse x-ray glow extending from the upper left to the lower right, along the direction of the disk of the galaxy. NASA’s Marshall Space Flight Center in Huntsville, Alabama manages the Chandra program. (NASA/CXC/UCLA/M. Muno et al.)

Chandra X-ray Center

Science.gov Websites

NHFP/Einstein Postdoctoral Fellows Selected NASA has announced the selection of the 2018 NASA Hubble . NASA press release Read the full CXC announcement here. 4/3/2018 Accretion in Stellar Systems August 8 Calibration Database User Community Chandra Users' Committee (CUC) NASA Hubble Fellowship Program

Supernova SN 2014C X-ray

NASA Image and Video Library

2017-01-24

This image from NASA's Chandra X-ray Observatory shows spiral galaxy NGC 7331, center, in a three-color X-ray image. Red, green and blue colors are used for low, medium and high-energy X-rays, respectively. An unusual supernova called SN 2014C has been spotted in this galaxy. http://photojournal.jpl.nasa.gov/catalog/PIA21089

Mrs. Chandrasekhar poses with model of the Chandra X-ray Observatory

NASA Technical Reports Server (NTRS)

1999-01-01

Mrs. Lalitha Chandrasekhar, wife of the late Indian-American Nobel Laureate Subrahmanyan Chandrasekhar, poses with a model of the Chandra X-ray Observatory in the TRW Media Hospitality Tent at the NASA Press Site at KSC. The name 'Chandra,' a shortened version of Chandrasekhar's name which he preferred among friends and colleagues, was chosen in a contest to rename the telescope. 'Chandra' also means 'Moon' or 'luminous' in Sanskrit. The observatory is scheduled to be launched aboard Columbia on Space Shuttle mission STS-93.

Chandra Detects Halo Of Hot Gas Around Milky Way-Like Galaxy

NASA Astrophysics Data System (ADS)

2001-07-01

The first unambiguous evidence for a giant halo of hot gas around a nearby, spiral galaxy much like our own Milky Way was found by astronomers using NASA's Chandra X-ray Observatory. This discovery may lead to a better understanding of our own Galaxy, as well the structure and evolution of galaxies in general. A team of astronomers, led by Professor Daniel Wang of the University of Massachusetts, Amherst, observed NGC 4631, a spiral galaxy approximately 25 million light years from Earth with both Chandra and NASA's Hubble Space Telescope. While previous X-ray satellites have detected extended X-ray emission from this and other spiral galaxies, because of Chandra's exceptional resolution this is the first time that astronomers were able to separate the individual X-ray sources from the diffuse halo. Chandra found the diffuse halo of X-ray gas to be radiating at a temperature of almost 3 million degrees and extending some 25,000 light years from the galactic plane. "Scientists have debated for over 40 years whether the Milky Way has an extended corona, or halo, of hot gas," said Wang, lead author of the paper which appeared this month in The Astrophysical Journal Letters. "Of course since we are within the Milky Way, we can't get outside and take a picture. However, by studying similar galaxies like NGC 4631, we can get an idea of what's going on within our own Galaxy." The Chandra image reveals a halo of hot gas that extends for approximately 25,000 light years above the disk of the galaxy. One important feature of the X-ray emission from NGC 4631 is that it closely resembles the overall size and shape seen in the radio emission from the galaxy. This indicates that there may be a close connection between the outflows of hot gas, seen in X-rays, and the galaxy's magnetic field, revealed by radio emission. The Hubble image of NGC 4631 shows filamentary, loop-like structures enclosing enhanced X-ray-emitting gas and emanating from regions of recent star formation in the galaxy's disk. These data clearly show the hot gas is heated by clusters of massive stars and is now expanding into the halo of the galaxy. NGC 4631 X-ray: NASA/CXC/UMass/D.Wang et al. UV: NASA/GSFC/UIT "What we see in NGC 4631 can be thought of as the bursting flames of a gigantic cosmic camp fire," said Wang. "Using Chandra and Hubble together, we really get a complete story of what is happening in this galaxy." NGC 4631 is a galaxy that has high amounts of star formation, possibly triggered by interaction with neighboring galaxies. Such star formation might have created the conditions necessary to heat the gas seen by Chandra, as vast amounts of energy are released from supernovas and massive stars in star-forming regions - enough to lift the gas out of the plane of the galaxy. These new results provide important clues about the cycling of energy and mass in a galaxy like our own Milky Way and about the evolutionary history of galaxies, which are thought to be more active in star formation in the past than at the present. Other members of the research team include: Stefan Immler, University of Massachusetts; Rene Walterbos, New Mexico State University; James Lauroesch, Northwestern University, Evanston, IL, and Dieter Breitschwerdt, Max Plank Institute, Germany. Chandra observed NGC 4631 with its Advanced CCD Imaging Spectrometer (ACIS) instrument, which was developed for NASA by Pennsylvania State University, University Park, and Massachusetts Institute of Technology, Cambridge. NASA's Marshall Space Flight Center in Huntsville, AL, manages the Chandra program, and TRW, Inc., Redondo Beach, CA, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, MA.

An Overview of the Performance of the Chandra X-ray Observatory

NASA Technical Reports Server (NTRS)

Weisskopf, M. C.; Aldcroft, T. L.; Bautz, M.; Cameron, R. A.; Dewey, D.; Drake, J. J.; Grant, C. E.; Marshall, H. L.; Murray, S. S.

2004-01-01

The Chandra X-ray Observatory is the X-ray component of NASA's Great Observatory Program which includes the recently launched Spitzer Infrared Telescope, the Hubble Space Telescope (HST) for observations in the visible, and the Compton Gamma-Ray Observatory (CGRO) which, after providing years of useful data has reentered the atmosphere. All these facilities provide, or provided, scientific data to the international astronomical community in response to peer-reviewed proposals for their use. The Chandra X-ray Observatory was the result of the efforts of many academic, commercial, and government organizations primarily in the United States but also in Europe. NASA s Marshall Space Flight Center (MSFC) manages the Project and provides Project Science; Northrop Grumman Space Technology (NGST - formerly TRW) served as prime contractor responsible for providing the spacecraft, the telescope, and assembling and testing the Observatory; and the Smithsonian Astrophysical Observatory (SAO) provides technical support and is responsible for ground operations including the Chandra X-ray Center (CXC). Telescope and instrument teams at SAO, the Massachusetts Institute of Technology (MIT), the Pennsylvania State University (PSU), the Space Research Institute of the Netherlands (SRON), the Max-Planck Institut fur extraterrestrische Physik (MPE), and the University of Kiel support also provide technical support to the Chandra Project. We present here a detailed description of the hardware, its on-orbit performance, and a brief overview of some of the remarkable discoveries that illustrate that performance.

Chandra Fellows Named

NASA Astrophysics Data System (ADS)

1999-02-01

Six scientists have been chosen as Fellows of the second annual Chandra X-ray Observatory Postdoctoral Fellowship Program. The fellowships are open to recent astronomy and astrophysics graduates worldwide. This year's winners will work for three years at a host astronomical institution in the United States where they will research problems broadly related to the scientific mission of the Chandra Observatory. The Chandra X-ray Observatory Fellowship Program is a joint venture between NASA and the Chandra X-ray Observatory Center in cooperation with the host institutions. The 1999 Fellows are: Markus Boettcher, a graduate of Bonn University, whose host institution will be Rice University; Jimmy Irwin, a graduate of the University of Virginia, will be hosted by the University of Michigan; Kristen Menou, a graduate of the University of Paris, will be hosted by Princeton University; Eliot Quataert, a graduate of Harvard University, will be hosted by the Institute for Advanced Study; Rudy Wijnands, a graduate of the University of Amsterdam, will be hosted by MIT; and Amy Barger, a graduate of Cambridge University, is a Fellow at large at the University of Hawaii Institute for Astronomy. The Chandra Fellowship Program attracted forty-five applicants from eleven countries. A member of the review panel commented, "I found it extremely difficult to choose between the many excellent entries." "We are very pleased with the response to the program, and I am confident that the work of these fellows will enhance our understanding of the scientific problems to be explored by the Chandra X-ray Observatory," said Nancy Remage Evans, coordinator of the Fellowship Program. NASA's Chandra X-ray Observatory, formerly know as AXAF, will provide stunning new images and data of the extremely hot, active regions in the universe. Such regions exist where stars have exploded, where matter is swirling into black holes, and where clusters of galaxies are merging. A tentative launch date of July 9, 1999 has been set by NASA for the Chandra X-ray Observatory. The Space Shuttle Columbia mission STS-93, commanded by astronaut Eileen Collins will carry the telescope into a low circular orbit of Earth. There the astronauts will deploy the Chandra spacecraft, which will then fire two Boeing Inertial Upper Stage solid motors in succession to place Chandra in a highly elliptical orbit. This orbit will be fine-tuned by the spacecraft's integral propulsion system made by TRW, until it reaches its final height of 10,000 km by 140,000 km. Further information about the Chandra X-ray Observatory is available at the World Wide Web at http://chandra.harvard.edu/. Further information about the Fellowship program is available at http://asc.harvard.edu/fellows/

Nobel Prize In Physics Awarded To Astronomer For NASA-Funded Research

NASA Astrophysics Data System (ADS)

2002-10-01

Riccardo Giacconi, the "father of X-ray astronomy," has received the Nobel Prize in physics for "pioneering contributions to astrophysics," which have led to the discovery of cosmic X-ray sources. Giaconni, president of the Associated Universities Inc., in Washington, and Research Professor of Physics and Astronomy at Johns Hopkins University, Baltimore, discovered the first X-ray stars and the X-ray background in the 1960s and conceived of and led the implementation of the Uhuru and High Energy Astronomy Observatory-2 (HEAO-2) X-ray observatories in the 1970s. With funding from NASA, he also detected sources of X-rays that most astronomers now consider to contain black holes. Giacconi said that receiving the award confirms the importance of X-ray astronomy. "I think I'm one of the first to get the Nobel prize for work with NASA, so that's good for NASA and I think it's also good for the field," he said. "It's also nice for all the other people who've worked in this field. I recognize that I was never alone. I'm happy for me personally, I'm happy for my family, and I'm happy for the field and for NASA," Giacconi added. In 1976, Giacconi along with Harvey Tananbaum of the Harvard- Smithsonian Center for Astrophysics, Cambridge, Mass., submitted a proposal letter to NASA to initiate the study and design of a large X-ray telescope. In 1977 work began on the program, which was then known as the Advanced X-ray Astrophysics Facility and in 1998 renamed the Chandra X-ray Observatory. "Partnerships with universities and scientists are essential in our quest to answer the fundamental questions of the universe," said Dr. Ed Weiler, NASA Associate Administrator for Space Science, Headquarters, Washington. "Dr. Giacconi's achievements are a brilliant example of this synergy among NASA, universities and their community of scientists and students," he said. Giacconi is Principal Investigator for the ultradeep survey with Chandra - the "Chandra Deep Field South" - that has already obtained the deepest X-ray exposures to date with a million-second observation. He was also the first director of the Hubble Space Telescope Science Institute in Baltimore. Giacconi, 71, received half the prize. Raymond Davis Jr., 87, of the University of Pennsylvania and Masatoshi Koshiba, 76, of the University of Tokyo will share the other half of the prize, worth about $1 million, for their research into cosmic neutrinos. For more information visit: http://nobelprize.org/ Chandra Chronicles: A High-Energy Visonary Wins Nobel Prize

Role of the Chandra X-Ray Observatory Observations for the Study of Ionized Plasmas

NASA Technical Reports Server (NTRS)

Weisskopf, Martin C.

2010-01-01

The Chandra X-Ray Observatory, launched in 1999, is now beginning its 12-th year of operation. Chandra, the X-ray component of NASA s Great Observatory program, continues to operate efficiently, somewhat remarkable considering that the Observatory was designed for three years of operation with a goal of five. The Observatory features X-ray optics with sub-arcsecond angular resolution and a small suite of instruments, including transmission gratings, which allow for high-resolution spectroscopy of point sources. We will detail the capabilities of the Observatory for making such spectroscopic measurements and discuss a number of examples of what has been learned about the astrophysical plasmas capable of producing bright X-ray emission.

Chandra X-Ray Observatory Image NGC 3603

NASA Technical Reports Server (NTRS)

2001-01-01

NGC 3603 is a bustling region of star birth in the Carina spiral arm of the Milky Way galaxy, about 20,000 light-years from Earth. For the first time, this Chandra image resolves the multitude of individual x-ray sources in this star-forming region. (The intensity of the x-rays observed by Chandra are depicted by the various colors in this image. Green represents lower intensity sources, while purple and red indicate increasing x-ray intensity.) Specifically, the Chandra image reveals dozens of extremely massive stars born in a burst of star formation about 2 million years ago. This region's activities may be indicative of what is happening in other distant 'starburst' galaxies (bright galaxies flush with new stars). In the case of NGC 3603, scientists now believe that these x-rays are emitted from massive stars and stellar winds, since the stars are too young to have produced supernovae or have evolved into neutron stars. The Chandra observations of NGC 3603 may provide new clues about x-ray emission in starburst galaxies as well as star formation itself. (Photo credit: NASA/GSFC/M. Corcoran et al)

History of Chandra X-Ray Observatory

NASA Image and Video Library

2001-01-01

NGC 3603 is a bustling region of star birth in the Carina spiral arm of the Milky Way galaxy, about 20,000 light-years from Earth. For the first time, this Chandra image resolves the multitude of individual x-ray sources in this star-forming region. (The intensity of the x-rays observed by Chandra are depicted by the various colors in this image. Green represents lower intensity sources, while purple and red indicate increasing x-ray intensity.) Specifically, the Chandra image reveals dozens of extremely massive stars born in a burst of star formation about 2 million years ago. This region's activities may be indicative of what is happening in other distant "starburst" galaxies (bright galaxies flush with new stars). In the case of NGC 3603, scientists now believe that these x-rays are emitted from massive stars and stellar winds, since the stars are too young to have produced supernovae or have evolved into neutron stars. The Chandra observations of NGC 3603 may provide new clues about x-ray emission in starburst galaxies as well as star formation itself. (Photo credit: NASA/GSFC/M. Corcoran et al)

Chandra Images Provide New Vision of Cosmic Explosions

NASA Astrophysics Data System (ADS)

1999-09-01

Images from NASA's Chandra X-ray Observatory released today reveal previously unobserved features in the remnants of three different supernova explosions. Two of the remnants G21.5-0.9 and PSR 0540-69 show dramatic details of the prodigious production of energetic particles by a rapidly rotating, highly magnetized neutron star, as well as the enormous shell structures produced by the explosions. The image of the third remnant, E0102-72, reveals puzzling spoke-like structures in its interior. G21.5-0.9, in the constellation of Scutum, is about 16,000 light years (1 light year = 6 trillion miles) from Earth. Chandra's image shows a bright nebula surrounded by a much larger diffuse cloud. Inside the inner nebula is a bright central source that is thought to be a rapidly rotating highly magnetized neutron star. A rotating neutron star acts like a powerful generator, creating intense electric voltages that accelerate electrons to speeds close to the speed of light. The total output of this generator is greater than a thousand suns. The fluffy appearance of the central nebula is thought to be due to magnetic field lines which constrain the motions of the high-energy electrons. "It's a remarkable image," said Dr. Patrick Slane of the Harvard-Smithsonian Center for Astrophysics. "Neither the inner core nor the outer shell has ever been seen before." "It is as though we have a set of Russian dolls, with structures embedded within structures," said Professor Gordon Garmire of Penn State University, and principal investigator of the Advanced CCD Imaging Spectrometer, the X-ray camera that was used to make two of the images. NASA's project scientist, Dr. Martin Weisskopf of the Marshall Space Flight Center said, "Chandra's capability to provide surprises and insights continues." PSR 0540-69 PSR 0540-69 The existence of a rotating neutron star, or pulsar, in the center of G21.5-0.9 is inferred from the appearance of the nebula and the energy distribution of X-rays and radio waves from the nebula. This distribution, called non-thermal radiation is characteristic of radiation produced by high-energy electrons in a magnetic field. A previously known pulsar is observed directly in the Chandra image of PSR 0540-69. This pulsar, located in a satellite galaxy to the Milky Way that is 180,000 light years distant, emits pulses of radio, optical, and X radiation at a rate of 50 per sec. These pulses which come from a neutron star rotating at this incredible rate, comprise only a few percent of the total energy output of the neutron star powerhouse. "The Chandra image gives us a much better idea of how this energy source works," said Dr. Stephen Murray, principal investigator for the High Resolution Camera, the X-ray camera used to make PSR 0540-69 image. "You can see X-ray jets blasting out from the pulsar in both directions." The third Chandra supernova image is E0102-72. Located in the Small Magellanic Cloud, another satellite galaxy of the Milky Way, E0102-72 is 190,000 light years from Earth. This object, like G21.5-0.9 and PSR 0540-69, is believed to have resulted from the explosion of a massive star several thousand years ago. Stretching across 40 light years of space, the multi-million degree source resembles a flaming cosmic wheel. "Chandra's gallery of supernova remnants is giving us a lot to think about," said Dr. Fred Seward, of Harvard-Smithsonian, who with his colleagues discovered E0102-72 and PSR 0540-69 with the Einstein Observatory over a decade ago. "We're seeing many things we thought should be there, and many others that we never expected. It's great!" To follow Chandra's progress, visit the Chandra News Web site at: http://chandra.harvard.edu AND http://chandra.nasa.gov NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra X-ray Observatory for NASA's Office of Space Science, NASA Headquarters, Washington, D.C. The Smithsonian Astrophysical Observatory's Chandra X-ray Center in Cambridge, Mass., manages the Chandra science program and controls the observatory for NASA. TRW Space and Electronics Group of Redondo Beach, Calif., leads the contractor team that built Chandra. High resolution digital versions of the X-ray image (300 dpi JPG, TIFF) and other information associated with this release are available on the Internet at: http://chandra.harvard.edu/photo/snrg/index.html or via links in: http://chandra.harvard.edu An animation of a supernova explosion and the formation of a supernova remnant can be found at: http://chandra.harvard.edu/resources/animations/pulsar.html

Astronomers Go Behind The Milky Way To Solve X-Ray Mystery

NASA Astrophysics Data System (ADS)

2001-08-01

Through layers of gas and dust that stretch for more than 30,000 light years, astronomers using NASA's Chandra X-ray Observatory have taken a long, hard look at the plane of the Milky Way galaxy and found that its X-ray glow comes from hot and diffuse gas. The findings, published in the August 10 issue of Science, help to settle a long-standing mystery about the source of the X-ray emission from the galactic plane. Scientists have debated whether the Milky Way plane's X-ray emission was diffuse light or from individual stars. Armed with Chandra, an international team led Dr. Ken Ebisawa of NASA's Goddard Space Flight Center, Greenbelt, MD zoomed in on a tiny region of the galactic plane in the constellation Scutum. "The point sources we saw in the galactic plane were actually active galaxies with bright cores millions of light years behind our galaxy," said Ebisawa. "The number of these sources is consistent with the expected number of extragalactic sources in the background sky. We saw few additional point sources within our Galaxy." The observation marks the deepest X-ray look at the so-called "zone of avoidance" -- a region of space behind which no optical observation has ever been taken because thick dust and gas in the spiral arms of the Milky Way galaxy block out visible radiation. Infrared, radio, and X-rays, however, can penetrate this dust and gas. Detection of diffuse X rays emanating from the Galactic plane, what we call the "Milky Way" in visible light, indicates the presence of plasma gas with temperatures of tens of millions of degrees Celsius. Smoothed X-ray Image of the Galactic Plane Smoothed X-ray Image of the Galactic Plane Gas this hot would escape the gravitational confines of the Milky Way galaxy under normal circumstances. The fact that it still lingers within the Galactic plane is the next mystery to solve. One possibility, suggested by Ebisawa is that hot plasma may be confined to the Milky Way by magnetic fields. The Chandra observation, conducted in February 2000, lasted 28 hours. The team observed what was known to be a "blank" region of the galactic plane where the Japanese X-ray satellite ASCA had previously observed but found no individual X-ray sources. The team also discovered 36 bright distant galaxies lurking in the background of this section of the galactic plane, while the foreground was devoid of stars or other individual objects emitting X-rays. Chandra, and now the European XMM-Newton satellite, are at long last beginning to collect light from behind our galaxy. X-radiation from the 36 newly discovered galaxies passes through the Milky Way on its journey towards Earth. This light, therefore, carries the imprint of all that it passes through and will allow astronomers to measure the distribution and physical condition of matter in our Galaxy. Participating in the Chandra observation and Science article are Yoshitomo Maeda of Pennsylvania State University; Hidehiro Kaneda of the Institute of Space and Astronautical Science in Japan; and Shigeo Yamauchi of Iwate University in Japan. Chandra observed the galactic plane with its Advanced CCD Imaging Spectrometer (ACIS) instrument, which was developed for NASA by Pennsylvania State University, University Park, and Massachusetts Institute of Technology, Cambridge. NASA's Marshall Space Flight Center in Huntsville, AL, manages the Chandra program, and TRW, Inc., Redondo Beach, CA, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, MA.

Planetary Protection: X-ray Super-Flares Aid Formation of "Solar Systems"

NASA Astrophysics Data System (ADS)

2005-05-01

New results from NASA's Chandra X-ray Observatory imply that X-ray super-flares torched the young Solar System. Such flares likely affected the planet-forming disk around the early Sun, and may have enhanced the survival chances of Earth. By focusing on the Orion Nebula almost continuously for 13 days, a team of scientists used Chandra to obtain the deepest X-ray observation ever taken of this or any star cluster. The Orion Nebula is the nearest rich stellar nursery, located just 1,500 light years away. These data provide an unparalleled view of 1400 young stars, 30 of which are prototypes of the early Sun. The scientists discovered that these young suns erupt in enormous flares that dwarf - in energy, size, and frequency -- anything seen from the Sun today. Illustration of Large Flares Illustration of Large Flares "We don't have a time machine to see how the young Sun behaved, but the next best thing is to observe Sun-like stars in Orion," said Scott Wolk of Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. "We are getting a unique look at stars between one and 10 million years old - a time when planets form." A key result is that the more violent stars produce flares that are a hundred times as energetic as the more docile ones. This difference may specifically affect the fate of planets that are relatively small and rocky, like the Earth. "Big X-ray flares could lead to planetary systems like ours where Earth is a safe distance from the Sun," said Eric Feigelson of Penn State University in University Park, and principal investigator for the international Chandra Orion Ultradeep Project. "Stars with smaller flares, on the other hand, might end up with Earth-like planets plummeting into the star." Animation of X-ray Flares from a Young Sun Animation of X-ray Flares from a "Young Sun" According to recent theoretical work, X-ray flares can create turbulence when they strike planet-forming disks, and this affects the position of rocky planets as they form. Specifically, this turbulence can help prevent planets from rapidly migrating towards the young star. "Although these flares may be creating havoc in the disks, they ultimately could do more good than harm," said Feigelson. "These flares may be acting like a planetary protection program." About half of the young suns in Orion show evidence for disks, likely sites for current planet formation, including four lying at the center of proplyds (proto-planetary disks) imaged by Hubble Space Telescope. X-ray flares bombard these planet-forming disks, likely giving them an electric charge. This charge, combined with motion of the disk and the effects of magnetic fields should create turbulence in the disk. handra X-ray Image of Orion Nebula, Full-Field Chandra X-ray Image of Orion Nebula, Full-Field The numerous results from the Chandra Orion Ultradeep Project will appear in a dedicated issue of The Astrophysical Journal Supplement in October, 2005. The team contains 37 scientists from institutions across the world including the US, Italy, France, Germany, Taiwan, Japan and the Netherlands. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate, Washington. Northrop Grumman of Redondo Beach, Calif., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

X-Rays from Pluto

NASA Image and Video Library

2016-09-14

The first detection of Pluto in X-rays has been made using NASA's Chandra X-ray Observatory in conjunction with observations from NASA's New Horizons spacecraft. As New Horizons approached Pluto in late 2014 and then flew by the planet during the summer of 2015, Chandra obtained data during four separate observations. During each observation, Chandra detected low-energy X-rays from the small planet. The main panel in this graphic is an optical image taken from New Horizons on its approach to Pluto, while the inset shows an image of Pluto in X-rays from Chandra. There is a significant difference in scale between the optical and X-ray images. New Horizons made a close flyby of Pluto but Chandra is located near the Earth, so the level of detail visible in the two images is very different. The Chandra image is 180,000 miles across at the distance of Pluto, but the planet is only 1,500 miles across. Pluto is detected in the X-ray image as a point source, showing the sharpest level of detail available for Chandra or any other X-ray observatory. This means that details over scales that are smaller than the X-ray source cannot be seen here. Detecting X-rays from Pluto is a somewhat surprising result given that Pluto - a cold, rocky world without a magnetic field - has no natural mechanism for emitting X-rays. However, scientists knew from previous observations of comets that the interaction between the gases surrounding such planetary bodies and the solar wind - the constant streams of charged particles from the sun that speed throughout the solar system -- can create X-rays. The researchers were particularly interested in learning more about the interaction between the gases in Pluto's atmosphere and the solar wind. The New Horizon spacecraft carries an instrument designed to measure that activity up-close -- Solar Wind Around Pluto (SWAP) -- and scientists examined that data and proposed that Pluto contains a very mild, close-in bowshock, where the solar wind first "meets" Pluto (similar to a shock wave that forms ahead of a supersonic aircraft) and a small wake or tail behind the planet. The immediate mystery is that Chandra's readings on the brightness of the X-rays are much higher than expected from the solar wind interacting with Pluto's atmosphere. The Chandra detection is also surprising since New Horizons discovered Pluto's atmosphere was much more stable than the rapidly escaping, "comet-like" atmosphere that many scientists expected before the spacecraft flew past in July 2015. In fact, New Horizons found that Pluto's interaction with the solar wind is much more like the interaction of the solar wind with Mars, than with a comet. While Pluto is releasing enough gas from its atmosphere to make the observed X-rays, there isn't enough solar wind flowing directly at Pluto at its great distance from the Sun to make them according to certain theoretical models. There are several suggested possibilities for the enhanced X-ray emission from Pluto. These include a much wider and longer tail of gases trailing Pluto than New Horizons detected using its SWAP instrument. Because Pluto is so small compared to the size of a Chandra point source, scientists may be unable to detect such a tail in X-rays. Other possibilities are that interplanetary magnetic fields are focusing more particles than expected from the solar wind into the region around Pluto, or the low density of the solar wind in the outer solar system at the distance of Pluto could allow for the formation of a doughnut, or torus, of neutral gas centered around Pluto's orbit. It will take deeper and higher resolution images of X-rays from Pluto's environment than we currently have from Chandra to distinguish between these possibilities. http://photojournal.jpl.nasa.gov/catalog/PIA21061

Titan Casts Revealing Shadow

NASA Astrophysics Data System (ADS)

2004-05-01

A rare celestial event was captured by NASA's Chandra X-ray Observatory as Titan -- Saturn's largest moon and the only moon in the Solar System with a thick atmosphere -- crossed in front of the X-ray bright Crab Nebula. The X-ray shadow cast by Titan allowed astronomers to make the first X-ray measurement of the extent of its atmosphere. On January 5, 2003, Titan transited the Crab Nebula, the remnant of a supernova explosion that was observed to occur in the year 1054. Although Saturn and Titan pass within a few degrees of the Crab Nebula every 30 years, they rarely pass directly in front of it. "This may have been the first transit of the Crab Nebula by Titan since the birth of the Crab Nebula," said Koji Mori of Pennsylvania State University in University Park, and lead author on an Astrophysical Journal paper describing these results. "The next similar conjunction will take place in the year 2267, so this was truly a once in a lifetime event." Animation of Titan's Shadow on Crab Nebula Animation of Titan's Shadow on Crab Nebula Chandra's observation revealed that the diameter of the X-ray shadow cast by Titan was larger than the diameter of its solid surface. The difference in diameters gives a measurement of about 550 miles (880 kilometers) for the height of the X-ray absorbing region of Titan's atmosphere. The extent of the upper atmosphere is consistent with, or slightly (10-15%) larger, than that implied by Voyager I observations made at radio, infrared, and ultraviolet wavelengths in 1980. "Saturn was about 5% closer to the Sun in 2003, so increased solar heating of Titan may account for some of this atmospheric expansion," said Hiroshi Tsunemi of Osaka University in Japan, one of the coauthors on the paper. The X-ray brightness and extent of the Crab Nebula made it possible to study the tiny X-ray shadow cast by Titan during its transit. By using Chandra to precisely track Titan's position, astronomers were able to measure a shadow one arcsecond in diameter, which corresponds to the size of a dime as viewed from about two and a half miles. Illustration of Crab, Titan's Shadow and Chandra Illustration of Crab, Titan's Shadow and Chandra Unlike almost all of Chandra's images which are made by focusing X-ray emission from cosmic sources, Titan's X-ray shadow image was produced in a manner similar to a medical X-ray. That is, an X-ray source (the Crab Nebula) is used to make a shadow image (Titan and its atmosphere) that is recorded on film (Chandra's ACIS detector). Titan's atmosphere, which is about 95% nitrogen and 5% methane, has a pressure near the surface that is one and a half times the Earth's sea level pressure. Voyager I spacecraft measured the structure of Titan's atmosphere at heights below about 300 miles (500 kilometers), and above 600 miles (1000 kilometers). Until the Chandra observations, however, no measurements existed at heights in the range between 300 and 600 miles. Understanding the extent of Titan's atmosphere is important for the planners of the Cassini-Huygens mission. The Cassini-Huygens spacecraft will reach Saturn in July of this year to begin a four-year tour of Saturn, its rings and its moons. The tour will include close flybys of Titan that will take Cassini as close as 600 miles, and the launching of the Huygens probe that will land on Titan's surface. Chandra's X-ray Shadow of Titan Chandra's X-ray Shadow of Titan "If Titan's atmosphere has really expanded, the trajectory may have to be changed." said Tsunemi. The paper on these results has been accepted and is expected to appear in a June 2004 issue of The Astrophysical Journal. Other members of the research team were Haroyoski Katayama (Osaka University), David Burrows and Gordon Garmine (Penn State University), and Albert Metzger (JPL). Chandra observed Titan from 9:04 to 18:46 UT on January 5, 2003, using its Advanced CCD Imaging Spectrometer instrument. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the Office of Space Science, NASA Headquarters, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Impact! Chandra Images a Young Supernova Blast Wave

NASA Astrophysics Data System (ADS)

2000-05-01

Two images made by NASA's Chandra X-ray Observatory, one in October 1999, the other in January 2000, show for the first time the full impact of the actual blast wave from Supernova 1987A (SN1987A). The observations are the first time that X-rays from a shock wave have been imaged at such an early stage of a supernova explosion. Recent observations of SN 1987A with the Hubble Space Telescope revealed gradually brightening hot spots from a ring of matter ejected by the star thousands of years before it exploded. Chandra's X-ray images show the cause for this brightening ring. A shock wave is smashing into portions of the ring at a speed of 10 million miles per hour (4,500 kilometers per second). The gas behind the shock wave has a temperature of about ten million degrees Celsius, and is visible only with an X-ray telescope. "With Hubble we heard the whistle from the oncoming train," said David Burrows of Pennsylvania State University, University Park, the leader of the team of scientists involved in analyzing the Chandra data on SN 1987A. "Now, with Chandra, we can see the train." The X-ray observations appear to confirm the general outlines of a model developed by team member Richard McCray of the University of Colorado, Boulder, and others, which holds that a shock wave has been moving out ahead of the debris expelled by the explosion. As this shock wave collides with material outside the ring, it heats it to millions of degrees. "We are witnessing the birth of a supernova remnant for the first time," McCray said. The Chandra images clearly show the previously unseen, shock-heated matter just inside the optical ring. Comparison with observations made with Chandra in October and January, and with Hubble in February 2000, show that the X-ray emission peaks close to the newly discovered optical hot spots, and indicate that the wave is beginning to hit the ring. In the next few years, the shock wave will light up still more material in the ring, and an inward moving, or reverse, shock wave will heat the material ejected in the explosion itself. "The supernova is digging up its own past," said McCray. The observations were made on October 6, 1999, using the Advanced CCD Imaging Spectrometer (ACIS) and the High Energy Transmission Grating, and again on January 17, 2000, using ACIS. Other members of the team were Eli Michael of the University of Colorado; Dr. Una Hwang, Dr. Steven Holt and Dr. Rob Petre of NASA's Goddard Space Flight Center in Greenbelt, MD; Professor Roger Chevalier of the University of Virginia, Charlottesville; and Professors Gordon Garmire and John Nousek of Pennsylvania State University. The results will be published in an upcoming issue of the Astrophysical Journal. The ACIS instrument was built for NASA by the Massachusetts Institute of Technology, Cambridge, and Pennsylvania State University. The High Energy Transmission Grating was built by the Massachusetts Institute of Technology. NASA's Marshall Space Flight Center in Huntsville, AL, manages the Chandra program. TRW, Inc., Redondo Beach, CA, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, MA. More About SN 1987A Images to illustrate this release and more information on Chandra's progress can be found on the Internet at: http://chandra.harvard.edu/photo/2000/sn1987a/index.html AND http://chandra.nasa.gov More About SN 1987A

The CHANDRA X-Ray Observatory: Thermal Design, Verification, and Early Orbit Experience

NASA Technical Reports Server (NTRS)

Boyd, David A.; Freeman, Mark D.; Lynch, Nicolie; Lavois, Anthony R. (Technical Monitor)

2000-01-01

The CHANDRA X-ray Observatory (formerly AXAF), one of NASA's "Great Observatories" was launched aboard the Shuttle in July 1999. CHANDRA comprises a grazing-incidence X-ray telescope of unprecedented focal-length, collecting area and angular resolution -- better than two orders of magnitude improvement in imaging performance over any previous soft X-ray (0.1-10 keV) mission. Two focal-plane instruments, one with a 150 K passively-cooled detector, provide celestial X-ray images and spectra. Thermal control of CHANDRA includes active systems for the telescope mirror and environment and the optical bench, and largely passive systems for the focal plans instruments. Performance testing of these thermal control systems required 1-1/2 years at increasing levels of integration, culminating in thermal-balance testing of the fully-configured observatory during the summer of 1998. This paper outlines details of thermal design tradeoffs and methods for both the Observatory and the two focal-plane instruments, the thermal verification philosophy of the Chandra program (what to test and at what level), and summarizes the results of the instrument, optical system and observatory testing.

Chandra Finds X-ray Star Bonanza in the Orion Nebula

NASA Astrophysics Data System (ADS)

2000-01-01

NASA's Chandra X-ray Observatory has resolved nearly a thousand faint X-ray-emitting stars in a single observation of young stars in the Orion Nebula. The discovery--the richest field of X-ray sources ever obtained in the history of X-ray astronomy--will be presented on Friday, January 14, at the 195th national meeting of the American Astronomical Society in Atlanta, Georgia. The Orion region is a dense congregation of about 2,000 very young stars formed during the past few million years. The discovery of such a wealth of X-ray stars in the closest massive star-forming region to Earth (only 1,500 light years away) is expected to have a profound impact on our understanding of star formation and evolution. "We've detected X-rays from so many fantastic objects, such as very young massive stars and stars so small that they may evolve into brown dwarfs," said Gordon Garmire, Evan Pugh Professor at Penn State University, University Park. "Chandra's superb angular resolution has resolved this dense cluster of stars with arcsecond accuracy and unsurpassed sensitivity." Garmire leads the team using Chandra's ACIS detector, the Advanced CCD Imaging Spectrometer, conceived and developed for NASA by Penn State University and the Massachusetts Institute of Technology. The brilliant Orion region has awed humankind for millennia. The most massive and brightest of these nascent stars are in the Orion Trapezium, which illuminates the Orion Nebula, also known as Messier 42. The Trapezium and its luminous gas can be seen with the unaided eye in the winter sky in the "sword" of the Orion constellation. Young stars, such as those found in Orion, are known to be much brighter in X-rays than middle-aged stars such as the Sun. The elevated X-ray emission is thought to arise from violent flares in strong magnetic fields near the surfaces of young stars. The Sun itself was probably thousands of times brighter in X-rays during its first few million years. Although the enhanced magnetic activity of young stars has been known for some time, the physical causes and evolution of the activity are poorly understood, according to Dr. Eric Feigelson, professor of astronomy and astrophysics at Penn State. "With hundreds of stars observed simultaneously, possessing a wide range of properties such as mass and rotation rates, we hope the Orion observation will help unravel the astrophysical principles underlying this phenomenon," Feigelson said. "X-ray astronomy now penetrates as deeply into the clouds as the best infrared and optical telescopes, permitting us to study high-energy processes during the earliest phases of star formation." "This Chandra image is a milestone in the field of X-ray astronomy and very gratifying to me personally," said Garmire. "Chandra's sensitivity is 20 times better than achieved with the best previous X-ray telescopes." A number of the ACIS X-ray sources in the Orion observation have special importance. Several are associated with a distinct cluster of higher-mass stars deeply embedded within the murky Orion Molecular Cloud, including the infrared-luminous Becklin-Neugebauer object. "This is the first time X-ray astronomy has resolved individual massive stars still embedded in their natal cloud," said Dr. Leisa Townsley, research associate in astronomy and astrophysics at Penn State. At least three ACIS sources are associated with cluster members with masses so small (roughly 1/20th of the Sun's mass), that they will evolve into brown dwarfs rather than true stars. "They more closely resemble proto-Jupiters than proto-stars," said Dr. Yohko Tsuboi, visiting research scholar in astronomy and astrophysics at Penn State. "Over a dozen X-ray sources have no known counterpart, even in the most sensitive Hubble Space Telescope or infrared studies. These too may be very low-mass stars." The ACIS team studying the Orion X-ray source includes Profs. Feigelson and Garmire and research scientists Patrick Broos, Leisa Townsley, and Yohko Tsuboi at Penn State; Steven Pravdo at the Jet Propulsion Laboratory; and Lynne Hillenbrand at the California Institute of Technology. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program. TRW, Inc., Redondo Beach, CA, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, MA. Other Press Room:Orion Nebula Press Release (PSU Sep 01) To follow Chandra's progress or download images visit the Chandra sites at http://chandra.harvard.edu/photo/2000/0054/index.html AND http://chandra.nasa.gov

Second Chandra Instrument Activated August 28

NASA Astrophysics Data System (ADS)

1999-08-01

Cambridge, MA--NASA's Chandra X-ray Observatory opened a new era in astronomy Saturday, August 28, by making the most precise measurements ever recorded of the energy output from the 10 million degree corona of a star. Last weekend's observations came after the successful activation of an instrument developed by MIT that will allow a one-thousand-fold improvement in the capability to measure X-ray spectra from space. The new measurements, made with the High Energy Transmission Grating Spectrometer, join spectacular images taken last week by Chandra of the aftermath of a gigantic stellar explosion. The spectrometer is one of four key instruments aboard Chandra, and the second to be activated. The others will be turned on over the next two weeks. The spectrometer activated yesterday spreads the X-rays from Chandra's mirrors into a spectrum, much as a prism spreads light into its colors. The spectrum then can be read by Chandra's imaging detectors like a kind of cosmic bar code from which scientists can deduce the chemical composition and temperature of the corona. A corona is a region of hot gas and magnetic loops that extend hundreds of thousands of miles above the star's visible surface and is best studied with X-rays. "The success of the new spectrometer is definitely a major milestone for modern astronomy," said MIT Professor Claude R. Canizares, principal investigator for the instrument and associate director of the Chandra X-ray Observatory Center (CXC). "Within the first hour we had obtained the best X-ray spectrum ever recorded for a celestial source. We can already see unexpected features that will teach us new things about stars and about matter at high temperatures." The spectrometer measured X-rays from the star Capella, which is 40 light years away in the constellation Auriga. Capella is actually two stars orbiting one another and possibly interacting in ways that pump extra heat into the corona, which appears more active than that of the Sun. How a star manages to heat its corona to temperatures a thousand times higher than its own surface is still a puzzle, which astronomers hope can be solved by observations like this one. Other prime targets for Chandra's spectrometers over the next few months include black holes, quasars and supernova explosions. The grating spectrometer consists of hundreds of gold gratings, each about the size of a postage stamp. The surface of each grating resembles a precise picket fence, with microscopic gold pickets 500 times thinner than a human hair. These are spaced every 2000 angstroms, or less than half the wavelength of visible light. The instrument was developed at MIT's Center for Space Research, which Professor Canizares directs, by adapting techniques usually used to make computer chips. Some of these adaptations have found their way back as improvements in the chip-making industry. The grating spectrometer is one of two such devices carried by Chandra. The other, a low-energy grating built by a Dutch-German team, will be activated next week. Chandra also contains two detectors. One, built by researchers at Pennsylvania State University and MIT, was turned on two weeks ago and has recorded all the images and spectra seen so far. The second, built by the Smithsonian Astrophysical Observatory, is being activated this week. Dr. Stephen Murray of the Harvard-Smithsonian Center for Astrophysics summarized the expected impact of Chandra's high resolution X-ray spectroscopy with these words: "A picture is worth a thousand words, a spectrum is worth a million." Capella's spectrum and further information about Chandra's High Energy Transmission Grating Spectrometer may be found at: http://space.mit.edu/CSR/hetg_info.html The Chandra X-ray Observatory Center was named in honor of the late Nobel laureate Subrahmanyan Chandrasekhar. NASA's Marshall Space Flight Center manages the Chandra program. TRW, Inc., Redondo Beach, CA, is the prime contractor for the spacecraft. The Smithsonian Astrophysical Observatory's Chandra X-ray Center controls science and flight operations from Cambridge, MA. The first Chandra images and more information on the Chandra X-ray Observatory Center are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Spectacular X-ray Jet Points Toward Cosmic Energy Booster

NASA Astrophysics Data System (ADS)

2000-06-01

NASA's Chandra X-ray Observatory has revealed a spectacular luminous spike of X rays that emanates from the vicinity of a giant black hole in the center of the radio galaxy Pictor A. The spike, or jet, is due to a beam of particles that streaks across hundreds of thousands of light years of intergalactic space toward a brilliant X-ray hot spot that marks its end point. Pictor A Image Press Image and Caption The hot spot is at least 800 thousand light years (8 times the diameter of our Milky Way galaxy) away from where the jet originates. It is thought to represent the advancing head of the jet, which brightens conspicuously where it plows into the tenuous gas of intergalactic space. The jet, powered by the giant black hole, originates from a region of space no bigger than the solar system. "Both the brightness and the spectrum of the X rays are very different from what theory predicts," Professor Andrew Wilson reported today at the 196th national meeting of the American Astronomical Society in Rochester, New York. Wilson, of the University of Maryland, College Park, along with Dr. Patrick Shopbell and Dr. Andrew Young, also of the University of Maryland, are submitting an article on this research to the Astrophysical Journal. "The Chandra observations are telling us that something out there is producing many more high-energy particles than we expected," said Wilson. One possible explanation for the X rays is that shock waves along the side and head of the X-ray jet are accelerating electrons and possibly protons to speeds close to that of light. In the process the electrons are boosted to energies as high as 100 million times their own rest mass energy. These electrons lose their energy rapidly as they produce X rays, so this could be the first direct evidence of this process so far outside a galaxy. The hot spot has been seen with optical and radio telescopes. Radio telescopes have also observed a faint jet. Jets are thought to be produced by the extreme electromagnetic forces created by magnetized gas swirling toward a black hole. Although most of the material falls into the black hole, some can be ejected at extremely high speeds. Magnetic fields spun out by these forces can extend over vast distances and may help explain the narrowness of the jet. The Chandra observation of Pictor A was made on January 18, 2000 for eight hours using the Advanced CCD Imaging Spectrometer (ACIS). The ACIS instrument was built for NASA by the Massachusetts Institute of Technology, Cambridge, and Pennsylvania State University, University Park. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program. TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass. Images associated with this release are available on the World Wide Web at: http://chandra.harvard.edu AND http://chandra.nasa.gov High resolution digital versions of the X-ray image (JPG, 300 dpi TIFF) are available at the Internet sites listed above. This image will be available on NASA Video File which airs at noon, 3:00 p.m., 6:00 p.m., 9:00 p.m. and midnight Eastern Time. NASA Television is available on GE-2, transponder 9C at 85 degrees West longitude, with vertical polarization. Frequency is on 3880.0 megahertz, with audio on 6.8 megahertz.

X-Rays Found From a Lightweight Brown Dwarf

NASA Astrophysics Data System (ADS)

2003-04-01

Using NASA's Chandra X-ray Observatory, scientists have detected X-rays from a low mass brown dwarf in a multiple star system, which is as young as 12 million years old. This discovery is an important piece in an increasingly complex picture of how brown dwarfs - and perhaps the very massive planets around other stars - evolve. Chandra's observations of the brown dwarf, known as TWA 5B, clearly resolve it from a pair of Sun-like stars known as TWA 5A. The system is about 180 light years from the Sun and a member of a group of about a dozen young stars in the southern constellation Hydra. The brown dwarf orbits the binary stars at a distance about 2.75 times that of Pluto's orbit around the Sun. This is first time that a brown dwarf this close to its parent star(s) has been resolved in X-rays. "Our Chandra data show that the X-rays originate from the brown dwarf's coronal plasma which is some 3 million degrees Celsius," said Yohko Tsuboi of Chuo University in Tokyo and lead author of the April 10th issue of Astrophysical Journal Letters paper describing these results. "The brown dwarf is sufficiently far from the primary stars that the reflection of X-rays is unimportant, so the X-rays must come the brown dwarf itself." TWA 5B is estimated to be only between 15 and 40 times the mass of Jupiter, making it one of the least massive brown dwarfs known. Its mass is rather near the currently accepted boundary (about 12 Jupiter masses) between planets and brown dwarfs. Therefore, these results may also have implications for very massive planets, including those that have been discovered as extrasolar planets in recent years. Brown Dwarf size comparison schematic Brown Dwarf size comparison schematic "This brown dwarf is as bright as the Sun today in X-ray light, while it is fifty times less massive than the Sun," said Tsuboi. "This observation, thus, raises the possibility that even massive planets might emit X-rays by themselves during their youth!" This research on TWA 5B also provides a link between an active X-ray state in young brown dwarfs (about 1 million years old) and a later, quieter period of brown dwarfs when they reach ages of 500 million to a billion years. Brown dwarfs are often referred to as "failed stars," as they are believed to be under the mass limit (about 80 Jupiter masses) needed to spark the nuclear fusion of hydrogen to helium, which characterizes traditional stars. Scientists hope to better understand the evolution of magnetic activity in brown dwarfs through the X-ray behavior. Chandra observed TWA 5B for about three hours on April 15, 2001, with its Advanced CCD Imaging Spectrometer (ACIS). Along with Chandra's mirrors, ACIS can achieve the angular resolution of a half arc second. TWA 5B Optical image of TWA 5B "This brown dwarf is about 200 times dimmer than the primary and located just two arcseconds away," said Gordon Garmire of Penn State University who led the ACIS team. "It's quite an achievement that Chandra was able to resolve it." Other members of the research team included Yoshitomo Maeda (Institute of Space and Astronautical Science, Kanagawa, Japan), Eric Feigelson, Gordon Garmire, George Chartas, and Koji Mori (Penn State University), and Steve Prado (Jet Propulsion Laboratory). NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program, and TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass., for the Office of Space Science at NASA Headquarters, Washington. Images and additional information about this result are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

A Deep Chandra ACIS Survey of M83

NASA Astrophysics Data System (ADS)

Long, Knox S.; Kuntz, Kip D.; Blair, William P.; Godfrey, Leith; Plucinsky, Paul P.; Soria, Roberto; Stockdale, Christopher; Winkler, P. Frank

2014-06-01

We have obtained a series of deep X-ray images of the nearby galaxy M83 using Chandra, with a total exposure of 729 ks. Combining the new data with earlier archival observations totaling 61 ks, we find 378 point sources within the D25 contour of the galaxy. We find 80 more sources, mostly background active galactic nuclei (AGNs), outside of the D25 contour. Of the X-ray sources, 47 have been detected in a new radio survey of M83 obtained using the Australia Telescope Compact Array. Of the X-ray sources, at least 87 seem likely to be supernova remnants (SNRs), based on a combination of their properties in X-rays and at other wavelengths. We attempt to classify the point source population of M83 through a combination of spectral and temporal analysis. As part of this effort, we carry out an initial spectral analysis of the 29 brightest X-ray sources. The soft X-ray sources in the disk, many of which are SNRs, are associated with the spiral arms, while the harder X-ray sources, mostly X-ray binaries (XRBs), do not appear to be. After eliminating AGNs, foreground stars, and identified SNRs from the sample, we construct the cumulative luminosity function (CLF) of XRBs brighter than 8 × 1035 erg s-1. Despite M83's relatively high star formation rate, the CLF indicates that most of the XRBs in the disk are low mass XRBs. Based on observations made with NASA's Chandra X-Ray Observatory. NASA's Chandra Observatory is operated by Smithsonian Astrophysical Observatory under contract NAS83060 and the data were obtained through program GO1-12115.

Historical Remembrances of the Chandra X-ray Observatory: How Partnerships Created Success

NASA Astrophysics Data System (ADS)

Burke, Robert

2009-09-01

As the astronomy community plans for new ventures in space, we're forced to find creative solutions to operate within the ever increasing fiscal constraints of the current economic environment. The Chandra X-ray Observatory program offers an example of how missions can be successfully developed within manageable budget constraints. The ten year anniversary offers us the chance to look back at the Chandra team's special partnership between scientists, managers, and industry that led to our success.Chandra experienced many of the challenges common to major observatories: state-of-the-art technical requirements, budget-induced slips, and restructurings. Yet the Chandra team achieved excellent performance for dramatically lower cost. In fact, Chandra completed its prime mission for billions of dollars less than originally planned. In 1992, NASA MSFC and Northrop Grumman (then TRW) together led a major restructure that saved approximately 3.4B in program cost, while we improved the imaging capability and observing efficiency of Chandra. This was accomplished by a combination of team-work, systems engineering, advanced technology insertion, and effective approaches for program implementation, combined with a high performance culture that aligned goals and focused on mission success. Northrop Grumman is proud of our role in supporting the NASA Marshall Space Flight Center and our academic partners in advancing the frontiers of x-ray astronomy and scientific discovery with Chandra. As Chandra continues its extended mission, the observatory continues to provide superb scientific performance.

NASA's Chandra Finds That Saturn Reflects X-rays From Sun

NASA Astrophysics Data System (ADS)

2005-05-01

When it comes to mysterious X-rays from Saturn, the ringed planet may act as a mirror, reflecting explosive activity from the sun, according to scientists using NASA's Chandra X-ray Observatory. The findings stem from the first observation of an X-ray flare reflected from Saturn's low-latitudes - the region that correlates to Earth's equator and tropics. Led by Dr. Anil Bhardwaj, a planetary scientist at NASA's Marshall Space Flight Center (MSFC) in Huntsville, Ala., the study revealed that Saturn acts as a diffuse mirror for solar X-rays. Counting photons - particles that carry electromagnetic energy including X-rays - was critical to this discovery. For every few thousand X-ray photons Saturn receives from the sun, it reflects a single X-ray photon back. Previous studies revealed that Jupiter, with a diameter 11 times that of Earth, behaves in a similar fashion. Saturn is about 9.5 times as big as Earth, but is twice as far from Earth as Jupiter. "The bigger the planet and nearer to the Sun, the more solar photons it will intercept - resulting in more reflected X-rays," said Bhardwaj. "These results imply we could use giant planets like Jupiter and Saturn as remote-sensing tools. By reflecting solar activity back to us, they could help us monitor X-ray flaring on portions of the sun facing away from Earth's space satellites." Massive solar explosions called flares often accompany coronal mass ejections, which emit solar material and magnetic field. When directed toward the Earth, these ejections can wreak havoc on communication systems from cell phones to satellites. Even as the research appears to have solved one mystery - the source of Saturn's X-rays, it fueled longstanding questions about magnetic fields. Earth's magnetic field is the reason compasses work, since the field acts like a huge bar magnet, causing the magnetic north pole of a compass to point to the magnetic south pole of the Earth. In addition, migratory birds seem to sense the magnetic field, which allows them to navigate. But other affects of magnetic fields, only recently studied in detail, are obvious only to those living at Earth's high latitudes, or to those observing the Earth from space. Of the three magnetic planets in our solar system that have been studied extensively, Jupiter and Earth emit two general types of X rays -- auroral emissions from polar regions and disk emissions from low latitudes. However, no research to-date - including the recent study using the Chandra Observatory - has observed unambiguous signatures of auroral X-ray emissions on Saturn. "We were surprised to find no clear evidence of auroral X-ray emissions during our observations," said Bhardwaj. "It is interesting to note that even as research solves some mysteries, it confirms there is much more we have to learn. The research appeared in the May 10, 2005 issue of Astrophysical J. Letters, and the team also included Ron Elsner of MSFC; Hunter Waite of the University of Michigan in Ann Arbor; Randy Gladstone of the Southwest Research Institute in San Antonio, Texas; Thomas Cravens of the University of Kansas in Lawrence and Peter Ford from the Massachusetts Institute of Technology in Cambridge. Bhardwaj is working at MSFC on leave from the Space Physics Laboratory of the Vikram Sarabhai Space Centre in India. The Marshall Center manages the Chandra program for NASA's Science Mission Directorate in Washington. Northrop Grumman of Redondo Beach, Calif., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Chandra Adds to Story of the Way We Were

NASA Astrophysics Data System (ADS)

2003-05-01

Data from NASA's Chandra X-ray Observatory have enabled astronomers to use a new way to determine if a young star is surrounded by a planet-forming disk like our early Sun. These results suggest that disks around young stars can evolve rapidly to form planets, or they can be disrupted by close encounters with other stars. Chandra observed two young star systems, TW Hydrae and HD 98800, both of which are in the TW Hydrae Association, a loose cluster of 10 million-year-old stars. Observations at infrared and other wavelengths have shown that several stars in the TW Hydrae Association are surrounded by disks of dust and gas. At a distance of about 180 light years from Earth, these systems are among the nearest analogs to the early solar nebula from which Earth formed. "X-rays give us an excellent new way to probe the disks around stars," said Joel Kastner of the Rochester Institute of Technology in Rochester, NY during a press conference today in Nashville, Tenn. at a meeting of the American Astronomical Society. "They can tell us whether a disk is very near to its parent star and dumping matter onto it, or whether such activity has ceased to be important. In the latter case, presumably the disk has been assimilated into larger bodies - perhaps planets--or disrupted." TW Hydrae and HD 98800A Chandra 0th Order Image of HD98800 Kastner and his colleagues found examples of each type of behavior in their study. One star, TW Hydrae, namesake of the TW Hydrae Association, exhibited features in its X-ray spectrum that provide strong, new evidence that matter is accreting onto the star from a circumstellar disk. They concluded that matter is guided by the star's magnetic field onto one or more hot spots on the surface of the star. In contrast, Chandra observations of the young multiple star system HD 98800 revealed that its brightest star, HD 98800A, is producing X-rays much as the Sun does, from a hot upper atmosphere or corona. HD 98800 is a complex multiple-star system consisting of two pairs of stars, called HD 98800A and HD 98800B. These pairs, each of which is about an Earth-Sun distance apart, orbit each other at about the same distance as Pluto orbits the Sun. "Our X-ray results are fully consistent with other observations that show that accretion of matter from a disk in HD 98800A has dropped to a low level," said Kastner. "So Chandra has thrown new weight behind the evidence that any disk in this system has been greatly diminished or destroyed in ten million years, perhaps by the ongoing formation of planets or by the companion stars." The new X-ray technique for studying disks around stars relies on the ability of Chandra's spectrometers to measure the energies of individual X-rays very precisely. By comparing the number of X-rays emitted by hot gas at specific energies from ions such as oxygen and neon, the temperature and density of particles can be determined. This new technique will help astronomers to distinguish between an accretion disk and a stellar corona as the origin of intense X-ray emission from a young star. Other members of the research team are David Huenemoerder, Norbert Schulz, and Claude Canizares from the Massachusetts Institute of Technology, and David Weintraub from Vanderbilt University. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program, and TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass., for the Office of Space Science at NASA Headquarters, Washington. The image and additional information are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Extended X-Ray Jet in Nearby Galaxy Reveals Energy Source

NASA Astrophysics Data System (ADS)

1999-10-01

NASA's Chandra X-ray Observatory has made an extraordinary image of Centaurus A, a nearby galaxy noted for its explosive activity. The image shows X-ray jets erupting from the center of the galaxy over a distance of 25,000 light years. Also detected are a group of X-ray sources clustered around the nucleus, which is believed to harbor a supermassive black hole. The X-ray jets and the cluster of sources may be a byproduct of a titanic collision between galaxies several hundred million years ago. "This image is great," said Dr. Ethan Schreier of the Space Telescope Science Institute, "For twenty years we have been trying to understand what produced the X rays seen in the Centaurus A jet. Now we at last know that the X-ray emission is produced by extremely high-energy electrons spiraling around a magnetic field." Schreier explained that the length and shape of the X-ray jet pinned down the source of the radiation. The entire length of the X-ray jet is comparable to the diameter of the Milky Way Galaxy. Other features of the image excite scientists. "Besides the jets, one of the first things I noticed about the image was the new population of sources in the center of the galaxy," said Dr. Christine Jones from the Harvard-Smithsonian Center for Astrophysics . "They are grouped in a sphere around the nucleus, which must be telling us something very fundamental about how the galaxy, and the supermassive black hole in the center, were formed." Astronomers have accumulated evidence with optical and infrared telescopes that Centaurus A collided with a small spiral galaxy several hundred million years ago. This collision is believed to have triggered a burst of star formation and supplied gas to fuel the activity of the central black hole. more - According to Dr. Giuseppina Fabbiano, of Harvard-Smithsonian, "The Chandra image is like having a whole new laboratory to work in. Now we can see the main jet, the counter jet, and the extension of the jets beyond the galaxy. It is gorgeous in the detail it reveals," she said. Dr. Allyn Tennnant of NASA's Marshall Space Flight Center agreed. "It's incredible, being able to see all that structure in the jet," he said. "We have one fine X-ray telescope." Indeed at a distance of eleven million light years from Earth, Centaurus A has long been a favorite target of astronomers because it is the nearest example of a class of galaxies called active galaxies. Active galaxies are noted for their explosive activity, which is presumed to be due to a supermassive black hole in their center. The energy output due to the huge central black hole can in many cases affect the appearance of the entire galaxy. The Chandra X-ray image of Cen A, made with the High Resolution Camera, shows a bright source in the nucleus of the galaxy at the location of the suspected supermassive black hole. The bright jet extending out from the nucleus to the upper left is due to explosive activity around the black hole which ejects matter at high speeds from the vicinity of the black hole. A "counter jet" extending to the lower right can also be seen. This jet is probably pointing away from us, which accounts for its faint appearance. One of the most intriguing features of supermassive black holes is that they do not suck up all the matter that falls within their sphere of influence. Some of the matter falls inexorably toward the black hole, and some explodes away from the black hole in high-energy jets that move at near the speed of light. The presence of bright X-ray jets in the Chandra image means that electric fields are continually accelerating electrons to extremely high energies over enormous distances. Exactly how this happens is a major puzzle that Chandra may help to solve. To follow Chandra's progress, visit the Chandra site at: http://chandra.harvard.edu AND http://chandra.nasa.gov Dr. Stephen Murray of the Harvard-Smithsonian Center for Astrophysics is the principal investigator for the High Resolution Camera. NASA's Marshall Space Flight Center in Huntsville, AL, manages the Chandra program. TRW, Inc., Redondo Beach, CA, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, MA. High resolution digital versions of the X-ray image (JPG, 300 dpi TIFF) and other information associated with this release are available on the Internet at: http://chandra.harvard.edu/photo/0157/index.html or via links in: http://chandra.harvard.edu

Chandra Sees Wealth Of Black Holes In Star-Forming Galaxies

NASA Astrophysics Data System (ADS)

2001-06-01

NASA's Chandra X-ray Observatory has found new populations of suspected mid-mass black holes in several starburst galaxies, where stars form and explode at an unusually high rate. Although a few of these objects had been found previously, this is the first time they have been detected in such large numbers and could help explain their relationship to star formation and the production of even more massive black holes. At the 198th meeting of the American Astronomical Society in Pasadena, California, three independent teams of scientists reported finding dozens of X-ray sources in galaxies aglow with star formation. These X-ray objects appear point-like and are ten to a thousand times more luminous in X-rays than similar sources found in our Milky Way and the M81 galaxy. "Chandra gives us the ability to study the populations of individual bright X-ray sources in nearby galaxies in extraordinary detail," said Andreas Zezas, lead author from the Harvard-Smithsonian Center for Astrophysics team that observed The Antennae, a pair of colliding galaxies, and M82, a well-known starburst galaxy. "This allows us to build on earlier detections of these objects and better understand their relationship to starburst galaxies." Antennae-True Color Image True Color Image of Antennae Credit: NASA/SAO/G.Fabbiano et al. Press Image and Caption Kimberly Weaver, of NASA's Goddard Space Flight Center in Greenbelt, MD, lead scientist of the team that studied the starburst galaxy NGC 253, discussed the importance of the unusual concentration of these very luminous X-ray sources near the center of that galaxy. Four sources, which are tens to thousands of times more massive than the Sun, are located within 3,000 light years of the galaxy core. "This may imply that these black holes are gravitating toward the center of the galaxy where they could coalesce to form a single supermassive black hole," Weaver suggested. "It could be that this starburst galaxy is transforming itself into a quasar-like galaxy as we watch. In NGC 253, Chandra may have found the causal connection between starburst activity and quasars." Chandra detected variability and a relatively large ratio of high- to low-energy X-rays in these sources - two characteristics of superheated gas falling into black holes. When combined with extreme luminosities, this tells astronomers that some of these objects must have masses many times greater than ordinary stellar black holes, if they radiate energy uniformly in all directions. Scenarios for the formation of such "intermediate-mass" black holes include the direct collapse of a single, massive cloud of gas into a black hole, or the coalescence of a cluster of stellar black holes, but no uniformly accepted model exists. M82-True Color Image True Color Image of M82 Credit: NASA/SAO/G.Fabbiano et al. Press Image and Caption An alternative possibility, mentioned by Giuseppina Fabbiano of the Harvard-Smithsonian team, is that the X-rays from such highly luminous sources are beamed toward us -- perhaps by a funnel formed by the infalling matter. This would imply that the mass of the underlying black hole is only about ten times the mass of the Sun, in line with the known black hole sources in our galaxy. In this event, they would represent a short-lived but common stage in the evolution of black holes in close binary star systems. Long-term monitoring of the very luminous X-ray sources should distinguish between these possibilities. Andrew Ptak, led a team from Carnegie-Mellon University in Pittsburgh, PA, and Penn State University, University Park, PA, that used Chandra data to survey 37 galaxies. Ptak’s team found that 25 percent of galaxies, which were chosen for their suspected central supermassive black holes and areas of star formation, had these very luminous X-ray sources. The team plans to expand their survey with Chandra to assess the probability of finding these very bright X-ray sources in other types of galaxies. NASA's Marshall Space Flight Center, Huntsville, AL, manages the Chandra program for the Office of Space Science, Washington, DC. TRW, Inc., Redondo Beach, California, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, MA. Images associated with this release are available on the World Wide Web at: http://chandra.harvard.edu AND http://chandra.nasa.gov

Chandra Images the Seething Cauldron of Starburst Galaxy

NASA Astrophysics Data System (ADS)

2000-01-01

NASA's Chandra X-ray Observatory has imaged the core of the nearest starburst galaxy, Messier 82 (M82). The observatory has revealed a seething cauldron of exploding stars, neutron stars, black holes, 100 million degree gas, and a powerful galactic wind. The discovery will be presented by a team of scientists from Carnegie Mellon University, Pittsburgh, Penn., Pennsylvania State University, University Park, and the University of Michigan, Ann Arbor, on January 14 at the 195th national meeting of the American Astronomical Society. "In the disk of our Milky Way Galaxy, stars form and die in a relatively calm fashion like burning embers in a campfire," said Richard Griffiths, Professor of Astrophysics at Carnegie Mellon University. "But in a starburst galaxy, star birth and death are more like explosions in a fireworks factory." Short-lived massive stars in a starburst galaxy produce supernova explosions, which heat the interstellar gas to millions of degrees, and leave behind neutron stars and black holes. These explosions emit light in the X rays rather than in visible light. Because the superhot components inside starburst galaxies are complex and sometimes confusing, astronomers need an X-ray-detecting telescope with the highest focusing power (spatial resolution) to clearly discriminate the various structures. "NASA's Chandra X-ray Observatory is the perfect tool for studying starburst galaxies since it has the critical combination of high-resolution optics and good sensitivity to penetrating X rays," said Gordon Garmire, the Evan Pugh Professor of Astronomy and Astrophysics at Pennsylvania State University, and head of the team that conceived and built Chandra's Advanced CCD Imaging Spectrograph (ACIS) X-ray camera, which acquired the data. Many intricate structures missed by earlier satellite observatories are now visible in the ACIS image, including more than twenty powerful X-ray binary systems that contain a normal star in a close orbit around a neutron star or a black hole. "Several sources are so bright that they are probably black holes, perhaps left over from past starburst episodes," Garmire explained. The astronomers report that the X-ray emitting gas in the galaxy's core region has a surprisingly hot temperature. "Determining the source of high-energy X rays from M82 may elucidate whether starburst galaxies throughout the universe contribute significantly to the X-ray background radiation that pervades intergalactic space," said Griffiths."The image also shows a chimney-like structure at the base of the galactic wind, which may help us understand how metal-rich starburst gas is dispersed into intergalactic space." "What we don't see may be as important as what we do see," said Garmire. "There is no indication of a single, high luminosity, compact X-ray source from a supermassive black hole at the very center of the galaxy, although considerable evidence exists that such central black holes are present in many or most galaxies.". The astronomers note that recent optical and infrared data suggest most galaxies were starbursts when the universe was young and that their galactic winds may have distributed carbon, oxygen, iron and other heavy atoms that now pervade the Universe. The starburst in M82 is thought to have been caused by a near collision with a large spiral galaxy, M81, about 100 million years ago. At a distance of 11 million light years, M82 is the closest starburst galaxy to our Milky Way Galaxy and provides the best view of this type of galactic structure, which may have played a critical role in the early history of the Universe. The Chandra image was taken with the Advanced CCD Imaging Spectrometer (ACIS) on September 20, 1999 in an observation that lasted about 13 ½ hours. ACIS was built by Penn State Univ. and Massachusetts Institute of Technology, Cambridge. To follow Chandra's progress or download images visit the Chandra sites at: http://chandra.harvard.edu/photo/2000/0094/index.html AND http://chandra.nasa.gov NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program. TRW, Inc., Redondo Beach, CA, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, MA. High resolution digital versions of the X-ray image (JPG, 300 dpi TIFF) are available at the Internet site listed above.

History of Chandra X-Ray Observatory

NASA Image and Video Library

1997-04-15

This photograph captures the installation of the Chandra X-Ray Observatory, formerly Advanced X-Ray Astrophysics Facility (AXAF), Advanced Charged-Coupled Device (CCD) Imaging Spectrometer (ACIS) into the Vacuum Chamber at the X-Ray Calibration Facility (XRCF) at Marshall Space Flight Center (MSFC). The AXAF was renamed Chandra X-Ray Observatory (CXO) in 1999. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It observes x-rays from high-energy regions of the universe, such as hot gas in the remnants of exploded stars. The ACIS is one of two focal plane instruments. As the name suggests, this instrument is an array of CCDs similar to those used in a camcorder. This instrument will be especially useful because it can make x-ray images and measure the energies of incoming x-rays. It is the instrument of choice for studying the temperature variation across x-ray sources, such as vast clouds of hot-gas intergalactic space. MSFC's XRCF is the world's largest, most advanced laboratory for simulating x-ray emissions from distant celestial objects. It produces a space-like environment in which components related to x-ray telescope imaging are tested and the quality of their performances in space is predicted. TRW, Inc. was the prime contractor for the development of the CXO and NASA's MSFC was responsible for its project management. The Smithsonian Astrophysical Observatory controls science and flight operations of the CXO for NASA from Cambridge, Massachusetts. The CXO was launched July 22, 1999 aboard the Space Shuttle Columbia (STS-93).

Flight Results of the Chandra X-ray Observatory Inertial Upper Stage Space Mission

NASA Technical Reports Server (NTRS)

Tillotson, R.; Walter, R.

2000-01-01

Under contract to NASA, a specially configured version of the Boeing developed Inertial Upper Stage (IUS) booster was provided by Boeing to deliver NASA's 1.5 billion dollar Chandra X-Ray Observatory satellite into a highly elliptical transfer orbit from a Shuttle provided circular park orbit. Subsequently, the final orbit of the Chandra satellite was to be achieved using the Chandra Integral Propulsion System (IPS) through a series of IPS burns. On 23 July 1999 the Shuttle Columbia (STS-93) was launched with the IUS/Chandra stack in the Shuttle payload bay. Unfortunately, the Shuttle Orbiter was unexpectantly inserted into an off-nominal park orbit due to a Shuttle propulsion anomaly occurring during ascent. Following the IUS/Chandra on-orbit deployment from the Shuttle, at seven hours from liftoff, the flight proven IUS GN&C system successfully injected Chandra into the targeted transfer orbit, in spite of the off-nominal park orbit. This paper describes the IUS GN&C system, discusses the specific IUS GN&C mission data load development, analyses and testing for the Chandra mission, and concludes with a summary of flight results for the IUS part of the Chandra mission.

Chandra Turns Up the Heat in the Milky Way Center

NASA Astrophysics Data System (ADS)

2004-06-01

A long look by NASA's Chandra X-ray Observatory has revealed new evidence that extremely hot gas exists in a large region at the center of the Milky Way. The intensity and spectrum of the high-energy X-rays produced by this gas present a puzzle as to how it is being heated. The discovery came to light as a team of astronomers, led by Michael Muno of UCLA used Chandra's unique resolving power to study a region about 100 light years across and painstakingly remove the contributions from 2,357 point-like X-ray sources due to neutron stars, black holes, white dwarfs, foreground stars, and background galaxies. What remained was an irregular, diffuse glow from a 10-million-degree Celsius gas cloud, embedded in a glow of higher-energy X-rays with a spectrum characteristic of 100-million-degree gas. Animation of Galactic Center Animation of Galactic Center "The best explanation for the Chandra data is that the high-energy X-rays come from an extremely hot gas cloud," says Muno, lead author on a paper describing the results to appear in the September 20, 2004 issue of The Astrophysical Journal. "This would mean that there is a significant shortcoming in our understanding of heat sources in the center of our Galaxy." The combined gravity from the known objects in the center of the Milky Way -- all the stars and the supermassive black hole in the center - is not strong enough to prevent the escape of the 100 million degree gas from the region. The escape time would be about 10,000 years, a small fraction of the 10-billion-year lifetime of the Galaxy. This implies that the gas would have to be continually regenerated and heated. The gas could be replenished by winds from massive stars, but the source of the heating remains a puzzle. The high-energy diffuse X-rays from the center of the Galaxy appear to be the brightest part of a ridge of X-ray emission observed by Chandra and previous X-ray observatories to extend for several thousand light years along the disk of the Galaxy. The extent of this hot ridge implies that it is probably not being heated by the supermassive black hole at the center of the Milky Way. VLA Radio Image of Galactic Center VLA Radio Image of Galactic Center Scientists have speculated that magnetic turbulence produced by supernova shock waves can heat the gas to 100 million degrees. Alternatively, high-energy protons and electrons produced by supernova shock waves could be the heat source. However, both these possibilities have problems. The spectrum is not consistent with heating by high-energy particles, the observed magnetic field in the Galactic center does not have the proper structure, and the rate of supernova explosions does not appear to be frequent enough to provide the necessary heating. The team also considered whether the high-energy X-rays only appear to be diffuse, and are in fact due to the combined glow of an as yet undetected population of point-like sources, like the diffuse lights of a city seen at a great distance. The difficulty with this explanation is that 200,000 sources would be required in the observed region. Although the total number of stars in this region is about 30 million, the number of stars of the type expected to produce X-rays at the required power and energy is estimated to be only 20 thousand. Further, such a large unresolved population of sources would produce a much smoother X-ray glow than is observed. Chandra Broadband X-ray Image of Galactic Center Chandra Broadband X-ray Image of Galactic Center, Without Point Sources "There is no known class of objects that could account for such a large number of high-energy X-ray sources at the Galactic center," said Fred Baganoff of the Massachusetts Institute of Technology (MIT) in Cambridge, a coauthor of the study. These results were based on over 170 hours of observations of a 17-by-17-arcminute region around the Milky Way's center using Chandra's Advanced CCD Imaging Spectrometer instrument. Other team members from UCLA, MIT, and Penn State are also co-authors on the upcoming paper in The Astrophysical Journal. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for NASA's Office of Space Science, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. http://chandra.harvard.edu and http://chandra.nasa.gov

Chandra Discovers Elusive "Hot Bubble" in Planetary Nebula

NASA Astrophysics Data System (ADS)

2000-06-01

NASA's Chandra X-ray Observatory has imaged for the first time a "hot bubble" of gas surrounding a dying, Sun-like star. This large region of very hot gas in the planetary nebula BD+30 3639 has a peculiar shape and contains elements produced in the core of the dying star. "The new Chandra image offers conclusive proof for the existence of the "hot bubble" that theorists have long predicted," said Professor Joel Kastner, of the Chester F. Carlson Center of Imaging Science at the Rochester Institute of Technology. Kastner leads a team of scientists who reported on this observation at the 196th national meeting of the American Astronomical Society in Rochester, New York. The Chandra image shows a region of 3 million degree Celsius gas that appears to fit inside the shell of ionized gas seen by the Hubble Space Telescope. The optical and X-ray emitting regions of BD+30 3639, which lies between 5000 and 8000 light years away, are roughly one million times the volume of our solar system. A planetary nebula (so called because it looks like a planet when viewed with a small telescope) is formed when a dying red giant star puffs off its outer layer, leaving behind a hot core that will eventually collapse to form a dense star called a white dwarf. According to theory, a "hot bubble" is formed when a new, two million mile per hour wind emanating from the hot core rams into the ejected atmosphere, producing energetic shocks and heating the interaction region to temperatures of millions of degrees. Previous X-ray observations hinted that X rays might be coming from a region larger than the central star but it remained for Chandra to provide definite proof. The shape of the X-ray emission was a surprise to the researchers. "This suggests that the red giant atmosphere was not ejected symmetrically,"said Kastner. "It might be pointing to an unseen companion star," The spectrum shows a large abundance of neon in the X-ray-emitting gas. This indicates that gas contained in the hot bubble gas was dredged up from the deepest layers of the central star, where nuclear fusion altered the chemical composition of the gas prior to its being ejected. Thus the Chandra data may offer new insight into the process whereby dying stars enrich the Milky Way in fusion products. The observation was made in March 2000 using the Advanced CCD Imaging Spectrometer (ACIS). Kastner's collaborators on the project are Prof. Noam Soker of the University of Haifa, Israel; Prof. Saul Rappaport of MIT; Dr. Ruth Knill-Dgani of the University of Texas, Austin; and Dr. Saeqa Vrtilek of the Harvard-Smithsonian Center for Astrophysics. The ACIS instrument was built for NASA by the Massachusetts Institute of Technology, Cambridge, and Pennsylvania State University, University Park. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program. TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass. High resolution digital versions of the X-ray image (JPG, 300 dpi TIFF ) and other information associated with this release are available on the Internet at: http://chandra.harvard.edu AND http://chandra.nasa.gov

The End of Days -- Chandra Catches X-ray Glow From Supernova

NASA Astrophysics Data System (ADS)

1999-12-01

Through a combination of serendipity and skill, scientists have used NASA's Chandra X-ray Observatory to capture a rare glimpse of X-radiation from the early phases of a supernova, one of the most violent events in nature. Although more than a thousand supernovas have been observed by optical astronomers, the early X-ray glow from the explosions has been detected in less than a dozen cases. The Chandra observations were made under the direction of a team of scientists from the Massachusetts Institute of Technology (MIT) in Cambridge, led by Walter Lewin and his graduate student, Derek Fox. When combined with simultaneous observations by radio and optical telescopes, the X-ray observations tell about the thickness of the shell that was blown off, its density, its speed, and how much material was shed by the star before it exploded. Chandra observed an X-ray glow from SN1999em with the total power of 50,000 suns. Ten days later it observed the supernova for another nine hours, and found that the X rays had faded to half their previous intensity. The optical luminosity, which had the brightness of 200 million suns, had faded somewhat less. No radio emission was detected at any time. With this information, the MIT group and their colleagues are already piecing together a picture of the catastrophic explosion. Observations by optical astronomers showed that SN1999em was a Type II supernova produced by the collapse of the core of a star ten or more times as massive as the Sun. The intense heat generated in the collapse produces a cataclysmic rebound that sends high speed debris flying outward at speeds in excess of 20 million miles per hour. The debris crashes into matter shed by the former star before the explosion. This awesome collision generates shock waves that heat expanding debris to three million degrees. The X-ray glow from this hot gas was detected by Chandra and gives astrophysicists a better understanding of the dynamics of the explosion, as well as the behavior of the doomed star in the years before the explosion. "The combination of X-ray detection and radio non-detection is unusual, but may have less to do with the supernova and more to do with the great sensitivity of Chandra," said Roger Chevalier of University of Virginia, Charlottesville. Chevalier explained that the combined observations indicate that SN1999em shed a relatively small amount of matter before it exploded, compared to other supernovas observed in X rays. The Chandra observation is important because it may represent a more common type of supernova. The Chandra observation also provides an inside look at the hectic, exciting world of the international "quick response" network that scientists have set up to track and investigate supernovas. On Friday, October 29, Alex Fillipenko of the University of California, Berkeley notified Bob Kirshner at Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass., that his automated supernova search project had a good candidate in a relatively nearby spiral galaxy, NGC 1637. Nearby in this case means about 25 million light years from Earth. Wei Dong Li, who is visiting Fillipenko's group from the Beijing Astronomical Observatory in China, called his colleagues in Beijing, who confirmed the supernova when the Earth rotated into a position to make viewing from China possible. The astronomers also notified the International Astronomical Union's central bureau for astronomical telegrams in Cambridge, Mass., from which the discovery was broadcast worldwide. Radio astronomers Christina Lacey and Kurt Weiler at the Naval Research Laboratory in Washington, D.C., Schuyler van Dyk at the California Institute of Technology, Pasadena and Richard Sramek at the National Radio Astronomy Observatory's Very Large Array, Socorro, N.M. were alerted. Kirshner then got in touch via e-mail with Harvey Tananbaum, director of the Chandra X-ray Center at Harvard-Smithsonian a little before 11 p.m. on Saturday night. The Chandra operations team replanned the telescope's observation activities and by Monday morning, and by Monday morning, Chandra was pointed at the supernova and observed it for about nine hours. Lewin, who had been awarded the rights to Chandra's first observation of a nearby supernova, was ecstatic. "This is a unique chance that we have been hoping for!!!!" he wrote in an e-mail to Tananbaum. "I was impressed by how rapid the Chandra response was, " said Kirshner. "Supernovae expand quickly and cool quickly, so each day we delay observing the supernova it has changed irretrievably," Filippenko said. "We caught this really early, only a day or two after the explosion. We were lucky." The Chandra observation was taken with the Advanced CCD Imaging Spectrometer (ACIS) on November 1 and 2, and 11 and 12, 1999 in two separate observations that lasted approximately nine hours each. ACIS was built by Pennsylvania State University, University Park. and MIT. To follow Chandra's progress, visit the Chandra site at: http://chandra.harvard.edu AND http://chandra.nasa.gov NASA's Marshall Space Flight Center in Huntsville, AL, manages the Chandra program. TRW, Inc., Redondo Beach, CA, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, MA. This image will be available on NASA Video File which airs at noon, 3:00 p.m., 6:00 p.m., 9:00 p.m. and midnight Eastern Time. NASA Television is available on GE-2, transponder 9C at 85 degrees West longitude, with vertical polarization. Frequency is on 3880.0 megahertz, with audio on 6.8 megahertz. High resolution digital versions of the X-ray image (JPG, 300 dpi TIFF ) and other information associated with this release are available on the Internet at: http://chandra.harvard.edu/photo/sn1999em/ or via links in: http://chandra.harvard.edu

Chandra Probes High-Voltage Auroras on Jupiter

NASA Astrophysics Data System (ADS)

2005-03-01

Scientists have obtained new insight into the unique power source for many of Jupiter's auroras, the most spectacular and active auroras in the Solar System. Extended monitoring of the giant planet with NASA's Chandra X-ray Observatory detected the presence of highly charged particles crashing into the atmosphere above its poles. X-ray spectra measured by Chandra showed that the auroral activity was produced by ions of oxygen and other elements that were stripped of most of their electrons. This implies that these particles were accelerated to high energies in a multimillion-volt environment above the planet's poles. The presence of these energetic ions indicates that the cause of many of Jupiter's auroras is different from auroras produced on Earth or Saturn. Chandra X-ray Image of Jupiter Chandra X-ray Image of Jupiter "Spacecraft have not explored the region above the poles of Jupiter, so X-ray observations provide one of the few ways to probe that environment," said Ron Elsner of the NASA Marshall Space Flight Center in Huntsville, Alabama, and lead author on a recently published paper describing these results in the Journal for Geophysical Research. "These results will help scientists to understand the mechanism for the power output from Jupiter's auroras, which are a thousand times more powerful than those on Earth." Electric voltages of about 10 million volts, and currents of 10 million amps - a hundred times greater than the most powerful lightning bolts - are required to explain the X-ray observations. These voltages would also explain the radio emission from energetic electrons observed near Jupiter by the Ulysses spacecraft. Schematic of Jupiter's Auroral Activity Production Schematic of Jupiter's Auroral Activity Production On Earth, auroras are triggered by solar storms of energetic particles, which disturb Earth's magnetic field. Gusts of particles from the Sun can also produce auroras on Jupiter, but unlike Earth, Jupiter has another way of producing auroras. Jupiter's rapid rotation, intense magnetic field, and an abundant source of particles from its volcanically active moon, Io, create a huge reservoir of electrons and ions. These charged particles, trapped in Jupiter's magnetic field, are continually accelerated down into the atmosphere above the polar regions where they collide with gases to produce the aurora, which are almost always active on Jupiter. If the particles responsible for the aurora came from the Sun, they should have been accompanied by large number of protons, which would have produced an intense ultraviolet aurora. Hubble ultraviolet observations made during the Chandra monitoring period showed relatively weak ultraviolet flaring. The combined Chandra and Hubble data indicate that this auroral activity was caused by the acceleration of charged ions of oxygen and other elements trapped in the polar magnetic field high above Jupiter's atmosphere. Hubble Ultraviolet Image of Jupiter Hubble Ultraviolet Image of Jupiter Chandra observed Jupiter in February 2003 for four rotations of the planet (approximately 40 hours) during intense auroral activity. These Chandra observations, taken with its Advanced CCD Imaging Spectrometer, were accompanied by one-and-a-half hours of Hubble Space Telescope observations at ultraviolet wavelengths. The research team also included Noe Lugaz, Hunter Waite, and Tariq Majeed (University of Michigan, Ann Arbor), Thomas Cravens (University of Kansas, Lawrence), Randy Gladstone (Southwest Research Institute, San Antonio, Texas), Peter Ford (Massachusetts Institute of Technology, Cambridge), Denis Grodent (University of Liege, Belgium), Anil Bhardwaj (Marshall Space Flight Center) and Robert MacDowell and Michael Desch (Goddard Space Flight Center, Greenbelt, Md.) NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for NASA's Office of Space Science, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Chandra Looks Over a Cosmic Four-Leaf Clover

NASA Astrophysics Data System (ADS)

2004-07-01

A careful analysis of observations by NASA's Chandra X-ray Observatory of a rare quadruple quasar has uncovered evidence that possibly a single star in a foreground galaxy magnified X-rays coming from the quasar. This discovery gives astronomers a new and extremely precise probe of the gas flow around the supermassive black hole that powers the quasar. "If our interpretation is correct, then we are seeing details around this black hole that are 50,000 times smaller than either the Hubble Space Telescope or Chandra could see under ordinary circumstances," said George Chartas of Penn State University in University Park, and lead author of a recent article on the Cloverleaf quasar in The Astrophysical Journal. The Cloverleaf quasar is a single object about 11 billion light years from Earth that appears as four images produced by a process known as gravitational lensing. If one or more galaxies lie along the line of sight to a more distant quasar, the gravitational field of the intervening galaxies can bend and magnify the light from the quasar and produce multiple images of it. The four images of the Cloverleaf quasar have been produced by one or more intervening galaxies. Cloverleaf Quasar Chandra X-ray Image of the Cloverleaf quasar One of the images (A), in the Cloverleaf is brighter than the others in both optical and X-ray light. Chartas and his colleagues found the relative brightness of this image was greater in X-ray than in optical light. The X-rays from iron atoms were also enhanced relative to X-rays at lower energies. Since the amount of brightening due to gravitational lensing does not vary with the wavelength, this means that an additional object has magnified the X-rays. The increased magnification of the X-ray light can be explained by gravitational microlensing, an effect which has been used to search for compact stars and planets in our galaxy. Microlensing occurs when a star or a multiple star system passes in front of light from a background object. Cloverleaf Quasar Hubble Optical Image of the Cloverleaf quasar If a single star or a multiple star system in one of the foreground galaxies passed in front of the light path for the brightest image, then that image would be selectively magnified. The X-rays would be magnified much more than the visible light, if they came from a smaller region around the black hole than the visible light. The enhancement of the X-rays from iron ions would be due to this same effect. The analysis indicates that the X-rays are coming from a very small region, about the size of the solar system, around the supermassive black hole. The visible light is coming from a region ten or more times larger. The angular size of these regions at a distance of 11 billion light years is tens of thousands times smaller than the smallest region that can be resolved by the Hubble Space Telescope. Illustration of Wind from Accretion Disk Around a Black Hole Illustration of Wind from Accretion Disk Around a Black Hole "The significance of the detection of microlensed X-rays from the Cloverleaf quasar lies in the extremely small region that is enhanced by the microlens," said Chartas. "This gives us the ability to make strong tests of models for the flow of gas around a supermassive black hole." Other team members include Michael Eracleous (Penn State), Eric Agol (University of Washington), and Sarah Gallagher (UCLA). NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for NASA's Office of Space Science, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Contributions of the "Great" X-Ray Observatories (XMM-Newton and Chandra) to Astronomy and Astrophysics

NASA Technical Reports Server (NTRS)

Weisskopf, Martin

2011-01-01

NASA s Chandra X-ray Observatory and ESA s XMM-Newton made their first observations over a decade ago. The unprecedented and complementary capabilities of these observatories to detect, image, and measure the energy of cosmic X-rays, achieved less than 50 years after the first detection of an extra-solar X-ray source, represent an increase in sensitivity comparable in going from naked-eye observations to the most powerful optical telescopes over the past 400 years. In this presentation we highlight some of the many discoveries made using these powerful X-ray observatories that have transformed 21st century astronomy. We briefly discuss future prospects for this truly exciting field.

Chandra Captures Venus In A Whole New Light

NASA Astrophysics Data System (ADS)

2001-11-01

Scientists have captured the first X-ray view of Venus using NASA's Chandra X-ray Observatory. The observations provide new information about the atmosphere of Venus and open a new window for examining Earth's sister planet. Venus in X-rays looks similar to Venus in visible light, but there are important differences. The optically visible Venus is due to the reflection of sunlight and, for the relative positions of Venus, Earth and Sun during these observations, shows a uniform half-crescent that is brightest toward the middle. The X-ray Venus is slightly less than a half-crescent and brighter on the limbs. The differences are due to the processes by which Venus shines in visible and X-ray light. The X-rays from Venus are produced by fluorescence, rather than reflection. Solar X-rays bombard the atmosphere of Venus, knock electrons out of the inner parts of the atoms, and excite the atoms to a higher energy level. The atoms almost immediately return to their lower energy state with the emission of a fluorescent X-ray. A similar process involving ultraviolet light produces the visible light from fluorescent lamps. For Venus, most of the fluorescent X-rays come from oxygen and carbon atoms between 120 and 140 kilometers (74 to 87 miles) above the planet's surface. In contrast, the optical light is reflected from clouds at a height of 50 to 70 kilometers (31 to 43 miles). As a result, Venus' Sun-lit hemisphere appears surrounded by an almost-transparent luminous shell in X-rays. Venus looks brightest at the limb since more luminous material is there. Venus X-ray/Optical Composite of Venus Credit: Xray: NASA/CXC/MPE/K.Dennerl et al., Optical: Konrad Dennerl "This opens up the exciting possibility of using X-ray observations to study regions of the atmosphere of Venus that are difficult to investigate by other means," said Konrad Dennerl of the Max Planck Institute for Extraterrestrial Physics in Garching, Germany, leader of an international team of scientists that conducted the research. The Chandra observation of Venus was also a technological tour de force. The angular separation of Venus from the Sun, as seen from Earth, never exceeds 48 degrees. This relative proximity has prevented star trackers and cameras on other X-ray astronomy satellites from locking onto guide stars and pointing steadily in the direction of Venus to perform such an observation. Venus was observed on Jan. 10, 2001, with the Advanced CCD Imaging Spectrometer (ACIS) detector plus the Low Energy Transmission Grating and on Jan. 13, 2001, with the ACIS alone. Other members of the team were Vadim Burwitz and Jakob Engelhauser, Max Planck Institute; Carey Lisse, University of Maryland, College Park; and Scott Wolk, Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass. These results were presented at this week's "New Visions of X-ray universe in the XMM-Newton and Chandra Era" symposium in Noordwijk, Netherlands. The Low Energy Transmission Grating was built by the Space Research Organization of the Netherlands and the Max Planck Institute, and the ACIS instrument was developed for NASA by The Pennsylvania State University, University Park, and the Massachusetts Institute of Technology (MIT), Cambridge. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass.

Chandra Finds a "Cool" Black Hole at the Heart of the Andromeda Galaxy

NASA Astrophysics Data System (ADS)

2000-01-01

In its first look at the Andromeda Galaxy (M31), NASA's Chandra X-ray Observatory has found that the gas funneling into a supermassive black hole in the heart of this galaxy is a "cool" million degrees Celsius. This unexpected result adds one more quirk to the strange behavior previously observed at the center of M31. A team of scientists from the Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass., reported on this observation at the 195th national meeting of the American Astronomical Society in Atlanta, Ga. The team is led by Drs. Stephen Murray and Michael Garcia, and includes Drs. Frank Primini, William Forman, Christine Jones, and Ralph Kraft. Chandra took its first X-ray picture of the Andromeda Galaxy with the Advanced CCD Imaging Spectrometer on October 13, 1999. More than100 individual X-ray sources were seen. One of these sources was at the previously determined position of the central supermassive black hole, which has the mass of 30 million suns. With many X-ray emitting stars in the center of M31 there was a slight chance that one of them might be at this position just by coincidence. The low temperature of the suspected central source, as compared to the other sources, gave the team the clue they needed. "When we found that what we suspected was the central object was also anomalously cool, we KNEW we had it- one coincidence might be believable, but two was too much to ignore!" said Garcia. While the gas falling into the central black hole is cool, it is only cool by comparison to the 100 other X-ray sources in the Andromeda Galaxy. To be detected by an X-ray telescope, the gas must have a temperature of more than a million degrees Celsius. The typical X-ray star in the Andromeda Galaxy has a temperature of several tens of millions of degrees. In contrast, the temperature of the supermassive black hole source is a few million degrees Celsius. The Andromeda Galaxy is our nearest neighbor spiral galaxy at a distance of two million light years. It is similar to our own Milky Way in size, shape, and also contains a supermassive black hole at the center. This central black hole has always been a bit odd when compared to central black holes in similar galaxies. Based on its X-ray luminosity, it is much fainter in radio waves than expected. Such behavior, coupled with Chandra's discovery of the low temperature gas, cannot be accommodated by standard models developed for supermassive black holes in galaxies like the Milky Way and Andromeda. "The Chandra observation is telling us that an entirely different flow pattern is operating around the Andromeda black hole," said Dr. Eliot Quataert, of the Institute for Advanced Study, Princeton, N.J. "This will require a different class of models than usually considered." One possibility is that the gas undergoes a large scale boiling motion which slows down the rate at which gas falls into the black hole. The best previous X-ray pictures were not sharp enough to clearly distinguish the X-ray source associated with the black hole in the center of the Andromeda Galaxy nor did they give information about the temperature of the source. "A good analogy might be to say that previous X-ray images were taken with a slightly out-of-focus black and white camera, while the Chandra image is taken with a sharp, color camera" said Murray. Another intriguing feature of this observation is the detection of a diffuse glow that extends for a thousand light years around the central region. It is not known if this is due to many individual sources, or to a hot wind expanding out from the center. "This is just a first, quick look at our nearest Milky Way analog," Murray emphasized. "I expect that our future pictures will lead to more exciting discoveries in the Andromeda Galaxy." The ACIS instrument was built for NASA by the Massachusetts Institute of Technology, Cambridge, and Pennsylvania State University, University Park. To follow Chandra's progress, visit the Chandra site at: http://chandra.harvard.edu/photo/2000/0007/index.html AND http://chandra.nasa.gov NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program. TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass. High resolution digital versions of the X-ray image (JPG, 300 dpi TIFF ) and other information associated with this release are available on the Internet at: http://chandra.harvard.edu/

All In The Family: Chandra Finds Evidence That Massive Stars Are More Like The Sun Than Previously Believed

NASA Astrophysics Data System (ADS)

2000-10-01

NASA's Chandra X-ray Observatory has found evidence that massive stars may be much more like the Sun than previously thought. Astronomers determined that magnetic loop structures, similar to those on the Sun, may exist on the surface of so-called O-type stars, some of the most luminous stars in the universe. "This result is quite surprising," says Wayne Waldron of Emergent Information Technologies, Inc., and co-author of a paper submitted to the Astrophysical Journal Letters. "This bucks conventional wisdom to find that these stars may really resemble our Sun." Zeta Orionis Press Image and Caption Using Chandra's High-Energy Transmission Grating Spectrometer (HETGS) in conjunction with a CCD X-ray camera, astronomers observed the star Zeta Orionis (one of the three belt stars in the constellation of Orion) and found strong X-ray line emission from ions of iron, oxygen, and other elements. The high-resolution X-ray spectrum enabled astronomers to determine that the X-ray emitting gas has a density 1000 times larger than predicted by current models, an amount comparable to the atmospheric density just above the surface of the star. For many years, solar astronomers have derived densities of X-ray producing plasmas on the Sun using emission lines of ions like helium, those with just two bound electrons remaining. Chandra allows this approach to be used for other stars and it has detected X-rays from silicon ions that have been stripped of 12 of their usual complement of 14 electrons. This ion is an especially useful diagnostic of plasma densities in the extremely ultraviolet-bright environment surrounding O-stars. Following the discovery of X-ray emission from O-class stars some 20 years ago, astronomers assumed that the X-rays were created in a hot corona near the star, similar to the Sun's corona. Those models were then abandoned in favor of the currently preferred explanation: the X-ray radiation is created by energetic shocks in the stellar winds (steady streams of matter ejected from many stars, including the Sun). However, these new Chandra spectral data reveal a much higher density for the hot, X-ray producing gas than predicted if such shock models were correct. The Chandra observations also contradict current understanding since the team of researchers found no evidence of expansion in the emission lines - a fundamental prediction for shock models. According to Waldron and co-author Joseph Cassinelli of the University of Wisconsin, Madison, their observations are best explained if the high density X-ray emission comes from confined structures of very hot plasma, similar to the magnetic loops found on the Sun. [For recent results on the Sun's magnetic loops, see the NASA HQ press release, "Fountains of Fire Illuminate Solar Mystery," issued September 26, 2000.] A challenge for scientists will be to explain how these magnetic loops are generated and maintained. Although O-type stars have inner convection zones in their core, they are believed to lack outer convection zones, an ingredient scientists considered necessary to create such hot and energetic plasmas confined in magnetic loops. Convection zones are regions where most of the energy is transported by fluid motions from hotter regions to cooler ones. Without these zones being located near the stellar surface, astronomers are currently unable to explain how such high-densities knots of X-rays could exist. O-type stars, often found in groups of similar stars known as "OB associations," are massive objects, which are typically 10 or more times the Sun's mass. These stars are known to have relatively short life spans, since they burn their nuclear fuel much faster than smaller stars. The star Waldron and Cassinelli observed with Chandra, Zeta Orionis, is classified as an O "supergiant," which is 30 times larger, 30 times more massive, and radiates one hundred thousand times more energy than the Sun. The binary system of Zeta Orionis can be seen with the unaided eye from both Hemispheres for much of the year. Viewing them east to west, Zeta Orionis is the first star in the belt of the famous constellation of Orion, the Hunter. The High Energy Transmission Grating Spectrometer was built by the Massachusetts Institute of Technology (MIT), Cambridge, MA. The Advanced CCD X-ray spectrometer (ACIS) X-ray camera was developed for NASA by Penn State and MIT. NASA's Marshall Space Flight Center in Huntsville, AL, manages the Chandra program. TRW, Inc., Redondo Beach, California, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, MA. Images associated with this release are available on the World Wide Web at: http://chandra.harvard.edu AND http://chandra.nasa.gov

Leon Van Speybroeck Wins Astrophysics Bruno Rossi Prize

NASA Technical Reports Server (NTRS)

2002-01-01

Leon Van Speybroeck of the Harvard-Smithsonian Center for Astrophysics in Cambridge Massachusetts was awarded the 2002 Bruno Rossi Prize of the High-Energy Astrophysics Division of the American Astronomy Society. The Rossi Prize is an arnual recognition of significant contributions in high-energy astrophysics in honor of the Massachusetts Institute of Technology's late Professor Bruno Rossi, an authority on cosmic ray physics and a pioneer in the field of x-ray astronomy. Van Speybroeck, who led the effort to design and make the x-ray mirrors for NASA's premier Chandra X-Ray Observatory, was recognized for a career of stellar achievements in designing precision x-ray optics. As Telescope Scientist for Chandra, he has worked for more than 20 years with a team that includes scientists and engineers from the Harvard-Smithsonian, NASA's Marshall Space Flight Center, TRW, Inc., Huhes-Danbury (now B.F. Goodrich Aerospace), Optical Coating Laboratories, Inc., and Eastman-Kodak on all aspects of the x-ray mirror assembly that is the heart of the observatory.

Chandra Finds Most Distant X-ray Galaxy Cluster

NASA Astrophysics Data System (ADS)

2001-02-01

The most distant X-ray cluster of galaxies yet has been found by astronomers using NASA’s Chandra X-ray Observatory. Approximately 10 billion light years from Earth, the cluster 3C294 is 40 percent farther than the next most distant X-ray galaxy cluster. The existence of such a distant galaxy cluster is important for understanding how the universe evolved. "Distant objects like 3C294 provide snapshots to how these galaxy clusters looked billions of years ago," said Andrew Fabian of the Institute of Astronomy, Cambridge, England and lead author of the paper accepted for publication in the Monthly Notices of Britain’s Royal Astronomical Society. "These latest results help us better understand what the universe was like when it was only 20 percent of its current age." Chandra’s image reveals an hourglass-shaped region of X-ray emission centered on the previously known central radio source. This X-ray emission extends outward from the central galaxy for at least 300,000 light years and shows that the known radio source is in the central galaxy of a massive cluster. Scientists have long suspected that distant radio-emitting galaxies like 3C294 are part of larger groups of galaxies known as "clusters." However, radio data provides astronomers with only a partial picture of these distant objects. Confirmation of the existence of clusters at great distances - and, hence, at early stages of the universe - requires information from other wavelengths. Optical observations can be used to pinpoint individual galaxies, but X-ray data are needed to detect the hot gas that fills the space within the cluster. "Galaxy clusters are the largest gravitationally bound structures in the universe," said Fabian. "We do not expect to find many massive objects, such as the 3C294 cluster, in early times because structure is thought to grow from small scales to large scales." The vast clouds of hot gas that envelope galaxies in clusters are thought to be heated by collapse toward the center of the cluster. Until Chandra, X-ray telescopes have not had the needed sensitivity to identify and measure hot gas clouds in distant clusters. Carolin Crawford, Stefano Ettori and Jeremy Sanders of the Institute of Astronomy were also members of the team that observed 3C294 for 5.4 hours on October 29, 2000 with the Advanced CCD Imaging Spectrometer (ACIS). The ACIS X-ray camera was developed for NASA by Pennsylvania State University and Massachusetts Institute of Technology. NASA's Marshall Space Flight Center in Huntsville, AL, manages the Chandra program for the Office of Space Science in Washington, DC. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, MA. Images associated with this release are available on the World Wide Web at: http://chandra.harvard.edu AND http://chandra.nasa.gov

Lunar Prospecting With Chandra

NASA Astrophysics Data System (ADS)

2003-09-01

Observations of the bright side of the Moon with NASA's Chandra X-ray Observatory have detected oxygen, magnesium, aluminum and silicon over a large area of the lunar surface. The abundance and distribution of those elements will help to determine how the Moon was formed. "We see X-rays from these elements directly, independent of assumptions about the mineralogy and other complications," said Jeremy Drake of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., at a press conference at the "Four Years with Chandra" symposium in Huntsville, Alabama. "We have Moon samples from the six widely-space Apollo landing sites, but remote sensing with Chandra can cover a much wider area," continued Drake. "It's the next best thing to being there, and it's very fast and cost-effective." The lunar X-rays are caused by fluorescence, a process similar to the way that light is produced in fluorescent lamps. Solar X-rays bombard the surface of the Moon, knock electrons out of the inner parts of the atoms, putting them in a highly unstable state. Almost immediately, other electrons rush to fill the gaps, and in the process convert their energy into the fluorescent X-rays seen by Chandra. According to the currently popular "giant impact" theory for the formation of the Moon, a body about the size of Mars collided with the Earth about 4.5 billion years ago. This impact flung molten debris from the mantle of both the Earth and the impactor into orbit around the Earth. Over the course of tens of millions of years, the debris stuck together to form the Moon. By measuring the amounts of aluminum and other elements over a wide area of the Moon and comparing them to the Earth's mantle, Drake and his colleagues plan to help test the giant impact hypothesis. "One early result," quipped Drake, "is that there is no evidence for large amounts of calcium, so cheese is not a major constituent of the Moon." Illustration of Earth's Geocorona Illustration of Earth's Geocorona The same Chandra data have also solved a long-running mystery about X-rays from the dark side of the Moon, as reported by Brad Wargelin of the Harvard-Smithsonian Center for Astrophysics. Wargelin discussed how data from the German Roentgen satellite (ROSAT) obtained in 1990 showed a clear X-ray signal from the dark side. These puzzling "dark-Moon X-rays" were tentatively ascribed to energetic electrons streaming away from the Sun and striking the lunar surface. However, Chandra's observations of the energies of individual X-rays, combined with simultaneous measurements of the number of particles flowing away from the Sun in the solar wind, indicate that the X-rays only appear to come from the Moon. In reality they come from much closer to home. "Our results strongly indicate that the so-called dark Moon X-rays do not come from the dark side of the Moon," said Wargelin. "The observed X-ray spectrum, the intensity of the X-rays, and the variation of the X-ray intensity with time, can all be explained by emission from Earth's extended outer atmosphere, through which Chandra is moving." In the model cited by Wargelin and colleagues, collisions of heavy ions of carbon, oxygen and neon in the solar wind with atmospheric hydrogen atoms located tens of thousands of miles above the surface of the Earth give rise to these X-rays. In the collisions, the solar ions capture electrons from hydrogen atoms. The solar ions then kick out X-rays as the captured electrons drop to lower energy states. "This idea has been kicking around among a small circle of believers for several years supported by theory and a few pieces of evidence," said Wargelin. "These new results should really clinch it." NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the Office of Space Science, NASA Headquarters, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass.

Chandra Observatory Uncovers Hot Stars In The Making

NASA Astrophysics Data System (ADS)

2000-11-01

Cambridge, Mass.--In resolving the hot core of one of the Earth's closest and most massive star-forming regions, the Chandra X-ray Observatory showed that almost all the young stars' temperatures are more extreme than expected. Orion Trapezium JPEG, TIFF, PS The Orion Trapezium as observed on October 31st UT 05:47:21 1999. The colors represent energy, where blue and white indicate very high energies and therefore exterme temperatures. The size of the X-ray source in the image also reflects its brightness, i.e. more bright sources appear larger in size. The is an artifact caused by the limiting blur of the telescope optics. The projected diameter of the field of view is about 80 light days. Credit: NASA/MIT Orion Trapezium JPEG, TIFF, PS The Orion Trapezium as observed on November 24th UT 05:37:54 1999. The colors represent energy, where blue and white indicate very high energies and therefore exterme temperatures. The size of the X-ray source in the image also reflects its brightness, i.e. more bright sources appear larger in size. The is an artifact caused by the limiting blur of the telescope optics. The projected diameter of the field of view is about 80 light days. Credit: NASA/MIT The Orion Trapezium Cluster, only a few hundred thousand years old, offers a prime view into a stellar nursery. Its X-ray sources detected by Chandra include several externally illuminated protoplanetary disks ("proplyds") and several very massive stars, which burn so fast that they will die before the low mass stars even fully mature. One of the major highlights of the Chandra observations are identification of proplyds as X-ray point source in the near vicinity of the most massive star in the Trapezium. Previous observations did not have the ability to separate the contributions of the different objects. "We've seen high temperatures in stars before, but what clearly surprised us was that nearly all the stars we see appear at rather extreme temperatures in X-rays, independent of their type," said Norbert S. Schulz, MIT research scientist at the Chandra X-ray Center, who leads the Orion Project. "And by extreme, we mean temperatures which are in some cases well above 60 million degrees." The hottest massive star known so far has been around 25 million degrees. The great Orion Nebula harbors the Orion Nebula Cluster (ONC), a loose association of around 2,000 mostly very young stars of a wide range of mass confined within a radius of less than 10 light years. The Orion Trapezium Cluster is a younger subgroup of stars at the core of the ONC confined within a radius of about 1.5 light years. Its median age is around 300,000 years. The constant bright light of the Trapezium and its surrounding stars at the heart of the Orion nebula (M42) are visible to the naked eye on clear nights. In X-rays, these young stars are constantly active and changing in brightness, sometimes within half a day, sometimes over weeks. "Never before Chandra have we seen images of stellar activity with such brilliance," said Joel Kastner, professor at the Chester F. Carlson Center for Imaging Science at the Rochester Institute of Technology. "Here the combination of very high angular resolution, with high quality spectra that Chandra offers, clearly pays off." The observation was performed using the High Energy Transmission Grating Spectrometer (HETGS) and the X-ray spectra were recorded with the spectroscopic array of the Advanced CCD Imaging Spectrometer (ACIS). The ACIS detector is a sophisticated version of the CCD detectors commonly used in video cameras or digital cameras. The orion stars are so bright in X-rays that they easily saturate the ccds. Here the team used the gratings as a blocking filter. Orion Trapezium - X-ray & Optical JPEG, TIFF, PS X-ray contours of the Chandra observation overlaid onto the optical Hubble image (courtesy of J. Bally, CASA Colorado). The field of view is 30"x30". Besides the bright main Trapezium stars, which were found to be extremely hot massive stars, several externally illuminated objects are also X-ray emitters. Some of them with temperatures up to 100 Million degrees. The ones that do not show X-ray contours are probably too faint to be detected in these particular Chandra observations. Credit: J. Bally, CASA Colorad It is generally assumed that low-mass stars like our Sun, when they are young, are more than 1,000 times more luminous in X-rays. The X-ray emission here is thought to arise from magnetic activity in connection with stellar rotation. Consequently, high temperatures would be observed in very violent and giant flares. Here temperatures as high as 60 million degrees have been observed in very few cases. The absence of many strong flares in the light curves, as well as temperatures in the Chandra ACIS spectra wich exceed the ones in giant flares, could mean that they are either young protostars (i.e stars in the making), or a special class of more evolved, hot young stars. Schulz concedes that although astronomers have gathered many clues in recent years about the X-ray behavior of very young stellar objects, "we are far from being able to uniquely classify evolutionary stages of their X-ray emission." The five main young and massive Trapezium stars are responsible for the illumination of the entire Orion Nebula. These stars are born with masses 15 to 30 times larger than the mass of our Sun. X-rays in such stars are thought to be produced by shocks that occur when high velocity stellar winds ram into slower dense material. The Chandra spectra show a temperature component of about 5 million to 10 million degrees, which is consistent with this model. However, four of these five stars also show additional components between 30 million and 60 million degrees. "The fact that some of these massive stars show such a hot component and some not, and that a hot component seems to be more common than previously assumed, is an important new aspect in the spectral behavior of these stars," said David Huenemoerder, research physicist at the MIT Center for Space Research. Standard shock models cannot explain such high temperatures, which may be caused by magnetically confined plasmas, which are generally only attributed to stars like the Sun. Such an effect would support the suspicion that some aspects in the X-ray emission of massive stars may not be different from our Sun, which also has a hot corona. More study is needed to confirm this conclusion. The latest in NASA's series of Great Observatories. Chandra is the "X-ray Hubble," launched in July 1999 into a deep-space orbit around the Earth. Chandra carries a large X-ray telescope to focus X-rays from objects in the sky. An X-ray telescope cannot work on the ground because the X-rays are absorbed by the Earth's atmosphere. The HETGS was built by the Massachusetts Institute of Technology with Bruno Rossi Professor Claude Canizares as Principal Investigator. The ACIS X-ray camera was conceived and developed for NASA by Penn State and the Massachusetts Institute of Technology under the leadership of Gordon Garmire, Evan Pugh Professor of Astronomy and Astrophysics at Penn State. The Orion observation was part of Prof. Canizares guaranteed observing time during the first round of Chandra observations. NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program. TRW Inc., Redondo Beach, California, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Massachusetts. Orion Trapezium Handout Constellation Orion To follow Chandra's progress, visit the Chandra site at: http://chandra.harvard.edu AND http://chandra.nasa.gov Various Images for this release and a postscript version of a preprint of the accepted science paper (The Astrophysical Main Journal) can be downloaded from http://space.mit.edu/~nss/orion/orion.html

Chandra Discovers X-ray Source at the Center of Our Galaxy

NASA Astrophysics Data System (ADS)

2000-01-01

Culminating 25 years of searching by astronomers, researchers at Massachusetts Institute of Technology say that a faint X-ray source, newly detected by NASA's Chandra X-ray Observatory, may be the long-sought X-ray emission from a known supermassive black hole at the center of our galaxy. Frederick K. Baganoff and colleagues from Pennsylvania State University, University Park, and the University of California, Los Angeles, will present their findings today in Atlanta at the 195th national meeting of the American Astronomical Society. Baganoff, lead scientist for the Chandra X-ray Observatory's Advanced CCD Imaging Spectrometer (ACIS) team's "Sagittarius A* and the Galactic Center" project and postdoctoral research associate at MIT, said that the precise positional coincidence between the new X-ray source and the radio position of a long-known source called Sagittarius A* "encourages us to believe that the two are the same." Sagittarius A* is a point-like, variable radio source at the center of our galaxy. It looks like a faint quasar and is believed to be powered by gaseous matter falling into a supermassive black hole with 2.6 million times the mass of our Sun. Chandra's remarkable detection of this X-ray source has placed astronomers within a couple of years of a coveted prize: measuring the spectrum of energy produced by Sagittarius A* to determine in detail how the supermassive black hole that powers it works. "The race to be the first to detect X-rays from Sagittarius A* is one of the hottest and longest-running in all of X-ray astronomy," Baganoff said. "Theorists are eager to hear the results of our observation so they can test their ideas." But now that an X-ray source close to Sagittarius A* has been found, it has taken researchers by surprise by being much fainter than expected. "There must be something unusual about the environment around this black hole that affects how it is fed and how the gravitational energy released from the infalling matter is converted into the X-ray light that we see," Baganoff said. "This new result provides fresh insight that will no doubt stir heated debates on these issues "Chandra's sensitivity is 20 times better than achieved with the best previous X-ray telescopes," said Gordon Garmire, the Evan Pugh Professor of Astronomy and Astrophysics at Penn State University and head of the team that conceived and built Chandra's Advanced CCD Imaging Spectrometer (ACIS) X-ray camera, which Chandra's mirrors, make Chandra the perfect tool for studying this faint X-ray source in its crowded field." "The luminosity of the X-ray source we have discovered already is a factor of five satelllite," Baganoff said. "This poses a problem for theorists. The galactic center is a crowded place. If we were to find that most or all of the X-ray emission is not from all up." Astronomers believe that most galaxies harbor massive black holes at their centers. Many of these black holes are thought to produce powerful and brilliant point-like sources of light that astronomers call quasars and active galactic nuclei. Why the center of our galaxy is so dim is a long-standing puzzle. One Source Standing Out in a Crowd Sagittarius A*, which stands out on a radio map as a bright dot, was detected at the dynamical center of the Milky Way galaxy by radio telescopes in 1974. More recently, infrared observations of the movements of stars around Sagittarius A* has convinced most astronomers that there is a supermassive black hole at the center of our galaxy and that it is probably associated with Sagittarius A*. A black hole is an object so compact that light itself cannot escape its gravitational pull. A black hole sucks up material thrown out by normal stars around it. Because there are a million times more stars in a given volume in the galactic center than elsewhere in the galaxy, researchers cannot yet say definitively that Sagittarius A* is the newly detected source of the X-rays. "We need more data to clarify our observations," Baganoff said. If Sagittarius A* is powered by a supermassive black hole, astronomers expected that there would be a lot of matter to suck up in a crowded place like the galactic center. The faintness of the source may indicate a dearth of matter floating toward the black hole or it may indicate that the environment of the black hole is for some reason rejecting most of the infalling material. Chandra's Powerful Vision Optical telescopes such as the Hubble Space Telescope cannot see the center of our galaxy, which is enshrouded in thick clouds of dust and gas in the plane of the galaxy. However, hot gas and charged particles moving at nearly the speed of light produce X-rays that penetrate this shroud. Only a few months after its launch, Chandra accomplished what no other optical or X-ray satellite was able to do: separate the emissions from the surrounding hot gas and nearby compact sources that prevented other satellites from detecting this new X-ray source. Mark Morris of the University of California at Los Angeles, who has studied this region intensely for 20 years, called Chandra's data "a gold mine" for astronomers. "With more observing time on Chandra in the next two or three years, we will be able to build up a spectrum that will allow us to rule out various classes of objects and either emission," Baganoff said. "If we show that the emission is from a supermassive black hole, we will then be set to begin a detailed study of the X-ray emission from the nearest analog of a quasar or active galactic nucleus." Chandra's ACIS detector, the Advanced CCD Imaging Spectrometer, was conceived and developed for NASA by Penn State University and MIT under the leadership of Penn State Professor Gordon Garmire. Related Press Press Room: Sagittarius A* Press Release (06 Jan 03) Press Room: Galactic Center (Survey) Press Release (09 Jan 02) To follow Chandra's progress or download images visit the Chandra sites at http://chandra.harvard.edu/photo/2000/0204/index.html AND http://chandra.nasa.gov NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program. TRW Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass.

Chandra Sees Remarkable Eclipse of Black Hole

NASA Astrophysics Data System (ADS)

2007-04-01

A remarkable eclipse of a supermassive black hole and the hot gas disk around it has been observed with NASA's Chandra X-ray Observatory. This eclipse has allowed two key predictions about the effects of supermassive black holes to be tested. Just as eclipses of the Sun and moon give astronomers rare opportunities to learn about those objects, an alignment in a nearby galaxy has provided a rare opportunity to investigate a supermassive black hole. Illustrations of Black Hole Eclipse Illustrations of Black Hole Eclipse The supermassive black hole is located in NGC 1365, a galaxy 60 million light years from Earth. It contains a so called active galactic nucleus, or AGN. Scientists believe that the black hole at the center of the AGN is fed by a steady stream of material, presumably in the form of a disk. Material just about to fall into a black hole should be heated to millions of degrees before passing over the event horizon, or point of no return. The disk of gas around the central black hole in NGC 1365 produces copious X-rays but is much too small to resolve directly with a telescope. However, the disk was eclipsed by an intervening cloud, so observation of the time taken for the disk to go in and out of eclipse allowed scientists to estimate the size of the disk. Black Hole Animation Black Hole Animation "For years we've been struggling to confirm the size of this X-ray structure," said Guido Risaliti of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass, and the Italian Institute of Astronomy (INAF). "This serendipitous eclipse enabled us to make this breakthrough." The Chandra team directly measured the size of the X-ray source as about seven times the distance between the Sun and the Earth. That means the source of X-rays is about 2 billion times smaller than the host galaxy and only about 10 times larger than the estimated size of the black hole's event horizon, consistent with theoretical predictions. Chandra X-ray Image of NGC 1365 Chandra X-ray Image of NGC 1365 "Thanks to this eclipse, we were able to probe much closer to the edge of this black hole than anyone has been able to before," said co-author Martin Elvis from CfA. "Material this close in will likely cross the event horizon and disappear from the universe in about a hundred years, a blink of an eye in cosmic terms." In addition to measuring the size of this disk of material, Risaliti and his colleagues were also able to estimate the location of the dense gas cloud that eclipsed the X-ray source and central black hole. The Chandra data show that this cloud is one hundredth of a light year from the black hole's event horizon, or 300 times closer than generally thought. "AGN include the brightest objects in the Universe and are powerful probes of the early universe. So, it's vital to understand their basic structure," said Risaliti. "It turns out that we still have work to do to understand these monsters." A series of six Chandra observations of NGC 1365 were made every two days over a period of two weeks in April 2006. During five of the observations, high energy X-rays from the central X-ray source were visible, but in the second one - corresponding to the eclipse - they were not. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center, Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Chandra Discovers Light Echo from the Milky Way's Black Hole

NASA Astrophysics Data System (ADS)

2007-01-01

Like cold case investigators, astronomers have used NASA's Chandra X-ray Observatory to uncover evidence of a powerful outburst from the giant black hole at the Milky Way's center. A light echo was produced when X-ray light generated by gas falling into the Milky Way's supermassive black hole, known as Sagittarius A* (pronounced "A-star"), was reflected off gas clouds near the black hole. While the primary X-rays from the outburst would have reached Earth about 50 years ago, the reflected X-rays took a longer path and arrived in time to be recorded by Chandra. Variability in Chandra Images of Light Echo Variability in Chandra Images of Light Echo "This dramatic event happened before we had satellites in space that could detect it," said Michael Muno of the California Institute of Technology in Pasadena. "So, it's remarkable that we can use Chandra to dig into the past and see this monster black hole's capacity for destruction." Previously, scientists have used Chandra to directly detect smaller and more recent outbursts from the black hole. This latest outburst revealed by the X-ray echo was about 1,000 times brighter and lasted well over 1,000 times longer than any of the recent outbursts observed by Chandra. Theory predicts that an outburst from Sagittarius A* would cause X-ray emission from the clouds to vary in both intensity and shape. Muno and his team found these changes for the first time, thus ruling out other interpretations. The latest results corroborate other independent, but indirect, evidence for light echoes generated by the black hole in the more distant past. Illustrations of Light Echo Illustrations of Light Echo Scientists have long known that Sagittarius A*, with a mass of about 3 million suns, lurked at the center for Milky Way. However, the black hole is incredibly faint at all wavelengths, especially in X-rays. "This faintness implies that stars and gas rarely get close enough to the black hole to be in any danger," said co-author Frederick K. Baganoff of the Massachusetts Institute of Technology in Cambridge. "The huge appetite is there, but it's not being satisfied." During the outburst, the area close to the black hole would have been about 100,000 times brighter than it is currently. If such an outburst had occurred more recently, it likely would have been detected by an X-ray instrument, or would have produced similar features in other nearby clouds. Chandra X-ray Image of Sagittarius A* Chandra X-ray Image of Sagittarius A* "Our data show it has been 50 years or so since the black hole had its last decent meal," said Muno. "This is nothing like the feasting that black holes in other galaxies sometimes enjoy, but it gives unique knowledge about the feeding habits of our closest supermassive black hole." The details of how Sagittarius A* feeds remain unclear. For example, one possibility is that the black hole grows by pulling in matter from the winds of nearby young stars. Also, if there is a disk of material swirling around Sagittarius A*, it might be unstable in such a way that material migrates toward the black hole's edge in clumps, emitting X-rays before disappearing from the universe forever. The theoretical work is still being developed. Studying this light echo is also important because it illuminates and probes the poorly understood molecular clouds near the center of the galaxy. In particular, it gives information about the dense cores of these clouds where new stars may be forming. Variability in the X-ray emission between three Chandra observations in 2002, 2004 and 2005 argues against an alternate source for the light echo, which is that it came from a neutron star or black hole pulling matter away from a binary companion. This explanation is not favored because the data show the outburst would have been unusually long and bright for such a binary. These results were presented at the American Astronomical Society meeting in Seattle, Wash., and will appear in an upcoming issue of The Astrophysical Journal Letters. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center, Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

NASA Scientists Witness a Supernova Cosmic Rite of Passage

NASA Astrophysics Data System (ADS)

2005-11-01

Scientists using NASA's Chandra X-ray Observatory have witnessed a cosmic rite of passage, the transition from a supernova to a supernova remnant, a process that has never been seen in much detail until now, leaving it poorly defined. A supernova is a massive star explosion; the remnant is the beautiful glowing shell that evolves afterwards. When does a supernova become supernova remnant? When does the shell appear and what powers its radiant glow? A science team led by Dr. Stefan Immler of NASA's Goddard Space Flight Center, Greenbelt, Md., has taken a fresh look at a supernova that exploded in 1970, called SN 1970G, just off the handle of the Big Dipper. This is the oldest supernova ever seen by X-ray telescopes. Chandra X-ray Image of SN 1970G Chandra X-ray Image of SN 1970G "Some astronomers have thought there's a moment when the supernova remnant magically turns on years after the supernova itself has faded away, when the shock wave of the explosion finally hits and lights up the interstellar medium," said Immler. "By contrast, our results show that a new supernova quickly and seamlessly evolves into a supernova remnant. The star's own debris, and not the interstellar medium gas, fuels the remnant." These results appear in The Astrophysical Journal, co-authored by Dr. Kip Kuntz, also of Goddard. They support previous Chandra observations of SN 1987A by Dr. Sangwook Park of Penn State. Using new data from Chandra and archived data from the European-led ROSAT and XMM-Newton observatories, Immler and Kuntz pieced together how SN 1970G evolved over the years. They found telltale signs of a supernova remnant - bright X-ray light - yet no evidence of interstellar gas, even across a distance around the site of the explosion 35 times larger than our solar system. Instead, the material that is heated by the supernova shock to glow in X-ray light, what we call the remnant, is from the stellar wind of the star itself and not distant gas in the interstellar medium. This wind, comprising energetic ions, was shed by the progenitor star thousands to million of years before the explosion. If this were from the interstellar medium, it would be much denser than this stellar wind. NOAO Optical Image of SN 1970G NOAO Optical Image of SN 1970G Immler and Kuntz next studied the density profiles of all other supernovae that have been detected over the past two decades. Sure enough, the low-density circumstellar matter from the stellar wind was the source of X-rays, not the interstellar medium. Immler said that historical supernova remnants such as Cassiopeia A, which exploded some 320 years ago, also show no signs of activity from the interstellar medium. This is more than just a name game, more than hypothetically changing SN 1970G to SNR 1970G. "We have to rethink this notion that a shock wave from the supernova crashes into the interstellar medium to create a supernova remnant," said Immler. "The luminous supernova remnants that we see can be created without the need of a dense interstellar medium. In fact, our study showed that all supernovae detected in X-rays over the past 25 years live in a low-density environment." SN 1970G is located in the galaxy M101, also called the Pinwheel Galaxy, a stunning spiral galaxy about 22 million light years away in the constellation Ursa Major, home of the Big Dipper. Although the galaxy itself is visible from dark skies with binoculars, telescopes cannot resolve much structure in SN 1970G, unlike for supernova remnants in our Milky Way galaxy. Discovered with an optical telescope in 1970, SN 1970G was not seen with X-ray telescopes until the 1990s. Immler's work at NASA Goddard is supported through the Universities Space Research Association. Kuntz is supported through University of Maryland, Baltimore County. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for the Agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Supernova SN 2014C Optical and X-Ray

NASA Image and Video Library

2017-01-24

This visible-light image from the Sloan Digital Sky Survey shows spiral galaxy NGC 7331, center, where astronomers observed the unusual supernova SN 2014C . The inset images are from NASA's Chandra X-ray Observatory, showing a small region of the galaxy before the supernova explosion (left) and after it (right). Red, green and blue colors are used for low, medium and high-energy X-rays, respectively. http://photojournal.jpl.nasa.gov/catalog/PIA21088

Most powerful X-ray telescope marks third anniversary

NASA Astrophysics Data System (ADS)

2002-08-01

A black hole gobbles up matter in our own Milky Way Galaxy. A hot spot of X-rays pulsates from near Jupiter's poles. An intergalactic web of hot gas, hidden from view since the time galaxies formed, is finally revealed. These scenarios sound like science fiction - but to those familiar with the latest developments in X-ray astronomy, they are just a few of the real-life discoveries made by NASA's Chandra X-ray Observatory during its third year of operation. "Within the last year, Chandra has revealed another series of never-before-seen phenomena in our galaxy and beyond," said Chandra project scientist Dr. Martin Weisskopf of NASA's Marshall Space Flight Center in Huntsville, Ala. "When you combine recent discoveries with the secrets revealed during the observatory's first two years in orbit, it's amazing how much Chandra has told us about the universe in a relatively short period of time." One such discovery was an unprecedented view of a supermassive black hole devouring material in the Milky Way Galaxy - a spectacle witnessed for the first time when Chandra observed a rapid X-ray flare emitted from the direction of the black hole residing at our galaxy's center. In a just few minutes, Sagittarius A, a source of radio emission believed to be associated with the black hole, became 45 times brighter in X-rays, before declining to pre-flare levels a few hours later, offering astronomers a never-before-seen view of the energetic processes surrounding this supermassive black hole. "When we launched the Chandra Observatory, we attempted to explain its amazing capabilities in Earthly terms, such as the fact it can 'see' so well, it's like someone reading the letters of a stop sign 12 miles away," said Chandra Program Manager Tony Lavoie of the Marshall Center. "But now that the observatory has been in orbit for three years, we have unearthly proof of the technological marvel Chandra really is. Not only has it continued to operate smoothly and efficiently, it has provided the highest quality X-ray images ever made. Now, we're not talking about stop signs, but rather black holes, star systems, galaxies and planets." One such discovery involved the planet Jupiter. Using the Chandra Observatory, astronomers discovered a pulsating hot spot of X-rays in the polar regions of the planet's upper atmosphere and uncovered evidence the X-ray source is not arising from the region of Jupiter where previously believed. By revealing that most of the X-rays come from a hot spot appearing at a fixed location near Jupiter's north magnetic pole, Chandra disproved the previous model, which placed the emission at a lower latitude of the planet's atmosphere and had no knowledge the X-rays were pulsed. "Sometimes new discoveries provide answers, and sometimes they pose more questions," said Weisskopf. "This is a good example, because by pinpointing the location of Jupiter's hot spot, Chandra ruled out the existing explanation for the planet's X-ray emission. Now we must search for a new process that explains Jupiter's X-rays. When we accomplish that, we can assemble yet another piece to the cosmic puzzle." One such piece fell into place when the Chandra Observatory discovered part of an intergalactic web of hot gas and dark matter that contains most of the material in the universe. The hot gas, which appeared to lie like a fog in channels carved by rivers of gravity, has been hidden from view since the time galaxies formed. These observations, together with ultraviolet observations, helped shed new light on how the universe evolved. The hot gas detected by Chandra can be used to trace the presence of the more massive dark matter component. The discovery of the hot gas may eventually enable astronomers to map the distribution of dark matter in the universe and perhaps understand its origin. These recent discoveries build on a series of groundbreaking findings made by the Chandra Observatory during its first two years of operation. Initial highlights include its discovery of an X-ray ring around the Crab Nebula , finding the most distant X-ray cluster of galaxies, capturing the deepest X-ray images ever recorded and discovering a new size of black hole. Because Earth's atmosphere blocks X-rays from reaching the surface, X-ray astronomy can only be performed from space. Launched in July 1999, the Chandra Observatory travels one-third of the way to the Moon during its orbit around the Earth every 64 hours. At its highest point, Chandra's highly elliptical, or egg-shaped, orbit is 200 times higher than that of its visible-light-gathering sister, the Hubble Space Telescope. The Marshall Center manages the Chandra program, and TRW, Inc. of Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian Astrophysical Observatory's Chandra X-ray Center controls science and flight operations from Cambridge, Mass.

Bayesian analysis of X-ray jet features of the high redshift quasar jets observed with Chandra

NASA Astrophysics Data System (ADS)

McKeough, Kathryn; Siemiginowska, Aneta; Kashyap, Vinay; Stein, Nathan; Cheung, Chi C.

2015-01-01

X-ray emission of powerful quasar jets may be a result of the inverse Compton (IC) process in which the Cosmic Microwave Background (CMB) photons gain energy by interactions with the jet's relativistic electrons. However, there is no definite evidence that IC/CMB process is responsible for the observed X-ray emission of large scale jets. A step toward understanding the X-ray emission process is to study the Radio and X-ray morphologies of the jet. Results from Chandra X-ray and multi-frequency VLA imaging observations of a sample of 11 high- redshift (z > 2) quasars with kilo-parsec scale radio jets are reported. The sample consists of a set of four z ≥ 3.6 flat-spectrum radio quasars, and seven intermediate redshift (z = 2.1 - 2.9) quasars comprised of four sources with integrated steep radio spectra and three with flat radio spectra.We implement a Bayesian image analysis program, Low-count Image Reconstruction and Analysis (LIRA) , to analyze jet features in the X-ray images of the high redshift quasars. Out of the 36 regions where knots are visible in the radio jets, nine showed detectable X-ray emission. Significant detections are based on the upper bound p-value test based on LIRA simulations. The X-ray and radio properties of this sample combined are examined and compared to lower-redshift samples.This work is supported in part by the National Science Foundation REU and the Department of Defense ASSURE programs under NSF Grant no.1262851 and by the Smithsonian Institution, and by NASA Contract NAS8-39073 to the Chandra X-ray Center (CXC). This research has made use of data obtained from the Chandra Data Archive and Chandra Source Catalog, and software provided by the CXC in the application packages CIAO, ChIPS, and Sherpa. Work is also supported by the Chandra grant GO4-15099X.

NASA's Great Observatories Celebrate the International Year of Astronomy

NASA Technical Reports Server (NTRS)

2009-01-01

[figure removed for brevity, see original site] Click on the image for larger version

In 1609, Galileo improved the newly invented telescope, turned it toward the heavens, and revolutionized our view of the universe. In celebration of the 400th anniversary of this milestone, 2009 has been designated as the International Year of Astronomy.

Today, NASA's Great Observatories are continuing Galileo's legacy with stunning images and breakthrough science from the Hubble Space Telescope, the Spitzer Space Telescope, and the Chandra X-ray Observatory.

While Galileo observed the sky using visible light seen by the human eye, technology now allows us to observe in many wavelengths, including Spitzer's infrared view and Chandra's view in X-rays. Each wavelength region shows different aspects of celestial objects and often reveals new objects that could not otherwise be studied.

This image of the spiral galaxy Messier 101 is a composite of views from Spitzer, Hubble, and Chandra. The red color shows Spitzer's view in infrared light. It highlights the heat emitted by dust lanes in the galaxy where stars can form. The yellow color is Hubble's view in visible light. Most of this light comes from stars, and they trace the same spiral structure as the dust lanes. The blue color shows Chandra's view in X-ray light. Sources of X-rays include million-degree gas, exploded stars, and material colliding around black holes.

Such composite images allow astronomers to see how features seen in one wavelength match up with those seen in another wavelength. It's like seeing with a camera, night vision goggles, and X-ray vision all at once.

In the four centuries since Galileo, astronomy has changed dramatically. Yet our curiosity and quest for knowledge remain the same. So, too, does our wonder at the splendor of the universe.

The International Year of Astronomy Great Observatories Image Unveiling is supported by the NASA Science Mission Directorate Astrophysics Division. The project is a collaboration between the Space Telescope Science Institute, the Spitzer Science Center, and the Chandra X-ray Center.

The Chandra X-Ray Observatory and its Role for the Study of Ionized Plasmas

NASA Technical Reports Server (NTRS)

Weisskopf, Martin C.

2010-01-01

NASA's Chandra X-Ray Observatory was launched in July of 1999. Featuring a 1000cm2-class X-ray telescope with sub-arcsecond angular resolution, the Observatory has observed targets from the solar system including the earth s moon, comets, and planets to the most distant galaxy clusters and active galactic nuclei. Capable of performing moderate energy resolution image-resolved spectroscopy using its CCD detectors, and high-resolution grating spectroscopy, the Observatory has produced, and continues to produce, valuable data and insights into the emission mechanisms of the ionized plasmas in which the X-rays originate. We present a brief overview of the Observatory to provide insight as to how to use it for your investigations. We also present an, admittedly brief and biased, overview of some of the results of investigations performed with Chandra that may be of interest to this audience.

Chandra X-Ray Observatory (CXO) on Orbit Animation

NASA Technical Reports Server (NTRS)

1999-01-01

This is an on-orbit animation of the Chandra X-Ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF). In 1999, the AXAF was renamed the CXO in honor of the late Indian-American Novel Laureate Subrahmanyan Chandrasekhar. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It is designed to observe x-rays from high energy regions of the Universe, such as hot gas in the remnants of exploded stars. It produces picture-like images of x-ray emissions analogous to those made in visible light, as well as gathers data on the chemical composition of x-ray radiating objects. The CXO helps astronomers worldwide better understand the structure and evolution of the universe by studying powerful sources of x-rays such as exploding stars, matter falling into black holes, and other exotic celestial objects. TRW, Inc. was the prime contractor for the development of the CXO and NASA's Marshall Space Flight Center was responsible for its project management. The Smithsonian Astrophysical Observatory controls science and flight operations of the CXO for NASA from Cambridge, Massachusetts. The Observatory was launched July 22, 1999 aboard the Space Shuttle Columbia, STS-93 mission.

KSC-chandra-xo2

NASA Image and Video Library

1999-01-21

The Chandra X-ray Observatory (CXO), NASA's newest space telescope, is seen above at the unveiling ceremony at TRW Space and Electronics Group in Redondo Beach, Calif. The photo was taken by Marshall Space Flight Center and appears on its Marshall News Center Web site, along with other digital images of the completely assembled observatory. Formerly called the Advanced X-ray Astrophysics Facility, the CXO is the world's most powerful X-ray telescope. Scientists believe its ability to see previously invisible black holes and high-temperature gas clouds give the observatory the potential to rewrite the books on the structure and evolution of our universe

Gamma-ray Bursts May Originate in Star-Forming Regions

NASA Astrophysics Data System (ADS)

2001-04-01

New findings from two X-ray satellites suggest that gamma-ray bursts, some of the most intense blasts in the universe, may be created in the same area where stars are born. Dr. Luigi Piro of the Consiglio Nazionale delle Ricerche (CNR) in Rome, Italy, presented data from NASA's Chandra X-ray Observatory and the Italian-Dutch ASI BeppoSAX observatory today at the Gamma Ray 2001 conference in Baltimore, MD. "We know that when a gamma-ray burst explodes, it produces a blast of material called a fireball, which expands at relativistic speeds like a rapidly inflating bubble," said Piro, who works within CNR's Istituto di Astrofisica Spaziale. "Our team found evidence that the blast wave caused by the fireball brakes against a wall of very dense gas, which we believe is the crowded region where stars form." Several theories exist about what causes gamma-ray bursts. Among more popular theories are that gamma-ray bursts come from various combinations of merging neutron stars and black holes, or, from the explosion of massive stars, called hypernovae. "Because gamma-ray bursts are going off in extremely distant galaxies, it is difficult to 'see' the regions that harbor them," said Piro. "We can only gather circumstantial evidence as to where and how they form." Piro's observations support the hypernova model. Scientists believe that within dense star-forming regions, the massive star required for a hypernova explosion evolves extremely rapidly. On astronomical time scales, the supermassive star would evolve over the course of only about one million years. Thus, the hypernova explosion may occur in the same stellar environment that originally produced the massive star itself, and perhaps may trigger even more star formation. The hint that gamma-ray bursts can occur in dense media came during a Chandra observation of an afterglow that occurred on September 26, 2000. Prof. Gordon Garmire of Pennsylvania State University, University Park, PA, found X-ray emission to be greater than that expected by the standard scenario of a fireball in a low-density medium - an important clue that the explosion occurred in a dense region. Next, on February 22, 2001, Piro said that Chandra observations of the burst's afterglow, one of the brightest bursts ever observed by BeppoSAX, provided evidence of a fireball expanding in a very dense gas. These recent results supported data from four other gamma-ray bursts observed by BeppoSAX and Chandra (GRB970508, GRB990705, GRB991216, and GRB000214). In these bursts, Piro and his team found evidence indicating that the burst had encountered an extremely dense gas. The properties of this gas suggest that it originated from a very massive progenitor before it exploded as a gamma-ray burst. A key element in the success of these observations has been the perfect timing and liaison between the two satellites, Chandra and BeppoSAX, according to Piro. Piro is the Mission Scientist for BeppoSAX, the instrument that first detected X-ray afterglows from gamma-ray bursts. Currently, astronomers are not usually notified about gamma-ray bursts until an hour or so after they occur. These bursts last only for a few milliseconds to about a minute, although their afterglow can linger in X-ray and optical light for days or weeks. The HETE-2 satellite, launched in October 2000, and Swift, scheduled for a 2003 launch, will provide nearly instant notification of bursts in action, providing satellites such as Chandra a better opportunity to study the afterglow phenomenon in depth. The ACIS X-ray camera was developed for NASA by Penn State and the Massachusetts Institute of Technology. The High Energy Transmission Grating Spectrometer was built by MIT. NASA's Marshall Space Flight Center in Huntsville, AL, manages the Chandra program. TRW, Inc., Redondo Beach, California, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, MA. Images associated with this release are available on the World Wide Web at: http://chandra.harvard.edu AND http://chandra.nasa.gov

Overview of the Chandra X-Ray Observatory Facility

NASA Technical Reports Server (NTRS)

Weisskopf, M. C.; Six, N. Frank (Technical Monitor)

2002-01-01

The Chandra X-Ray Observatory (originally called the Advanced X-Ray Astrophysics Facility - AXAF) is the X-Ray component of NASA's "Great Observatory" Program. Chandra is a NASA facility that provides scientific data to the international astronomical community in response to scientific proposals for its use. The Observatory is the product of the efforts of many organizations in the United States and Europe. The Great Observatories also include the Hubble Space Telescope for space-based observations of astronomical objects primarily in the visible portion of the electromagnetic spectrum, the now defunct Compton Gamma- Ray Observatory that was designed to observe gamma-ray emission from astronomical objects, and the soon-to-be-launched Space Infrared Telescope Facility (SIRTF). The Chandra X-Ray Observatory (hereafter CXO) is sensitive to X-rays in the energy range from below 0.1 to above 10.0 keV corresponding to wavelengths from 12 to 0.12 nanometers. The relationship among the various parts of the electromagnetic spectrum, sorted by characteristic temperature and the corresponding wavelength, is illustrated. The German physicist Wilhelm Roentgen discovered what he thought was a new form of radiation in 1895. He called it X-radiation to summarize its properties. The radiation had the ability to pass through many materials that easily absorb visible light and to free electrons from atoms. We now know that X-rays are nothing more than light (electromagnetic radiation) but at high energies. Light has been given many names: radio waves, microwaves, infrared, visible, ultraviolet, X-ray and gamma radiation are all different forms. Radio waves are composed of low energy particles of light (photons). Optical photons - the only photons perceived by the human eye - are a million times more energetic than the typical radio photon, whereas the energies of X-ray photons range from hundreds to thousands of times higher than that of optical photons. Very low temperature systems (hundreds of degrees below zero Celsius) produce low energy radio and microwave photons, whereas cool bodies like our own (about 30 degrees Celsius) produce infrared radiation. Very high temperatures (millions of degrees Celsius) are one way of producing X-rays.

Precocious Supermassive Black Holes Challenge Theories

NASA Astrophysics Data System (ADS)

2004-11-01

NASA's Chandra X-ray Observatory has obtained definitive evidence that a distant quasar formed less than a billion years after the Big Bang contains a fully-grown supermassive black hole generating energy at the rate of twenty trillion Suns. The existence of such massive black holes at this early epoch of the Universe challenges theories of the formation of galaxies and supermassive black holes. Astronomers Daniel Schwartz and Shanil Virani of the Harvard-Smithsonian Center for Astrophysics in Cambridge, MA observed the quasar, known as SDSSp J1306, which is 12.7 billion light years away. Since the Universe is estimated to be 13.7 billion years old, we see the quasar as it was a billion years after the Big Bang. They found that the distribution of X-rays with energy, or X-ray spectrum, is indistinguishable from that of nearby, older quasars. Likewise, the relative brightness at optical and X-ray wavelengths of SDSSp J1306 was similar to that of the nearby group of quasars. Optical observations suggest that the mass of the black hole is about a billion solar masses. Illustration of Quasar SDSSp J1306 Illustration of Quasar SDSSp J1306 Evidence of another early-epoch supermassive black hole was published previously by a team of scientists from the California Institute of Technology and the United Kingdom using the XMM-Newton X-ray satellite. They observed the quasar SDSSp J1030 at a distance of 12.8 billion light years and found essentially the same result for the X-ray spectrum as the Smithsonian scientists found for SDSSp J1306. Chandra's precise location and spectrum for SDSSp J1306 with nearly the same properties eliminate any lingering uncertainty that precocious supermassive black holes exist. "These two results seem to indicate that the way supermassive black holes produce X-rays has remained essentially the same from a very early date in the Universe," said Schwartz. "This implies that the central black hole engine in a massive galaxy was formed very soon after the Big Bang." There is general agreement among astronomers that X-radiation from the vicinity of supermassive black holes is produced as gas is pulled toward a black hole, and heated to temperatures ranging from millions to billions of degrees. Most of the infalling gas is concentrated in a rapidly rotating disk, the inner part of which has a hot atmosphere or corona where temperatures can climb to billions of degrees. Although the precise geometry and details of the X-ray production are not known, observations of numerous quasars, or supermassive black holes, have shown that many of them have very similar X-ray spectra, especially at high X-ray energies. This suggests that the basic geometry and mechanism are the same for these objects. Chandra X-ray Image of SDSSp J1306 Chandra X-ray Image of SDSSp J1306 The remarkable similarity of the X-ray spectra of the young supermassive black holes to those of much older ones means that the supermassive black holes and their accretion disks, were already in place less than a billion years after the Big Bang. One possibility is that millions of 100 solar mass black holes formed from the collapse of massive stars in the young galaxy, and subsequently built up a billion-solar mass black hole in the center of the galaxy through mergers and accretion of gas. To answer the question of how and when supermassive black holes were formed, astronomers plan to use the very deep Chandra exposures and other surveys to identify and study quasars at even earlier ages. The paper by Schwartz and Virani on SDSSp J1306 was published in the November 1, 2004 issue of The Astrophysical Journal. The paper by Duncan Farrah and colleagues on SDSS J1030 was published in the August 10, 2004 issue of The Astrophysical Journal. Chandra observed J1306 with its Advanced CCD Imaging Spectrometer (ACIS) instrument for approximately 33 hours in November 2003. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for NASA's Office of Space Science, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

History of Chandra X-Ray Observatory

NASA Image and Video Library

2000-12-18

This Chandra image of Jupiter shows concentrations of aurora x-rays near the north and south poles due to a single `hot spot' that pulsates with a period of 45 minutes, similar to high-latitude radio pulsation previously detected by NASA's Galileo and Cassini spacecraft. Previous x-ray detections of Jupiter have been made with other x-ray telescopes, but did not reveal that the sources of the x-rays, energetic oxygen and sulfur ions, would be located so near the poles. Previous theories held that ions were mostly coming from Jupiter's moon, lo. Chandra's ability to pinpoint the source of the x-rays discards this theory since ions coming from near lo's orbit carnot reach the observed high latitudes. One possibility is that particles flowing out from the Sun are captured in the outer regions of Jupiter's magnetic field, then accelerated and directed toward its magnetic pole. Once captured, the ions would bounce back and forth in the magnetic field from Jupiter's north pole to the south pole in an oscillating motion that could explain the pulsation.

Chandra Pinpoints Edge Of Accretion Disk Around Black Hole

NASA Astrophysics Data System (ADS)

2001-05-01

Using four NASA space observatories, astronomers have shown that a flaring black hole source has an accretion disk that stops much farther out than some theories predict. This provides a better understanding of how energy is released when matter spirals into a black hole. On April 18, 2000, the Hubble Space Telescope and the Extreme Ultraviolet Explorer observed ultraviolet radiation from the object known as XTE J1118+480, a black hole roughly seven times the mass of the Sun, locked in a close binary orbit with a Sun-like star. Simultaneously, the Rossi X-ray Timing Explorer observed high-energy X-rays from matter plunging toward the black hole, while the Chandra X-ray Observatory focused on the critical energy band between the ultraviolet and high-energy X-rays, providing the link that tied all the data together. "By combining the observations of XTE J1118+480 at many different wavelengths, we have found the first clear evidence that the accretion disk can stop farther out," said Jeffrey McClintock of the Harvard-Smithsonian Center for Astrophysics who led the Chandra observations. "The Chandra data indicate that this accretion disk gets no closer to the event horizon than about 600 miles, a far cry from the 25 miles that some had expected." Scientists theorize that the accretion disk is truncated there because the material erupts into a hot bubble of gas before taking its final plunge into the black hole. Matter stripped from a companion star by a black hole can form a flat, pancake-like structure, called an “accretion disk.” As material spirals toward the inner edge of the accretion disk, it is heated by the immense gravity of the black hole, which causes it to radiate in X-rays. By examining the X-rays, researchers can gauge how far inward the accretion disk extends. Most astronomers agree that when material is transferred onto the black hole at a high rate, then the accretion disk will reach to within about 25 miles of the event horizon -- the surface of “no return” for matter or light falling into a black hole. However, scientists disagree on how close the accretion disk comes when the rate of transfer is much less. "The breakthrough came when Chandra did not detect the X-ray signature one would expect if the accretion disk came as near as 25 miles," said Ann Esin, a Caltech theoretical astrophysicist who led a group that explored the implications of the observations. "This presents a fundamental problem for models in which the disk extends close to the event horizon." In March 2000, XTE J1118+480 experienced a sudden eruption in X-rays that led to the discovery of the object by RXTE. The X-ray source was in a direction where absorption by gas and dust was minimal, allowing ultraviolet and low-energy X-rays to be observed. In the following month, an international team organized observations of XTE J1118+480 in other wavelengths. Chandra observed XTE J1118+480 for 27,000 seconds with its Low-Energy Transmission Grating (LETG) and the Advanced CCD Imaging Spectrometer (ACIS). The research team for this investigation also included scientists from both the United States (CfA, MIT, University of Notre Dame, Lawrence Livermore National Laboratory, NASA Goddard Space Flight Center) and the United Kingdom (The Open University, University of Southampton, Mullard Radio Astronomy Observatory). The LETG was built by the SRON and the Max Planck Institute, and the ACIS instrument by the Massachusetts Institute of Technology, Cambridge, Mass., and Penn State University, University Park. NASA's Marshall Space Flight Center in Huntsville, AL, manages the Chandra program. TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass. Images associated with this release are available on the World Wide Web at: http://chandra.harvard.edu AND http://chandra.nasa.gov

Chandra Observes Cloud Powered by Black Hole in Distant Galaxy

NASA Astrophysics Data System (ADS)

2000-06-01

NASA's Chandra X-ray Observatory has shown that a large gas cloud is being blasted by X rays from the vicinity of a giant black hole which lurks in its center. The observation is of special interest because it shows the disruptive effects that a massive black hole can have over thousands of light years. The results are being presented today by Drs. Patrick M. Ogle, Herman L. Marshall, Julia C. Lee, and Claude Canizares of the Massachusetts Institute of Technology (MIT), Cambridge, at the 196th national meeting of the American Astronomical Society in Rochester, NY. The observation also demonstrates that the searchlight beam of X rays from the black hole can be used to probe the environment around a black hole. The galaxy NGC 4151 is located at a distance of 50 million light years in a direction just south of the Big Dipper. It is a prominent example of a class of galaxies that show unusual energetic activity in their nucleus. This activity is now known to be due to the presence of a giant black hole in the nucleus with an estimated mass 10 million times that of the Sun. As matter swirls toward the black hole, it releases a prodigious amount of energy, much of it in X rays. Previous observations showed that X rays are also coming from an enormous cloud 3000 light years across that surrounds the black hole. The precise mirrors of Chandra allowed astronomers to make an X-ray image showing unprecedented detail of the massive cloud in the center of NGC 4151. The brightest regions in the cloud correspond to wisps that were previously observed in visible light by the Hubble Space Telescope. The shape of the cloud confirms that X rays from the black hole are collimated into a narrow beam, and illuminate only certain quadrants of the galaxy. "The black hole is shining an X-ray searchlight which illuminates the clouds in the night sky of NGC 4151" said Ogle. By using the High Energy Transmission Grating (HETG), astronomers were able to resolve the X-ray spectrum from the nebula surrounding the black hole into emission from its constituent elements. It was found that the gas cloud contains nitrogen, oxygen, neon, magnesium, aluminum, silicon, and iron. However, the atoms of these elements have been stripped of most of their electrons by energetic X rays coming from the center of NGC 4151. This provides direct evidence that the cloud is powered by the giant black hole which resides there. "The cloud is being thoroughly cooked by the powerful beam from the black hole," said Ogle. In addition, the Chandra HETG spectrum reveals that portions of the cloud are moving away from us at a velocity of 800,000 mph. "We're probably seeing gas that is being blown away from the far side of the black hole by the pressure of the radiation from the black hole," Ogle said. Chandra data were taken with the HETG in conjunction with the Advanced CCD Imaging Spectrometer (ACIS) on March 5-6, 2000. HETG was built by MIT and ACIS was built by Pennsylvania State University, University Park, and MIT. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program. TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass. High resolution digital versions of the X-ray image (JPG, 300 dpi TIFF ) and other information associated with this release are available on the Internet at: http://chandra.harvard.edu AND http://chandra.nasa.gov

Chandra Reads the Cosmic Bar Code of Gas Around a Black Hole

NASA Astrophysics Data System (ADS)

2000-02-01

An international team of astronomers has used NASA's Chandra X-ray Observatory to make an energy bar code of hot gas in the vicinity of a giant black hole. These measurements, the most precise of their kind ever made with an X-ray telescope, demonstrate the existence of a blanket of warm gas that is expanding rapidly away from the black hole. The team consists of Jelle Kaastra, Rolf Mewe and Albert Brinkman of Space Research Organization Netherlands (SRON) in Utrecht, Duane Liedahl of Lawrence Livermore National Laboratory in Livermore, Calif., and Stefanie Komossa of Max Planck Institute in Garching, Germany. A report of their findings will be published in the March issue of the European journal Astronomy & Astrophysics. Kaastra and colleagues used the Low Energy Transmission Grating in conjunction with the High Resolution Camera to measure the number of X rays present at each energy. With this information they constructed an X-ray spectrum of the source. Their target was the central region, or nucleus of the galaxy NGC 5548, which they observed for 24 hours. This galaxy is one of a class of galaxies known to have unusually bright nuclei that are associated with gas flowing around and into giant black holes. This inflow produces an enormous outpouring of energy that blows some of the matter away from the black hole. Astronomers have used optical, ultraviolet, and X-ray telescopes in an effort to disentangle the complex nature of inflowing and outflowing gas at different distances from the black hole in NGC 5548. X-ray observations provide a ringside seat to the action around the black hole. By using the Low Energy Transmission Grating, the Dutch-US-German team concentrated on gas that forms a warm blanket that partially covers the innermost region where the highest energy X-rays are produced. As the high-energy X rays stream away from the vicinity of the black hole, they heat the blanketing gas to temperatures of a few million degrees, and the blanket absorbs some of the X rays from the central source. This produces dark stripes, or absorption lines in the X-ray spectrum. Bright stripes or emission lines due to emission from the blanketing gas are also present. Since each element has its own unique structure, these lines can be read like a cosmic bar code to take inventory of the gas. The team was able to determine what atoms the gas contains and how many, the number of electrons each atom has retained in the hostile environment of the black hole, and how the gas is moving there. They found lines from eight different elements including carbon, nitrogen, oxygen, and iron. The amount of this gas was found to be about 100 times greater than that found with optical and ultraviolet observations. The Low Energy Transmission Grating was built by the SRON. and the Max Planck Institute under the direction of Albert Brinkman. The High Resolution Camera was built by the Smithsonian Astrophysical Observatory in Cambridge, Mass. under the direction of Stephen Murray. To follow Chandra's progress or download images visit the Chandra sites at: http://chandra.harvard.edu/photo/2000/0170/index.html AND http://chandra.nasa.gov NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program. TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass. High resolution digital versions of the X-ray spectrum (JPG, 300 dpi TIFF ) and other information associated with this release are available on the Internet at: http://chandra.harvard.edu

X-ray insights into star and planet formation.

PubMed

Feigelson, Eric D

2010-04-20

Although stars and planets form in cold environments, X-rays are produced in abundance by young stars. This review examines the implications of stellar X-rays for star and planet formation studies, highlighting the contributions of NASA's (National Aeronautics and Space Administration) Chandra X-ray Observatory. Seven topics are covered: X-rays from protostellar outflow shocks, X-rays from the youngest protostars, the stellar initial mass function, the structure of young stellar clusters, the fate of massive stellar winds, X-ray irradiation of protoplanetary disks, and X-ray flare effects on ancient meteorites. Chandra observations of star-forming regions often show dramatic star clusters, powerful magnetic reconnection flares, and parsec-scale diffuse plasma. X-ray selected samples of premain sequence stars significantly advance studies of star cluster formation, the stellar initial mass function, triggered star-formation processes, and protoplanetary disk evolution. Although X-rays themselves may not play a critical role in the physics of star formation, they likely have important effects on protoplanetary disks by heating and ionizing disk gases.

NASA's Great Observatories Celebrate the International Year of Astronomy With a National Unveiling of Spectacular Images

NASA Astrophysics Data System (ADS)

2009-02-01

In 1609, Galileo first turned his telescope to the heavens and gave birth to modern astronomy. To commemorate four hundred years of exploring the universe, 2009 is designated the International Year of Astronomy. NASA's Great Observatories - the Hubble Space Telescope, Spitzer Space Telescope, and Chandra X-ray Observatory - are marking the occasion with the release of a suite of images at over 100 planetariums, museums, nature centers, and schools across the country in conjunction with Galileo's birthday on February 15. The selected sites will unveil a large 9-square-foot print of the spiral galaxy Messier 101 that combines the optical view of Hubble, the infrared view of Spitzer, and the X-ray view of Chandra into one multi-wavelength picture. "It's like using your eyes, night vision goggles, and X-ray vision all at the same time," says Dr. Hashima Hasan, lead scientist for the International Year of Astronomy at NASA Headquarters in Washington. Cas A animation Chandra X-ray Image of M101 Participating institutions also will display a matched trio of Hubble, Spitzer, and Chandra images of Messier 101. Each image shows a different wavelength view of the galaxy that illustrates not only the different science uncovered by each observatory, but also just how far astronomy has come since Galileo. Messier 101 is a face-on spiral galaxy about 22 million light-years away in the constellation Ursa Major. It is in many ways similar to, but larger than, our own Milky Way galaxy. Hubble's visible light view shows off the swirls of bright stars and glowing gas that give the galaxy its nickname the Pinwheel Galaxy. In contrast, Spitzer's infrared-light image sees into the spiral arms and reveals the glow of dust lanes where dense clouds can collapse to form new stars. Chandra's X-ray picture uncovers the high-energy features in the galaxy, such as remnants of exploded stars or matter zooming around black holes. The juxtaposition of observations from these three telescopes provides an in-depth view of the galaxy for both astronomers and the public. People Who Read This Also Read... Cosmic Heavyweights in Free-for-all Milky Way’s Giant Black Hole Awoke from Slumber 300 Years Ago Chandra Data Reveal Rapidly Whirling Black Holes Jet Power and Black Hole Assortment Revealed in New Chandra Image "The amazing scientific discoveries made by Galileo four centuries ago are continued today by scientists using NASA's space observatories," says Dr. Denise Smith, the unveiling Project Manager at the Space Telescope Science Institute in Baltimore, Md. "NASA's Great Observatories are distributing huge prints of spectacular images so that the public can share in the exploration and wonder of the universe." The unveilings will take place between February 14 and 28 at 76 museums and 40 schools and universities in 39 states, reaching both big cities and small towns. Sites are planning celebrations involving the public, schools, and the local media. A complete listing of the national unveiling sites accompanies this press release. The International Year of Astronomy Great Observatories Image Unveiling is supported by the NASA Science Mission Directorate Astrophysics Division. The project is a collaboration between the Space Telescope Science Institute, the Spitzer Science Center, and the Chandra X-ray Center.

Chandra Reviews Black Hole Musical: Epic But Off-Key

NASA Astrophysics Data System (ADS)

2006-10-01

A gigantic sonic boom generated by a supermassive black hole has been found with NASA's Chandra X-ray Observatory, along with evidence for a cacophony of deep sound. This discovery was made by using data from the longest X-ray observation ever of M87, a nearby giant elliptical galaxy. M87 is centrally located in the Virgo cluster of galaxies and is known to harbor one of the Universe's most massive black holes. Scientists detected loops and rings in the hot, X-ray emitting gas that permeates the cluster and surrounds the galaxy. These loops provide evidence for periodic eruptions that occurred near the supermassive black hole, and that generate changes in pressure, or pressure waves, in the cluster gas that manifested themselves as sound. Chandra Low Energy X-ray Images of M87 Chandra Low Energy X-ray Images of M87 "We can tell that many deep and different sounds have been rumbling through this cluster for most of the lifetime of the Universe," said William Forman of the Harvard-Smithsonian Center for Astrophysics (CfA). The outbursts in M87, which happen every few million years, prevent the huge reservoir of gas in the cluster from cooling and forming many new stars. Without these outbursts and resultant heating, M87 would not be the elliptical galaxy it is today. "If this black hole wasn't making all of this noise, M87 could have been a completely different type of galaxy," said team member Paul Nulsen, also of the CfA, "possibly a huge spiral galaxy about 30 times brighter than the Milky Way." Chandra High Energy X-ray Image of M87 Chandra High Energy X-ray Image of M87 The outbursts result when material falls toward the black hole. While most of the matter is swallowed, some of it was violently ejected in jets. These jets are launched from regions close to the black hole (neither light nor sound can escape from the black hole itself) and push into the cluster's gas, generating cavities and sound which then propagate outwards. Chandra's M87 observations also give the strongest evidence to date of a shock wave produced by the supermassive black hole, a clear sign of a powerful explosion. This shock wave appears as a nearly circular ring of high-energy X-rays that is 85,000 light years in diameter and centered on the black hole. Other remarkable features are seen in M87 for the first time including narrow filaments of X-ray emission -- some over 100,000 light years long -- that may be due hot gas trapped by magnetic fields. Also, a large, previously unknown cavity in the hot gas, created by an outburst from the black hole about 70 million years ago, is seen in the X-ray image. Animation Showing a Supermassive Black Hole Outburst in M87 Animation Showing a Supermassive Black Hole Outburst in M87 "We can explain some of what we see, like the shock wave, with textbook physics," said team member Christine Jones, also of the CfA. "However, other details, like the filaments we find, leave us scratching our heads." Sound has been detected from another black hole in the Perseus cluster, which was calculated to have a note some 57 octaves below middle C. However, the sound in M87 appears to be more discordant and complex. A series of unevenly spaced loops in the hot gas gives evidence for small outbursts from the black hole about every 6 million years. These loops imply the presence of sound waves, not visible in the Chandra image, which are about 56 octaves below middle C. The presence of the large cavity and the sonic boom gives evidence for even deeper notes -- 58 or 59 octaves below middle C -- powered by large outbursts. These new results on M87 were presented at the High-Energy Astrophysics Division meeting being held in San Francisco. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center, Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Scientists Discover Supernova May Control Activity in the Center of Our Galaxy

NASA Astrophysics Data System (ADS)

2001-02-01

10 January 2001 -- Scientists using NASA's Chandra X-ray Observatory have discovered that an apparent supernova remnant in the center of our galaxy might help regulate a nearby supermassive black hole and that such relationships between supernova remnants and black holes might be common throughout the universe. The scientists studied Sagittarius A East, previously known by its ring-shaped radio emission, located nearly 26,000 light years from Earth in the constellation Sagittarius. Sgr A East appears to surround the black hole Sagittarius A* (denoted with an asterisk because it is a point source that emits radio waves) with its center offset by about six light years from that of the black hole. Using Chandra, scientists were able to separate Sgr A East from other complex structures for the first time in X-ray wavelengths. The properties they discovered support the long-standing hypothesis that Sgr A East is a single supernova remnant that exploded about 10,000 years ago. "With Chandra, we found hot gas concentrated within the larger radio shell of Sgr A East," said Yoshitomo Maeda, an astronomy and astrophysics research associate at Penn State who presented the research team's results at the 197th national meeting of the American Astronomical Society in San Diego, California, on 10 January 2001. "The gas is highly enriched by heavy elements, with four times more calcium and iron than the Sun, and that confirms earlier suspicions that Sgr A East is most likely a remnant of a supernova explosion. While dozens of supernova remnants are known in our galaxy, the proximity of Sgr A East to the black hole in the center of our galaxy makes it important." After a supernova explosion, scientists believe two shock waves are formed, with one moving inward and one outward. The inward shock wave heated up the ejecta that was detected with X-rays by the Advanced CCD Imaging Spectrometer (ACIS) aboard Chandra. The temperature of gas in that shock wave was measured at 20 million degrees by Chandra. Scientists believe the outward shock wave moved the cooler, heavier gas that comprises the intergalactic medium--compressing and plowing that gas past the black hole as the shock wave spread and feeding the black hole in the process. They believe the result was a period of intense feeding of material into the black hole, followed by a period of black hole "starvation." "The important question to be raised here is what effect the plowed gas has on its environment," said Frederick Baganoff, a research associate at Massachusetts Institute of Technology and lead scientist for Chandra's Galactic Center project. "It is possible that the plowed gas has passed over the supermassive black hole at some time in the recent past. During the passage, a lot of gas could have been captured by the black hole." When black holes pull matter inward, they are able to accelerate those particles to almost the speed of light. The matter accreting into a black hole releases a great deal of energy, much of it in X rays that can ionize the surrounding gas and make it visible with instruments such as ACIS. Because X-ray emissions from the black hole are weak at this time, scientists believe the shock wave already has passed by the black hole. "Radio astronomers already found that the gas in a halo surrounding Sgr A East and the supermassive black hole is largely ionized," said Mark Morris, professor of astronomy and physics at the University of California at Los Angeles. "If the gas plowed by the supernova remnant was pushed past the black hole, the spectacular interaction would very possibly have occurred as recently as a few hundred years ago, and the resulting flash of energy would likely have irradiated and ionized the surrounding gas. This could explain why the ionization of the gas still survives." In a broader sense, that activity might serve as a model for other black holes and other phenomena throughout the universe because the Chandra scientists suggest supernova explosions might regulate the activity of those phenomena. Many scientists believe black holes thrive at the center of most galaxies and when those black holes accrete material, scientists can detect an active galactic nucleus with X rays. According to the Chandra scientists, individual supernova explosions might be relevant for providing material that activates the accretion activity of black holes, thereby turning the active nucleus on and off. The Chandra observations were made 21 September 1999 using ACIS, which was conceived and developed for NASA by Penn State and Massachusetts Institute of Technology under the leadership of Gordon Garmire, Evan Pugh Professor of Astronomy and Astrophysics at Penn State. NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program. TRW, Inc., of Redondo Beach, California, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Massachusetts. The ACIS detector is a sophisticated version of the CCD detectors commonly used in digital cameras or video cameras. Chandra carries an X-ray telescope to focus the X-rays from objects in the sky. An X-ray telescope cannot work on the ground because X-rays are absorbed by the Earth's atmosphere. The Chandra X-ray Observatory is the third of NASA's "Great Observatories," following the Hubble Space Telescope and the Compton Gamma-Ray Observatory. Along with Maeda and Garmire, the Penn State contingent of collaborators for results of this research presented at the astronomical society meeting comprises: Niel Brandt, David Burrows, Eric Feigelson, and Leisa Townsley. Along with Baganoff and Morris, other collaborators include: Mark Bautz, John Doty, and George Ricker from Massachusetts Institute of Technology; and Steve Pravdo from the Jet Propulsion Laboratory. This research is supported by NASA contract NAS 8-38252 and, in part, by the Jet Propulsion Laboratory, under contract with NASA. Images associated with this release are available on the World Wide Web at: http://chandra.harvard.edu AND http://chandra.nasa.gov

NASA's Chandra Finds Black Holes Are "Green"

NASA Astrophysics Data System (ADS)

2006-04-01

Black holes are the most fuel efficient engines in the Universe, according to a new study using NASA's Chandra X-ray Observatory. By making the first direct estimate of how efficient or "green" black holes are, this work gives insight into how black holes generate energy and affect their environment. The new Chandra finding shows that most of the energy released by matter falling toward a supermassive black hole is in the form of high-energy jets traveling at near the speed of light away from the black hole. This is an important step in understanding how such jets can be launched from magnetized disks of gas near the event horizon of a black hole. Illustration of Fuel for a Black Hole Engine Illustration of Fuel for a Black Hole Engine "Just as with cars, it's critical to know the fuel efficiency of black holes," said lead author Steve Allen of the Kavli Institute for Particle Astrophysics and Cosmology at Stanford University, and the Stanford Linear Accelerator Center. "Without this information, we cannot figure out what is going on under the hood, so to speak, or what the engine can do." Allen and his team used Chandra to study nine supermassive black holes at the centers of elliptical galaxies. These black holes are relatively old and generate much less radiation than quasars, rapidly growing supermassive black holes seen in the early Universe. The surprise came when the Chandra results showed that these "quiet" black holes are all producing much more energy in jets of high-energy particles than in visible light or X-rays. These jets create huge bubbles, or cavities, in the hot gas in the galaxies. Animation of Black Hole in Elliptical Galaxy Animation of Black Hole in Elliptical Galaxy The efficiency of the black hole energy-production was calculated in two steps: first Chandra images of the inner regions of the galaxies were used to estimate how much fuel is available for the black hole; then Chandra images were used to estimate the power required to produce the cavities. "If a car was as fuel-efficient as these black holes, it could theoretically travel over a billion miles on a gallon of gas," said coauthor Christopher Reynolds of the University of Maryland, College Park. New details are given about how black hole engines achieve this extreme efficiency. Some of the gas first attracted to the black holes may be blown away by the energetic activity before it gets too near the black hole, but a significant fraction must eventually approach the event horizon where it is used with high efficiency to power the jets. The study also implies that matter flows towards the black holes at a steady rate for several million years. Chandra X-ray Images of Elliptical Galaxies Chandra X-ray Images of Elliptical Galaxies "These black holes are very efficient, but it also takes a very long time to refuel them," said Steve Allen who receives funding from the Office of Science of the Department of Energy. This new study shows that black holes are green in another important way. The energy transferred to the hot gas by the jets should keep hot gas from cooling, thereby preventing billions of new stars from forming. This will place limits on the growth of the largest galaxies, and prevent galactic sprawl from taking over the neighborhood. These results will appear in an upcoming issue of the Monthly Notices of the Royal Astronomical Society. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center, Cambridge, Mass. Additional information and images can be found at: http://chandra.harvard.edu and http://chandra.nasa.gov For information about NASA and agency programs on the Web, visit: http://www.nasa.gov

The Vital Infrared to X-ray Link in the Sgr A* Accretion Flow

NASA Astrophysics Data System (ADS)

Fazio, Giovanni; Ashby, Matthew; Baganoff, Frederick; Becklin, Eric; Boyce, Hope; Carey, Sean; Gammie, Charles; Ghez, Andrea; Glaccum, William; Gurwell, Mark; Haggard, Daryl; Herrero-Illana, Ruben; Hora, Joseph; Ingalls, James; Lowrance, Patrick; Markoff, Sera; Marrone, Daniel; Morris, Mark; Narayan, Ramesh; Neilsen, Joseph; Ponti, Gabriele; Smith, Howard; Willner, Steven; Witzel, Gunther

2018-05-01

Black hole accretion drives extreme astrophysical phenomena in the universe. Sgr A*, the radiating counterpart of the nearest supermassive black hole, is highly variable, but sparse data and short observations have left its emission physics in question. Despite enormous advances in accretion models, physical description of the interacting radiation mechanisms is incomplete. The X-ray emission mechanism in particular remains unknown. Because the necessary information is contained in the time-dependent relation between X-ray and infrared emission, we have begun monitoring Sgr A* simultaneously with Chandra in X-rays and with Spitzer in the infrared. Defining the X-ray to infrared flux density ratio will allow the entire energy distribution to be understood. We therefore request two new 24-hour epochs of Spitzer monitoring at 4.5 microns simultaneous with Chandra time already approved. This will increase the exposure time for X-ray flares where the NIR state is known, moving us out of the realm of small-number statistics and enabling diagnostics of the true X-ray/IR ratio. Under current NASA plans, this will be the last chance for these valuable Spitzer+Chandra observations.

Chandra Clinches Case for Missing Link Black Hole

NASA Astrophysics Data System (ADS)

2000-09-01

The strongest evidence yet that the universe is home to a new type of black hole was reported by several groups of scientists today Using NASA's Chandra X-ray Observatory, scientists have zeroed in on a mid-mass black hole in the galaxy M82. This black hole - located 600 light years away from the center of a galaxy - may represent the missing link between smaller stellar black holes and the supermassive variety found at the centers of galaxies. "This opens a whole new field of research," said Martin Ward of the University of Leicester, UK, a lead author involved with the observations. "No one was sure that such black holes existed, especially outside the centers of galaxies." The black hole in M82 packs the mass of at least 500 suns into a region about the size of the Moon. Such a black hole would require extreme conditions for its creation, such as the collapse of a "hyperstar" or the merger of scores of black holes. The result comes as Chandra starts its second year of operation and is testimony to how Chandra's power and precision is changing the field of astronomy. "This black hole might eventually sink to the center of the galaxy," said Dr. Hironori Matsumoto of the Massachusetts Institute of Technology, the lead author on one of three Chandra papers scheduled to be published on the mid-mass black hole, "where it could grow to become a supermassive black hole." Although previous X-ray data from the German-U.S. Roentgen Satellite and the Japan-U.S. ASCA Satellite suggested that a mid-mass black hole might exist in M82, the crucial breakthrough came when astronomers compared the new high resolution Chandra data with optical, radio, and infrared maps of the region. They determined that most of the X-rays were coming from a single bright source. Repeated observations of M82 over a period of eight months showed the bright X-ray source gradually peaking in X-ray brightness before dimming. Another critical discovery was that the intensity of the X rays was rising and falling every 600 seconds. "This flickering of the X-ray intensity is similar to the well-studied characteristics of black holes swallowing gas from a nearby star or cloud. Explanations other than a massive black hole for this object are implausible," said Dr. Philip Kaaret of the Harvard-Smithsonian Center for Astrophysics, lead author on the paper reporting the 10 minute variations. "The brightness of the source requires that the black hole have a mass greater than 500 suns." Possible explanations for the object include the merger of stars to form a hyperstar that collapsed, or growth of a black hole through mergers with other nearby black holes and neutron stars. Observations with the Japan Nobeyama Millimeter Array by Dr. Satoki Matsushita of Harvard-Smithsonian and colleagues have revealed a large expanding superbubble of gas centered on the mid-mass black hole in M82. The energy of several thousand supernovas would be required to produce the expanding superbubble. In the past, our Milky Way galaxy could have produced mid-mass black holes during periods of vigorous star formation. Hundreds of these massive black holes may exist unseen in our galaxy, in addition to the dozen or so known stellar black holes and the supermassive black hole that is safely confined to the galaxy's nucleus. Other scientists involved with the Chandra observations include: Drs. A. H. Prestwich, A. Zezas, and S.S.Murray of Harvard-Smithsonian; C. Canizares of MIT; T. G. Tsuru and K. Koyama of Kyoto University, Japan; H. Awaki of Ehime University, Japan; N. Kawai of RIKEN (The Institute of Chemical & Physical Research) Japan; R. Kawabe of the Nobeyama Radio Observatory, Japan. M82 was observed by Chandra 6 times for approximately 30 hours total. The observations were made with the High Resolution Camera (HRC) and the Advanced CCD Imaging Spectrometer (ACIS). The HRC was built for NASA by the Smithsonian Astrophysical Observatory, Cambridge, MA. The ACIS instrument was built for NASA by the Massachusetts Institute of Technology, Cambridge, and Pennsylvania State University, University Park. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program. TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass. Images associated with this release are available on the World Wide Web at: http://chandra.harvard.edu AND http://chandra.nasa.gov High resolution digital versions of the X-ray image (JPG, 300 dpi TIFF) are available at the Internet sites listed above. This image will be available on NASA Video File which airs at noon, 3:00 p.m., 6:00 p.m., 9:00 p.m. and midnight Eastern Time. NASA Television available on GE-2, transponder 9C at 85 degrees West longitude, with vertical polarization. Frequency is on 3880.0 megahertz, with audio on 6.8 megahertz.

NASA Extends Chandra Science and Operations Support Contract

NASA Astrophysics Data System (ADS)

2010-01-01

NASA has extended a contract with the Smithsonian Astrophysical Observatory in Cambridge, Mass., to provide science and operational support for the Chandra X-ray Observatory, a powerful tool used to better understand the structure and evolution of the universe. The contract extension with the Smithsonian Astrophysical Observatory provides continued science and operations support to Chandra. This approximately 172 million modification brings the total value of the contract to approximately 545 million for the base effort. The base effort period of performance will continue through Sept. 30, 2013, except for the work associated with the administration of scientific research grants, which will extend through Feb. 28, 2016. The contract type is cost reimbursement with no fee. In addition to the base effort, the contract includes two options for three years each to extend the period of performance for an additional six years. Option 1 is priced at approximately 177 million and Option 2 at approximately 191 million, for a total possible contract value of about $913 million. The contract covers mission operations and data analysis, which includes observatory operations, science data processing and astronomer support. The operations tasks include monitoring the health and status of the observatory and developing and uplinking the observation sequences during Chandra's communication coverage periods. The science data processing tasks include the competitive selection, planning and coordination of science observations and processing and delivery of the resulting scientific data. NASA's Marshall Space Flight Center in Huntsville, Ala, manages the Chandra program for the agency's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations. For more information about the Chandra X-ray Observatory visit: http://chandra.nasa.gov

Highlights and discoveries from the Chandra X-ray Observatory.

PubMed

Tananbaum, H; Weisskopf, M C; Tucker, W; Wilkes, B; Edmonds, P

2014-06-01

Within 40 years of the detection of the first extra-solar x-ray source in 1962, NASA's Chandra X-ray Observatory has achieved an increase in sensitivity of 10 orders of magnitude, comparable to the gain in going from naked-eye observations to the most powerful optical telescopes over the past 400 years. Chandra is unique in its capabilities for producing sub-arcsecond x-ray images with 100-200 eV energy resolution for energies in the range 0.08 < E < 10 keV, locating x-ray sources to high precision, detecting extremely faint sources, and obtaining high-resolution spectra of selected cosmic phenomena. The extended Chandra mission provides a long observing baseline with stable and well-calibrated instruments, enabling temporal studies over timescales from milliseconds to years. In this report we present a selection of highlights that illustrate how observations using Chandra, sometimes alone, but often in conjunction with other telescopes, have deepened, and in some instances revolutionized, our understanding of topics as diverse as protoplanetary nebulae; massive stars; supernova explosions; pulsar wind nebulae; the superfluid interior of neutron stars; accretion flows around black holes; the growth of supermassive black holes and their role in the regulation of star formation and growth of galaxies; impacts of collisions, mergers, and feedback on growth and evolution of groups and clusters of galaxies; and properties of dark matter and dark energy.

"Wonderful" Star Reveals its Hot Nature

NASA Astrophysics Data System (ADS)

2005-04-01

For the first time an X-ray image of a pair of interacting stars has been made by NASA's Chandra X-ray Observatory. The ability to distinguish between the interacting stars - one a highly evolved giant star and the other likely a white dwarf - allowed a team of scientists to observe an X-ray outburst from the giant star and find evidence that a bridge of hot matter is streaming between the two stars. "Before this observation it was assumed that all the X-rays came from a hot disk surrounding a white dwarf, so the detection of an X-ray outburst from the giant star came as a surprise," said Margarita Karovska of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., and lead author article in the latest Astrophysical Journal Letters describing this work. An ultraviolet image made by the Hubble Space Telescope was a key to identifying the location of the X-ray outburst with the giant star. X-ray studies of this system, called Mira AB, may also provide better understanding of interactions between other binary systems consisting of a "normal" star and a collapsed star such as a white dwarf, black hole or a neutron star, where the stellar objects and gas flow cannot be distinguished in an image. HST Ultraviolet Image of Mira HST Ultraviolet Image of Mira The separation of the X-rays from the giant star and the white dwarf was made possible by the superb angular resolution of Chandra, and the relative proximity of the star system at about 420 light years from Earth. The stars in Mira AB are about 6.5 billion miles apart, or almost twice the distance of Pluto from the Sun. Mira A (Mira) was named "The Wonderful" star in the 17th century because its brightness was observed to wax and wane over a period of about 330 days. Because it is in the advanced, red giant phase of a star's life, it has swollen to about 600 times that of the Sun and it is pulsating. Mira A is now approaching the stage where its nuclear fuel supply will be exhausted, and it will collapse to become a white dwarf. The internal turmoil in Mira A could create magnetic disturbances in the upper atmosphere of the star and lead to the observed X-ray outbursts, as well as the rapid loss of material from the star in a blustery, strong, stellar wind. Some of the gas and dust escaping from Mira A is captured by its companion Mira B. In stark contrast to Mira A, Mira B is thought to be a white dwarf star about the size of the Earth. Some of the material in the wind from Mira A is captured in an accretion disk around Mira B, where collisions between rapidly moving particles produce X-rays. Animation of Interacting Stars Animation of Interacting Stars One of the more intriguing aspects of the observations of Mira AB at both X-ray and ultraviolet wavelengths is the evidence for a faint bridge of material joining the two stars. The existence of a bridge would indicate that, in addition to capturing material from the stellar wind, Mira B is also pulling material directly off Mira A into the accretion disk. Chandra observed Mira with its Advanced CCD Imaging Spectrometer on December 6, 2003 for about 19 hours. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate, Washington. Northrop Grumman of Redondo Beach, Calif., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Chandra Observation of Polaris: Census of Low-Mass Companions

NASA Astrophysics Data System (ADS)

Evans, Nancy Remage; Wolk, Scott; Guinan, Edward; Engle, Scott; Schlegel, Eric; Mason, Brian; Karovska, Margarita; Spitzbart, Bradley

2009-09-01

We have observed Polaris = HD 8890 with Chandra ACIS-I for 10 ksec and found an X-ray source at the location of the Cepheid Polaris A = Aa + Ab with log L_X = 28.89 ergs s^{-1} and a kT = 0.6 keV. Either the F7 Ib supergiant or the F6 V spectroscopic companion could produce a spectrum this soft. Polaris B is not an X-ray source, which is consistent with its early F spectral type. However, this shows that it does not itself have a lower mass companion. Two resolved low mass stars ``C and D" are not physical companions based on the lack of X-rays (indicating an older age than the Cepheid) and inconsistent motion. In addition, a possible more distant companion is identified, and also less plausible one. Thus, this observation provides a complete census of companions down to masses as small as an order of magnitude less than the Cepheid and nearly 15 mag fainter within the surrounding 0.1 pc.Funding for this work was provided by Chandra grant GO6-7011A Chandra X-ray Center NASA Contract NAS8-39073

Close Encounters of the Stellar Kind

NASA Astrophysics Data System (ADS)

2003-07-01

NASA's Chandra X-ray Observatory has confirmed that close encounters between stars form X-ray emitting, double-star systems in dense globular star clusters. These X-ray binaries have a different birth process than their cousins outside globular clusters, and should have a profound influence on the cluster's evolution. A team of scientists led by David Pooley of the Massachusetts Institute of Technology in Cambridge took advantage of Chandra's unique ability to precisely locate and resolve individual sources to determine the number of X-ray sources in 12 globular clusters in our Galaxy. Most of the sources are binary systems containing a collapsed star such as a neutron star or a white dwarf star that is pulling matter off a normal, Sun-like companion star. "We found that the number of X-ray binaries is closely correlated with the rate of encounters between stars in the clusters," said Pooley. "Our conclusion is that the binaries are formed as a consequence of these encounters. It is a case of nurture not nature." A similar study led by Craig Heinke of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. confirmed this conclusion, and showed that roughly 10 percent of these X-ray binary systems contain neutron stars. Most of these neutron stars are usually quiet, spending less than 10% of their time actively feeding from their companion. NGC 7099 NGC 7099 A globular cluster is a spherical collection of hundreds of thousands or even millions of stars buzzing around each other in a gravitationally-bound stellar beehive that is about a hundred light years in diameter. The stars in a globular cluster are often only about a tenth of a light year apart. For comparison, the nearest star to the Sun, Proxima Centauri, is 4.2 light years away. With so many stars moving so close together, interactions between stars occur frequently in globular clusters. The stars, while rarely colliding, do get close enough to form binary star systems or cause binary stars to exchange partners in intricate dances. The data suggest that X-ray binary systems are formed in dense clusters known as globular clusters about once a day somewhere in the universe. Observations by NASA's Uhuru X-ray satellite in the 1970's showed that globular clusters seemed to contain a disproportionately large number of X-ray binary sources compared to the Galaxy as a whole. Normally only one in a billion stars is a member of an X-ray binary system containing a neutron star, whereas in globular clusters, the fraction is more like one in a million. The present research confirms earlier suggestions that the chance of forming an X-ray binary system is dramatically increased by the congestion in a globular cluster. Under these conditions two processes, known as three-star exchange collisions, and tidal captures, can lead to a thousandfold increase in the number of X-ray sources in globular clusters. 47 Tucanae 47 Tucanae In an exchange collision, a lone neutron star encounters a pair of ordinary stars. The intense gravity of the neutron star can induce the most massive ordinary star to "change partners," and pair up with the neutron star while ejecting the lighter star. A neutron star could also make a grazing collision with a single normal star, and the intense gravity of the neutron star could distort the gravity of the normal star in the process. The energy lost in the distortion, could prevent the normal star from escaping from the neutron star, leading to what is called tidal capture. "In addition to solving a long-standing mystery, Chandra data offer an opportunity for a deeper understanding of globular cluster evolution," said Heinke. "For example, the energy released in the formation of close binary systems could keep the central parts of the cluster from collapsing to form a massive black hole." NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the Office of Space Science, NASA Headquarters, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. The image and additional information are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Era of Galaxy and Black Hole Growth Spurt Discovered

NASA Astrophysics Data System (ADS)

2005-04-01

Distant galaxies undergoing intense bursts of star formation have been shown by NASA's Chandra X-ray Observatory to be fertile growing grounds for the largest black holes in the Universe. Collisions between galaxies in the early Universe may be the ultimate cause for both the accelerated star formation and black hole growth. By combining the deepest X-ray image ever obtained with submillimeter and optical observations, an international team of scientists has found evidence that some extremely luminous adolescent galaxies and their central black holes underwent a phenomenal spurt of growth more than 10 billion years ago. This concurrent black hole and galaxy growth spurt is only seen in these galaxies and may have set the stage for the birth of quasars - distant galaxies that contain the largest and most active black holes in the Universe. Simulation of a Galaxy Collision Simulation of a Galaxy Collision "The extreme distances of these galaxies allow us to look back in time, and take a snapshot of how today's largest galaxies looked when they were producing most of their stars and growing black holes," said David Alexander of the University of Cambridge, UK, and lead author of a paper in the April 7, 2005 issue of Nature that describes this work. The galaxies studied by Alexander and his colleagues are known as submillimeter galaxies, so-called because they were originally identified by the James Clerk Maxwell submillimeter telescope (JCMT) on Mauna Kea in Hawaii. The submillimeter observations along with optical data from Keck indicate these galaxies had an unusually large amount of gas. The gas in each galaxy was forming into stars at a rate of about one per day, or 100 times the present rate in the Milky Way galaxy. The Chandra X-ray data show that the supermassive black holes in the galaxies were also growing at the same time. Chandra X-ray Image of CDFN Chandra X-ray Image of CDFN These galaxies are very faint and it is only with the deepest observations of the Universe that they can be detected at all. "The deeper we look into the Universe with Chandra, the more fascinating things we find" says Niel Brandt of Penn State University in University Park. "Who knows what nature has in store for us as we push the boundaries yet further." The X-ray observations also showed that the black holes are surrounded by a dense shroud of gas and dust. This is probably the material that will be consumed by the growing black holes. Hubble Space Telescope observations indicate that most of the submillimeter galaxies are actually two galaxies that are colliding and merging. Recent sophisticated computer simulations performed by Tiziana Di Matteo of Carnegie Mellon University in Pittsburgh, Penn., and her collaborators have shown that such mergers drive gas toward the central regions of galaxies, triggering a burst of star formation and providing fuel for the growth of a central black hole. Chandra's X-ray Image of Black Holes in the Early Universe Chandra's X-ray Image of Black Holes in the Early Universe "It is exciting that these recent observations are in good agreement with our simulation," says Di Matteo, "We seem to be converging on a consistent picture of galaxy formation with both observations and theory." In particular, this work will help scientists to understand the observed link in the present epoch between the total mass of stars in the central bulges of large galaxies and the size of their central, supermassive black holes. The James Clerk Maxwell Telescope (JCMT) is operated on behalf of the United Kingdom, Canada & Netherlands by the Joint Astronomy Centre. With its 15-meter (50-foot) diameter dish the JCMT detects light with "submillimeter" wavelengths, between infrared light and radio waves on the wavelength scale. The W. M. Keck Observatory is operated by the California Association for Research in Astronomy. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate, Washington. Northrop Grumman of Redondo Beach, Calif., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Chandra Independently Determines Hubble Constant

NASA Astrophysics Data System (ADS)

2006-08-01

A critically important number that specifies the expansion rate of the Universe, the so-called Hubble constant, has been independently determined using NASA's Chandra X-ray Observatory. This new value matches recent measurements using other methods and extends their validity to greater distances, thus allowing astronomers to probe earlier epochs in the evolution of the Universe. "The reason this result is so significant is that we need the Hubble constant to tell us the size of the Universe, its age, and how much matter it contains," said Max Bonamente from the University of Alabama in Huntsville and NASA's Marshall Space Flight Center (MSFC) in Huntsville, Ala., lead author on the paper describing the results. "Astronomers absolutely need to trust this number because we use it for countless calculations." Illustration of Sunyaev-Zeldovich Effect Illustration of Sunyaev-Zeldovich Effect The Hubble constant is calculated by measuring the speed at which objects are moving away from us and dividing by their distance. Most of the previous attempts to determine the Hubble constant have involved using a multi-step, or distance ladder, approach in which the distance to nearby galaxies is used as the basis for determining greater distances. The most common approach has been to use a well-studied type of pulsating star known as a Cepheid variable, in conjunction with more distant supernovae to trace distances across the Universe. Scientists using this method and observations from the Hubble Space Telescope were able to measure the Hubble constant to within 10%. However, only independent checks would give them the confidence they desired, considering that much of our understanding of the Universe hangs in the balance. Chandra X-ray Image of MACS J1149.5+223 Chandra X-ray Image of MACS J1149.5+223 By combining X-ray data from Chandra with radio observations of galaxy clusters, the team determined the distances to 38 galaxy clusters ranging from 1.4 billion to 9.3 billion light years from Earth. These results do not rely on the traditional distance ladder. Bonamente and his colleagues find the Hubble constant to be 77 kilometers per second per megaparsec (a megaparsec is equal to 3.26 million light years), with an uncertainty of about 15%. This result agrees with the values determined using other techniques. The Hubble constant had previously been found to be 72, give or take 8, kilometers per second per megaparsec based on Hubble Space Telescope observations. The new Chandra result is important because it offers the independent confirmation that scientists have been seeking and fixes the age of the Universe between 12 and 14 billion years. Chandra X-ray Image of CL J1226.9+3332 Chandra X-ray Image of CL J1226.9+3332 "These new results are entirely independent of all previous methods of measuring the Hubble constant," said team member Marshall Joy also of MSFC. The astronomers used a phenomenon known as the Sunyaev-Zeldovich effect, where photons in the cosmic microwave background (CMB) interact with electrons in the hot gas that pervades the enormous galaxy clusters. The photons acquire energy from this interaction, which distorts the signal from the microwave background in the direction of the clusters. The magnitude of this distortion depends on the density and temperature of the hot electrons and the physical size of the cluster. Using radio telescopes to measure the distortion of the microwave background and Chandra to measure the properties of the hot gas, the physical size of the cluster can be determined. From this physical size and a simple measurement of the angle subtended by the cluster, the rules of geometry can be used to derive its distance. The Hubble constant is determined by dividing previously measured cluster speeds by these newly derived distances. Chandra X-ray Image of Abell 1689 Chandra X-ray Image of Abell 1689 This project was championed by Chandra's telescope mirror designer, Leon Van Speybroeck, who passed away in 2002. The foundation was laid when team members John Carlstrom (University of Chicago) and Marshall Joy obtained careful radio measurements of the distortions in the CMB radiation using radio telescopes at the Berkeley-Illinois-Maryland Array and the Caltech Owens Valley Radio Observatory. In order to measure the precise X-ray properties of the gas in these distant clusters, a space-based X-ray telescope with the resolution and sensitivity of Chandra was required. "It was one of Leon's goals to see this project happen, and it makes me very proud to see this come to fruition," said Chandra Project Scientist Martin Weisskopf of MSFC. The results are described in a paper appearing in the August 10th issue of The Astrophysical Journal. MSFC manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center, Cambridge, Mass. Additional information and images can be found at: http://chandra.harvard.edu and http://chandra.nasa.gov

CIAO: CHANDRA/X-RAY DATA ANALYSIS FOR EVERYONE

NASA Astrophysics Data System (ADS)

McDowell, Jonathan; CIAO Team

2018-01-01

Eighteen years after the launch of Chandra, the archive is full of scientifically rich data and new observations continue. Improvements in recent years to the data analysis package CIAO (Chandra Interactive Analysis of Observations) and its extensive accompanying documentation make it easier for astronomers without a specialist background in high energy astrophysics to take advantage of this resource.The CXC supports hundreds of CIAO users around the world at all levels of training from high school and undergraduate students to the most experienced X-ray astronomers. In general, we strive to provide a software system which is easy for beginners, yet powerful for advanced users.Chandra data cover a range of instrument configurations and types of target (pointlike, extended and moving), requiring a flexible data analysis system. In addition to CIAO tools using the familiar FTOOLS/IRAF-style parameter interface, CIAO includes applications such as the Sherpa fitting engine which provide access to the data via Python scripting.In this poster we point prospective (and existing!) users to the high level Python scripts now provided to reprocess Chandra or other X-ray mission data, determine source fluxes and upper limits, and estimate backgrounds; and to the latest documentation including the CIAO Gallery, a new entry point featuring the system's different capabilities.This work has been supported by NASA under contract NAS 8-03060 to the Smithsonian Astrophysical Observatory for operation of the Chandra X-ray Center.

SNR 1E0102.2-7219 after Six Years with Chandra

NASA Astrophysics Data System (ADS)

Rutkowski, M. J.; Schlegel, E. M.; Keohane, J.

2005-12-01

We present Chandra X-ray Observatory archived observations of the supernova remnant 1E0102.2-7219 in the Small Magellanic Cloud. Combining 22 ACIS-I observations for 230 ks of total exposure time, we present ACIS images with an unprecedented signal to noise ratio for this remnant. We present three upper limits on the X-ray flux for the remnant's elusive central compact object, which are consistent with current neutron star cooling models, based on a Cas A-like blackbody spectrum. Additionally, we discuss the elliptical structure of the remnant and the relative positions of the blast wave, the reverse shock, and the extent of 1E0102.2-7219's rim. This research was supported by the NSF REU Program at SAO under Eric Schlegel, whose research was supported by contract number NAS8-39073 from NASA to SAO for operation of the Chandra X-Ray Observatory. Jonathan Keohane's research was supported by Chandra award GO3-4070C.

A high spatial resolution X-ray and Hα study of hot gas in the halos of star-forming disk galaxies -- testing feedback models

NASA Astrophysics Data System (ADS)

Strickland, D. K.; Heckman, T. M.; Colbert, E. J. M.; Hoopes, C. G.; Weaver, K. A.

2002-12-01

We present arcsecond resolution Chandra X-ray and ground-based optical Hα imaging of a sample of ten edge-on star-forming disk galaxies (seven starburst and three ``normal'' spiral galaxies), a sample which covers the full range of star-formation intensity found in disk galaxies. The X-ray observations make use of the unprecented spatial resolution of the Chandra X-ray observatory to robustly remove X-ray emission from point sources, and hence obtain the X-ray properties of the diffuse thermal emission alone. This data has been combined with existing, comparable-resolution, ground-based Hα imaging. We compare these empirically-derived diffuse X-ray properties with various models for the generation of hot gas in the halos of star-forming galaxies: supernova feedback-based models (starburst-driven winds, galactic fountains), cosmologically-motivated accretion of the IGM and AGN-driven winds. SN feedback models best explain the observed diffuse X-ray emission. We then use the data to test basic, but fundamental, aspects of wind and fountain theories, e.g. the critical energy required for disk "break-out." DKS is supported by NASA through Chandra Postdoctoral Fellowship Award Number PF0-10012.

Chandra Catches the `Mouse'

NASA Technical Reports Server (NTRS)

2004-01-01

Astronomers have used an x-ray image to make the first detailed study of the behavior of high-energy particles around a fast moving pulsar. This image, from NASA's Chandra X-Ray Observatory (CXO), shows the shock wave created as a pulsar plows supersonically through interstellar space. These results will provide insight into theories for the production of powerful winds of matter and antimatter by pulsars. Chandra's image of the glowing cloud, known as the Mouse, shows a stubby bright column of high-energy particles, about four light years in length, swept back by the pulsar's interaction with interstellar gas. The intense source at the head of the X-ray column is the pulsar, estimated to be moving through space at about 1.3 million miles per hour. A cone-shaped cloud of radio-wave-emitting particles envelopes the x-ray column. The Mouse, a.k.a. G359.23-0.82, was discovered in 1987 by radio astronomers using the National Science Foundation's Very Large Array in New Mexico. G359.23-0.82 gets its name from its appearance in radio images that show a compact snout, a bulbous body, and a remarkable long, narrow, tail that extends for about 55 light years. NASA's Marshall Space Flight Center in Huntsville, Alabama manages the Chandler program.

The X-Ray Surveyor Mission: A Concept Study

NASA Technical Reports Server (NTRS)

Gaskin, Jessica A.; Weisskopf, Martin C.; Vikhlinin, Alexey; Tananbaum, Harvey D.; Bandler, Simon R.; Bautz, Marshall W.; Burrows, David N.; Falcone, Abraham D.; Harrison, Fiona A.; Heilmann, Ralf K.;

Chandra's Cosmos: Dark Matter, Black Holes, and Other Wonders Revealed by NASA's Premier X-ray Observatory

NASA Astrophysics Data System (ADS)

Tucker, Wallace H.

2017-03-01

On July 23, 1999, the Chandra X-Ray Observatory, the most powerful X-ray telescope ever built, was launched aboard the space shuttle Columbia. Since then, Chandra has given us a view of the universe that is largely hidden from telescopes sensitive only to visible light. In Chandra's Cosmos, the Smithsonian Astrophysical Observatory's Chandra science spokesperson Wallace H. Tucker uses a series of short, connected stories to describe the telescope's exploration of the hot, high-energy face of the universe. The book is organized in three parts: "The Big," covering the cosmic web, dark energy, dark matter, and massive clusters of galaxies; "The Bad," exploring neutron stars, stellar black holes, and supermassive black holes; and "The Beautiful," discussing stars, exoplanets, and life. Chandra has imaged the spectacular, glowing remains of exploded stars and taken spectra showing the dispersal of their elements. Chandra has observed the region around the supermassive black hole in the center of our Milky Way and traced the separation of dark matter from normal matter in the collision of galaxies, contributing to both dark matter and dark energy studies. Tucker explores the implications of these observations in an entertaining, informative narrative aimed at space buffs and general readers alike.

Young Pulsar Reveals Clues to Supernova

NASA Astrophysics Data System (ADS)

2001-09-01

Astronomers examined the remnants of a stellar explosion with NASA's Chandra X-ray Observatory and discovered one of the youngest known pulsars. The properties of this pulsar, a neutron star rotating 15 times a second, will enable scientists to better understand how neutron stars are formed in the seconds just before a supernova explosion, and how they pump energy into the space around them for thousands of years after the explosion. A team led by Stephen Murray of the Harvard-Smithsonian Center for Astrophysics in Cambridge, MA studied 3C58, the remains of a supernova observed on Earth in 1181 AD in the constellation Cassiopeia. In addition to a pulsating central source they observed an extended X-ray source surrounding the pulsar thought to be produced by a cloud of high-energy particles about 20 light years across. These results were presented at the "Two Years of Science with Chandra" symposium in Washington, D.C. According to Murray, "Our discovery shows that all pulsars are not born equal. This pulsar is about the same age as the Crab Nebula pulsar, but there is little family resemblance." Murray explained that the 3C58 pulsar, which is now rotating at about half the rate of the Crab pulsar, is rotating almost as fast as it was when it was formed. In contrast, the Crab pulsar was formed spinning much more rapidly and has slowed to about half its initial speed. Conventional theory has assumed that all pulsars were like the Crab, born with rapid rotation and then have spun down considerably. The observations of 3C58, along with Chandra observations by another group of scientists of a pulsar associated with the supernova of 386 AD have cast doubt on that assumption, however. Furthermore, the X-ray power of 3C58 and its surrounding nebula are 20,000 and 1,000 times weaker than the Crab pulsar and its surrounding nebula respectively. One possibility for the low power of 3C58 is that the energy flow from its pulsar is primarily in the form of electromagnetic fields, so the energy is transported to much greater distances from the pulsar, where it has yet to be detected. Another possibility is that the association of 3C58 with the supernova of 1181 AD is spurious, in which case 3C58 would be much older. In view of the lack of other radio and X-ray sources that could be the remnant of Supernova 1181 AD, this is considered unlikely. The team also used X-ray data taken by NASA's Rossi X-ray Timing Explorer satellite in 1997 to confirm the existence of the pulsar and to measure its present slow-down rate. The Chandra observations were made on November 30, 1999, and December 23, 2000, using the High Resolution Camera (HRC), which was built by the Smithsonian Astrophysical Observatory in Cambridge, Mass. under the direction of Stephen Murray. NASA's Marshall Space Flight Center, Huntsville, AL, manages the Chandra program for the Office of Space Science, Washington, DC. TRW, Inc., Redondo Beach, California, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, MA. Images associated with this release are available on the World Wide Web at: http://chandra.harvard.edu AND http://chandra.nasa.gov

X-Ray Outburst from Young Star in McNeil's Nebula

NASA Astrophysics Data System (ADS)

2004-07-01

Observations with NASA's Chandra X-ray Observatory captured an X-ray outburst from a young star, revealing a probable scenario for the intermittent brightening of the recently discovered McNeil's Nebula. It appears the interaction between the young star's magnetic field and an orbiting disk of gas can cause dramatic, episodic increases in the light from the star and disk, illuminating the surrounding gas. "The story of McNeil's Nebula is a wonderful example of the importance of serendipity in science," said Joel Kastner of the Rochester Institute of Technology in Rochester, New York, lead author of a paper in the July 22 issue of Nature describing the X-ray results. "Visible-light images were made of this region several months before Jay McNeil made his discovery, so it could be determined approximately when and by how much the star flared up to produce McNeil's Nebula." The small nebula, which lies in the constellation Orion about 1300 light years from Earth, was discovered with a 3-inch telescope by McNeil, an amateur astronomer from Paducah, Kentucky, in January 2004. In November 2002, a team led by Ted Simon of the Institute for Astronomy in Hawaii had observed the star-rich region with Chandra in search of young, X-ray emitting stars, and had detected several objects. Optical and infrared astronomers had, as part of independent surveys, also observed the region about a year later, in 2003. After the announcement of McNeil's discovery, optical, infrared and X-ray astronomers rushed to observe the region again. They found that a young star buried in the nebula had flared up, and was illuminating the nebula. This star was coincident with one of the X-ray sources discovered earlier by Simon. Chandra observations obtained by Kastner's group just after the optical outburst showed that the source had brightened fifty-fold in X-rays when compared to Simon's earlier observation. The visible-light eruption provides evidence that the cause of the X-ray outburst is the sudden infall of matter onto the surface of the star from an orbiting disk of gas. In general, the coupling of the magnetic field of the star and the magnetic field of its circumstellar disk regulates the inflow of gas from the disk onto the star. This slow, steady inflow suddenly can become much more rapid if a large amount of gas accumulates in the disk, and the disk and the star are rotating at different rates. The differing rotation rates would twist and shear the magnetic field, storing up energy. This energy is eventually released in an energetic, X-ray producing outburst as the magnetic field violently rearranges back to a more stable state. During this period, a large amount of gas can fall onto the star, producing the observed optical and infrared outburst. A new buildup of gas in the disk could lead to a new outburst in the future. Such a scenario may explain why the brightness of McNeil's Nebula appears to vary with time. It is faintly present in surveys of this region of Orion in images taken in the 1960s, but absent from images taken in the 1950s and 1990s. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for NASA's Office of Space Science, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Chandra Shows New Way to Measure Cosmic Distances

NASA Astrophysics Data System (ADS)

2000-04-01

Using NASA's Chandra X-ray Observatory, a team of scientists has attacked one of astronomy's oldest and thorniest problems, determining the distance to a cosmic object. Through measuring the distance to an X-ray source by observing the delay and smearing out of X-ray signals traversing 30,000 light years of interstellar gas and dust, Chandra "opened a new world," said Peter Predehl of the Max-Planck Institute, Garching, Germany, the lead author on a report to be published in the European journal, Astronomy and Astrophysics. "Geometrical distance measurements are of particular importance for astronomy. Now we have a new method that works for distant sources," Predehl said. One of the most crucial pieces of information needed in astronomy is the distance to the stars and galaxies. They are also among the most difficult to obtain because, with rare exceptions, astronomers cannot measure distance directly and must use a variety of ingenious but uncertain techniques. This new method relies on the scattering of X-rays by interstellar dust grains between a source and the Earth. Although the scattering material is different, the dust produces a halo, much like the halo around a traffic light on a foggy night. "When the light switches from red to green (or vice versa), the halo around the light is also slightly delayed," Predehl explained. "No one would use this delay for determining the distance to the traffic light, of course, (the delay is only a few billionths of a second). But if the 'traffic light' is 30,000 light years away, the delay is on the order 15 minutes. Using the excellent and unprecedented resolution of the Chandra observatory, we can distinguish between light which was 30,000 years on its way and other light which needed only a few minutes more. " Other members of the team included Vadim Burwitz and Joachim Trumper, also of the Max-Planck Institute, and Frits Paerels of Columbia University, New York. Trumper and a colleague proposed using this method 27 years ago, but it could not be applied until an X-ray observatory with Chandra's unique capability was available. The X-ray source Cygnus X-3 acts like a cosmic traffic light, or more appropriately, lighthouse. Its X-ray emission varies regularly with a 4.8 hour period, as a neutron star or black hole circles a nearby companion star. The radiation from the halo is delayed and smeared out, so the variations are damped. For the inner part of the halo, the damping is small, whereas for the outer part, the periodic variation is completely washed out. By observing the time delay and variations at different parts of the halo, the distance to the source can be determined. Seismologists use a similar method based on the propagation of sound waves through the Earth to determine the epicenters of earthquakes or to locate unusual geological formations. Predehl and colleagues observed Cygnus X-3 for 3.5 hours with Chandra using the Advanced CCD Imaging Spectrometer (ACIS). By analyzing the time variations in the halo, the astronomers determined that the distance to Cygnus X-3 is 30,000 light years, within about 20 percent accuracy. The accuracy was limited by the short observing time, which was less than the full 4.8 hour period of variation. The team hopes to refine this estimate in the near future as data from a longer observation of the source becomes available. The X-ray scattering method of measuring cosmic distances depends on the fact that X-rays, because of their high energies, are scattered through small angles by dust grains. It cannot be used with optical telescopes because visible light photons have lower energy and are scattered through much larger angles by the dust grains. In principle, the method could also work for nearby galaxies, such as the Small and Large Magellanic Clouds and the Andromeda Nebula. If so, it would help astronomers in their quest to understand the size and age of the universe, since it would provide an independent estimate of the size of the first steps on the cosmic distance ladder. The ACIS instrument was built for NASA by the Massachusetts Institute of Technology, Cambridge, Mass., and Penn State University, University Park. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program. TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass. For images connected to this release, and to follow Chandra's progress, visit the Chandra site at: http://chandra.harvard.edu/photo/2000/cygx399/index.html AND http://chandra.nasa.gov High resolution digital versions of the X-ray image (JPG, 300 dpi TIFF) are available at the Internet sites listed above.

NASA's Future X-ray Missions: From Constellation-X to Generation-X

NASA Technical Reports Server (NTRS)

Hornschemeier, A.

2006-01-01

Among the most important topics in modern astrophysics are the formation and evolution of supermassive black holes in concert with galaxy bulges, the nature of the dark energy equation of state, and the self-regulating symmetry imposed by both stellar and AGN feedback. All of these topics are readily addressed with observations at X-ray wavelengths. NASA's next major X-ray observatory is Constellation-X, which is being developed to perform spatially resolved high-resolution X-ray spectroscopy. Con-X will directly measure the physical properties of material near black holes' last stable orbits and the absolute element abundances and velocities of hot gas in clusters of galaxies. The Con-X mission will be described, as well as its successor, Generation-X (anticipated to fly approx.1 decade after Con-X). After describing these missions and their driving science areas, the talk will focus on areas in which Chandra observing programs may enable science with future X-ray observatories. These areas include a possible ultra-deep Chandra imaging survey as an early Universe pathfinder, a large program to spatially resolve the hot intracluster medium of massive clusters to aid dark energy measurements, and possible deep spectroscopic observations to aid in preparatory theoretical atomic physics work needed for interpreting Con-X spectra.

A Supernova Shockwaves

NASA Image and Video Library

2007-06-13

Supernovae are the explosive deaths of the universe most massive stars. This false-color composite from NASA Spitzer Space Telescope and NASA Chandra X-ray Observatory shows the remnant of N132D, the wispy pink shell of gas at center.

The Restless Universe - Understanding X-Ray Astronomy in the Age of Chandra and Newton

NASA Astrophysics Data System (ADS)

Schlegel, Eric M.

2002-10-01

Carl Sagan once noted that there is only one generation that gets to see things for the first time. We are in the midst of such a time right now, standing on the threshold of discovery in the young and remarkable field of X-ray astronomy. In The Restless Universe , astronomer Eric Schlegel offers readers an informative survey of this cutting-edge science. Two major space observatories launched in the last few years--NASA's Chandra and the European Newton --are now orbiting the Earth, sending back a gold mine of data on the X-ray universe. Schlegel, who has worked on the Chandra project for seven years, describes the building and launching of this space-based X-ray observatory. But the book goes far beyond the story of Chandra . What Schlegel provides here is the background a nonscientist would need to grasp the present and follow the future of X-ray astronomy. He looks at the relatively brief history of the field, the hardware used to detect X-rays, the satellites--past, present, and future--that have been or will be flown to collect the data, the way astronomers interpret this data, and, perhaps most important, the insights we have already learned as well as speculations about what we may soon discover. And throughout the book, Schlegel conveys the excitement of looking at the universe from the perspective brought by these new observatories and the sharper view they deliver. Drawing on observations obtained from Chandra, Newton , and previous X-ray observatories, The Restless Universe gives a first look at an exciting field which significantly enriches our understanding of the universe.

AEGIS: An Astrophysics Experiment for Grating and Imaging Spectroscopy---a Soft X-ray, High-resolution Spectrometer

NASA Astrophysics Data System (ADS)

Huenemoerder, David; Bautz, M. W.; Davis, J. E.; Heilmann, R. K.; Houck, J. C.; Marshall, H. L.; Neilsen, J.; Nicastro, F.; Nowak, M. A.; Schattenburg, M. L.; Schulz, N. S.; Smith, R. K.; Wolk, S.; AEGIS Team

2012-01-01

AEGIS is a concept for a high-resolution soft X-ray spectroscopic observatory developed in response to NASA's request for definitions of the next X-ray astronomy mission. At a small fraction of the cost of the once-planned International X-ray Observatory (IXO), AEGIS has capabilities that surpass IXO grating spectrometer requirements, and which are far superior to those of existing soft X-ray spectrometers. AEGIS incorporates innovative technology in X-ray optics, diffraction gratings and detectors. The mirror uses high area-to-mass ratio segmented glass architecture developed for IXO, but with smaller aperture and larger graze angles optimized for high-throughput grating spectroscopy with low mass and cost. The unique Critical Angle Transmission gratings combine low mass and relaxed figure and alignment tolerances of Chandra transmission gratings but with high diffraction efficiency and resolving power of blazed reflection gratings. With more than an order of magnitude better performance over Chandra and XMM grating spectrometers, AEGIS can obtain high quality spectra of bright AGN in a few hours rather than 10 days. Such high resolving power allows detailed kinematic studies of galactic outflows, hot gas in galactic haloes, and stellar accretion flows. Absorption line spectroscopy will be used to study large scale structure, cosmic feedback, and growth of black holes in thousands of sources to great distances. AEGIS will enable powerful multi-wavelength investigations, for example with Hubble/COS in the UV to characterize the intergalactic medium. AEGIS will be the first observatory with sufficient resolution below 1 keV to resolve thermally-broadened lines in hot ( 10 MK) plasmas. Here we describe key science investigations enable by Aegis, its scientific payload and mission plan. Acknowledgements: Support was provided in part by: NASA SAO contract SV3-73016 to MIT for the Chandra X-ray Center and Science Instruments; NASA grant NNX08AI62G; and the MKI Instrumentation Development Fund.

An Overview of the Performance and Scientific Results From the Chandra X-Ray Observatory (CXO)

NASA Technical Reports Server (NTRS)

Weisskopf, M. C.; Brinkman, B.; Canizares, C.; Garmine, G.; Murray, S.; VanSpeybroeck, L. P.; Six, N. Frank (Technical Monitor)

2001-01-01

The Chandra X-Ray Observatory (CXO), the x-ray component of NASA's Great Observatories, was launched on 1999, July 23 by the Space Shuttle Columbia. After satellite systems activation, the first x-rays focused by the telescope were observed on 1999, August 12. Beginning with the initial observation it was clear that the telescope had survived the launch environment and was operating as expected. Despite an initial surprise due to the discovery that the telescope was far more efficient for concentrating CCD-damaging low-energy protons than had been anticipated, the observatory is performing well and is returning superb scientific data. Together with other space observatories, most notably XMM-Newton, it is clear that we have entered a new era of discovery in high-energy astrophysics.

Briefings Set for Launch of Next "Great Observatory" in Space

NASA Astrophysics Data System (ADS)

1999-06-01

NASA's next Space Shuttle flight will provide astronomers with a new look at the universe and make history with NASA's first female mission commander. Reporters can get an overview of the mission at a series of briefings July 7. The briefings will begin at 9 a.m. EDT at NASA's Johnson Space Center in Houston. The five-day flight is scheduled for launch no earlier than July 20. STS-93 will be led by U.S. Air Force Colonel Eileen Collins, the first woman to command an American space mission. The flight's primary objective will be to deploy the Chandra X-Ray Observatory, the third of NASA's Great Observatories. Collins and her crew of four will carry Chandra, the heaviest payload ever deployed from the shuttle, into orbit and deploy it approximately seven hours after launch. An upper stage will carry the observatory to its final orbit, more than one-third of the way to the Moon. Chandra will allow scientists to obtain unprecedented X-ray images of exploding stars, black holes and other exotic environments to help them understand the structure and evolution of the universe. The first two briefings will provide an overview of mission operations and science to be conducted by Chandra. The NASA Television Video File will follow at noon. The crew press conference will begin at 2 p.m. EDT. The briefings will be carried live on NASA Television, with question-and-answer capability for reporters covering the event from participating NASA centers. NASA Television is available on transponder 9C of the GE-2 satellite at 85 degrees West longitude, vertical polarization, frequency 3880 MHz, audio of 6.8 MHz. Media planning to attend the briefings must notify the Johnson Space Center newsroom by June 28 to ensure proper badging. Each reporter's name, affiliation and country of citizenship should be faxed to the newsroom at 281/483-2000. IMPORTANT NOTE: Reporters can schedule in-person or telephone interviews STS-93 crew. These interviews will begin at about 3:15 p.m. EDT. Media wishing to participate must make their request to the Johnson Space Center Newsroom by June 28. STS-93 PREFLIGHT BRIEFINGS July 7, 1999 9 a.m. EDT Mission Overview Bryan Austin, STS-93 Lead Flight Director, Johnson Space Center Fred Wojtalik, Chandra Program Manager, Marshall Space Flight Center, Huntsville, AL Ken Ledbetter, Director, Mission and Payload Development Division, NASA Headquarters, Washington, DC 10:30 a.m. EDT Chandra Science Briefing Dr. Ed Weiler, Associate Administrator, Office of Space Science, NASA Headquarters Dr. Alan Bunner, Chandra Program Scientist, NASA Headquarters Dr. Martin Weisskopf, Chandra Project Scientist, Marshall Space Flight Center Dr. Harvey Tananbaum, Director, Chandra X-Ray Center, Cambridge, MA Dr. Kimberly Weaver, Astrophysicist, Goddard Space Flight Center, Greenbelt, MD Noon EDT NASA TV Video File 2 p.m. EDT STS-93 Crew Press Conference Eileen M. Collins, Mission Commander Jeffrey S. Ashby, Pilot Catherine G. Coleman, Mission Specialist -1 Steven A. Hawley, Mission Specialist-2 Michel Tognini, Mission Specialist-3 3:15 p.m. EDT STS-93 Crew Round Robins (not televised)

Deepest Image of Exploded Star Uncovers Bipolar Jets

NASA Astrophysics Data System (ADS)

2004-08-01

A spectacular new image of Cassiopeia A from NASA's Chandra X-ray Observatory released today has nearly 200 times more data than the "First Light" Chandra image of this object made five years ago. The new image reveals clues that the initial explosion caused by the collapse of a massive star was far more complicated than suspected. Chandra Broadband Image of Cassiopeia A Chandra Broadband Image of Cassiopeia A "Although this young supernova remnant has been intensely studied for years, this deep observation is the most detailed ever made of the remains of an exploded star," said Martin Laming of the Naval Research Laboratory in Washington, D.C. Laming is part of a team of scientists led by Una Hwang of the Goddard Space Flight Center in Greenbelt, Maryland. "It is a gold mine of data that astronomers will be panning through for years to come." The one-million-second (about 11.5-day) observation of Cassiopeia A uncovered two large, opposed jet-like structures that extend to about 10 light years from the center of the remnant. Clouds of iron that have remained nearly pure for the approximately 340 years since the explosion were also detected. "The presence of the bipolar jets suggests that jets could be more common in relatively normal supernova explosions than supposed by astronomers," said Hwang. A paper by Hwang, Laming and others on the Cassiopeia A observation will appear in an upcoming issue of The Astrophysical Journal Letters. Chandra Enhanced Silicon Image of Cassiopeia A Chandra Enhanced Silicon Image of Cassiopeia A X-ray spectra show that the jets are rich in silicon atoms and relatively poor in iron atoms. In contrast, fingers of almost pure iron gas extend in a direction nearly perpendicular to the jets. This iron was produced in the central, hottest regions of the star. The high silicon and low iron abundances in the jets indicate that massive, matter-dominated jets were not the immediate cause of the explosion, as these should have carried out large quantities of iron from the central regions of the star. A working hypothesis is that the explosion produced high-speed jets similar to those in hypernovae that produce gamma-ray bursts, but in this case, with much lower energies. The explosion also left a faint neutron star at the center of the remnant. Unlike the rapidly rotating neutron stars in the Crab Nebula and Vela supernova remnants that are surrounded by dynamic magnetized clouds of electrons, this neutron star is quiet and faint. Nor has pulsed radiation been detected from it. It may have a very strong magnetic field generated during the explosion that helped to accelerate the jets, and today resembles other strong-field neutron stars (a.k.a. "magnetars") in lacking a wind nebula. Chandra 3-color X-ray Image of Cassiopeia A Chandra 3-color X-ray Image of Cassiopeia A Chandra was launched aboard the Space Shuttle Columbia on July 23, 1999. Less than a month later, it was able to start taking science measurements along with its calibration data. The original Cassiopeia A observation was taken on August 19, 1999, and then released to the scientific community and the public one week later on August 26. At launch, Chandra's original mission was intended to be five years. Having successfully completed that objective, NASA announced last August that the mission would be extended for another five years. The data for this new Cassiopeia A image were obtained by Chandra's Advanced Charged Coupled Device Imaging Spectrometer (ACIS) instrument during the first half of 2004. Due to its value to the astronomical community, this rich dataset was made available immediately to the public. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for NASA's Office of Space Science, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Chandra Discovers Eruption and Pulsation in Nova Outburst

NASA Astrophysics Data System (ADS)

2001-09-01

NASA's Chandra X-ray Observatory has discovered a giant outburst of X-rays and unusual cyclical pulsing from a white dwarf star that is closely orbiting another star -- the first time either of these phenomena has been seen in X-rays. The observations are helping scientists better understand the thermonuclear explosions that occur in certain binary star systems. The observations of Nova Aquilae were reported today at the "Two Years of Science with Chandra" symposium by an international team led by Sumner Starrfield of Arizona State University. "We found two important results in our Chandra observations. The first was an underlying pulsation every 40 minutes in the X-ray brightness, which we believe comes from the cyclical expansion and contraction of the outer layers of the white dwarf," said Starrfield. "The other result was an enormous flare of X-rays that lasted for 15 minutes. Nothing like this has been seen before from a nova, and we don't know how to explain it." Novas occur on a white dwarf (a star which used up all its nuclear fuel and shrank to roughly the size of the Earth) that is orbiting a normal size star. Strong gravity tides drag hydrogen gas off the normal star and onto the white dwarf, where it can take more than 100,000 years for enough hydrogen to accumulate to ignite nuclear fusion reactions. Gradually, these reactions intensify until a cosmic-sized hydrogen bomb blast results. The outer layers of the white dwarf are then blown away, producing a nova outburst that can be observed for a period of months to years as the material expands into space. "Chandra has allowed us to see deep into the gases ejected by this giant explosion and extract unparalleled information on the evolution of the white dwarf whose surface is exploding," said Jeremy Drake of the Harvard-Smithsonian Center for Astrophysics. The brightening of Nova Aquilae was first detected by optical astronomers in December 1999. "Although this star is at a distance of more than 6,000 light years, it could be seen with the naked eye for about a month, during which it was about 100,000 times brighter than our own Sun," said R. Mark Wagner of the University of Arizona. Nova Aquilae Chandra observed the nova, so-called because early astronomers believed they heralded the appearance of a new star, four times from April 2000 through October 2000. "Our first Chandra observations showed that the expanding gas around Nova Aquilae was hot and nearly opaque," said Joachim Krautter of the State Observatory in Heidelberg, Germany. "When we looked months later with Chandra, the expanding gases cleared enough for us to see through them to the underlying star on which the explosion occurred." The latter Chandra X-ray data revealed the cyclical changes in brightness are due to the white dwarf expanding and shrinking over a 40-minute period. They also showed that the temperature on the surface of the white dwarf was 300,000 degrees Celsius, making Nova Aquilae one of the hottest stars ever observed to undergo such pulsations. "The observations told us that thermonuclear fusion reactions were still occurring on the surface layers of the white dwarf - more than eight months after the explosion first began!" said Robert Gehrz of the University of Minnesota. Other members of the team are Howard Bond (Space Telescope Science Institute), Yousaf Butt (Harvard-Smithsonian Center for Astrophysics), Koji Mukai (Goddard Space Flight Center), Peter Hauschildt (University of Georgia), Margarida Hernanz (Institute for Space Studies, Catalonia, Spain), Marina Orio (University of Wisconsin and the Torino Observatory in Italy), and Charles Woodward (University of Minnesota). Chandra observed Nova Aquilae for a total of 10 hours with the High Resolution Camera (HRC) and the Advanced CCD Imaging Spectrometer (ACIS). The HRC was built for NASA by the Smithsonian Astrophysical Observatory, Cambridge, MA. The ACIS instrument was built for NASA by the Massachusetts Institute of Technology, Cambridge, and Pennsylvania State University, University Park. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program. TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass. Images associated with this release are available on the World Wide Web at: http://chandra.harvard.edu AND http://chandra.nasa.gov

Optics Requirements For The Generation-X X-Ray Telescope

NASA Technical Reports Server (NTRS)

O'Dell, S. .; Elsner, R. F.; Kolodziejczak, J. J.; Ramsey, B. D.; Weisskopf, M. C.; Zhang, W. W.; Content, D. A.; Petre, R.; Saha, T. T.; Reid, P. B.;

Chandra Reveals The X-Ray Glint In The Cat's Eye

NASA Astrophysics Data System (ADS)

2001-01-01

SAN DIEGO -- Scientists have discovered a glowing bubble of hot gas and an unexpected X-ray bright central star within the planetary nebula known as the Cat's Eye using NASA's Chandra X-ray Observatory. The new results, presented today at the American Astronomical Society meeting, provide insight into the ways that stars like our Sun end their lives. Scientists believe they are witnessing the expulsion of material from a star that is in the last stages of its existence as a normal star. Material shed by the star is flying away at a speed of about 4 million miles per hour, and the star itself is expected to collapse to become a white dwarf star in a few million years. The X-ray data from the Cat's Eye Nebula, also known as NGC 6543, clearly show a bright central star surrounded by a cloud of multimillion-degree gas. By comparing the Chandra data with those from the Hubble Space Telescope, researchers are able to see where the hotter, X-ray emitting gas appears in relation to the cooler material seen in optical wavelengths by Hubble. "Despite the complex optical appearance of the nebula, the X-ray emission illustrates unambiguously that the hot gas in the central bubble is driving the expansion of the optical nebula," said You-Hua Chu of the University of Illinois and lead author of the paper submitted to the Astrophysical Journal. "The Chandra data will help us to better understand how stars similar to our Sun produce planetary nebulas and evolve into white dwarfs as they grow old." With Chandra, astronomers measured the temperature of the central bubble of X-ray emitting material, and this presents a new puzzle. Though still incredibly energetic and hot enough to emit X-rays, this hot gas is cooler than scientists would have expected from the stellar wind that has come to stagnation from the initial high speed of 4 million miles per hour. At first, the researchers thought that the cooler, outer shell might have mixed with the energetic material closer to the central star to create this "lukewarm" area. However, this theory apparently does not apply for NGC 6543. Chu and her colleagues found that the chemical abundances within the hot gas were like those in the wind from the star, and different from the cooler outer material. These results indicate that mixing is not occurring, and that the cooling between the inner and outer shells of material is due to some other process. The intensity of the X-rays from the central star was also unexpected. The star itself has a surface temperature of about 60,000 degrees, whereas the X-ray measurement indicates a temperature of a few million degrees. "We could be seeing shock waves in the fast stellar wind itself," said Martin Guerrero of the University of Illinois, lead author on a companion paper that describes the central star. "This is the first time we see such X-ray emission from the central star of a planetary nebula." A planetary nebula (so called because it looks like a planet when viewed with a small telescope) is formed when a dying red giant star puffs off its outer layer, leaving behind a hot core that will eventually collapse to form a dense star called a white dwarf. A fast wind emanating from the hot core rams into the ejected atmosphere, pushes it outward, and creates the graceful filamentary structures seen with optical telescopes. With Chandra, it is now possible to see the high-pressure hot bubble inside these filaments and study how the nebula is formed in more detail. The Cat's Eye Nebula, which is about 3,000 light years from Earth, was formed about a thousand years ago. Other members of the research team include Robert Gruendl, and James Kaler (University of Illinois), and Rosa Williams (National Research Council). NGC 6543 was observed with the Advanced CCD Imaging Spectrometer (ACIS) on May 10-11, 1999, for a total exposure time of 46,000 seconds. The ACIS X-ray camera was developed for NASA by Pennsylvania State University and MIT. NASA's Marshall Space Flight Center in Huntsville, AL, manages the Chandra program. TRW, Inc., Redondo Beach, California, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, MA. The color composite of optical and X-ray images was made by Zoltan G. Levay (Space Telescope Science Institute). The optical images were taken by J.P. Harrington and K.J. Borkowski (University of Maryland) with the Hubble Space Telescope. During the AAS meeting, the scientists involved in this release can be reached at the AAS Press Room at the Town & Country Resort in San Diego, CA. The phone numbers for the Press Room are (619) 908-5057, (619) 908-5040, and (619) 908-5041 from January 8-11. Images associated with this release are available on the World Wide Web at: http://chandra.harvard.edu AND http://chandra.nasa.gov

NASA Telescopes Join Forces To Observe Unprecedented Explosion

NASA Image and Video Library

2017-12-08

NASA image release April 6, 2011 NASA's Chandra X-ray Observatory completed this four-hour exposure of GRB 110328A on April 4. The center of the X-ray source corresponds to the very center of the host galaxy imaged by Hubble (red cross). Credit: NASA/CXC/ Warwick/A. Levan NASA's Swift, Hubble Space Telescope and Chandra X-ray Observatory have teamed up to study one of the most puzzling cosmic blasts yet observed. More than a week later, high-energy radiation continues to brighten and fade from its location. Astronomers say they have never seen anything this bright, long-lasting and variable before. Usually, gamma-ray bursts mark the destruction of a massive star, but flaring emission from these events never lasts more than a few hours. Although research is ongoing, astronomers say that the unusual blast likely arose when a star wandered too close to its galaxy's central black hole. Intense tidal forces tore the star apart, and the infalling gas continues to stream toward the hole. According to this model, the spinning black hole formed an outflowing jet along its spin axis. A powerful blast of X- and gamma rays is seen if this jet is pointed in our direction. To read more go to: www.nasa.gov/topics/universe/features/star-disintegration... NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Join us on Facebook

History of Chandra X-Ray Observatory

NASA Image and Video Library

2000-10-01

This most distant x-ray cluster of galaxies yet has been found by astronomers using Chandra X-ray Observatory (CXO). Approximately 10 billion light-years from Earth, the cluster 3C294 is 40 percent farther than the next most distant x-ray galaxy cluster. The existence of such a faraway cluster is important for understanding how the universe evolved. CXO's image reveals an hourglass-shaped region of x-ray emissions centered on the previously known central radio source (seen in this image as the blue central object) that extends outward for 60,000 light- years. The vast clouds of hot gas that surround such galaxies in clusters are thought to be heated by collapse toward the center of the cluster. Until CXO, x-ray telescopes have not had the needed sensitivity to identify such distant clusters of galaxies. Galaxy clusters are the largest gravitationally bound structures in the universe. The intensity of the x-rays in this CXO image of 3C294 is shown as red for low energy x-rays, green for intermediate, and blue for the most energetic x-rays. (Photo credit: NASA/loA/A. Fabian et al)

History of Chandra X-Ray Observatory

NASA Image and Video Library

1997-05-01

This photograph shows the Chandra X-Ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF), High Resolution Mirror Assembly (HRMA) being removed from the test structure in the X-Ray Calibration Facility (XRCF) at the Marshall Space Flight Center (MSFC). The AXAF was renamed CXO in 1999. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It observes x-rays from high-energy regions of the universe, such as hot gas in the remnants of exploded stars. The HRMA, the heart of the telescope system, is contained in the cylindrical "telescope" portion of the observatory. Since high-energy x-rays would penetrate a normal mirror, special cylindrical mirrors were created. The two sets of four nested mirrors resemble tubes within tubes. Incoming x-rays graze off the highly polished mirror surface and are furneled to the instrument section for detection and study. MSFC's XRCF is the world's largest, most advanced laboratory for simulating x-ray emissions from distant celestial objects. It produces a space-like environment in which components related to x-ray telescope imaging are tested and the quality of their performances in space is predicted. TRW, Inc. was the prime contractor for the development of the CXO and NASA's MSFC was responsible for its project management. The Smithsonian Astrophysical Observatory controls science and flight operations of the CXO for NASA from Cambridge, Massachusetts. The CXO was launched July 22, 1999 aboard the Space Shuttle Columbia (STS-93).

History of Chandra X-Ray Observatory

NASA Image and Video Library

1996-12-16

This is a photograph of the Chandra X-Ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF), High Resolution Mirror Assembly (HRMA) integration at the X-Ray Calibration Facility (XRCF) at the Marshall Space Flight Center (MSFC). The AXAF was renamed CXO in 1999. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It observes x-rays from high-energy regions of the universe, such as hot gas in the remnants of exploded stars. The HRMA, the heart of the telescope system, is contained in the cylindrical "telescope" portion of the observatory. Since high-energy x-rays would penetrate a normal mirror, special cylindrical mirrors were created. The two sets of four nested mirrors resemble tubes within tubes. Incoming x-rays graze off the highly polished mirror surface and are furneled to the instrument section for detection and study. MSFC's XRCF is the world's largest, most advanced laboratory for simulating x-ray emissions from distant celestial objects. It produces a space-like environment in which components related to x-ray telescope imaging are tested and the quality of their performances in space is predicted. TRW, Inc. was the prime contractor for the development of the CXO and NASA's MSFC was responsible for its project management. The Smithsonian Astrophysical Observatory controls science and flight operations of the CXO for NASA from Cambridge, Massachusetts. The CXO was launched July 22, 1999 aboard the Space Shuttle Columbia (STS-93).

History of Chandra X-Ray Observatory

NASA Image and Video Library

1997-12-16

This is a photograph of the Chandra X-Ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF), High Resolution Mirror Assembly (HRMA) integration at the X-Ray Calibration Facility (XRCF) at the Marshall Space Flight Center (MSFC). The AXAF was renamed CXO in 1999. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It observes x-rays from high-energy regions of the universe, such as hot gas in the remnants of exploded stars. The HRMA, the heart of the telescope system, is contained in the cylindrical "telescope" portion of the observatory. Since high-energy x-rays would penetrate a normal mirror, special cylindrical mirrors were created. The two sets of four nested mirrors resemble tubes within tubes. Incoming x-rays graze off the highly polished mirror surface and are furneled to the instrument section for detection and study. MSFC's XRCF is the world's largest, most advanced laboratory for simulating x-ray emissions from distant celestial objects. It produces a space-like environment in which components related to x-ray telescope imaging are tested and the quality of their performances in space is predicted. TRW, Inc. was the prime contractor for the development of the CXO and NASA's MSCF was responsible for its project management. The Smithsonian Astrophysical Observatory controls science and flight operations of the CXO for NASA from Cambridge, Massachusetts. The CXO was launched July 22, 1999 aboard the Space Shuttle Columbia (STS-93).

History of Chandra X-Ray Observatory

NASA Image and Video Library

1997-05-01

This photograph shows the Chandra X-ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF), High Resolution Mirror Assembly (HRMA) being removed from the test structure in the X-Ray Calibration Facility (XRCF) at the Marshall Space Flight Center (MSFC). The AXAF was renamed CXO in 1999. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It observes x-rays from high-energy regions of the universe, such as hot gas in the remnants of exploded stars. The HRMA, the heart of the telescope system, is contained in the cylindrical "telescope" portion of the observatory. Since high-energy x-rays would penetrate a normal mirror, special cylindrical mirrors were created. The two sets of four nested mirrors resemble tubes within tubes. Incoming x-rays graze off the highly polished mirror surface and are furneled to the instrument section for detection and study. MSFC's XRCF is the world's largest, most advanced laboratory for simulating x-ray emissions from distant celestial objects. It produces a space-like environment in which components related to x-ray telescope imaging are tested and the quality of their performances in space is predicted. TRW, Inc. was the prime contractor for the development of the CXO and NASA's MSFC was responsible for its project management. The Smithsonian Astrophysical Observatory controls science and flight operations of the CXO for NASA from Cambridge, Massachusetts. The CXO was launched July 22, 1999 aboard the Space Shuttle Columbia (STS-93).

Ghost Remains After Black Hole Eruption

NASA Astrophysics Data System (ADS)

2009-05-01

NASA's Chandra X-ray Observatory has found a cosmic "ghost" lurking around a distant supermassive black hole. This is the first detection of such a high-energy apparition, and scientists think it is evidence of a huge eruption produced by the black hole. This discovery presents astronomers with a valuable opportunity to observe phenomena that occurred when the Universe was very young. The X-ray ghost, so-called because a diffuse X-ray source has remained after other radiation from the outburst has died away, is in the Chandra Deep Field-North, one of the deepest X-ray images ever taken. The source, a.k.a. HDF 130, is over 10 billion light years away and existed at a time 3 billion years after the Big Bang, when galaxies and black holes were forming at a high rate. "We'd seen this fuzzy object a few years ago, but didn't realize until now that we were seeing a ghost", said Andy Fabian of the Cambridge University in the United Kingdom. "It's not out there to haunt us, rather it's telling us something - in this case what was happening in this galaxy billions of year ago." Fabian and colleagues think the X-ray glow from HDF 130 is evidence for a powerful outburst from its central black hole in the form of jets of energetic particles traveling at almost the speed of light. When the eruption was ongoing, it produced prodigious amounts of radio and X-radiation, but after several million years, the radio signal faded from view as the electrons radiated away their energy. HDF 130 Chandra X-ray Image of HDF 130 However, less energetic electrons can still produce X-rays by interacting with the pervasive sea of photons remaining from the Big Bang - the cosmic background radiation. Collisions between these electrons and the background photons can impart enough energy to the photons to boost them into the X-ray energy band. This process produces an extended X-ray source that lasts for another 30 million years or so. "This ghost tells us about the black hole's eruption long after it has died," said co-author Scott Chapman, also of Cambridge University. "This means we don't have to catch the black holes in the act to witness the big impact they have." This is the first X-ray ghost ever seen after the demise of radio-bright jets. Astronomers have observed extensive X-ray emission with a similar origin, but only from galaxies with radio emission on large scales, signifying continued eruptions. In HDF 130, only a point source is detected in radio images, coinciding with the massive elliptical galaxy seen in its optical image. This radio source indicates the presence of a growing supermassive black hole. People Who Read This Also Read... Milky Way's Super-efficient Particle Accelerators Caught in The Act NASA Joins "Around the World in 80 Telescopes" Celebrate the International Year of Astronomy Galaxies Coming of Age in Cosmic Blobs "This result hints that the X-ray sky should be littered with such ghosts," said co-author Caitlin Casey, also of Cambridge, "especially if black hole eruptions are as common as we think they are in the early Universe." The power contained in the black hole eruption was likely to be considerable, equivalent to about a billion supernovas. The energy is dumped into the surroundings and transports and heats the gas. "Even after the ghost disappears, most of the energy from the black hole's eruption remains", said Fabian. "Because they're so powerful, these eruptions can have profound effects lasting for billions of years." The details of Chandra's data of HDF 130 helped secure its true nature. For example, in X-rays, HDF 130 has a cigar-like shape that extends for some 2.2 million light years. The linear shape of the X-ray source is consistent with the shape of radio jets and not with that of a galaxy cluster, which is expected to be circular. The energy distribution of the X-rays is also consistent with the interpretation of an X-ray ghost. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass.

Face Illusion in the Cosmic Clouds

NASA Image and Video Library

2014-10-22

In this image of PSR B1509-58 about 170,000 light-years from Earth, X-rays from NASA Chandra in gold are seen along with infrared data from NASA Wide-field Infrared Survey Explorer WISE telescope in red, green and blue.

History of Chandra X-Ray Observatory

NASA Image and Video Library

1998-01-01

This is a computer rendering of the fully developed Chandra X-Ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF). In 1999, the AXAF was renamed the CXO in honor of the late Indian-American Novel Laureate Subrahmanyan Chandrasekhar. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It is designed to observe x-rays from high energy regions of the Universe, such as hot gas in the renmants of exploded stars. It produces picture-like images of x-ray emissions analogous to those made in visible light, as well as gathers data on the chemical composition of x-ray radiating objects. The CXO helps astronomers world-wide better understand the structure and evolution of the universe by studying powerful sources of x-ray such as exploding stars, matter falling into black holes, and other exotic celestial objects. The Observatory has three major parts: (1) the x-ray telescope, whose mirrors will focus x-rays from celestial objects; (2) the science instruments that record the x-rays so that x-ray images can be produced and analyzed; and (3) the spacecraft, which provides the environment necessary for the telescope and the instruments to work. TRW, Inc. was the prime contractor for the development of the CXO and NASA's Marshall Space Flight Center was responsible for its project management. The Smithsonian Astrophysical Observatory controls science and flight operations of the CXO for NASA from Cambridge, Massachusetts. The Observatory was launched July 22, 1999 aboard the Space Shuttle Columbia, STS-93 mission. (Image courtesy of TRW).

History of Chandra X-Ray Observatory

NASA Image and Video Library

1995-01-14

This is an artist's concept of the Chandra X-Ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF), fully developed in orbit in a star field with Earth. In 1999, the AXAF was renamed the CXO in honor of the late Indian-American Novel Laureate Subrahmanyan Chandrasekhar. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It is designed to observe x-rays from high energy regions of the Universe, such as hot gas in the renmants of exploded stars. It produces picture-like images of x-ray emissions analogous to those made in visible light, as well as gathers data on the chemical composition of x-ray radiating objects. The CXO helps astronomers world-wide better understand the structure and evolution of the universe by studying powerful sources of x-ray such as exploding stars, matter falling into black holes, and other exotic celestial objects. The Observatory has three major parts: (1) the x-ray telescope, whose mirrors will focus x-rays from celestial objects; (2) the science instruments that record the x-rays so that x-ray images can be produced and analyzed; and (3) the spacecraft, which provides the environment necessary for the telescope and the instruments to work. TRW, Inc. was the prime contractor for the development the CXO and NASA's Marshall Space Flight Center was responsible for its project management. The Smithsonian Astrophysical Observatory controls science and flight operations of the CXO for NASA from Cambridge, Massachusetts. The Observatory was launched July 22, 1999 aboard the Space Shuttle Columbia, STS-93 mission. (Image courtesy of TRW).

History of Chandra X-Ray Observatory

NASA Image and Video Library

1999-01-01

This is a computer rendering of the fully developed Chandra X-ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF), in orbit in a star field. In 1999, the AXAF was renamed the CXO in honor of the late Indian-American Novel Laureate Subrahmanyan Chandrasekhar. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It is designed to observe x-rays from high energy regions of the Universe, such as hot gas in the renmants of exploded stars. It produces picture-like images of x-ray emissions analogous to those made in visible light, as well as gathers data on the chemical composition of x-ray radiating objects. The CXO helps astronomers world-wide better understand the structure and evolution of the universe by studying powerful sources of x-rays such as exploding stars, matter falling into black holes, and other exotic celestial objects. The Observatory has three major parts: (1) the x-ray telescope, whose mirrors will focus x-rays from celestial objects; (2) the science instruments that record the x-rays so that x-ray images can be produced and analyzed; and (3) the spacecraft, which provides the environment necessary for the telescope and the instruments to work. TRW, Inc. was the prime contractor for the development of the CXO and NASA's Marshall Space Flight Center was responsible for its project management. The Smithsonian Astrophysical Observatory controls science and flight operations of the CXO for NASA from Cambridge, Massachusetts. The Observatory was launched July 22, 1999 aboard the Space Shuttle Columbia, STS-93 mission. (Image courtesy of TRW).

Giant Galaxy's Violent Past Comes Into Focus

NASA Astrophysics Data System (ADS)

2004-05-01

Long-exposure images of the giant elliptical galaxy M87 by NASA's Chandra X-ray Observatory, together with radio observations, have provided spectacular evidence of repetitive outbursts from the vicinity of the galaxy's supermassive black hole. Magnetized rings, bubbles, plumes and jets ranging in size from a few thousand to a few hundred thousand light years point to ongoing violent activity for hundreds of millions of years. "The hot X-ray emitting gas extending for hundreds of thousands of light years around M87 reveals a record of episodes of black hole activity," said Paul Nulsen of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass. and an author of an Astrophysical Journal paper describing the latest Chandra observations. "With these detailed observations, we are beginning to understand how the central supermassive black hole transfers enormous amounts of energy over vast reaches of space." M87, located in the middle of the Virgo galaxy cluster, is surrounded by an extensive atmosphere of multi-million degree Celsius gas. Chandra's long-exposure image has allowed astronomers to see in more detail structures discovered by previous observations with Chandra and other X-ray telescopes, to discover new features, and to make specific comparisons with radio images, which trace the presence of high-energy electrons in a magnetic field." X-ray Image of M87 Chandra X-ray Image of M87, Close-Up The picture that emerges is one in which the infall of material toward a central supermassive black hole produces a magnetized jet of high-energy particles that blasts away from the vicinity of the black hole at near the speed of light. As a jet plows into the surrounding gas, a buoyant, magnetized bubble of high-energy particles is created, and an intense sound wave rushes ahead of the expanding bubble. In Chandra's image of M87, X-rays from the jet dominate the central region of the galaxy. The jet is thought to be pointed at a small angle toward the line of sight, out of the plane of the image. Bright arcs around dark cavities of faint X-ray emission appear to be gas that has been swept up on rising, buoyant bubbles that were created a few million years ago (in M87 time - M87 is 50 million light years from Earth). These bubbles, which rise like hot air from a fire or explosion in the atmosphere, show up as bright regions in radio images. An alternative interpretation, presented in the June 1, 2004 issue of Astrophysical Journal Letters by Hua Feng of Tsinghau University in China and colleagues, is that the rings are shock waves that surround the jet and are seen in projection. An image processed to bring out faint features reveals two circular rings with radii of 45 thousand and 55 thousand light years, respectively. These features are likely sound waves produced by earlier explosions about 10 million and 14 million years ago, respectively. A very faint arc at an even larger distance has a probable age of 100 million years. X-ray Image of M87 Chandra X-ray Image of M87, Minus Radial Gradient Spectacular, curved X-ray plumes extending from the upper left to the lower right illustrate in dramatic fashion how the central black hole can affect the galaxy and its environment over huge distances. The arm on the upper left extends more than 75 thousand light years, and the one on the lower right more than 100 thousand light years from the center of the galaxy. These features are thought to be gas carried out from the center of the galaxy onbuoyant bubbles created by outbursts tens of millions of years ago. A growing body of evidence from other galaxy clusters suggests that episodic outbursts from supermassive black holes in giant, centrally located galaxies are a common feature. These outbursts, which produce magnetized jets and bubbles of high energy particles, along with mammoth sound waves, could be due to the self-regulated inflow of gas into the black hole – gas around the black hole cools and flows inward to feed the black hole, producing an outburst which shuts down the inflow for a few million years, at which point the cycle begins again. Or, the cause could be a much more dramatic event, like the cannibalization of a smaller galaxy, with the subsequent merger of two supermassive black holes in the center. The results from Nulsen's team, which included William Forman and other colleagues from the CfA, were based on approximately 40 hours of Chandra observations with its Advanced CCD Imaging Spectrometer. Andrew Young of the University of Maryland in College Park, and colleagues, have published a paper identifying many of the X-ray features in M87 in the November 10, 2002 issue of The Astrophysical Journal based on a shorter Chandra observation. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the Office of Space Science, NASA Headquarters, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

M Stars in the TW Hydra Association: A Chandra Large Program Survey

NASA Astrophysics Data System (ADS)

Punzi, Kristina; Kastner, Joel; Principe, David; Stelzer, Beate; Gorti, Uma; Pascucci, Illaria; Argiroffi, Costanza

2018-01-01

We have conducted a Cycle 18 Chandra Large Program survey of very cool members of the $\\sim$ 8 Myr-old TW Hydra Association (TWA) to extend our previous study of the potential connections between M star disks and X-rays (Kastner et al. 2016, AJ, 152, 3) to the extreme low-mass end of the stellar initial mass function. The spectral types of our targets extend down to the M/L borderline. Thus we can further investigate the potential connection between the intense X-ray emission from young, low-mass stars and the lifetimes of their circumstellar planet-forming discs, as well as better constrain the age at which coronal activity declines for stellar masses approaching the H-burning limit of $\\sim$ 0.08 M$_{\\odot}$. We present preliminary results from the Cycle 18 survey, including X-ray detection statistics and measurements of relative X-ray luminosities and coronal (X-ray) temperatures for those TWA stars detected by Chandra. This research is supported by SAO/CXC grant GO7-18002A and NASA Astrophysics Data Analysis program grants NNX12AH37G and NNX16AG13G to RIT.

XAssist: A System for the Automation of X-ray Astrophysics Analysis

NASA Astrophysics Data System (ADS)

Ptak, A.; Griffiths, R.

XAssist is a NASA AISR-funded project for the automation of X-ray astrophysics, with emphasis on galaxies. It is nearing completion of its initially funded effort, and is working well for Chandra and ROSAT data. Initial support for XMM-Newton data is present as well. It is capable of data reprocessing, source detection, and preliminary spatial, temporal and spectral analysis for each source with sufficient counts. The bulk of the system is written in Python, which in turn drives underlying software (CIAO for Chandra data, etc.). Future work will include a GUI (mainly for beginners and status monitoring) and the exposure of at least some functionality as web services. The latter will help XAssist to eventually become part of the VO, making advanced queries possible, such as determining the X-ray fluxes of counterparts to HST or SDSS sources (including the use of unpublished X-ray data), and add the ability of ``on-the-fly'' X-ray processing. Pipelines are running on ROSAT, Chandra and now XMM-Newton observations of galaxies to demonstrate XAssist's capabilities, and the results are available online (in real time) at http://www.xassist.org. XAssist itself as well as various associated projects are available for download.

A Deep Chandra ACIS Survey of M51

NASA Astrophysics Data System (ADS)

Kuntz, K. D.; Long, Knox S.; Kilgard, Roy E.

2016-08-01

We have obtained a deep X-ray image of the nearby galaxy M51 using Chandra. Here we present the catalog of X-ray sources detected in these observations and provide an overview of the properties of the point-source population. We find 298 sources within the D 25 radii of NGC 5194/5, of which 20% are variable, a dozen are classical transients, and another half dozen are transient-like sources. The typical number of active ultraluminous X-ray sources in any given observation is ˜5, and only two of those sources persist in an ultraluminous state over the 12 yr of observations. Given reasonable assumptions about the supernova remnant population, the luminosity function is well described by a power law with an index between 1.55 and 1.7, only slightly shallower than that found for populations dominated by high-mass X-ray binaries (HMXBs), which suggests that the binary population in NGC 5194 is also dominated by HMXBs. The luminosity function of NGC 5195 is more consistent with a low-mass X-ray binary dominated population. Based on observations made with NASA's Chandra X-ray Observatory, which is operated by the Smithsonian Astrophysical Observatory under contract #NAS83060, and the data were obtained through program GO1-12115.

Highlights from Three Years of the Chandra X-Ray Observatory

NASA Technical Reports Server (NTRS)

Weisskopf, Martin C.; Six, N. Frank (Technical Monitor)

2002-01-01

August 12, 2002 marked the third anniversary of the first light observed with the Chandra X-Ray Observatory (CXO) which had been launched on July 23 of that same year. The CXO is the X-ray component of NASA's Great Observatory Program that also includes the Hubble Space Telescope for observations in the visible portion of the electromagnetic spectrum, the now defunct Compton Gamma-Ray Observatory and the soon-to-be-launched Space Infra-Red Telescope Facility. The scientific return from the Observatory has been spectacular. Images of objects as local as the moon's of Jupiter and comets, to those which show the details of the emission of the hot gas pervading clusters of galaxies have been obtained. The technical status of the instrumentation and the performance of the X-ray optics will be reviewed and an overview of some of the exciting results will be presented.

History of Chandra X-Ray Observatory

NASA Image and Video Library

2002-07-31

This is a photo taken by NASA's Chandra X-ray Observatory that reveals the remains of an explosion in the form of two enormous arcs of multimillion-degree gas in the galaxy Centaurus A that appear to be part of a ring 25,000 light years in diameter. The size and location of the ring suggest that it could have been an explosion that occurred about 10 million years ago. A composite image made with radio (red and green), optical (yellow-orange), and X-ray data (blue) presents a sturning tableau of a turbulent galaxy. A broad band of dust and cold gas is bisected at an angle by opposing jets of high-energy particles blasting away from the supermassive black hole in the nucleus. Lying in a plane perpendicular to the jets are the two large arcs of x-ray emitting multi-million degree gas. This discovery can help astronomers better understand the cause and effect of violent outbursts from the vicinity of supermassive black holes of active galaxies. The Chandra program is managed by the Marshall Space Flight Center in Huntsville, Alabama.

NASA's Chandra Reveals Origin of Key Cosmic Explosions

NASA Astrophysics Data System (ADS)

2010-02-01

WASHINGTON -- New findings from NASA's Chandra X-ray Observatory have provided a major advance in understanding a type of supernova critical for studying the dark energy that astronomers think pervades the universe. The results show mergers of two dense stellar remnants are the likely cause of many of the supernovae that have been used to measure the accelerated expansion of the universe. These supernovae, called Type Ia, serve as cosmic mile markers to measure expansion of the universe because they can be seen at large distances, and they follow a reliable pattern of brightness. However, until now, scientists have been unsure what actually causes the explosions. "These are such critical objects in understanding the universe," said Marat Gilfanov of the Max Planck Institute for Astrophysics in Germany and lead author of the study that appears in the Feb. 18 edition of the journal Nature. "It was a major embarrassment that we did not know how they worked. Now we are beginning to understand what lights the fuse of these explosions." Most scientists agree a Type Ia supernova occurs when a white dwarf star -- a collapsed remnant of an elderly star -- exceeds its weight limit, becomes unstable and explodes. Scientists have identified two main possibilities for pushing the white dwarf over the edge: two white dwarfs merging or accretion, a process in which the white dwarf pulls material from a sun-like companion star until it exceeds its weight limit. "Our results suggest the supernovae in the galaxies we studied almost all come from two white dwarfs merging," said co-author Akos Bogdan, also of Max Planck. "This is probably not what many astronomers would expect." The difference between these two scenarios may have implications for how these supernovae can be used as "standard candles" -- objects of a known brightness -- to track vast cosmic distances. Because white dwarfs can come in a range of masses, the merger of two could result in explosions that vary somewhat in brightness. Because these two scenarios would generate different amounts of X-ray emission, Gilfanov and Bogdan used Chandra to observe five nearby elliptical galaxies and the central region of the Andromeda galaxy. A Type 1a supernova caused by accreting material produces significant X- ray emission prior to the explosion. A supernova from a merger of two white dwarfs, on the other hand, would create significantly less X-ray emission than the accretion scenario. The scientists found the observed X-ray emission was a factor of 30 to 50 times smaller than expected from the accretion scenario, effectively ruling it out. This implies that white dwarf mergers dominate in these galaxies. An open question remains whether these white dwarf mergers are the primary catalyst for Type Ia supernovae in spiral galaxies. Further studies are required to know if supernovae in spiral galaxies are caused by mergers or a mixture of the two processes. Another intriguing consequence of this result is that a pair of white dwarfs is relatively hard to spot, even with the best telescopes. "To many astrophysicists, the merger scenario seemed to be less likely because too few double-white-dwarf systems appeared to exist," said Gilfanov. "Now this path to supernovae will have to be investigated in more detail." In addition to the X-rays observed with Chandra, other data critical for this result came from NASA's Spitzer Space Telescope and the ground-based, infrared Two Micron All Sky Survey. The infrared brightness of the galaxies allowed the team to estimate how many supernovae should occur. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass. More information, including images and other multimedia, can be found at: http://chandra.harvard.edu and http://chandra.nasa.gov

Composite Image of the Cat's Eye From Chandra X-Ray Observatory and Hubble Space Telescope

NASA Technical Reports Server (NTRS)

2001-01-01

Left image: The x-ray data from the Chandra X-Ray Observatory (CXO) has revealed a bright central star surrounded by a cloud of multimillion-degree gas in the planetary nebula known as the Cat's Eye. This CXO image, where the intensity of the x-ray emission is correlated to the brightness of the orange coloring, captures the expulsion of material from a star that is expected to collapse into a white dwarf in a few million years. The intensity of x-rays from the central star was unexpected, and it is the first time astronomers have seen such x-ray emission from the central star of a planetary nebula. Right image: An image of Cat's Eye taken by the Hubble Space Telescope (HST). By comparing the CXO data with that from the HST, researchers are able to see where the hotter, x-ray emitting gas appears in relation to the cooler material seen in optical wavelengths by the HST. The CXO team found that the chemical abundance in the region of hot gas (its x-ray intensity is shown in purple) was not like those in the wind from the central star and different from the outer cooler material (the red and green structures.) Although still incredibly energetic and hot enough to radiate x-rays, CXO shows the hot gas to be somewhat cooler than scientists would have expected for such a system. CXO image credit: (NASA/UIUC/Y. Chu et al.) HST image credit: (NASA/HST)

History of Chandra X-Ray Observatory

NASA Image and Video Library

2001-01-01

Left image: The x-ray data from the Chandra X-Ray Observatory (CXO) has revealed a bright central star surrounded by a cloud of multimillion-degree gas in the planetary nebula known as the Cat's Eye. This CXO image, where the intensity of the x-ray emission is correlated to the brightness of the orange coloring, captures the expulsion of material from a star that is expected to collapse into a white dwarf in a few million years. The intensity of x-rays from the central star was unexpected, and it is the first time astronomers have seen such x-ray emission from the central star of a planetary nebula. Right image: An image of Cat's Eye taken by the Hubble Space Telescope (HST). By comparing the CXO data with that from the HST, researchers are able to see where the hotter, x-ray emitting gas appears in relation to the cooler material seen in optical wavelengths by the HST. The CXO team found that the chemical abundance in the region of hot gas (its x-ray intensity is shown in purple) was not like those in the wind from the central star and different from the outer cooler material (the red and green structures.) Although still incredibly energetic and hot enough to radiate x-rays, CXO shows the hot gas to be somewhat cooler than scientists would have expected for such a system. CXO image credit: (NASA/UIUC/Y. Chu et al.) HST image credit: (NASA/HST)

Chandra X-Ray Observatory Image of Black Hole

NASA Technical Reports Server (NTRS)

2000-01-01

This Chandra X-Ray Observatory (CXO) image is a spectrum of a black hole, which is similar to the colorful spectrum of sunlight produced by a prism. The x-rays of interest are shown here recorded in bright stripes that run rightward and leftward from the center of the image. These x-rays are sorted precisely according to their energy with the highest-energy x-rays near the center of the image and the lower-energy x-rays farther out. The spectrum was obtained by using the Low Energy Transmission Grating (LETG), which intercepts x-rays and changes their direction by the amounts that depend sensitively on the x-ray energy. The assembly holds 540 gold transmission gratings. When in place behind the mirrors, the gratings intercept the x-rays reflected from the telescope. The bright spot at the center is due to a fraction of the x-ray radiation that is not deflected by the LETG. The spokes that intersect the central spot and the faint diagonal rays that flank the spectrum itself are artifacts due to the structure that supports the LETG grating elements. (Photo credit: NASA Cfa/J. McClintock et al)

History of Chandra X-Ray Observatory

NASA Image and Video Library

2000-04-01

This Chandra X-Ray Observatory (CXO) image is a spectrum of a black hole, which is similar to the colorful spectrum of sunlight produced by a prism. The x-rays of interest are shown here recorded in bright stripes that run rightward and leftward from the center of the image. These x-rays are sorted precisely according to their energy with the highest-energy x-rays near the center of the image and the lower-energy x-rays farther out. The spectrum was obtained by using the Low Energy Transmission Grating (LETG), which intercepts x-rays and changes their direction by the amounts that depend sensitively on the x-ray energy. The assembly holds 540 gold transmission gratings. When in place behind the mirrors, the gratings intercept the x-rays reflected from the telescope. The bright spot at the center is due to a fraction of the x-ray radiation that is not deflected by the LETG. The spokes that intersect the central spot and the faint diagonal rays that flank the spectrum itself are artifacts due to the structure that supports the LETG grating elements. (Photo credit: NASA Cfa/J. McClintock et al)

Supernova Remnant W49B

NASA Image and Video Library

2017-12-08

Release date Dec. 30, 2009 In the supernova remnant W49B, Suzaku found another fossil fireball. It detected X-rays produced when heavily ionized iron atoms recapture an electron. This view combines infrared images from the ground (red, green) with X-ray data from NASA's Chandra X-Ray Observatory (blue). Credit: Caltech/SSC/J. Rho and T. Jarrett and NASA/CXC/SSC/J. Keohane et al. To learn more about this image go to: www.nasa.gov/mission_pages/astro-e2/news/fossil-fireballs... NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

Chandra Captures Flare From Brown Dwarf

NASA Astrophysics Data System (ADS)

2000-07-01

The first flare ever seen from a brown dwarf, or failed star, was detected by NASA's Chandra X-ray Observatory. The bright X-ray flare has implications for understanding the explosive activity and origin of magnetic fields of extremely low mass stars. Chandra detected no X-rays at all from LP 944-20 for the first nine hours of a twelve hour observation, then the source flared dramatically before it faded away over the next two hours. "We were shocked," said Dr. Robert Rutledge of the California Institute of Technology in Pasadena, the lead author on the discovery paper to appear in the July 20 issue of Astrophysical Journal Letters. "We didn't expect to see flaring from such a lightweight object. This is really the 'mouse that roared.'" Chandra LP 944-20 X-ray Image Press Image and Caption The energy emitted in the brown dwarf flare was comparable to a small solar flare, and was a billion times greater than observed X-ray flares from Jupiter. The flaring energy is believed to come from a twisted magnetic field. "This is the strongest evidence yet that brown dwarfs and possibly young giant planets have magnetic fields, and that a large amount of energy can be released in a flare," said Dr. Eduardo Martin, also of Caltech and a member of the team. Professor Gibor Basri of the University of California, Berkeley, the principal investigator for this observation, speculated that the flare "could have its origin in the turbulent magnetized hot material beneath the surface of the brown dwarf. A sub-surface flare could heat the atmosphere, allowing currents to flow and give rise to the X-ray flare -- like a stroke of lightning." LP 944-20 is about 500 million years old and has a mass that is about 60 times that of Jupiter, or 6 percent that of the Sun. Its diameter is about one-tenth that of the Sun and it has a rotation period of less than five hours. Located in the constellation Fornax in the southern skies, LP 944-20 is one of the best studied brown dwarfs because it is only 16 light years from Earth. The absence of X-rays from LP 944-20 during the non-flaring period is in itself a significant result. It sets the lowest limit on steady X-ray power produced by a brown dwarf, and shows that the million degree Celsius upper atmospheres, or coronas, cease to exist as the surface temperature of a brown dwarf cools below about 2500 degrees Celsius. "This is an important confirmation of the trend that hot gas in the atmospheres of lower mass stars is produced only in flares," said Professor Lars Bildsten of the University of California, Santa Barbara, also a member of the team. Brown dwarfs have too little mass to sustain significant nuclear reactions in their cores. Their primary source of energy is the release of gravitational energy as they slowly contract. They are very dim ­ less than a tenth of a percent as luminous as the Sun -- and of great interest to astronomers because they are poorly understood and probably a very common class of objects that are intermediate between normal stars and giant planets. The 12-hour observation of LP 944-20 was made on December 15, 1999, using the Advanced CCD Imaging Spectrometer (ACIS). The ACIS instrument was built for NASA by the Massachusetts Institute of Technology, Cambridge, and Pennsylvania State University, University Park. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program. TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass. Images associated with this release are available on the World Wide Web at: http://chandra.harvard.edu AND http://chandra.nasa.gov High resolution digital versions of the X-ray image (JPG, 300 dpi TIFF) are available at the Internet sites listed above.

Magnetic Dynamos and X-Ray Activity in Ultracool Dwarfs (UCDs): Surprises in the Radio Band

NASA Astrophysics Data System (ADS)

Williams, Peter K.; Cook, B. A.; Berger, E.

2014-01-01

Radio observations established early on that some brown dwarfs host kilogauss magnetic fields, despite their low temperatures and the absence of the shearing tachocline that is believed to be key to the solar dynamo. The observed radio emission is often surprisingly bright, exceeding the standard magnetic radio/X-ray (Güdel-Benz) relation by as much as five orders of magnitude. This effect is still not satisfactorily explained. In an attempt to improve matters, we have constructed and analyzed a comprehensive database of ultracool dwarfs with both radio and X-ray data, including new observations of seven targets with Chandra and the upgraded VLA. While all of the newly-observed objects were detected in the X-ray, only one was detected in the radio. These new targets are thus consistent with the standard relation, in striking contrast with some previous data. Some pairs of dwarfs with outwardly similar characteristics (spectral type, v sin i) have dramatically different emission properties, with radio/X-ray ratios that differ by two orders of magnitude. These results suggest that there is dramatic variance in ultracool magnetic activity. As we also discuss in a companion poster examining the relation between rotation and activity, variation in the topology of the magnetic field may explain the data. This work is supported in part by the NSF REU and DOD ASSURE programs under NSF grant no. 1262851 and by the Smithsonian Institution. We also acknowledge support from the NSF through Grant AST-1008361 and from NASA through Chandra Award Number G02-13007A issued by the Chandra X-ray Observatory Center, operated by the Smithsonian Astrophysical Observatory and NASA under contract NAS8-03060.

History of Chandra X-Ray Observatory

NASA Image and Video Library

1997-01-01

This photograph shows the mirrors of the High Resolution Mirror Assembly (HRMA) for the Chandra X-Ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF), being assembled in the Eastman Kodak Company in Rochester, New York. The AXAF was renamed CXO in 1999. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It observes x-rays from high-energy regions of the universe, such as hot gas in the remnants of exploded stars. The HRMA, the heart of the telescope system, is contained in the cylindrical "telescope" portion of the observatory. Since high-energy x-rays would penetrate a normal mirror, special cylindrical mirrors were created. The two sets of four nested mirrors resemble tubes within tubes. Incoming x-rays graze off the highly polished mirror surface and are furneled to the instrument section for detection and study. TRW, Inc. was the prime contractor for the development of the CXO and NASA's Marshall Space Flight Center was responsible for its project management. The Observatory was launched July 22, 1999 aboard the Space Shuttle Columbia, STS-93 mission.

Chandra X-Ray Observatory High Resolution Mirror Assembly

NASA Technical Reports Server (NTRS)

1997-01-01

This photograph shows the mirrors of the High Resolution Mirror Assembly (HRMA) for the Chandra X-Ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF), being assembled in the Eastman Kodak Company in Rochester, New York. The AXAF was renamed CXO in 1999. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It observes x-rays from high-energy regions of the universe, such as hot gas in the remnants of exploded stars. The HRMA, the heart of the telescope system, is contained in the cylindrical 'telescope' portion of the observatory. Since high-energy x-rays would penetrate a normal mirror, special cylindrical mirrors were created. The two sets of four nested mirrors resemble tubes within tubes. Incoming x-rays graze off the highly polished mirror surface and are furneled to the instrument section for detection and study. TRW, Inc. was the prime contractor for the development of the CXO and NASA's Marshall Space Flight Center was responsible for its project management. The Observatory was launched July 22, 1999 aboard the Space Shuttle Columbia, STS-93 mission.

Cosmic Forensics Confirms Gamma-Ray Burst And Supernova Connection

NASA Astrophysics Data System (ADS)

2003-03-01

Scientists announced today that they have used NASA's Chandra X-ray Observatory to confirm that a gamma-ray burst was connected to the death of a massive star. This result is an important step in understanding the origin of gamma-ray bursts, the most violent events in the present-day universe. "If a gamma-ray burst were a crime, then we now have strong circumstantial evidence that a supernova explosion was at the scene," said Nathaniel Butler of Massachusetts Institute of Technology in Cambridge, lead author of a paper presented today at the meeting of the High Energy Division of the American Astronomical Society. Chandra was able to obtain an unusually long observation (approximately 21 hours) of the afterglow of GRB 020813 (so named because the High-Energy Transient Explorer, HETE, discovered it on August 13, 2002.) A grating spectrometer aboard Chandra revealed an overabundance of elements characteristically dispersed in a supernova explosion. Narrow lines, or bumps, due to silicon and sulfur ions (atoms stripped of most of their electrons) were clearly identified in the X-ray spectrum of GRB 020813. "Our observation of GRB 020813 supports two of the most important features of the popular supra-nova model for gamma-ray bursts," said Butler. "An extremely massive star likely exploded less than two months prior to the gamma-ray burst, and the radiation from the gamma-ray burst was beamed into a narrow cone." An analysis of the data showed that the ions were moving away from the site of the gamma-ray burst at a tenth the speed of light, probably as part of a shell of matter ejected in the supernova explosion. The line features were observed to be sharply peaked, indicating that they were coming from a narrow region of the expanding shell. This implies that only a small fraction of the shell was illuminated by the gamma-ray burst, as would be expected if the burst was beamed into a narrow cone. The observed duration of the afterglow suggests a delay of about 60 days between the supernova and the gamma ray burst. The supra-nova model involves a two-step process: the first step is the collapse of the core of an extremely massive star accompanied by the ejection of the outer layers of the star. The collapsed core forms a rapidly rotating black hole surrounded by a swirling disk of matter. In the second step this black hole-disk system produces a jet of high-energy particles. Shock waves within the jet produce the burst of X-rays and gamma rays that is observed to last only a few minutes. Interaction of the jet with the ejected supernova shell produces the X-ray afterglow, which can last for days or even months. The reason for the delay between the formation of the black hole and the production of the jet is not understood. Earlier observations with Japan's ASCA, the Italian-Netherlands Beppo-SAX, and the European Space Agency's XMM-Newton satellites, as well as Chandra had given some indication of the presence of elements expected in a shell ejected by a supernova. However, the number of X-rays detected in those observations was small, and the possibility remained that the reported lines were an instrumental effect or statistical fluctuation. Since Chandra was able to observe X-ray lines from GRB 020813 for almost an entire day, the number of X-rays detected was five times larger than for previous observations. This enabled the team to make a definitive identification of the silicon and sulfur lines. Chandra observed GRB 020813 for about 77,000 seconds, approximately 21 hours after the initial burst. Other members of the research team included Herman Marshall, George Ricker, Roland Vanderspek, Peter Ford, Geoffrey Crew (MIT), and Donald Lamb (University of Chicago). The High Energy Transmission Grating Spectrometer was built by MIT. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program, and TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass., for the Office of Space Science at NASA Headquarters, Washington.

Chandra X-Ray Observatory Image of Andromeda Galaxy

NASA Technical Reports Server (NTRS)

1999-01-01

Chandra X-Ray Observatory took this first x-ray picture of the Andromeda Galaxy (M31) on October 13, 1999. The blue dot in the center of the image is a 'cool' million-degree x-ray source where a supermassive black hole with the mass of 30-million suns is located. The x-rays are produced by matter furneling toward the black hole. Numerous other hotter x-ray sources are also apparent. Most of these are probably due to x-ray binary systems, in which a neutron star or black hole is in close orbit around a normal star. While the gas falling into the central black hole is cool, it is only cool by comparison to the 100 other x-ray sources in the Andromeda Galaxy. To be detected by an x-ray telescope, the gas must have a temperature of more than a million degrees. The Andromeda Galaxy is our nearest neighbor spiral galaxy at a distance of two million light years. It is similar to our own Milky Way in size, shape, and also contains a supermassive black hole at the center. (Photo Credit: NASA/CXC/SAO/S. Murray, M. Garcia)

Chandra X-Ray Observatory Image of the Distant Galaxy, 3C294

NASA Technical Reports Server (NTRS)

2000-01-01

This most distant x-ray cluster of galaxies yet has been found by astronomers using Chandra X-ray Observatory (CXO). Approximately 10 billion light-years from Earth, the cluster 3C294 is 40 percent farther than the next most distant x-ray galaxy cluster. The existence of such a faraway cluster is important for understanding how the universe evolved. CXO's image reveals an hourglass-shaped region of x-ray emissions centered on the previously known central radio source (seen in this image as the blue central object) that extends outward for 60,000 light- years. The vast clouds of hot gas that surround such galaxies in clusters are thought to be heated by collapse toward the center of the cluster. Until CXO, x-ray telescopes have not had the needed sensitivity to identify such distant clusters of galaxies. Galaxy clusters are the largest gravitationally bound structures in the universe. The intensity of the x-rays in this CXO image of 3C294 is shown as red for low energy x-rays, green for intermediate, and blue for the most energetic x-rays. (Photo credit: NASA/loA/A. Fabian et al)

History of Chandra X-Ray Observatory

NASA Image and Video Library

1999-10-13

Chandra X-Ray Observatory took this first x-ray picture of the Andromeda Galaxy (M31) on October 13, 1999. The blue dot in the center of the image is a "cool" million-degree x-ray source where a supermassive black hole with the mass of 30-million suns is located. The x-rays are produced by matter furneling toward the black hole. Numerous other hotter x-ray sources are also apparent. Most of these are probably due to x-ray binary systems, in which a neutron star or black hole is in close orbit around a normal star. While the gas falling into the central black hole is cool, it is only cool by comparison to the 100 other x-ray sources in the Andromeda Galaxy. To be detected by an x-ray telescope, the gas must have a temperature of more than a million degrees. The Andromeda Galaxy is our nearest neighbor spiral galaxy at a distance of two million light years. It is similar to our own Milky Way in size, shape, and also contains a supermassive black hole at the center. (Photo Credit: NASA/CXC/SAO/S. Murray, M. Garcia)

Chandra/ACIS Spectra of the 30 Doradus Star Forming Region

NASA Astrophysics Data System (ADS)

Townsley, L.; Broos, P.; Feigelson, E.; Burrows, D.; Chu, Y.-H.; Garmire, G.; Griffiths, R.; Maeda, Y.; Tsuboi, Y.

2000-12-01

We present the first high-spatial-resolution X-ray spectra of constituents of the 30 Doradus star-forming region in the Large Magellanic Cloud, obtained with the Advanced CCD Imaging Spectrometer (ACIS) aboard the Chandra X-ray Observatory. Our continuing efforts to remove the spectral effects of CCD charge transfer inefficiency (CTI) due to radiation damage are described. The central cluster of young high-mass stars, R136, is resolved at the arcsecond level by ACIS, allowing spectral analysis of several constituents. Other Wolf-Rayet stars and multiple systems (e.g. R139, R140) are also detected. Spatially-resolved spectra are presented for N157B, the plerion SNR recently shown by X-ray observations to contain a 16-msec pulsar (Marshall et al., ApJ 499, L179). The spectrally soft superbubble structures seen by ROSAT are visible in the Chandra image; a composite spectrum, improved with CTI correction, is presented. Support for this effort was provided by NASA contract NAS8-38252 to Gordon Garmire, the ACIS Principal Investigator.

Chandra Discovers X-Ray Ring Around Cosmic Powerhouse in Crab Nebula

NASA Astrophysics Data System (ADS)

1999-09-01

After barely two months in space, NASA's Chandra X-ray Observatory has taken a stunning image of the Crab Nebula, the spectacular remains of a stellar explosion, and has revealed something never seen before: a brilliant ring around the nebula's heart. Combined with observations from the Hubble Space Telescope, the image provides important clues to the puzzle of how the cosmic "generator," a pulsing neutron star, energizes the nebula, which still glows brightly almost 1,000 years after the explosion. "The inner ring is unique," said Professor Jeff Hester of Arizona State University, Tempe, AZ. "It has never been seen before, and it should tell us a lot about how the energy from the pulsar gets into the nebula. It's like finding the transmission lines between the power plant and the light bulb." Professor Mal Ruderman of Columbia University, New York, NY, agreed. "The X-rays Chandra sees are the best tracer of where the energy is. With images such as these, we can directly diagnose what is going on." What is going on, according to Dr. Martin Weisskopf, Chandra Project Scientist from NASA's Marshall Space Flight Center, Huntsville, AL, is awesome. "The Crab pulsar is accelerating particles up to the speed of light and flinging them out into interstellar space at an incredible rate." The image shows tilted rings or waves of high-energy particles that appear to have been flung outward over the distance of a light year from the central star, and high-energy jets of particles blasting away from the neutron star in a direction perpendicular to the spiral. Hubble Space Telescope images have shown moving knots and wisps around the neutron star, and previous X-ray images have shown the outer parts of the jet and hinted at the ring structure. With Chandra's exceptional resolution, the jet can be traced all the way in to the neutron star, and the ring pattern clearly appears. The image was made with Chandra's Advanced CCD Imaging Spectrometer and High Energy Transmission Grating. The Crab Nebula, easily the most intensively studied object beyond our solar system, is the remnant of a star that was observed to explode in 1054 A.D. Chinese astronomers in that year reported a "guest star" that appeared suddenly and remained visible for weeks, even during daytime. From gamma-ray telescopes to radio telescopes, the Crab has been observed using virtually every astronomical instrument that could see that part of the sky. Unraveling the mysteries of the Crab has proven to be the door to insight after insight into the workings of the universe. The Crab convincingly tied the origin of enigmatic "pulsars" to the stellar cataclysms known as supernovas. Observations of the expanding cloud of filaments in the Crab were instrumental in confirming the cosmic origin of the chemical elements from which planets (and people) are made. The nebula is located 6,000 light years from Earth in the constellation Taurus. The Crab pulsar, which was discovered by radio astronomers in 1968, is a neutron star rotating 30 times per second. Neutron stars are formed in the seconds before a supernova explosion when gravity crushes the central core of the star to densities 50 trillion times that of lead and a diameter of only 12 miles. Another consequence of the dramatic collapse is that neutron stars are rapidly rotating and highly magnetized. Like a gigantic cosmic generator, the rotating magnet generates 10 quadrillion volts of electricity, 30 million times that of a typical lightning bolt. "It is an incredibly efficient generator," Ruderman explained. "More than ninety-five percent efficient. There's nothing like it on Earth." Press: Fact Sheet To follow Chandra's progress, visit the Chandra News Web site at: http://chandra.harvard.edu AND http://chandra.nasa.gov NASA's Marshall Space Flight Center manages the Chandra program. TRW, Inc., Redondo Beach, CA, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, MA. High resolution digital versions of the X-ray image (300 dpi JPG, TIFF) and other information associated with this release are available on the Internet at: http://chandra.harvard.edu/photo/0052/index.html or via links in: http://chandra.harvard.edu An animation of a supernova explosion and the formation of a supernova remnant can be found at: http://chandra.harvard.edu/resources/animations/pulsar.html

Chandra’s first decade of discovery

PubMed Central

Swartz, Douglas A.; Wolk, Scott J.; Fruscione, Antonella

2010-01-01

We review some of the many scientific results reported at a symposium held in September 2009 celebrating the 10th anniversary of National Aeronautics and Space Administration's (NASA's) Chandra X-ray Observatory. These results were contributed by scientists who were among the more than 300 symposium participants. We highlight those results that most emphasize the unique imaging and spectroscopic capabilities of Chandra. PMID:20406906

Trigger-Happy Cloud

NASA Image and Video Library

2009-08-12

This composite image, combining data from NASA Chandra X-ray Observatory and Spitzer Space Telescope shows the star-forming cloud Cepheus B, located in our Milky Way galaxy about 2,400 light years from Earth

Coronet: A Star-Formation Neighbor

NASA Image and Video Library

2007-09-13

This composite image shows the Coronet in X-rays from Chandra and infrared from NASA Spitzer Space Telescope orange, green, and cyan. The Spitzer data show young stars plus diffuse emission from dust.

Chandra X-Ray Observatory Image of Cassiopeia A

NASA Technical Reports Server (NTRS)

1999-01-01

This is an extraordinary first image from the Chandra X-Ray Observatory (CXO), the supernova remnant Cassiopeia A, tracing the aftermath of a gigantic stellar explosion in such sturning detail that scientists can see evidence of what may be a neutron star or black hole near the center. The red, green, and blue regions in this image of the supernova remnant Cassiopeia A show where the intensity of low, medium, and high energy X-rays, respectively, is greatest. The red material on the left outer edge is enriched in iron, whereas the bright greenish white region on the low left is enriched in silicon and sulfur. In the blue region on the right edge, low and medium energy X-rays have been filtered out by a cloud of dust and gas in the remnant . The image was made with the CXO's Advanced Charged-Coupled Device (CCD) Imaging Spectrometer (ACIS). Photo credit: NASA/CXC/SAO/Rutgers/J.Hughes

History of Chandra X-Ray Observatory

NASA Image and Video Library

1999-08-01

This is an extraordinary first image from the Chandra X-Ray Observatory (CXO), the supernova remnant Cassiopeia A, tracing the aftermath of a gigantic stellar explosion in such sturning detail that scientists can see evidence of what may be a neutron star or black hole near the center. The red, green, and blue regions in this image of the supernova remnant Cassiopeia A show where the intensity of low, medium, and high energy X-rays, respectively, is greatest. The red material on the left outer edge is enriched in iron, whereas the bright greenish white region on the low left is enriched in silicon and sulfur. In the blue region on the right edge, low and medium energy X-rays have been filtered out by a cloud of dust and gas in the remnant . The image was made with the CXO's Advanced Charged-Coupled Device (CCD) Imaging Spectrometer (ACIS). Photo credit: NASA/CXC/SAO/Rutgers/J.Hughes

XAssist: A System for the Automation of X-ray Astrophysics Analysis

NASA Astrophysics Data System (ADS)

Ptak, A.

2004-08-01

XAssist is a NASA AISR-funded project for the automation of X-ray astrophysics. It is capable of data reprocessing, source detection, and preliminary spatial, temporal and spectral analysis for each source with sufficient counts. The bulk of the system is written in Python, which in turn drives underlying software (CIAO for Chandra data, etc.). Future work will include a GUI (mainly for beginners and status monitoring) and the exposure of at least some functionality as web services. The latter will help XAssist to eventually become part of the VO, making advanced queries possible, such as determining the X-ray fluxes of counterparts to HST or SDSS sources (including the use of unpublished X-ray data), and add the ability of ``on-the-fly'' X-ray processing. Pipelines are running on Chandra and XMM-Newton observations of galaxies to demonstrate XAssist's capabilities, and the results are available online (in real time) at http://www.xassist.org. XAssist itself as well as various associated projects are available for download.

Motions in Nearby Galaxy Cluster Reveal Presence of Hidden Superstructure

NASA Astrophysics Data System (ADS)

2004-09-01

A nearby galaxy cluster is facing an intergalactic headwind as it is pulled by an underlying superstructure of dark matter, according to new evidence from NASA's Chandra X-ray Observatory. Astronomers think that most of the matter in the universe is concentrated in long large filaments of dark matter and that galaxy clusters are formed where these filaments intersect. A Chandra survey of the Fornax galaxy cluster revealed a vast, swept-back cloud of hot gas near the center of the cluster. This geometry indicates that the hot gas cloud, which is several hundred thousand light years in length, is moving rapidly through a larger, less dense cloud of gas. The motion of the core gas cloud, together with optical observations of a group of galaxies racing inward on a collision course with it, suggests that an unseen, large structure is collapsing and drawing everything toward a common center of gravity. X-ray Image of Fornax with labels X-ray Image of Fornax with labels "At a relatively nearby distance of about 60 million light years, the Fornax cluster represents a crucial laboratory for studying the interplay of galaxies, hot gas and dark matter as the cluster evolves." said Caleb Scharf of Columbia University in New York, NY, lead author of a paper describing the Chandra survey that was presented at an American Astronomical Society meeting in New Orleans, LA. "What we are seeing could be associated directly with the intergalactic gas surrounding a very large scale structure that stretches over millions of light years." The infalling galaxy group, whose motion was detected by Michael Drinkwater of the University of Melbourne in Australia, and colleagues, is about 3 million light years from the cluster core, so a collision with the core will not occur for a few billion years. Insight as to how this collision will look is provided by the elliptical galaxy NGC 1404 that is plunging into the core of the cluster for the first time. As discussed by Scharf and another group led by Marie Machacek of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., the hot gas cloud surrounding this galaxy has a sharp leading edge and a trailing tail of gas being stripped from the galaxy. Illustration of Fornax Cluster Illustration of Fornax Cluster "One thing that makes what we see in Fornax rather compelling is that it looks a lot like some of the latest computer simulations," added Scharf. "The Fornax picture, with infalling galaxies, and the swept back geometry of the cluster gas - seen only with the Chandra resolution and the proximity of Fornax - is one of the best matches to date with these high-resolution simulations." Over the course of hundreds of millions of years, NGC 1404's orbit will take it through the cluster core several times, most of the gas it contains will be stripped away, and the formation of new stars will cease. In contrast, galaxies that remain outside the core will retain their gas, and new stars can continue to form. Indeed, Scharf and colleagues found that galaxies located in regions outside the core were more likely to show X-ray activity which could be associated with active star formation. Dissolve from Optical to X-ray View of Fornax Animation Dissolve from Optical to X-ray View of Fornax Animation The wide-field and deep X-ray view around Fornax was obtained through ten Chandra pointings, each lasting about 14 hours. Other members of the research team were David Zurek of the American Museum of Natural History, New York, NY, and Martin Bureau, a Hubble Fellow currently at Columbia. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for NASA's Office of Space Science, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

KSC-99pp0976

NASA Image and Video Library

1999-07-19

KENNEDY SPACE CENTER, FLA. -- Mrs. Lalitha Chandrasekhar, wife of the late Indian-American Nobel Laureate Subrahmanyan Chandrasekhar, poses with a model of the Chandra X-ray Observatory in the TRW Media Hospitality Tent at the NASA Press Site at KSC. The name "Chandra," a shortened version of Chandrasekhar's name which he preferred among friends and colleagues, was chosen in a contest to rename the telescope. "Chandra" also means "Moon" or "luminous" in Sanskrit. The observatory is scheduled to be launched aboard Columbia on Space Shuttle mission STS-93

History of Chandra X-Ray Observatory

NASA Image and Video Library

2000-11-01

This image is a color composite of the supernova remnant E0102-72: x-ray (blue), optical (green), and radio (red). E0102-72 is the remnant of a star that exploded in a nearby galaxy known as the Small Magellanic Cloud. The star exploded outward at speeds in excess of 20 million kilometers per hour (12 million mph) and collided with surrounding gas. This collision produced two shock waves, or cosmic sonic booms, one traveling outward, and the other rebounding back into the material ejected by the explosion. The radio image, shown in red, was made using the Australia Telescope Compact Array. The radio waves are due to extremely high-energy electrons spiraling around magnetic field lines in the gas and trace the outward moving shock wave. The Chandra X-ray Observatory image, shown in blue, shows gas that has been heated to millions of degrees by the rebounding, or reverse shock wave. The x-ray data show that this gas is rich in oxygen and neon. These elements were created by nuclear reactions inside the star and hurled into space by the supernova. The Hubble Space Telescope optical image, shown in green, shows dense clumps of oxygen gas that have "cooled" to about 30,000 degrees. Photo Credit: X-ray (NASA/CXC/SAO); optical (NASA/HST): radio: (ACTA)

Space Science Research and Technology at NASA's Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Johnson, Charles L.

2007-01-01

This presentation will summarize the various projects and programs managed in the Space Science Programs and Projects Office at NASA's Marshall Space Flight Center in Huntsville, Alabama. Projects in the portfolio include NASA's Chandra X-Ray telescope, Hinode solar physics satellite, various advanced space propulsion technologies, including solar sails and tethers, as well as NASA's Discovery and New Frontiers Programs.

History of Chandra X-Ray Observatory

NASA Image and Video Library

1997-03-16

This photo shows the High Resolution Camera (HRC) for the Chandra X-Ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF), being integrated with the High Resolution Mirror Assembly (HRMA) in Marshall Space Flight Center's (MSFC's) 24-foot Vacuum Chamber at the X-Ray Calibration Facility (XRCF). The AXAF was renamed CXO in 1999. The CXO is the most sophisticated and the world's most poweful x-ray telescope ever built. It observes x-rays from high-energy regions of the universe, such as hot gas in the remnants of exploded stars. The HRC is one of the two instruments used at the focus of CXO, where it will detect x-rays reflected from an assembly of eight mirrors. The unique capabilities of the HRC stem from the close match of its imaging capability to the focusing of the mirrors. When used with CXO mirrors, the HRC makes images that reveal detail as small as one-half an arc second. This is equivalent to the ability to read a newspaper at a distance of 1 kilometer. MSFC's XRCF is the world's largest, most advanced laboratory for simulating x-ray emissions from distant celestial objects. It produces a space-like environment in which components relatedto x-ray telescope imaging are tested and the quality of their performances in space is predicted. TRW, Inc. was the prime contractor for the development of the CXO and NASA's MSFC was responsible for its project management. The Smithsonian Astrophysical Observatory controls science and flight operations of the CXO for NASA from Cambridge, Massachusetts. The CXO was launched July 22, 1999 aboard the Space Shuttle Columbia (STS-93).

History of Chandra X-Ray Observatory

NASA Image and Video Library

1997-03-16

This photo shows the High Resolution Camera (HRC) for the Chandra X-Ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF), being integrated with the High Resolution Mirror Assembly (HRMA) in Marshall Space Flight Center's (MSFC's) 24-foot Vacuum Chamber at the X-Ray Calibration Facility (XRCF). The AXAF was renamed CXO in 1999. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It observes x-rays from high-energy regions of the universe, such as hot gas in the remnants of exploded stars. The HRC is one of the two instruments used at the focus of CXO, where it will detect x-rays reflected from an assembly of eight mirrors. The unique capabilities of the HRC stem from the close match of its imaging capability to the focusing of the mirrors. When used with CXO mirrors, the HRC makes images that reveal detail as small as one-half an arc second. This is equivalent to the ability to read a newspaper at a distance of 1 kilometer. MSFC's XRCF is the world's largest, most advanced laboratory for simulating x-ray emissions from distant celestial objects. It produces a space-like environment in which components related to x-ray telescope imaging are tested and the quality of their performances in space is predicted. TRW, Inc. was the prime contractor for the development of the CXO and NASA's MSFC was responsible for its project management. The Smithsonian Astrophysical Observatory controls science and flight operations of the CXO for NASA from Cambridge, Massachusetts. The CXO was launched July 22, 1999 aboard the Space Shuttle Columbia (STS-93).

History of Chandra X-Ray Observatory

NASA Image and Video Library

2004-09-24

Astronomers have used an x-ray image to make the first detailed study of the behavior of high-energy particles around a fast moving pulsar. This image, from NASA's Chandra X-Ray Observatory (CXO), shows the shock wave created as a pulsar plows supersonically through interstellar space. These results will provide insight into theories for the production of powerful winds of matter and antimatter by pulsars. Chandra's image of the glowing cloud, known as the Mouse, shows a stubby bright column of high-energy particles, about four light years in length, swept back by the pulsar's interaction with interstellar gas. The intense source at the head of the X-ray column is the pulsar, estimated to be moving through space at about 1.3 million miles per hour. A cone-shaped cloud of radio-wave-emitting particles envelopes the x-ray column. The Mouse, a.k.a. G359.23-0.82, was discovered in 1987 by radio astronomers using the National Science Foundation's Very Large Array in New Mexico. G359.23-0.82 gets its name from its appearance in radio images that show a compact snout, a bulbous body, and a remarkable long, narrow, tail that extends for about 55 light years. NASA’s Marshall Space Flight Center in Huntsville, Alabama manages the Chandler program.

Space Science

NASA Image and Video Library

2003-04-09

The Eastman-Kodak mirror assembly is being tested for the James Webb Space Telescope (JWST) project at the X-Ray Calibration Facility at Marshall Space Flight Center (MSFC). In this photo, one of many segments of the mirror assembly is being set up inside the 24-ft vacuum chamber where it will undergo x-ray calibration tests. MSFC is supporting Goddard Space Flight Center (GSFC) in developing the JWST by taking numerous measurements to predict its future performance. The tests are conducted in a vacuum chamber cooled to approximate the super cold temperatures found in space. During its 27 years of operation, the facility has performed testing in support of a wide array of projects, including the Hubble Space Telescope (HST), Solar A, Chandra technology development, Chandra High Resolution Mirror Assembly and science instruments, Constellation X-Ray Mission, and Solar X-Ray Imager, currently operating on a Geostationary Operational Environment Satellite. The JWST is NASA's next generation space telescope, a successor to the Hubble Space Telescope, named in honor of NASA's second administrator, James E. Webb. It is scheduled for launch in 2010 aboard an expendable launch vehicle. It will take about 3 months for the spacecraft to reach its destination, an orbit of 940,000 miles in space.

Trail of Black Holes and Neutron Stars Points to Ancient Collision

NASA Astrophysics Data System (ADS)

2003-12-01

An image of an elliptical galaxy by NASA's Chandra X-ray Observatory has revealed a trail of black holes and neutron stars stretching more than fifty thousand light years across space. The trail of intense X-ray sources is evidence that this apparently sedate galaxy collided with another galaxy a few billion years ago. "This discovery shows that X-ray observations may be the best way to identify the ancient remains of mergers between galaxies," said Lars Hernquist of the Harvard-Smithsonian Center for Astrophysics in Cambridge (CfA), Massachusetts, and a coauthor on an article on the galaxy NGC 4261 in an upcoming issue of The Astrophysical Journal Letters. "It could be a significant tool for probing the origin of elliptical galaxies." "From the optical and radio images, we knew something unusual was going on in the nucleus of this galaxy, but the real surprise turned out to be on the outer edges of the galaxy," said Andreas Zezas, also of CfA, and lead-author of the paper on NGC 4261. "Dozens of black holes and neutron stars were strung out across space like beads on a necklace." The spectacular structure is thought to represent the aftermath of the destruction of a smaller galaxy that was pulled apart by gravitational tidal forces as it fell into NGC 4261. As the doomed galaxy fell into the larger one, large streams of gas were pulled out into long tidal tails. Shock waves generated as these tidal tails fell into the larger galaxy triggered the formation of large numbers of massive stars which over the course of a few million years evolved into neutron stars or black holes. A few of these extremely compact objects had companion stars, and became bright X-ray sources as gas from the companions was captured by the intense gravitational fields of the neutron stars and black holes. The origin of elliptical galaxies has long been a subject of intense debate among astronomers. The currently favored view is that they are produced by collisions between spiral galaxies. Computer simulations of galaxy collisions support this idea, and optical evidence of tails, shells, ripples, arcs and other structures have been interpreted as evidence for this theory. However the optical evidence rather quickly fades into the starry background of the galaxy, whereas the NGC 4261 X-ray observations show that the X-ray signature may linger for hundreds of millions of years. NGC 4261 is approximately 100 million light years away from Earth. The data for these results were taken from the Chandra archive. NGC 4261 was originally observed with the Advanced CCD Imaging Spectrometer on May 6, 2000. Other members of the research team were Pepi Fabbiano and Jon Miller, both from the CfA. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the Office of Space Science, NASA Headquarters, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Chandra X-ray Observatory

NASA Astrophysics Data System (ADS)

Elvis, M.; Murdin, P.

2002-10-01

Launched on 23 July 1999 on board the SpaceShuttle Columbia from Cape Canaveral, the ChandraX-ray Observatory is the first x-ray astronomytelescope to match the 1/2 arcsecond imagingpower and the 0.1% spectral resolving power ofoptical telescopes. Chandra is named afterSubramanian Chandrasekhar, known as Chandra, andauthor of the Chandrasekhar limit. Chandra hasbeen extremely successful and produc...

Going to Extremes: Pulsar Gives Insight on Ultra Dense Matter and Magnetic Fields

NASA Astrophysics Data System (ADS)

2004-12-01

A long look at a young pulsar with NASA's Chandra X-ray Observatory revealed unexpectedly rapid cooling, which suggests that it contains much denser matter than previously expected. The pulsar's cool temperature and the vast magnetic web of high-energy particles that surrounds it have implications for the theory of nuclear matter and the origin of magnetic fields in cosmic objects. Animation: Layers of Chandra's 3-Color Image Animation: Layers of Chandra's 3-Color Image An international team of scientists used the Chandra data to measure the temperature of the pulsar at the center of 3C58, the remains of a star observed to explode in the year 1181. Chandra's image of 3C58 also shows spectacular jets, rings and magnetized loops of high-energy particles generated by the pulsar. "We now have strong evidence that, in slightly more than 800 years, the surface of the 3C58 pulsar has cooled to a temperature of slightly less than a million degrees Celsius," said Patrick Slane of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., and lead author on a paper describing these results in the November 20, 2004 issue of The Astrophysical Journal. "A million degrees may sound pretty hot, but for a young neutron star that's like the frozen tundra in Green Bay, Wisconsin." Optical & Chandra X-ray Composite of 3C58 Optical & Chandra X-ray Composite of 3C58 Pulsars are formed when the central core of a massive star collapses to create a dense object about 15 miles across that is composed almost entirely of neutrons. Collisions between neutrons and other subatomic particles in the interior of the star produce neutrinos that carry away energy as they escape from the star. This cooling process depends critically on the density and type of particles in the interior, so measurements of the surface temperature of pulsars provide a way to probe extreme conditions where densities are so high that our current understanding of how particles interact with one another is limited. They represent the maximum densities that can be attained before the star collapses to form a black hole. The relatively cool temperature of the 3C58 pulsar, combined with evidence from the Vela pulsar and other young neutron stars, points to rapid cooling due to unexpected conditions in the neutron stars. One possibility is that more protons than expected survived the crush to neutron star densities, or perhaps an exotic form of sub-nuclear particles is responsible for more rapid cooling. Animation: Comparison of 3C58 and the Crab Nebula Animation: Comparison of 3C58 and the Crab Nebula Surrounding the pulsar is a bright doughnut-shaped, or toroidal, structure, with jet-like features extending in a perpendicular direction away from the torus. These features, which are due to radiation from extremely high energy particles produced by the pulsar, show a strong resemblance to the rings and jets around the Crab pulsar. Chandra images of the 3C58, Crab, and a growing list of other pulsars provide dramatic proof that strong electromagnetic fields around rapidly rotating neutron stars are powerful generators of high-energy particles. One of the more intriguing implications of these results is that pulsars can spin magnetic fields as well as high-energy particles far out into space. VLA Radio & Chandra X-ray Composite of 3C58 VLA Radio & Chandra X-ray Composite of 3C58 The intricate structure of X-ray loops visible in the Chandra image and radio images of 3C58 in the nebula that extends a dozen light years from the pulsar likely represents the complex magnetic field structure there. Detailed analysis and comparison of these structures with those seen in the Crab Nebula and other pulsars should help astrophysicists to better understand how magnetic fields are produced by pulsars, and on a much larger scale by disks of matter swirling into supermassive black holes in galaxies. Chandra observed 3C58, which is about 10,000 light years from Earth, for almost 100 hours between April 22-26, 2003, with its Advanced CCD Imaging Spectrometer instrument. Other members of the research team were David Helfand (Columbia University), Eric van der Swaluw (FOM Institute of Plasma Physics, the Netherlands), and Stephen Murray (Harvard-Smithsonian Center for Astrophysics). NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for NASA's Office of Space Science, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

The Mouse That Soared

NASA Astrophysics Data System (ADS)

2004-09-01

Astronomers have used an X-ray image to make the first detailed study of the behavior of high-energy particles around a fast moving pulsar. The image, from NASA's Chandra X-ray Observatory, shows the shock wave created as a pulsar plows supersonically through interstellar space. These results will provide insight into theories for the production of powerful winds of matter and antimatter by pulsars. Chandra's image of the glowing cloud, known as the Mouse, shows a stubby bright column of high-energy particles, about four light years in length, swept back by the pulsar's interaction with interstellar gas. The intense source at the head of the X-ray column is the pulsar, estimated to be moving through space at about 1.3 million miles per hour. VLA Radio Image of the Mouse, Full Field VLA Radio Image of the Mouse, Full Field A cone-shaped cloud of radio-wave-emitting particles envelopes the X-ray column. The Mouse, a.k.a. G359.23-0.82, was discovered in 1987 by radio astronomers using the National Science Foundation's Very Large Array in New Mexico. It gets its name from its appearance in radio images that show a compact snout, a bulbous body, and a remarkable long, narrow, tail that extends for about 55 light years. "A few dozen pulsar wind nebulae are known, including the spectacular Crab Nebula, but none have the Mouse's combination of relatively young age and incredibly rapid motion through interstellar space," said Bryan Gaensler of the Harvard-Smithsonian Center for Astrophysics and lead author of a paper on the Mouse that will appear in an upcoming issue of The Astrophysical Journal. "We effectively are seeing a supersonic cosmic wind tunnel, in which we can study the effects of a pulsar's motion on its pulsar wind nebula, and test current theories." Illustration of the Mouse System Illustration of the Mouse System Pulsars are known to be rapidly spinning, highly magnetized neutron stars -- objects so dense that a mass equal to that of the Sun is packed into a diameter of about 12 miles. Their formation is associated with a Type II supernova, the collapse and subsequent explosion of a massive star. The origin of a pulsar's high velocity is not known, but many astrophysicists suspect that it is directly related to the explosive circumstances involved in the birth of the pulsar. The rapid rotation and strong magnetic field of a pulsar can generate a wind of high-energy matter and antimatter particles that rush out at near the speed of light. These pulsar winds create large, magnetized bubbles of high-energy particles called pulsar wind nebulae. The X-ray and radio data on the Mouse have enabled Gaensler and his colleagues to constrain the properties of the ambient gas, to estimate the velocity of the pulsar, and to analyze the structure of the various shock waves created by the pulsar, the flow of particles away from the pulsar, and the magnetic field in the nebula. Zoom into Chandra's Image of the Mouse Zoom into Chandra's Image of the Mouse Other members of the research team were Eric van der Swaluw (FOM Institute of Physics, The Netherlands), Fernando Camilo (Columbia Univ., New York), Vicky Kaspi (McGill Univ., Montreal), Frederick K. Baganoff (MIT, Cambridge, Mass.), Farhad Yusef-Zadeh (Northwestern), and Richard Manchester (Australia Telescope National Facility). The pulsar in the Mouse was originally detected by Camilo et al. in 2002 using Australia's Parkes radio telescope. Chandra observed the Mouse on October 23 and 24, 2002. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for NASA's Office of Space Science, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Mechanical Overview of the International X-Ray Observatory

NASA Technical Reports Server (NTRS)

Robinson, David W.; McClelland, Ryan S.

2009-01-01

The International X-ray Observatory (IXO) is a new collaboration between NASA, ESA, and JAXA which is under study for launch in 2020. IXO will be a large 6600 kilogram Great Observatory-class mission which will build upon the legacies of the Chandra and XMM-Newton X-ray observatories. It combines elements from NASA's Constellation-X program and ESA's XEUS program. The observatory will have a 20-25 meter focal length, which necessitates the use of a deployable instrument module. Currently the project is actively trading configurations and layouts of the various instruments and spacecraft components. This paper will provide a snapshot of the latest observatory configuration under consideration and summarize the observatory from the mechanical engineering perspective.

Chandra Catches Early Phase of Cosmic Assembly

NASA Astrophysics Data System (ADS)

2004-08-01

A NASA Chandra X-ray Observatory image has revealed a complex of several intergalactic hot gas clouds in the process of merging. The superb Chandra spatial resolution made it possible to distinguish individual galaxies from the massive clouds of hot gas. One of the clouds, which that envelops hundreds of galaxies, has an extraordinarily low concentration of iron atoms, indicating that it is in the very early stages of cluster evolution. "We may be seeing hot intergalactic gas in a relatively pristine state before it has been polluted by gas from galaxies," said Q. Daniel Wang of the University of Massachusetts in Amherst, and lead author on an upcoming Astrophysical Journal article describing the study. "This discovery should provide valuable insight into how the most massive structures in the universe are assembled." 3-Panel Image of Abell 2125, Its Core & Galaxy C153 3-Panel Image of Abell 2125, Its Core & Galaxy C153 The complex, known as Abell 2125,is about 3 billion light years from Earth, and is seen at a time about 11 billion years after the Big Bang, when many galaxy clusters are believed to have formed. The Chandra Abell 2125 image shows several huge elongated clouds of multimillion degree gas coming together from different directions. These hot gas clouds, each of which contains hundreds of galaxies, appear to be in the process of merging to form a single massive galaxy cluster. Chandra, Hubble Space Telescope, and Very Large Array radio telescope data show that several galaxies in the Abell 2125 core cluster are being stripped of their gas as they fall through surrounding high-pressure hot gas. This stripping process has enriched the core cluster's gas in heavy elements such as iron. Abell 2125's Core & Galaxy C153 Abell 2125's Core & Galaxy C153 The gas in the pristine cloud, which is still several million light years away from the core cluster, is conspicuous for its lack of iron atoms. This anemic cloud must be in a very early evolutionary stage. The iron atoms produced by supernovas in the embedded galaxies must still be contained in and around the galaxies, perhaps in grains of dust not well mixed with the observed X-ray-emitting gas. Over time, as the cluster merges with the other clusters and the hot gas pressure increases, the dust grains will be driven from the galaxies, mixed with the hot gas, and destroyed, liberating the iron atoms. Building a massive galaxy cluster is a step-by-step enterprise that takes billions of years. Exactly how long it takes for such a cluster to form depends on many factors, such as the density of subclusters in the vicinity, the rate of the expansion of the universe, and the relative amounts of dark energy and dark matter. Chandra X-ray Image of Abell 2125, Low Energy Chandra X-ray Image of Abell 2125, Low Energy Cluster formation also involves complex interactions between the galaxies and the hot gas that may determine how large the galaxies in the cluster can ultimately become. These interactions determine how the galaxies maintain their gas content, the fuel for star formation. The observations of Abell 2125 provide a rare glimpse into the early steps in this process. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for NASA's Office of Space Science, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Chandra Uncovers New Evidence For Event Horizons Surrounding Black Holes

NASA Astrophysics Data System (ADS)

2001-01-01

SAN DIEGO -- Astronomers have used NASA's Chandra X-ray Observatory to study some of the darkest black holes yet observed. Their work strongly confirms the reality of the "event horizon," the one-way membrane around black holes predicted by Einstein's theory of relativity. The findings were presented today at the American Astronomical Society meeting by Drs. Michael Garcia, Jeffrey McClintock, Ramesh Narayan, and Stephen Murray of the Harvard-Smithsonian Center for Astrophysics and Dr. Paul Callanan of University College, Cork, Ireland. With results that fundamentally differ from earlier black hole studies, Garcia and his colleagues have shown that some recently discovered black holes are not only ultra-dense, but actually possess event horizons that "vacuum up" energy from their surroundings. "It is a bit odd to say we've discovered something by seeing almost nothing at all -- less than the smile of the Cheshire cat, so to speak," said Garcia, lead author on a paper submitted to the Astrophysical Journal, "but, in essence, this is what we have done." Using data from Chandra and previous X-ray satellites like ROSAT, the Chandra team studied a dozen "X-ray novas," so named because they occasionally erupt as brilliant X-ray sources then settle into decades of dormancy. The great outpouring of X rays is due to a stream of gas that is pulled from the surface of a Sun-like companion star onto a compact object, either a black hole or a neutron star. By comparing the energy output from the dormant X-ray novas, the team discovered that the sources with black holes emitted only one percent as much energy while dormant as did the X-ray novae with neutron stars. "The most straightforward explanation of these observations is that the black hole candidates we have studied have event horizons that swallow just about all of the energy that surrounds them," said Murray. "Indeed, one could even say that this work shows why black holes deserve to be called ‘black.’" "The event horizon is the defining characteristic of a black hole, but obviously it is very difficult to detect since any infalling material at the event horizon is observable for only an instant as it plunges inward at the speed of light," said McClintock. "The comparison of black holes and their close cousins, the neutron stars, may be the most promising way to get a handle on the event horizon." If the collapsed star is a neutron star with a solid surface, energy must be released when infalling matter strikes that surface. In contrast, if the accreting object is a black hole, there is no surface for the matter to strike. Instead, both the energy and the matter will be lost from view forever once they cross the event horizon. A small amount of energy can escape just before the matter crosses the event horizon, but the scientists believe that it should be much less than the energy released by matter hitting a neutron star surface. "Watching matter flowing into a black hole is like sitting upstream of a waterfall and watching the water seemingly vanish over the edge," said Narayan, chairman of the Harvard Astronomy Department. "However, if the waterfall were replaced by a dam -- the analog of a neutron star surface -- then the water would pile up and one would see a mighty lake". Why are dormant black hole sources a hundred times fainter than the neutron star sources? The amount of material falling towards the collapsed star and the subsequent energy release are believed to be nearly the same, whether the compact object is a black hole or a neutron star. Therefore, the remarkable difference in brightness comes, according to the team, because of the event horizon, where the inward pull of gravity becomes infinitely strong. This is in contrast to the situation of neutron stars that have a more normal surface. By observing the motion of the companion star in an X-ray nova, the mass of the collapsed star can be estimated. In some cases, this mass is more than three times that of the Sun. Over that limit, gravitational forces would crush a neutron star or any compact object into a black hole, according to Einstein’s relativity theory. This provides a crucial test for identifying black holes. "It is difficult to appreciate the astounding sensitivity of Chandra to X rays," said Callanan. "For the faintest black hole we detected, Chandra measured literally a handful of photons." The researchers used the Advanced CCD Imaging Spectrometer (ACIS) on the Chandra X-ray Observatory for exposure times varying roughly from 10,000 to 40,000 seconds per object. The ACIS X-ray camera was developed for NASA by Pennsylvania State University and MIT. NASA's Marshall Space Flight Center in Huntsville, AL, manages the Chandra program. TRW, Inc., Redondo Beach, California, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, MA. This work was supported by funds from NASA and NSF. During the AAS meeting, the scientists involved in this release can be reached at the AAS Press Room at the Town & Country Resort in San Diego, CA. The phone numbers for the Press Room are (619) 908-5057, (619) 908-5040, and (619) 908-5041 from January 8-11. Images associated with this release are available on the World Wide Web at: http://chandra.harvard.edu AND http://chandra.nasa.gov

Astronomers Take the Measure of Dark Matter in the universe

NASA Astrophysics Data System (ADS)

2001-09-01

Using NASA's Chandra X-ray Observatory, astronomers have obtained their most accurate determination to date of the amount of dark matter in galaxy clusters, the most massive objects in the universe. The results provide an important step towards a precise measurement of the total matter density of the universe. These results were presented today by Steven W. Allen of the Institute of Astronomy in Cambridge, UK at a press conference at the `Two Years of Science with Chandra' symposium in Washington, DC. Allen and his colleagues Robert W. Schmidt and Andrew C. Fabian at the Institute of Astronomy observed a carefully chosen sample of five of the largest clusters of galaxies known, whose distances range from 1.5 to 4 billion light years. The team made temperature maps of the hot multimillion-degree gas that fills the clusters. "The temperature maps can be used to determine the mass needed to prevent the hot gas from escaping the clusters" explained Allen. "We found that the stars in the galaxies and hot gas together contribute only about 13 percent of the mass. The rest must be in the form of dark matter." The nature of the dark matter is not known, but most astronomers think that it is in the form of an as yet unknown type of elementary particle that contributes to gravity through its mass but otherwise interacts weakly with normal matter. These dark matter particles are often called WIMPs, an acronym for `weakly interacting massive particles'. Clusters of galaxies are vast concentrations of galaxies, hot gas and dark matter spanning millions of light years, held together by gravity. Because of their size, clusters of galaxies are thought to provide a fair sample of the proportion of dark matter in the universe as a whole. "The implication of our results is that we live in a low-density universe" said Allen. "The total mass-density is only about thirty percent of that needed to stop the universe from expanding forever." The result reinforces recent findings from measurements of the cosmic microwave background radiation, the large-scale distribution of galaxies, and the properties of distant supernovas. The Institute of Astronomy team minimized systematic errors in their work by placing independent constraints on the masses of the clusters using data from NASA's Hubble Space Telescope and the Canada-France-Hawaii Telescope atop Mauna Kea, HI. The new Chandra results also show how the average X-ray luminosity and temperature of the hot gas varies with the mass of a cluster. These findings should allow astronomers to use the data from large cluster catalogues, for which only X-ray luminosities are generally available, to get even more accurate measurements of the mean mass density of the universe, and to understand further the processes by which clusters form and grow. The Chandra observations were carried out using the Advanced CCD Imaging Spectrometer, which was built for NASA by the Massachusetts Institute of Technology, Cambridge, and Pennsylvania State University, University Park. NASA's Marshall Space Flight Center in Huntsville, AL, manages the Chandra program, and TRW, Inc., Redondo Beach, CA, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, MA. The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. Images associated with this release are available on the World Wide Web at: http://chandra.harvard.edu AND http://chandra.nasa.gov

NASA Sees Orbiting Stars Flooding Space with Gravitational Waves

NASA Astrophysics Data System (ADS)

2005-05-01

A scientist using NASA's Chandra X-ray Observatory has found evidence that two white dwarf stars are orbiting each other in a death grip, destined to merge. The data indicate that gravitational waves are carrying energy away from the star system at a prodigious rate - making it a prime candidate for future missions designed to directly detect these subtle ripples in space-time. Einstein's General Theory of Relativity predicts that a binary star system should emit gravitational waves, which rush away at the speed of light and cause the stars to move closer together. The orbital period of this system, known as RX J0806.3+1527, or J0806, is decreasing by 1.2 milliseconds every year, a rate consistent with theory. Animation of White Dwarfs Animation of White Dwarfs The white dwarf pair in J0806 might have the smallest orbit of any known binary system with the stars only about 50,000 miles apart, a fifth of the distance from the Earth to the Moon. As the stars swirl closer together, traveling in excess of a million miles per hour, the production of gravitational waves increases. "If confirmed, J0806 could be one of the brightest sources of gravitational waves in our Galaxy," said Tod Strohmayer of NASA's Goddard Space Flight Center of Greenbelt, Md., who presents his results today at the American Astronomical Society meeting in Minneapolis, Minn. "It could be among the first to be detected directly with an upcoming space mission called LISA, the Laser Interferometer Space Antenna." White dwarfs are remnants of stars like our Sun that have used up all their fuel. Along with neutron stars and black holes, white dwarfs are called compact objects because they pack a lot of mass into a small volume. The white dwarfs in the J0806 system each have an estimated mass half that of the Sun, yet are only about the size of Earth. Chandra Light Curve of RX J0806.3+1527 Chandra Light Curve of RX J0806.3+1527 Optical and X-ray observations of J0806 show periodic variations with a period of 321.5 seconds - barely more than five minutes. The observed five-minute period in J0806 is most likely the orbital period of the white dwarf system. However the possibility that it represents the spin of one of its white dwarfs cannot yet be completely ruled out. "It's either the most compact binary known or one of the most unusual systems we've ever seen," said Strohmayer. "Either way it's got a great story to tell." Strohmayer's Chandra X-ray observations, which will be published in an upcoming issue of The Astrophysical Journal, tighten orbital decay estimates made through optical observations in recent years independently by teams led by GianLuca Israel of the Astronomical Observatory of Rome and by Pasi Hakala of the University of Helsinki. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate, Washington. Northrop Grumman of Redondo Beach, Calif., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

ACIS Door Failure Investigation and Mitigation Procedures

NASA Technical Reports Server (NTRS)

Podgorski, William A.; Tice, Neil W.; Plucinsky, Paul P.

2000-01-01

NASA's Chandra X-ray Observatory (formerly AXAF) was launched on July 23, 1999 and is currently in orbit performing scientific studies. Chandra is the third of NASA's Great Observatories to be launched, following the Hubble Space Telescope and the Compton Gamma Ray Observatory. One of four primary science instruments on Chandra, and one of only two focal plane instruments, is the Advanced CCD Imaging Spectrometer, or ACIS. The ACIS focal plane and Optical Blocking Filter (OBF) must be launched under vacuum, so a tightly sealed, functioning door and venting subsystem were implemented. The door was opened two and one-half weeks after launch (after most out-gassing of composite materials) and allowed X-rays to be imaged by the ACIS CCD's in the focal plane. A failure of this door to open on-orbit would have eliminated all ACIS capabilities, severely degrading mission science. During the final pre-flight thermal-vacuum test of the fully integrated Chandra Observatory at TRW, the ACIS door failed to open when commanded to do so. This paper describes the efforts, under considerable time pressure, by NASA, its contractors and outside review teams to investigate the failure and to develop modified hardware and procedures which would correct the problem. Of interest is the fact that the root cause of the test failure was never clearly identified despite massive effort. We ultimately focussed on hardware and procedures designed to mitigate the effects of potential, but unproven, failure modes. We describe a frequent real-world engineering situation in which one must proceed on the best basis possible in the absence of the complete set of facts.

Adjustable Grazing-Incidence X-Ray Optics

NASA Technical Reports Server (NTRS)

O'Dell, Stephen L.; Reid, Paul B.

2015-01-01

With its unique subarcsecond imaging performance, NASA's Chandra X-ray Observatory illustrates the importance of fine angular resolution for x-ray astronomy. Indeed, the future of x-ray astronomy relies upon x-ray telescopes with comparable angular resolution but larger aperture areas. Combined with the special requirements of nested grazing-incidence optics, mass, and envelope constraints of space-borne telescopes render such advances technologically and programmatically challenging. The goal of this technology research is to enable the cost-effective fabrication of large-area, lightweight grazing-incidence x-ray optics with subarcsecond resolution. Toward this end, the project is developing active x-ray optics using slumped-glass mirrors with thin-film piezoelectric arrays for correction of intrinsic or mount-induced distortions.

Galaxy in Different Lights

NASA Image and Video Library

2014-10-08

The comparison from NASA Hubble telescope and Chandra X-ray Observatory highlights how different the universe can look when viewed in other wavelengths of light. M82 is located 12 million light-years away in the Ursa Major constellation.

History of Chandra X-Ray Observatory

NASA Image and Video Library

1998-01-01

This photograph shows a TRW technician inspecting the completely assembled Chandra X-ray Observatory (CXO) in the Thermal Vacuum Chamber at TRW Space and Electronics Group of Redondo Beach, California. The CXO is formerly known as the Advanced X-Ray Astrophysics Facility (AXAF), which was renamed in honor of the late Indian-American Astronomer, Subrahmanyan Chandrasekhar in 1999. The CXO will help astronomers worldwide better understand the structure and evolution of the universe by studying powerful sources of x-rays such as exploding stars, matter falling into black holes and other exotic celestial objects. X-ray astronomy can only be done from space because Earth's atmosphere blocks x-rays from reaching the surface. The Observatory provides images that are 50 times more detailed than previous x-ray missions. At more than 45 feet in length and weighing more than 5 tons, it will be one of the largest objects ever placed in Earth orbit by the Space Shuttle. TRW, Inc. was the prime contractor and assembled and tested the observatory for NASA. The CXO program is managed by the Marshall Space Flight Center. The Observatory was launched on July 22, 1999 aboard the Space Shuttle Columbia, STS-93 mission. (Image courtesy of TRW)

History of Chandra X-Ray Observatory

NASA Image and Video Library

1999-01-01

This photograph shows TRW technicians preparing the assembled Chandra X-Ray Observatory (CXO) for an official unveiling at TRW Space and Electronics Group of Redondo Beach, California. The CXO is formerly known as the Advanced X-Ray Astrophysics Facility (AXAF), which was renamed in honor of the late Indian-American Astronomer, Subrahmanyan Chandrasekhar in 1999. The CXO will help astronomers world-wide better understand the structure and evolution of the universe by studying powerful sources of x-rays such as exploding stars, matter falling into black holes, and other exotic celestial objects. X-ray astronomy can only be done from space because Earth's atmosphere blocks x-rays from reaching the surface. The Observatory provides images that are 50 times more detailed than previous x-ray missions. At more than 45 feet in length and weighing more than 5 tons, it will be one of the largest objects ever placed in Earth orbit by the Space Shuttle. TRW, Inc. was the prime contractor and assembled and tested the observatory for NASA. The CXO program is managed by the Marshall Space Flight Center. The Observatory was launched on July 22, 1999 aboard the Space Shuttle Columbia, STS-93 mission. (Image courtesy of TRW)

Observatories Combine to Crack Open the Crab Nebula

NASA Image and Video Library

2017-12-08

Astronomers have produced a highly detailed image of the Crab Nebula, by combining data from telescopes spanning nearly the entire breadth of the electromagnetic spectrum, from radio waves seen by the Karl G. Jansky Very Large Array (VLA) to the powerful X-ray glow as seen by the orbiting Chandra X-ray Observatory. And, in between that range of wavelengths, the Hubble Space Telescope's crisp visible-light view, and the infrared perspective of the Spitzer Space Telescope. This composite image of the Crab Nebula, a supernova remnant, was assembled by combining data from five telescopes spanning nearly the entire breadth of the electromagnetic spectrum: the Very Large Array, the Spitzer Space Telescope, the Hubble Space Telescope, the XMM-Newton Observatory, and the Chandra X-ray Observatory. Credits: NASA, ESA, NRAO/AUI/NSF and G. Dubner (University of Buenos Aires) #nasagoddard #space #science

Cassiopeia A supernova

NASA Image and Video Library

2017-12-08

NASA's Fermi Closes on Source of Cosmic Rays New images from NASA's Fermi Gamma-ray Space Telescope show where supernova remnants emit radiation a billion times more energetic than visible light. The images bring astronomers a step closer to understanding the source of some of the universe's most energetic particles -- cosmic rays. This composite shows the Cassiopeia A supernova remnant across the spectrum: Gamma rays (magenta) from NASA's Fermi Gamma-ray Space Telescope; X-rays (blue, green) from NASA's Chandra X-ray Observatory; visible light (yellow) from the Hubble Space Telescope; infrared (red) from NASA's Spitzer Space Telescope; and radio (orange) from the Very Large Array near Socorro, N.M. Credit: NASA/DOE/Fermi LAT Collaboration, CXC/SAO/JPL-Caltech/Steward/O. Krause et al., and NRAO/AUI For more information: www.nasa.gov/mission_pages/GLAST/news/cosmic-rays-source.... NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe. Follow us on Twitter Join us on Facebook

Normal Spiral Galaxies Really Do Have Hot Gas in Their Halos: Chandra Observations of NGC 4013 and NGC 4217.

NASA Astrophysics Data System (ADS)

Strickland, D. K.; Colbert, E. J. M.; Heckman, T. M.; Hoopes, C. G.; Howk, J. C.; Rand, R. J.

2004-08-01

Although soft X-ray emission from million degree plasma has long been observed in the halos of starburst galaxies known to have supernova-driven galactic superwinds, X-ray observations have generally failed to detect hot halos around normal spiral galaxies. Indeed, the Milky Way and NGC 891 have historically been the only genuinely "normal" spiral galaxies with unambiguous X-ray halo detections, until now. Here we report on deep observations of NGC 4013 and NGC 4217, two Milky-Way-mass spiral galaxies with star formation rates per unit area similar to the Milky Way and NGC 891, using the Chandra X-ray observatory. Preliminary investigation of the observations clearly show extra-planar diffuse X-ray emission extending several kpc into the halo of NGC 4013. We will present the results of these observations, compare them to the non-detections of hot gas around normal spirals, and relate them to galactic fountain and IGM accretion based models for hot halos. DKS acknowledges funding from NASA through the Smithsonian Astrophysical Observatory. grant G045095X.

Kodak Mirror Assembly Tested at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

2003-01-01

This photo (rear view) is of one of many segments of the Eastman-Kodak mirror assembly being tested for the James Webb Space Telescope (JWST) project at the X-Ray Calibration Facility at Marshall Space Flight Center (MSFC). MSFC is supporting Goddard Space Flight Center (GSFC) in developing the JWST by taking numerous measurements to predict its future performance. The tests are conducted in a vacuum chamber cooled to approximate the super cold temperatures found in space. During its 27 years of operation, the facility has performed testing in support of a wide array of projects, including the Hubble Space Telescope (HST), Solar A, Chandra technology development, Chandra High Resolution Mirror Assembly and science instruments, Constellation X-Ray Mission, and Solar X-Ray Imager, currently operating on a Geostationary Operational Environment Satellite. The JWST is NASA's next generation space telescope, a successor to the Hubble Space Telescope, named in honor of NASA's second administrator, James E. Webb. It is scheduled for launch in 2010 aboard an expendable launch vehicle. It will take about 3 months for the spacecraft to reach its destination, an orbit of 940,000 miles in space.

Around Marshall

NASA Image and Video Library

2003-04-09

This photo (a frontal view) is of one of many segments of the Eastman-Kodak mirror assembly being tested for the James Webb Space Telescope (JWST) project at the X-Ray Calibration Facility at Marshall Space Flight Center (MSFC). MSFC is supporting Goddard Space Flight Center (GSFC) in developing the JWST by taking numerous measurements to predict its future performance. The tests are conducted in a vacuum chamber cooled to approximate the super cold temperatures found in space. During its 27 years of operation, the facility has performed testing in support of a wide array of projects, including the Hubble Space Telescope (HST), Solar A, Chandra technology development, Chandra High Resolution Mirror Assembly and science instruments, Constellation X-Ray Mission, and Solar X-Ray Imager, currently operating on a Geostationary Operational Environment Satellite. The JWST is NASA's next generation space telescope, a successor to the Hubble Space Telescope, named in honor of NASA's second administrator, James E. Webb. It is scheduled for launch in 2010 aboard an expendable launch vehicle. It will take about 3 months for the spacecraft to reach its destination, an orbit of 940,000 miles in space.

Fifteen Years of Chandra Operation: Scientific Highlights and Lessons Learned

NASA Technical Reports Server (NTRS)

Weisskopf, Martin C.

2014-01-01

NASA's Chandra X-Ray Observatory, designed for three years of operation with a goal of five years is now entering its 15-th year of operation. Thanks to its superb angular resolution, the Observatory continues to yield new and exciting results, many of which were totally unanticipated prior to launch. We will review some scientific highlights and present "lessons learned" from the experience of operating this great observatory.

Stellar Debris in the Large Magellanic Cloud

NASA Image and Video Library

2006-12-08

This is a composite image of N49, the brightest supernova remnant in optical light in the Large Magellanic Cloud; the image combines data from the Chandra X-ray Telescope blue and NASA Spitzer Space Telescope red.

Superbubbles Bespeak Toil and Trouble

NASA Astrophysics Data System (ADS)

2000-08-01

Like children blowing bubbles on the front porch steps, the merging Antennae Galaxies in constellation Corvus are producing massive bubbles of expanding X-ray-emitting gas at such astonishing rates that they are bumping into each other, forming "superbubbles" -- and surprising astronomers with their sheer numbers and X-ray luminosity. Drs. Giuseppina Fabbiano, Andreas Zezas and Stephen Murray of Harvard-Smithsonian Center for Astrophysics used NASA's Chandra X-ray Observatory to capture in unprecedented detail this phenomenon that is anything but child's play. In a talk presented today at the General Assembly of the International Astronomical Union in Manchester, UK, Fabbiano said that the observations provide a nearby example of the what it was like fifteen billion years ago when our universe was young and galaxies were just forming. "Galaxies were much closer together then," explained Fabbiano. "Collisions like the ones that produced the Antennae were much more common, and played a major role in shaping the galaxies we see around us today." The Antennae Galaxies, about 60 million light years from Earth (in the constellation Corvus), are two colliding and visually stunning galaxies named NGC 4038 and NGC 4039. They acquired their nickname from the wispy, antennae-like streams of gas caused by their merging, seen by early optical telescopes. Many astronomers believe our own Milky Way galaxy is the product of a merger. While galaxies may collide, the stars contained within usually do not, because stars comprise only a small fraction of the space within a galaxy. However, during a hundred-million-year collision, that makes the movement of glaciers look like a lightning bolt, one galaxy can pull the other apart gravitationally. Shock wave compression of massive clouds of gas and dust can lead to the rapid birth of millions of stars. The explosion of these stars a few million years later creates thousands of supernova remnants-bubbles of multimillion degree Celsius gas enriched with oxygen, iron and other heavy elements. These expanding bubbles, collide and coalesce to form superbubbles that are five thousand light years in diameter. Earlier data from the Rosat X-ray observatory showed extended patches of X-ray light in the Antennae, but according to Fabbiano, "We didn't know for sure that the superbubbles existed." Now scientists know that in addition to the superbubbles, the Antennae contain dozens of bright point-like sources- neutron stars and black holes-- left behind by the flurry of supernova activity. The X-rays from these sources are generated by gas that is heated to tens of millions of degrees Celsius as it streams from nearby companion stars onto neutron stars or into black holes. The ability to observe the neutron star/black hole sources and the superbubbles in the Antennae will enhance astronomers' understanding of the evolution of galaxies over the eons through the interplay of galaxy collisions, star formation, gravity and supernovas. "What we are witnessing with Chandra is galaxy ecology in action," said Andreas Zezas, "Over tens of millions of years, the superbubbles gradually enrich the galaxy's supply of oxygen and other elements, and may provide the energy needed to trigger the collapse of more clouds to form more stars and more supernovas in a continuing cycle of star birth, death and renewal." The next step will be to pin down the temperature and energy content more exactly, and to determine how much iron and other heavy elements are in the bubbles, and do some statistics based on the number of bubbles to refine the "galactic ecology." Chandra observed the Antennae with the Advanced CCD Imaging Spectrometer (ACIS) for 20 hours on December 1, 1999. The ACIS instrument was built for NASA by the Massachusetts Institute of Technology, Cambridge, and Pennsylvania State University, University Park. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program. TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass. To follow Chandra's progress, visit the Chandra site at: http://chandra.harvard.edu AND http://chandra.nasa.gov

15 Years of Chandra Observations of Capella

NASA Astrophysics Data System (ADS)

Kashyap, Vinay

2014-11-01

Capella is the strongest coronal line source accessible to Chandra. It has been cumulatively observed with gratings for over 1.2 Ms. The accumulated spectrum represents astrophysical ground truth for atomic physics calculations that is unprecedented in quality. We analyze co-added spectra to generate a comprehensive list of detectable lines and their locations, spanning two orders of magnitude in photon energy. We compare the locations of identifiable lines with locations from atomic databases ATOMDB and Chianti and characterize the uncertainties in the databases. The full line lists and comparisons will be made available at the Dataverse at http://dx.doi.org/10.7910/DVN/27084 This work is supported by Chandra grant AR0-11001X and NASA Contract NAS8-03060 to the Chandra X-Ray Center.

Jet Power and Black Hole Assortment Revealed in New Chandra Image

NASA Astrophysics Data System (ADS)

2008-01-01

A dramatic new Chandra image of the nearby galaxy Centaurus A provides one of the best views to date of the effects of an active supermassive black hole. Opposing jets of high-energy particles can be seen extending to the outer reaches of the galaxy, and numerous smaller black holes in binary star systems are also visible. The image was made from an ultra-deep look at the galaxy Centaurus A, equivalent to more than seven days of continuous observations. Centaurus A is the nearest galaxy to Earth that contains a supermassive black hole actively powering a jet. X-ray Image of Centaurus A, Labeled X-ray Image of Centaurus A, Labeled A prominent X-ray jet extending for 13,000 light years points to the upper left in the image, with a shorter "counterjet" aimed in the opposite direction. Astronomers think that such jets are important vehicles for transporting energy from the black hole to the much larger dimensions of a galaxy, and affecting the rate at which stars form there. High-energy electrons spiraling around magnetic field lines produce the X-ray emission from the jet and counterjet. This emission quickly saps the energy from the electrons, so they must be continually reaccelerated or the X-rays will fade out. Knot-like features in the jets detected in the Chandra image show where the acceleration of particles to high energies is currently occurring, and provides important clues to understanding the process that accelerates the electrons to near-light speeds. People Who Read This Also Read... NASA’s Swift Satellite Catches First Supernova in The Act of Exploding Black Holes Have Simple Feeding Habits Chandra Data Reveal Rapidly Whirling Black Holes Erratic Black Hole Regulates Itself The inner part of the X-ray jet close to the black hole is dominated by these knots of X-ray emission, which probably come from shock waves -- akin to sonic booms -- caused by the jet. Farther from the black hole there is more diffuse X-ray emission in the jet. The cause of particle acceleration in this part of the jet is unknown. Hundreds of point-like sources are also seen in the Chandra image. Many of these are X-ray binaries that contain a stellar-mass black hole and a companion star in orbit around one another. Determining the population and properties of these black holes should help scientists better understand the evolution of massive stars and the formation of black holes. Another surprise was the detection of two particularly bright X-ray binaries. These sources may contain stellar mass black holes that are unusually massive, and this Chandra observation might have caught them gobbling up material at a high rate. In this image, low-energy X-rays are colored red, intermediate-energy X-rays are green, and the highest-energy X-rays detected by Chandra are blue. The dark green and blue bands running almost perpendicular to the jet are dust lanes that absorb X-rays. This dust lane was created when Centaurus A merged with another galaxy perhaps 100 million years ago. This research was presented at the American Astronomical Society meeting on January 9th by Gregory Sivakoff (The Ohio State University). Other team members include Ralph Kraft (Harvard-Smithsonian Center for Astrophysics), Martin Hardcastle (University of Hertfordshire), Diana Worrall (University of Bristol), and Andres Jordan (Smithsonian Astrophysical Observatory). NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass.

Chandra Observation of Polaris: Census of Low-mass Companions

NASA Astrophysics Data System (ADS)

Evans, Nancy Remage; Guinan, Edward; Engle, Scott; Wolk, Scott J.; Schlegel, Eric; Mason, Brian D.; Karovska, Margarita; Spitzbart, Bradley

2010-05-01

We have observed Cepheid Polaris (α UMi A: F7 Ib [Aa] + F6 V [Ab]) with Chandra ACIS-I for 10 ks. An X-ray source was found at the location of Polaris with log LX = 28.89 erg s-1 (0.3-8 keV) and kT = 0.6 keV. A spectrum this soft could come from either the supergiant or the dwarf, as shown by comparable coronal stars. Two resolved low-mass visual companions, "C" and "D," are not physical members of the system based on the lack of X-rays (indicating an age older than the Cepheid) and inconsistent proper motions. Polaris B is not an X-ray source, consistent with its early F spectral type, and probably does not have a lower mass companion itself. A possible more distant member is identified, and an additional less plausible one. This provides a complete census of companions out to 0.1 pc covering a mass ratio range of an order of magnitude and a ΔV of nearly 15 mag. Based on observations made with the NASA Chandra Satellite.

Most Powerful Eruption in the Universe Discovered

NASA Astrophysics Data System (ADS)

2005-01-01

Astronomers have found the most powerful eruption seen in the Universe using NASA's Chandra X-ray Observatory. A supermassive black hole generated this eruption by growing at a remarkable rate. This discovery shows the enormous appetite of large black holes, and the profound impact they have on their surroundings. The huge eruption is seen in a Chandra image of the hot, X-ray emitting gas of a galaxy cluster called MS 0735.6+7421. Two vast cavities extend away from the supermassive black hole in the cluster's central galaxy. The eruption - which has lasted for 100 million years and is still going - has generated the energy equivalent to hundreds of millions of gamma-ray bursts. Animation of Eruption from Supermassive Black Hole Animation of Eruption from Supermassive Black Hole This event was caused by gravitational energy release as enormous amounts of matter fell toward a black hole. Most of the matter was swallowed, but some of it was violently ejected before being captured by the black hole. "I was stunned to find that a mass of about 300 million Suns was swallowed," said Brian McNamara of Ohio University in Athens, lead author of the study that appears in the January 6, 2005 issue of Nature. "This is almost as massive as the supermassive black hole that swallowed it." Astronomers are not sure where such large amounts of matter came from. One theory is that gas from the host galaxy catastrophically cooled and was then swallowed by the black hole. Illustration of MS 0735.6+742 Illustration of MS 0735.6+742 The energy released shows that the black hole in MS 0735 has grown very dramatically during this eruption. Previous studies suggest that other large black holes have grown very little in the recent past, and that only smaller black holes are still growing quickly. "This new result is as surprising as it is exciting", said co-author Paul Nulsen of the Harvard-Smithsonian Center of Astrophysics. "This black hole is feasting when it should be fasting." Radio emission within the cavities shows that jets from the black hole erupted to create the cavities. Gas is being pushed away from the black hole at supersonic speeds over a distance of about a million light years. The mass of the displaced gas equals about a trillion Suns, more than the mass of all the stars in the Milky Way. LA Radio & Chandra X-ray Composite of MS 0735.6+7421 VLA Radio & Chandra X-ray Composite of MS 0735.6+7421 The rapid growth of supermassive black holes is usually detected by observing very bright radiation from the centers of galaxies in the optical and X-ray wavebands, or luminous radio jets. In MS 0735 no bright central radiation is found and the radio jets are faint. Therefore, the true nature of MS 0735 is only revealed through X-ray observations of the hot cluster gas. "Until now we had no idea that this black hole was gorging itself", said co-author Michael Wise of the Massachusetts Institute of Technology. "The discovery of this eruption shows that X-ray telescopes are necessary to understand some of the most violent events in the Universe." The astronomers estimated how much energy was needed to create the cavities by calculating the density, temperature and pressure of the hot gas. By making a standard assumption, that 10% of the gravitational energy goes into launching the jets, they estimated how much material the black hole swallowed. Size Comparison of MS 0735.6+7421 & Perseus Cluster Size Comparison of MS 0735.6+7421 & Perseus Cluster Besides generating the cavities, some of the energy from this eruption should keep the hot gas around the black hole from cooling, and some of it may also generate large-scale magnetic fields in the galaxy cluster. Chandra observers have discovered other cavities in galaxy clusters, but this one is easily the largest and the most powerful. For example, the energy content here exceeds that of the Perseus cavities by 250 times, and dwarfs the cavities in M87 by a factor of 10,000. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for NASA's Office of Space Science, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Chandra HETGs Observation of the Warm Absorber in Mrk 290

NASA Astrophysics Data System (ADS)

Zhang, Shuinai; Marshall, H. L.; Ji, L. L.

2009-01-01

Four Chandra High Energy Transmission Grating spectra of Mrk 290, a bright Seyfert 1, were carried out in 2003 with a total integration time of 251 ks. The nuclear X-ray spectrum is best described by a absorbed power law of photon index Γ 1.83 plus a black body model with a temperature of 90 eV. Using the combined spectra, we detect significant absorption lines due to intervening ionized outflowing gas. Some absorption lines show a discrete velocity structure. The outflow velocity 500 km/s is comparable with that in ultraviolet band. Support for this work was provided by the National Aeronautic Space Administration through the Smithonian Astrophysics of Observation contract SV3-73016 to MIT for support of the Chandra X-ray Center, which is operated by SAO for and on behalf of NASA under contract NAS8-03060.

Kodak Mirror Assembly Tested at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

2003-01-01

The Eastman-Kodak mirror assembly is being tested for the James Webb Space Telescope (JWST) project at the X-Ray Calibration Facility at Marshall Space Flight Center (MSFC). In this photo, one of many segments of the mirror assembly is being set up inside the 24-ft vacuum chamber where it will undergo x-ray calibration tests. MSFC is supporting Goddard Space Flight Center (GSFC) in developing the JWST by taking numerous measurements to predict its future performance. The tests are conducted in a vacuum chamber cooled to approximate the super cold temperatures found in space. During its 27 years of operation, the facility has performed testing in support of a wide array of projects, including the Hubble Space Telescope (HST), Solar A, Chandra technology development, Chandra High Resolution Mirror Assembly and science instruments, Constellation X-Ray Mission, and Solar X-Ray Imager, currently operating on a Geostationary Operational Environment Satellite. The JWST is NASA's next generation space telescope, a successor to the Hubble Space Telescope, named in honor of NASA's second administrator, James E. Webb. It is scheduled for launch in 2010 aboard an expendable launch vehicle. It will take about 3 months for the spacecraft to reach its destination, an orbit of 940,000 miles in space.

Chandra Sees Shape of Universe During Formative, Adolescent Years

NASA Astrophysics Data System (ADS)

2003-03-01

Scientists using NASA's Chandra X-ray Observatory have taken a snapshot of the adolescent universe from about five billion years ago when the familiar web-like structure of galaxy chains and voids first emerged. The observation reveals distant and massive galaxies dotting the sky, clustered together under the gravitational attraction of deep, unseen pockets of dark matter. This provides important clues of how the universe matured from its chaotic beginnings to its elegant structure we see today. These results are presented today in a press conference at the meeting of the High Energy Astrophysics Division of the American Astronomical Society at Mt. Tremblant, Quebec. "Piece by piece, we are assembling a photo album of the universe through the ages," said Yuxuan Yang, a doctorate candidate at the University of Maryland, College Park, who conducted the analysis. "Last month we saw a picture of the infant universe taken with the Wilkinson Microwave Anisotropy Probe. Now we can add a snapshot of its adolescence." The Chandra observation traced a patch of sky known as the Lockman Hole in the constellation Ursa Major (containing the Big Dipper). Chandra saw a rich density of active galaxies, seven times denser than what has been detected in previous optical and radio surveys at similar distances. This provides the clearest picture yet at the large-scale structure of the universe at such distances (and age), according to Dr. Richard Mushotzky of NASA Goddard Space Flight Center in Greenbelt, Md., who led the observation. Lockman Hole JPEG, TIFF, PS An image that has been "blurred" to allow better view of the structures outlined by the X-ray sources. The color represents the spectra of the AGN. The red color indicates the sources on average radiates at longer wavelength while green and blue colors indicates the sources radiates at shorter wavelength. The Green and blue regions appear to form a wall, or shows more lumpiness than the "red" sources. If one could capture the universe in a box, scientists say that the large scale structure -- that is, galaxies, galaxy clusters and voids of seemingly empty space -- takes the appearance of a web. Galaxies and intergalactic gas are strung like pearls on unseen filaments of dark matter, which comprises over 85 percent of all matter. Galaxies are attracted to dark matter's gravitational potential. Dark matter does not shine, like ordinary matter made of atoms, and may very well be intrinsically different. Chandra's observation of distant galaxies in the Lockman Hole, spread out over several billion light years from Earth, essentially maps the distribution of dark matter. This provides clues to how the universe grew. "We are seeing the universe during its formative years," said Mushotzky. "This is billions of years after galaxies were born, during a period when the universe began to take on the trappings of an adult." The galaxies that the team saw with Chandra were either dim or altogether undetectable with optical and radio telescopes. This may be because they are enshrouded in dust and gas, which blocks radio waves and optical light. X-rays, a higher-energy form of light, can penetrate this shroud. "Chandra is the only X-ray telescope with a spatial resolution comparable to the optical telescopes," according to Dr. Amy Barger of University of Wisconsin at Madison, who led the optical follow-up with the 10-meter Keck telescope on Mauna Kea, Hawaii. "This is critical to unambiguously identify the optical counterparts of the X-ray sources and measuring distances, or redshifts. This allows scientists to create a three-dimensional image of the large-scale structure." The additive effect of future deep and long Chandra surveys over the next few years will provide an even sharper picture of the young universe. Other scientists who participated in this observation include Drs. Len Cowie and Dave Sanders of the University of Hawaii, and Ph.D. student Aaron Steffen of the University of Wisconsin at Madison. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program, and TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass., for the Office of Space Science at NASA Headquarters, Washington.

Chandra Discovers the X-ray Signature of a Powerful Wind from a Galactic Microquasar

NASA Astrophysics Data System (ADS)

2000-11-01

NASA's Chandra X-ray Observatory has detected, for the first time in X rays, a stellar fingerprint known as a P Cygni profile--the distinctive spectral signature of a powerful wind produced by an object in space. The discovery reveals a 4.5-million-mile-per-hour wind coming from a highly compact pair of stars in our galaxy, report researchers from Penn State and the Massachusetts Institute of Technology in a paper they will present on 8 November 2000 during a meeting of the High-Energy Astrophysics Division of the American Astronomical Society in Honolulu, Hawaii. The paper also has been accepted for publication in The Astrophysical Journal Letters. "To our knowledge, these are the first P Cygni profiles reported in X rays," say researchers Niel Brandt, assistant professor of astronomy and astrophysics at Penn State, and Norbert S. Schulz, research scientist at the Massachusetts Institute of Technology. The team made the discovery during their first observation of a binary-star system with the Chandra X-ray Observatory, which was launched into space in July 1999. The system, known as Circinus X-1, is located about 20,000 light years from Earth in the constellation Circinus near the Southern Cross. It contains a super-dense neutron star in orbit around a normal fusion-burning star like our Sun. Although Circinus X-1 was discovered in 1971, many properties of this system remain mysterious because Circinus X-1 lies in the galactic plane where obscuring dust and gas have blocked its effective study in many wavelengths. The P Cygni spectral profile, previously detected primarily at ultraviolet and optical wavelengths but never before in X rays, is the textbook tool astronomers rely on for probing stellar winds. The profile looks like the outline of a roller coaster, with one really big hill and valley in the middle, on a data plot with velocity on one axis and the flow rate of photons per second on the other. It is named after the famous star P Cygni, in which such profiles have been observed for over one hundred years. "When you see a P Cygni profile, you immediately know the object you are observing is producing a powerful outflow," Brandt says. Chandra is the first X-ray observatory capable of capturing data of sufficiently high resolution to reveal an X-ray P Cygni profile. Brandt and Schulz say their discovery occurred because they were able to use Chandra continuously for one-third of a day to observe Circinus X-1, plus its signal in X rays is generally very bright, partly because it is relatively nearby in our own Galaxy. P Cygni lines at ultraviolet or optical wavelengths had not been previously seen from Circinus X-1 because a large amount of dust in the galactic plane lies between Earth and this system and this dust is an efficient absorber of ultraviolet and optical light. However, the energetic X rays created by Circinus X-1 could easily penetrate through the obscuring dust and gas--similar to the way medical X-rays on Earth can penetrate through people's bodies. "We were hoping to detect some kind of X-ray line emission from the accreting neutron star in Circinus X-1, but it caught us totally by surprise to observe a complex emission structure like a P Cygni profile in high-energy X rays." schulz says. "This detection clearly marks a new area in X-ray astrophysics, where we will be able to study dynamical structures in the universe like we currently do at ultraviolet or optical wavelengths." Brandt and Schulz used two of Chandra's instruments, known together as the High-Energy Transmission Grating Spectrometer (HETGS), to detect the X rays and produce a high-resolution X-ray spectrum of Circinus X-1. This spectrum is analogous to the rainbow we can see at optical wavelengths. "Chandra's X-ray spectrum is 50 times more detailed than previous X-ray observatories could obtain," Schulz says. First, the super-fine transmission gratings acted like a prism to separate the X-rays into discrete energy bands. Then, the Advanced CCD Imaging Spectrometer (ACIS) was used as a camera to record the X-ray spectral data, which computers processed and plotted onto a graph, revealing the P Cygni signature. Specific elements, such as silicon or iron, emit specific X-ray wavelengths, revealing their presence in the emitting material to astronomers. Before the observation with Chandra, astronomers knew the force of gravity in an X-ray binary system strips material off the surface of the normal star and then pulls this material toward the surface of the super-dense neutron star, forming a relatively flat spiraling cloud of gas called an accretion disk. The detailed Chandra data revealed, in addition, that the radiation and rotational forces in the Circinus X-1 disk are blasting some of the inward-spiraling gas back out into space in a powerful wind, which creates the P Cygni lines in the object's spectrum. P Cygni profiles carry much diagnostic information that is hard to obtain in other ways--such as how fast the wind is moving, how much material it contains, how dense it is, and its chemical composition. "The wind coming out of Circinus X-1 is composed of gas that contains highly ionized atoms of silicon, neon, iron, magnesium, and sulfur, and its peak observed velocity is about 4.5 million miles per hour--so fast it would cross the entire radius of the Earth in about three seconds," Brandt reports. The astronomers used Doppler techniques that detect positive velocities from material moving away from Earth, with signals shifted toward the red end of the spectrum, and negative velocities from material that is coming toward Earth, with signals shifted toward the blue end of the spectrum. "We learned these two stars clearly interact dramatically with each other while this wind is blowing outward at high velocity, which appears to be causing certain properties of the wind to change over time," Schulz says. The researchers produced a time-lapse movie of one of their spectra, which is available on the World Wide Web, along with other information about the discovery, at http://www.astro.psu.edu/users/niel/cirx1/cirx1.html. A binary-star system 20,000 light years from Earth in the constellation of Circinus. Animation showing the strong variability over time of one of the P Cygni spectral lines seen by Chandra from Circinus X-1 (Click Image to View Animation) Credit: Niel Brandt and Norbert Schulz (Note: This animation is the same as the one referred to in the above paragraph) Atoms irradiated with energetic X-rays can emit as well as absorb them at specific wavelengths. Whether astronomers observe emission or absorption depends on the state and environment of the irradiated atoms, so these processes carry vital information about the emitting and absorbing material. Regarding the time-lapse movie, Schulz commented "You can see this profile flipping up and down between a strong emission line on the red side and a strong absorption line on the blue side. We don't yet fully understand what this means, but it does indicate the dynamic nature of this system. We see indications that sometimes either the emitting or the absorbing region gets obscured by matter so thick that not even X rays can penetrate it." The researchers say one reason their discovery that Circinus X-1 has a high-velocity wind is important is that this small two-star system now has striking similarities with a type of luminous active galaxy known as a broad-absorption-line quasar. Broad-absorption-line quasars are galaxies containing a violent centers powered by supermassive black holes. "This type of galaxy has an accretion disk circling its black hole plus very powerful winds created when radiation pushes material off of the disk and out into space," Brandt says. "The disk winds from broad-absorption-line quasars create P Cygni lines in the spectra of these objects. Circinus X-1, with the newly detected X-ray P Cygni profiles, appears in many ways to be a microscopic version of a broad-absorption-line quasar." "Although a typical AGN has a roughly ten-million-solar-mass black hole at its center while the Circinus X-1 system has a neutron star only slightly more massive than our Sun, both systems must obey the same laws of physics," Brandt says. "Gas is gas and gravity is gravity and that's all there is to it--you put gas and gravity together and they make a disk and often, apparently, a disk-generated wind." The researchers hope X-ray P Cygni profiles will be found to be a fairly common property of X-ray binaries containing neutron stars and black holes. "If we can find X-ray P Cygni profiles in more systems, we can learn a great deal about the geometry and the dynamics of the winds these systems emit," Schulz says. "Due to the penetrating nature of X rays, X-ray P Cygni lines have the significant advantage that they can be used to probe winds even from systems that are heavily obscured by dust along the line of sight." The High-Energy Transmission Grating Spectrometer was built by the Massachusetts Institute of Technology with Bruno Rossi Professor Claude Canizares as Principal Investigator. The ACIS X-ray camera was conceived and developed for NASA by Penn State and the Massachusetts Institute of Technology under the leadership of Gordon Garmire, Evan Pugh Professor of Astronomy and Astrophysics at Penn State. The observation of Circinus X-1 was part of the first round of Chandra's guest observer program. The guest observer program is a competitive one open to the World science community. NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program. TRW Inc., Redondo Beach, California, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Massachusetts. Circinus X-1 Handout Constellation Circinus To follow Chandra's progress, visit the Chandra site at: http://chandra.harvard.edu AND http://chandra.nasa.gov This research was supported by the Chandra X-ray Center, the Alfred P. Sloan Foundation, and the Smithsonian Astrophysical Observatory. This is a joint press release from Penn State and the Massachusetts Institute of Technology Digital images and movies are available on the World Wide Web at http://www.astro.psu.edu/users/niel/cirx1/cirx1.html Science Contacts: Niel Brandt: 814-865-3509 Norbert S. Schulz: 617-258-5767 Barbara K. Kennedy (PIO at Penn State): 814-863-4682 Deborah Halber (PIO at MIT): 617-253-2700 or 617-258-9276

The Chandra Source Catalog: Statistical Characterization

NASA Astrophysics Data System (ADS)

Primini, Francis A.; Nowak, M. A.; Houck, J. C.; Davis, J. E.; Glotfelty, K. J.; Karovska, M.; Anderson, C. S.; Bonaventura, N. R.; Chen, J. C.; Doe, S. M.; Evans, I. N.; Evans, J. D.; Fabbiano, G.; Galle, E. C.; Gibbs, D. G., II; Grier, J. D.; Hain, R.; Hall, D. M.; Harbo, P. N.; He, X.; Lauer, J.; McCollough, M. L.; McDowell, J. C.; Miller, J. B.; Mitschang, A. W.; Morgan, D. L.; Nichols, J. S.; Plummer, D. A.; Refsdal, B. L.; Rots, A. H.; Siemiginowska, A. L.; Sundheim, B. A.; Tibbetts, M. S.; van Stone, D. W.; Winkelman, S. L.; Zografou, P.

2009-09-01

The Chandra Source Catalog (CSC) will ultimately contain more than ˜250000 x-ray sources in a total area of ˜1% of the entire sky, using data from ˜10000 separate ACIS and HRC observations of a multitude of different types of x-ray sources (see Evans et al. this conference). In order to maximize the scientific benefit of such a large, heterogeneous dataset, careful characterization of the statistical properties of the catalog, i.e., completeness, sensitivity, false source rate, and accuracy of source properties, is required. Our Characterization efforts include both extensive simulations of blank-sky and point source datasets, and detailed comparisons of CSC results with those of other x-ray and optical catalogs. We present here a summary of our characterization results for CSC Release 1 and preliminary plans for future releases. This work is supported by NASA contract NAS8-03060 (CXC).

Chandra Finds Evidence for Swarm of Black Holes Near the Galactic Center

NASA Astrophysics Data System (ADS)

2005-01-01

A swarm of 10,000 or more black holes may be orbiting the Milky Way's supermassive black hole, according to new results from NASA's Chandra X-ray Observatory. This would represent the highest concentration of black holes anywhere in the Galaxy. These relatively small, stellar-mass black holes, along with neutron stars, appear to have migrated into the Galactic Center over the course of several billion years. Such a dense stellar graveyard has been predicted for years, and this represents the best evidence to date of its existence. The Chandra data may also help astronomers better understand how the supermassive black hole at the center of the Milky Way grows. The discovery was made as part of Chandra's ongoing program of monitoring the region around Sagittarius A* (Sgr A*), the supermassive black hole at the center of the Milky Way. It was announced today by Michael Muno of the University of California, Los Angeles (UCLA) at a meeting of the American Astronomical Society in San Diego, CA. Animation: Sequence Showing Evidence of Black Hole Swarm in Context Animation: Sequence Showing Evidence of Black Hole Swarm in Context Among the thousands of X-ray sources detected within 70 light years of Sgr A*, Muno and his colleagues searched for those most likely to be active black holes and neutron stars by selecting only the brightest sources that also exhibited large variations in their X-ray output. These characteristics identify black holes and neutron stars that are in binary star systems and are pulling matter from nearby companion stars. Of the seven sources that met these criteria, four are within three light years of Sgr A*. "Although the region around Sgr A* is crowded with stars, we expected that there was only a 20 percent chance that we would find even one X-ray binary within a three-light-year radius," said Muno. "The observed high concentration of these sources implies that a huge number of black holes and neutron stars have gathered in the center of the Galaxy." Mark Morris, also of UCLA and a coauthor on the present work, had predicted a decade ago that a process called dynamical friction would cause stellar black holes to sink toward the center of the Galaxy. Black holes are formed as remnants of the explosions of massive stars and have masses of about 10 suns. As black holes orbit the center of the Galaxy at a distance of several light years, they pull on surrounding stars, which pull back on the black holes. Combined Chandra X-ray Image of Galactic Center X-ray Binaries Combined Chandra X-ray Image of Galactic Center X-ray Binaries The net effect is that black holes spiral inward, and the low-mass stars move out. From the estimated number of stars and black holes in the Galactic Center region, dynamical friction is expected to produce a dense swarm of 20,000 black holes within three light years of Sgr A*. A similar effect is at work for neutron stars, but to a lesser extent because they have a lower mass. Once black holes are concentrated near Sgr A*, they will have numerous close encounters with normal stars there, some of which are in binary star systems. The intense gravity of a black hole can induce an ordinary star to "change partners" and pair up with the black hole while ejecting its companion. This process and a similar one for neutron stars are expected to produce several hundreds of black hole and neutron star binary systems. "If only one percent of these binary systems are X-ray active each year, they can account for the sources we see," said Eric Pfahl of the University of Virginia in Charlottesville and a coauthor of a paper describing these results that has been submitted to the Astrophysical Journal Letters. "Although the evidence is mostly circumstantial, it makes a strong case for the existence of a large population of neutron stars and stellar-mass black holes within three light-years of the center of our Galaxy." Galactic Center X-ray Binaries in Context Galactic Center X-ray Binaries in Context The black holes and neutron stars in the cluster are expected to gradually be swallowed by the supermassive black hole, Sgr A*, at a rate of about one every million years. At this rate, about 10,000 black holes and neutron stars would have been captured in a few billion years, adding about 3 percent to the mass of the central supermassive black hole, which is currently estimated to contain the mass of 3.7 million suns. In the meantime, the acceleration of low-mass stars by black holes will eject low-mass stars from the central region. This expulsion will reduce the likelihood that normal stars will be captured by the central supermassive black hole. This may explain why the central regions of some galaxies, including the Milky Way, are fairly quiet even though they contain a supermassive black hole. The region analyzed in this research near Sgr A* has been observed 16 times between 1999 and 2004 using Chandra's Advanced CCD Imaging Spectrometer (ACIS) instrument. Other members of the research team include Frederick K. Baganoff (Massachusetts Institute of Technology), Niel Brandt (Penn State), Andrea Ghez and Jessica Lu (UCLA). NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate, Washington. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Bayesian Multiscale Analysis of X-Ray Jet Features in High Redshift Quasars

NASA Astrophysics Data System (ADS)

McKeough, Kathryn; Siemiginowska, A.; Kashyap, V.; Stein, N.

2014-01-01

X-ray emission of powerful quasar jets may be a result of the inverse Compton (IC) process in which the Cosmic Microwave Background (CMB) photons gain energy by interactions with the jet’s relativistic electrons. However, there is no definite evidence that IC/CMB process is responsible for the observed X-ray emission of large scale jets. A step toward understanding the X-ray emission process is to study the Radio and X-ray morphologies of the jet. We implement a sophisticated Bayesian image analysis program, Low-count Image Reconstruction and Analysis (LIRA) (Esch et al. 2004; Conners & van Dyk 2007), to analyze jet features in 11 Chandra images of high redshift quasars (z ~ 2 - 4.8). Out of the 36 regions where knots are visible in the radio jets, nine showed detectable X-ray emission. We measured the ratios of the X-ray and radio luminosities of the detected features and found that they are consistent with the CMB radiation relationship. We derived a range of the bulk lorentz factor (Γ) for detected jet features under the CMB jet emission model. There is no discernible trend of Γ with redshift within the sample. The efficiency of the X-ray emission between the detected jet feature and the corresponding quasar also shows no correlation with redshift. This work is supported in part by the National Science Foundation REU and the Department of Defense ASSURE programs under NSF Grant no.1262851 and by the Smithsonian Institution, and by NASA Contract NAS8-39073 to the Chandra X-ray Center (CXC). This research has made use of data obtained from the Chandra Data Archive and Chandra Source Catalog, and software provided by the CXC in the application packages CIAO, ChIPS, and Sherpa. We thank Teddy Cheung for providing the VLA radio images. Connors, A., & van Dyk, D. A. 2007, Statistical Challenges in Modern Astronomy IV, 371, 101 Esch, D. N., Connors, A., Karovska, M., & van Dyk, D. A. 2004, ApJ, 610, 1213

Flickering Quasar Helps Chandra Measure the Expansion Rate of the universe

NASA Astrophysics Data System (ADS)

2000-11-01

Astronomers using the Chandra X-ray Observatory have identified a flickering, four-way mirage image of a distant quasar. A carefully planned observation of this mirage may be used to determine the expansion rate of the universe as well as to measure the distances to extragalactic objects, arguably two of the most important pursuits in modern astronomy. quasar RX J0911.4+0551 This figure is a composite of the X-ray image of the gravitational lens RX J0911.4+551 (top panel) and the light curves of the lensed images A2 (left panel) and A1 (right panel). Credit: NASA George Chartas, senior research associate at The Pennsylvania State University (Penn State) and Marshall W. Bautz, principal research scientist at the Massachusetts Institute of Technology (MIT) Center for Space Research, present their findings today at the meeting of the High Energy Astrophysics Division of the American Astronomical Society in Honolulu, Hawaii. "With a carefully planned follow-up, the Chandra observation of quasar RX J0911.4+0551 may lead to a measurement of the Hubble constant, the expansion rate of the universe, in less than a day," said Chartas. The observation would be done not with mirrors but with mirages--four images of a single quasar that capture the quasar's light at different moments of time due to the speed of light and the location of the mirages. Quasars are extremely distant galaxies with cores that glow with the intensity of 10 trillion Suns, a phenomenon likely powered by a supermassive black hole in the heart of the galaxy. This single "point source" image of a quasar may appear as four or five sources when the quasar--from our vantage point on Earth--is behind a massive intervening deflector, such as a dim galaxy. A mirage of images form when the gravity of the intervening deflector forces light rays to bend and take different paths to reach us. The time it takes for light to reach us from the distant object will depend on which path a ray decides to take. "An intervening galaxy can act as a lens," said Bautz. "Now imagine that the distant lensed quasar suddenly became brighter. The mirage images of the quasar will brighten up at different times depending on the difference in the light travel delay." Unlike ordinary galaxies, quasars do vary greatly in their intensity, especially in the X-ray waveband, said Gordon Garmire, Evan Pugh Professor of Astronomy and Astrophysics at Penn State. This is caused by the violent and erratic flow of gas into the black hole that is powering the quasar. In quasar RX J0911.4+0551, the astronomers saw a sudden brightening of X-ray intensity that lasted for about 2,000 seconds. This was observed in one of the four mirage images. Measuring the time-delay of the 2,000-second flare--or any flare-- from mirage to mirage can provide the absolute distance to the deflector (intervening galaxy) and can thus be used to estimate the expansion rate of the universe. Sjur Refsdal first proposed this promising method in 1964. The method avoids many uncertainties associated with the classic distance-ladder technique used to measure objects and the Hubble constant. The main difficulty in measuring time-delays is that the brightness of each image has to be carefully monitored over several periods of the time-delay. Also, the quasar has to show sufficient variability over time scales smaller than the time-delay. Most attempts to measure time-delays until now have been made in the optical and radio bands. The modest variability of quasars in these wavebands, however, has made it extremely difficult to place accurate constraints on time-delays. X-ray observations of gravitationally lensed quasars, on the other hand, show strong variability over time scales of hours to days. For example, it has taken almost 20 years of optical and radio monitoring to obtain a universal accepted time-delay for the lensed quasar Q0957+561 to an accuracy of 3percent. Chandra has the potential, the team has found, to determine the time-delay in one observation. "Based on computer models developed at Penn State and MIT, we have identified about ten gravitational lens systems with time-delays of less than a day," said Chartas. "One long observation of each source with a superior X-ray telescope could provide enough data to nail down the Hubble constant in the blink of an eye." The team is planning to apply the gravitational-lens method in the near future to several of these systems using the Chandra and XMM-Newton X-ray observatories. The Chandra observations of quasar RX J0911.4+0551 were made on November 2, 1999, using the Advanced CCD Imaging Spectrometer (ACIS). The effort involved several scientists from Penn State and MIT. ACIS was conceived and developed for NASA by Penn State and MIT under Garmire's leadership. NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program. TRW, Inc., in Redondo Beach, California, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Massachusetts. RX J0911.4+551 Handout Constellation Hydra To follow Chandra's progress, visit the Chandra site at: http://chandra.harvard.edu AND http://chandra.nasa.gov

Space Movie Reveals Shocking Secrets Of The Crab Pulsa

NASA Astrophysics Data System (ADS)

2002-09-01

Just when it seemed like the summer movie season had ended, two of NASA's Great Observatories have produced their own action movie. Multiple observations made over several months with NASA's Chandra X-ray Observatory and the Hubble Space Telescope captured the spectacle of matter and antimatter propelled to near the speed of light by the Crab pulsar, a rapidly rotating neutron star the size of Manhattan. "Through this movie, the Crab Nebula has come to life," said Jeff Hester of Arizona State University in Tempe, lead author of a paper in the September 20th issue of The Astrophysical Journal Letters. "We can see how this awesome cosmic generator actually works." The Crab was first observed by Chinese astronomers in 1054 A.D. and has since become one of the most studied objects in the sky. By combining the power of both Chandra and Hubble, the movie reveals features never seen in still images. By understanding the Crab, astronomers hope to unlock the secrets of how similar objects across the universe are powered. Crab Nebula Composite Image Crab Nebula Composite Image Bright wisps can be seen moving outward at half the speed of light to form an expanding ring that is visible in both X-ray and optical images. These wisps appear to originate from a shock wave that shows up as an inner X-ray ring. This ring consists of about two dozen knots that form, brighten and fade, jitter around, and occasionally undergo outbursts that give rise to expanding clouds of particles, but remain in roughly the same location. "These data leave little doubt that the inner X-ray ring is the location of the shock wave that turns the high-speed wind from the pulsar into extremely energetic particles," said Koji Mori of Penn State University in University Park, a coauthor of the paper. Another dramatic feature of the movie is a turbulent jet that lies perpendicular to the inner and outer rings. Violent internal motions are obvious, as is a slow motion outward into the surrounding nebula of particles and magnetic field. "The jet looks like steam from a high pressure boiler," said David Burrows of Penn State, another coauthor of the paper. "Except when you realize you are looking at a stream of matter and anti-matter electrons moving at half the speed of light!" Time-Lapse Movie Of Crab Pulsar Wind Time-Lapse Movie Of Crab Pulsar Wind The inner region of the Crab Nebula around the pulsar was observed with Hubble on 24 occasions between August 2000 and April 2001 at 11-day intervals, and with Chandra on eight occasions between November 2000 and April 2001. The Crab was observed with Chandra's Advanced CCD Imaging Spectrometer and Hubble's Wide-Field Planetary Camera. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program, and TRW, Inc., Redondo Beach, Calif., is the prime contractor. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass. The Space Telescope Science Institute is operated by the Association of Universities for Research in Astronomy, Inc. (AURA), for NASA, under contract with the Goddard Space Flight Center, Greenbelt, Md. The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency (ESA).

Dark Matter Reality Check: Chandra Casts Cloud On Alternative Theory

NASA Astrophysics Data System (ADS)

2002-10-01

New evidence from NASA's Chandra X-ray Observatory challenges an alternative theory of gravity that eliminates the need for dark matter. The observation also narrows the field for competing forms of dark matter, the elusive material thought to be the dominant form of matter in the universe. An observation of the galaxy NGC 720 shows it is enveloped in a slightly flattened, or ellipsoidal cloud of hot gas that has an orientation different from that of the optical image of the galaxy. The flattening is too large to be explained by theories in which stars and gas are assumed to contain most of the mass in the galaxy. "The shape and orientation of the hot gas cloud require it to be confined by an egg-shaped dark matter halo," said David Buote of the University of California, Irvine, and lead author of a report on this research in the 2002 September 20 issue of The Astrophysical Journal. "This means that dark matter is not just an illusion due to a shortcoming of the standard theory of gravity - it is real." According to the generally accepted standard theory of gravity, the hot X-ray cloud would need an additional source of gravity - a halo of dark matter - to keep the hot gas from expanding away. The mass of dark matter required would be about five to ten times the mass of the stars in the galaxy. If the dark matter tracked the optical light from the stars in the galaxy, the hot X-ray cloud would be more round than it is. The flattened shape of the hot gas cloud requires a flattened dark matter halo. An alternative theory of gravity called MOND, for Modified Newtonian Dynamics, was proposed in 1983 by Mordecai Milgrom of the Weizmann Institute in Israel, and has remained viable over the years. MOND does away with the need for dark matter by modifying the theory where the acceleration produced by gravity is very small, such as the outskirts of galaxies. However, MOND cannot explain the Chandra observation of NGC 720. This is apparently the first dynamical evidence that has successfully distinguished dark matter from MOND. The researchers also found that the Chandra data fit predictions of the cold dark matter theories, according to which dark matter consists of slowly moving particles, which interact with each other and "normal" matter only through gravity. Other forms of dark matter, such as self-interacting dark matter, and cold molecular dark matter, are not consistent with the observation in that they require a dark matter halo that is too round or too flat, respectively. "Chandra's ability to precisely identify and locate the point-like sources contaminating the diffuse emission in the X-ray image was absolutely essential," said Buote. "Only then could we make accurate measurements of the shape and orientation of the X-ray image contours." The conclusion from the Chandra data that NGC 720 possesses a dark matter halo assumes that the hot gas cloud has not been unduly disturbed by collisions or mergers with other galaxies in the last 100 million years. The lack of evidence of such activity indicates that this assumption is valid. Chandra observed NGC 720, which is about 80 million light years from Earth, for 11 hours with the Advanced CCD Imaging Spectrometer (ACIS). Other members of the team include Tesla Jeltema and Claude Canizares of Massachusetts Institute of Technology (MIT) in Cambridge, and Gordon Garmire of Pennsylvania State University in University Park. Penn State and MIT developed the instrument for NASA. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program, and TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass.

NASA's Great Observatories Celebrate International Year of Astronomy

NASA Astrophysics Data System (ADS)

2009-11-01

A never-before-seen view of the turbulent heart of our Milky Way galaxy is being unveiled by NASA on Nov. 10. This event will commemorate the 400 years since Galileo first turned his telescope to the heavens in 1609. In celebration of this International Year of Astronomy, NASA is releasing images of the galactic center region as seen by its Great Observatories to more than 150 planetariums, museums, nature centers, libraries, and schools across the country. The sites will unveil a giant, 6-foot-by-3-foot print of the bustling hub of our galaxy that combines a near-infrared view from the Hubble Space Telescope, an infrared view from the Spitzer Space Telescope, and an X-ray view from the Chandra X-ray Observatory into one multiwavelength picture. Experts from all three observatories carefully assembled the final image from large mosaic photo surveys taken by each telescope. This composite image provides one of the most detailed views ever of our galaxy's mysterious core. Participating institutions also will display a matched trio of Hubble, Spitzer, and Chandra images of the Milky Way's center on a second large panel measuring 3 feet by 4 feet. Each image shows the telescope's different wavelength view of the galactic center region, illustrating not only the unique science each observatory conducts, but also how far astronomy has come since Galileo. The composite image features the spectacle of stellar evolution: from vibrant regions of star birth, to young hot stars, to old cool stars, to seething remnants of stellar death called black holes. This activity occurs against a fiery backdrop in the crowded, hostile environment of the galaxy's core, the center of which is dominated by a supermassive black hole nearly four million times more massive than our Sun. Permeating the region is a diffuse blue haze of X-ray light from gas that has been heated to millions of degrees by outflows from the supermassive black hole as well as by winds from massive stars and by stellar explosions. Infrared light reveals more than a hundred thousand stars along with glowing dust clouds that create complex structures including compact globules, long filaments, and finger-like "pillars of creation," where newborn stars are just beginning to break out of their dark, dusty cocoons. The unveilings will take place at 152 institutions nationwide, reaching both big cities and small towns. Each institution will conduct an unveiling celebration involving the public, schools, and local media. The Astrophysics Division of NASA's Science Mission Directorate supports the International Year of Astronomy Great Observatories image unveiling. The project is a collaboration among the Space Telescope Science Institute in Baltimore, Md., the Spitzer Science Center in Pasadena, Calif., and the Chandra X-ray Center in Cambridge, Mass. Images of the Milky Way galactic center region and a list of places exhibiting these images can be found at: http://hubblesite.org/news/2009/28 & http://www.nasa.gov/hubble http://spitzer.caltech.edu & http://www.nasa.gov/spitzer http://chandra.harvard.edu & http://www.nasa.gov/chandra http://astronomy2009.nasa.gov

Chandra and the VLT Jointly Investigate the Cosmic X-Ray Background

NASA Astrophysics Data System (ADS)

2001-03-01

Summary Important scientific advances often happen when complementary investigational techniques are brought together . In the present case, X-ray and optical/infrared observations with some of the world's foremost telescopes have provided the crucial information needed to solve a 40-year old cosmological riddle. Very detailed observations of a small field in the southern sky have recently been carried out, with the space-based NASA Chandra X-Ray Observatory as well as with several ground-based ESO telescopes, including the Very Large Telescope (VLT) at the Paranal Observatory (Chile). Together, they have provided the "deepest" combined view at X-ray and visual/infrared wavelengths ever obtained into the distant Universe. The concerted observational effort has already yielded significant scientific results. This is primarily due to the possibility to 'identify' most of the X-ray emitting objects detected by the Chandra X-ray Observatory on ground-based optical/infrared images and then to determine their nature and distance by means of detailed (spectral) observations with the VLT . In particular, there is now little doubt that the so-called 'X-ray background' , a seemingly diffuse short-wave radiation first detected in 1962, in fact originates in a vast number of powerful black holes residing in active nuclei of distant galaxies . Moreover, the present investigation has permitted to identify and study in some detail a prime example of a hitherto little known type of object, a distant, so-called 'Type II Quasar' , in which the central black hole is deeply embedded in surrounding gas and dust. These achievements are just the beginning of a most fruitful collaboration between "space" and "ground". It is yet another impressive demonstration of the rapid progress of modern astrophysics, due to the recent emergence of a new generation of extremely powerful instruments. PR Photo 09a/01 : Images of a small part of the Chandra Deep Field South , obtained with ESO telescopes in three different wavebands. PR Photo 09b/01 : A VLT/FORS1 spectrum of a 'Type II Quasar' discovered during this programme. The 'Chandra Deep Field South' and the X-Ray Background ESO PR Photo 09a/01 ESO PR Photo 09a/01 [Preview - JPEG: 400 x 183 pix - 76k] [Normal - JPEG: 800 x 366 pix - 208k] [Hires - JPEG: 3000 x 1453 pix - 1.4M] Caption : PR Photo 09a/01 shows optical/infrared images in three wavebands ('Blue', 'Red', 'Infrared') from ESO telescopes of the Type II Quasar CXOCDFS J033229.9 -275106 (at the centre), one of the distant X-ray sources identified in the Chandra Deep Field South (CDFS) area during the present study. Technical information about these photos is available below. The 'Chandra Deep Field South (CDFS)' is a small sky area in the southern constellation Fornax (The Oven). It measures about 16 arcmin across, or roughly half the diameter of the full moon. There is unusually little gas and dust within the Milky Way in this direction and observations towards the distant Universe within this field thus profit from an particularly clear view. That is exactly why this sky area was selected by an international team of astronomers [1] to carry out an ultra-deep survey of X-ray sources with the orbiting Chandra X-Ray Observatory . In order to detect the faintest possible sources, NASA's satellite telescope looked in this direction during an unprecedented total of almost 1 million seconds of exposure time (11.5 days). The main scientific goal of this survey is to understand the nature and evolution of the elusive sources that make up the 'X-ray background' . This diffuse glare in the X-ray sky was discovered by Riccardo Giacconi and his collaborators during a pioneering rocket experiment in 1962. The excellent imaging quality of Chandra (the angular resolution is about 1 arcsec) makes it possible to do extremely deep exposures without encountering problems introduced by the "confusion effect". This refers to the overlapping of images of sources that are seen close to each other in the sky and thus are difficult to study individually. Previous X-ray satellites were not able to obtain sufficiently sharp X-ray images and the earlier deep X-ray surveys therefore suffered severely from this effect. Moreover, Chandra has much better sensitivity at shorter wavelengths (higher energies) which are less affected by obscuration effects. It can therefore better detect faint sources that emit very energetic ("hard") X-rays. X-ray and optical surveys in the Chandra Deep Field South The one-million second Chandra observations were completed in December 2000. In parallel, a group of astronomers based at institutes in Europe and the USA (the CFDS-team [1]) has been collecting deep images and extensive spectroscopic data with the VLT during the past 2 years (cf. PR Photo 09a/01 ). Their aim was to 'identify' the Chandra X-ray sources, i.e., to unveil their nature and measure their distances. For the identification of these sources, the team has also made extensive use of the observations that were carried out as a part of the comprehensive ESO Imaging Survey Project (EIS). More than 300 X-ray sources were detected in the CDFS by Chandra . A significant fraction of these objects shine so faintly in the optical and near-infrared wavebands that only long-exposure observations with the VLT have been able to detect them. During five observing nights with the FORS1 multi-mode instrument at the 8.2-m VLT ANTU telescope in October and November 2000, the CDFS team was able to identify and obtain spectra of more than one hundred of the X-ray sources registered by Chandra . Nature of the X-ray sources The first results from this study have now confirmed that the 'hard' X-ray background is mainly due to Active Galactic Nuclei (AGN) . The observations also reveal that a large fraction of them are of comparatively low brightness (referred to as 'low-luminosity AGN'), heavily enshrouded by dust and located at distances of 8,000 - 9,000 million light-years (corresponding to a redshift of about 1 and a look-back time of 57% of the age of the Universe [2]) . It is generally believed that all these sources are powered by massive black holes at their centres. Previous X-ray surveys missed most of these objects because they were too faint to be observed by the telescopes then available, in particular at short X-ray wavelengths ('hard X-ray photons') where more radiation from the highly active centres is able to pass through the surrounding, heavily absorbing gas and dust clouds. Other types of well-known X-ray sources, e.g., QSOs ('quasars' = high-luminosity AGN) as well as clusters or groups of galaxies were also detected during these observations. Studies of all classes of objects in the CDFS are also being carried out by several other European groups. This sky field, already a standard reference in the southern hemisphere, will be the subject of several multi-wavelength investigations for many years to come. A prime example will be the Great Observatories Origins Deep Survey (GOODS) which will be carried out by the NASA SIRTF infrared satellite in 2003. Discovery of a distant Type II Quasar ESO PR Photo 09b/01 ESO PR Photo 09b/01 [Preview - JPEG: 400 x 352 pix - 56k] [Normal - JPEG: 800 x 703 pix - 128k] Caption : PR Photo 09b/01 displays the optical spectrum of the distant Type II Quasar CXOCDFS J033229.9 -275106 in the Chandra Deep Field South (CDFS), obtained with the FORS1 multi-mode instrument at VLT ANTU. Strong, redshifted emission lines of Hydrogen and ionised Helium, Oxygen, Nitrogen and Carbon are marked. Technical information about this photo is available below. One particular X-ray source that was identified with the VLT during the present investigation has attracted much attention - it is the discovery of a dust-enshrouded quasar (QSO) at very high redshift ( z = 3.7, corresponding to a distance of about 12,000 million light-years; [2]), cf. PR Photo 09a/01 and PR Photo 09b/01 . It is the first very distant representative of this elusive class of objects (referred to as ' Type II Quasars ') which are believed to account for approximately 90% of the black-hole-powered quasars in the distant Universe. The 'sum' of the identified Chandra X-ray sources in the CDFS was found to match both the intensity and the spectral properties of the observed X-ray background. This important result is a significant step forward towards the definitive resolution of this long-standing cosmological problem. Naturally, ESO astronomer Piero Rosati and his colleagues are thrilled: " It is clearly the combination of the new and detailed Chandra X-ray observations and the enormous light-gathering power of the VLT that has been instrumental to this success. " However, he says, " the identification of the remaining Chandra X-ray sources will be the next challenge for the VLT since they are extremely faint. This is because they are either heavily obscured by dust or because they are extremely distant ". More Information This Press Release is issued simultaneously with a NASA Press Release (see also the Harvard site ). Some of the first results are described in a research paper ("First Results from the X-ray and Optical Survey of the Chandra Deep Field South" available on the web at astro-ph/0007240. More information about science results from the Chandra X-Ray Observatory may be found at: http://asc.harvard.edu/. The optical survey of CDFS at ESO with the Wide-Field Imager is described in connection with PR Photos 46a-b/99 ('100,000 galaxies at a glance'). An image of the Chandra Deep Field South is available at the ESO website on the EIS Image Gallery webpage. . Notes [1]: The Chandra Team is lead by Riccardo Giacconi (Association of Universities Inc. [AUI], Washington, USA) and includes: Piero Rosati , Jacqueline Bergeron , Roberto Gilmozzi , Vincenzo Mainieri , Peter Shaver (European Southern Observatory [ESO]), Paolo Tozzi , Mario Nonino , Stefano Borgani (Osservatorio Astronomico, Trieste, Italy), Guenther Hasinger , Gyula Szokoly (Astrophysical Institute Potsdam [AIP], Germany), Colin Norman , Roberto Gilli , Lisa Kewley , Wei Zheng , Andrew Zirm , JungXian Wang (Johns Hopkins University [JHU], Baltimore, USA), Ken Kellerman (National Radio Astronomy Observatory [NRAO], Charlottesville, USA), Ethan Schreier , Anton Koekemoer and Norman Grogin (Space Telescope Science Institute (STScI), Baltimore, USA). [2] In astronomy, the redshift denotes the fraction by which the lines in the spectrum of an object are shifted towards longer wavelengths. The observed redshift of a distant galaxy or quasar gives a direct estimate of the apparent recession velocity as caused by the universal expansion. Since the expansion rate increases with the distance, the velocity is itself a function (the Hubble relation) of the distance to the object. Redshifts of 1 and 3.7 correspond to when the Universe was about 43% and 12% of its present age. The distances indicated in this Press Release depend on the cosmological model chosen and are based on an age of 19,000 million years. Technical information about the photos PR Photo 09a/01 shows B-, R- and I-band images of a 20 x 20 arcsec 2 area within the CDFS, centred on the Type II Quasar CXOCDFS J033229.9 -275106 . They were obtained with the MPG/ESO 2.2-m telescope and the Wide-Field Imager (WFI) at La Silla (B-band; 8 hrs exposure time) and the 8.2-m VLT ANTU telescope with the FORS1 multi-mode instrument at Paranal (R- and I-bands; each 2 hrs exposure). The measured magnitudes are R=23.5 and I=22.7. The overlaid contours show the associated Chandra X-ray source (smoothed with a sigma = 1 arcsec gaussian profile). North is up and East is left. The spectrum shown in PR Photo 09b/01 was obtained on November 25, 2000, with VLT ANTU and FORS1 in the multislit mode (150-I grism, 1.2 arcsec slit). The exposure time was 3 hours.

Detection of Hot Halo Gets Theory Out of Hot Water

NASA Astrophysics Data System (ADS)

2006-02-01

Scientists using NASA's Chandra X-ray Observatory have detected an extensive halo of hot gas around a quiescent spiral galaxy. This discovery is evidence that galaxies like our Milky Way are still accumulating matter from the gradual inflow of intergalactic gas. "What we are likely witnessing here is the ongoing galaxy formation process," said Kristian Pedersen of the University of Copenhagen, Denmark, and lead author of a report on the discovery. Chandra observations show that the hot halo extends more than 60,000 light years on either side of the disk of the galaxy known as NGC 5746. The detection of such a large halo alleviates a long-standing problem for the theory of galaxy formation. Spiral galaxies are thought to form from enormous clouds of intergalactic gas that collapse to form giant, spinning disks of stars and gas. Chandra X-ray Image of NGC 5746 Chandra X-ray Image of NGC 5746 One prediction of this theory is that large spiral galaxies should be immersed in halos of hot gas left over from the galaxy formation process. Hot gas has been detected around spiral galaxies in which vigorous star formation is ejecting matter from the galaxy, but until now hot halos due to infall of intergalactic matter have not been detected. "Our observations solve the mystery of the missing hot halos around spiral galaxies," said Pedersen. "The halos exist, but are so faint that an extremely sensitive telescope such as Chandra is needed to detect them." DSS Optical Image of NGC 5746 DSS Optical Image of NGC 5746 NGC 5746 is a massive spiral galaxy about a 100 million light years from Earth. Its disk of stars and gas is viewed almost edge-on. The galaxy shows no signs of unusual star formation, or energetic activity from its nuclear region, making it unlikely that the hot halo is produced by gas flowing out of the galaxy. "We targeted NGC 5746 because we thought its distance and orientation would give us the best chance to detect a hot halo caused by the infall of intergalactic gas," said Jesper Rasmussen of the University of Birmingham, United Kingdom and a coauthor of the report. "What we found is in good agreement with computer simulations in which galaxies are built up gradually from the merger of smaller clouds of hot gas and dark matter." The computer simulations were done by Jesper Sommer-Larsen (also a coauthor of the report) and collaborators at the University of Copenhagen. The paper describing these results will be published in the April issue of the journal New Astronomy. Other researchers on this project were Sune Toft, Yale University; Andrew Benson, University of Oxford, United Kingdom; and Richard Bower, University of Durham, United Kingdom. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. http://chandra.harvard.edu and http://chandra.nasa.gov

Stellar Forensics with Striking Image from Chandra

NASA Astrophysics Data System (ADS)

2007-10-01

A spectacular new image shows how complex a star's afterlife can be. By studying the details of this image made from a long observation by NASA's Chandra X-ray Observatory, astronomers can better understand how some stars die and disperse elements like oxygen into the next generation of stars and planets. At a distance of about 20,000 light years, G292.0+1.8 is one of only three supernova remnants in the Milky Way known to contain large amounts of oxygen. The image shows a rapidly expanding, intricately structured, debris field that contains, along with oxygen, other elements such as neon and silicon that were forged in the star before it exploded. Hard X-ray Image of G292.0+1.8 Hard X-ray Image of G292.0+1.8 "We are finding that, just like snowflakes, each supernova remnant is complicated and beautiful in its own way," said Sangwook Park of Penn State who led the work, released in conjunction with the "8 Years of Chandra" symposium in Huntsville, Ala. The new, deep Chandra image - equaling nearly 6 days worth of observing time - shows an incredibly complex structure. Understanding the details of G292.0+1.8 is especially important because astronomers have considered it to be a "textbook" case of a supernova created by the death of a massive star. Chandra X-ray Image of G292.0+1.8 Chandra X-ray Image of G292.0+1.8 By mapping the distribution of X-rays in different energy bands, the Chandra image traces the distribution of chemical elements ejected in the supernova. The results imply that the explosion was not symmetrical. For example, blue (silicon and sulfur) and green (magnesium) are seen strongly in the upper right, while yellow and orange (oxygen) dominate the lower left. These elements light up at different temperatures, indicating that the temperature is higher in the upper right portion of G292.0+1.8. Slightly below and to the left of the center of G292.0+1.8 is a pulsar, a dense, rapidly rotating neutron star that remained behind after the original star exploded. Assuming that the pulsar was born at the center of the remnant, it is thought that recoil from the lopsided explosion may have kicked the pulsar in this direction. Pulsar Wind Nebula in G292.0+1.8 Pulsar Wind Nebula in G292.0+1.8 Surrounding the pulsar is a so-called pulsar wind nebula, a magnetized bubble of high-energy particles. The narrow, jet-like feature running from north to south in the image is likely parallel to the spin axis of the pulsar. This structure is most easily seen in high energy X-rays. In the case of G292.0+1.8, the spin direction and the kick direction do not appear to be aligned, in contrast to apparent spin-kick alignments in some other supernova remnants. Another intriguing feature of this remnant is the bright equatorial belt of X-ray emission that extends across the center of the remnant. This structure is thought to have been created when the star - before it died - expelled material from around its equator via winds. The orientation of the equatorial belt suggests that the parent star maintained the same spin axis both before and after it exploded. DSS Optical Image of G292.0+1.8 DSS Optical Image of G292.0+1.8 "The detection of the pulsar and its wind nebula confirms that the supernova that led to G292 produced a neutron star through the collapse of the core of a massive star," said coauthor John Hughes of Rutgers University, "The ability to study the asymmetry of the original explosion using X-ray images of the remnant gives us a powerful new technique for learning about these cataclysmic events." These results will appear in an upcoming issue of The Astrophysical Journal Letters. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass.

The Chandra Source Catalog: Background Determination and Source Detection

NASA Astrophysics Data System (ADS)

McCollough, Michael; Rots, Arnold; Primini, Francis A.; Evans, Ian N.; Glotfelty, Kenny J.; Hain, Roger; Anderson, Craig S.; Bonaventura, Nina R.; Chen, Judy C.; Davis, John E.; Doe, Stephen M.; Evans, Janet D.; Fabbiano, Giuseppina; Galle, Elizabeth C.; Danny G. Gibbs, II; Grier, John D.; Hall, Diane M.; Harbo, Peter N.; He, Xiang Qun (Helen); Houck, John C.; Karovska, Margarita; Kashyap, Vinay L.; Lauer, Jennifer; McCollough, Michael L.; McDowell, Jonathan C.; Miller, Joseph B.; Mitschang, Arik W.; Morgan, Douglas L.; Mossman, Amy E.; Nichols, Joy S.; Nowak, Michael A.; Plummer, David A.; Refsdal, Brian L.; Siemiginowska, Aneta L.; Sundheim, Beth A.; Tibbetts, Michael S.; van Stone, David W.; Winkelman, Sherry L.; Zografou, Panagoula

2009-09-01

The Chandra Source Catalog (CSC) is a major project in which all of the pointed imaging observations taken by the Chandra X-Ray Observatory are used to generate one of the most extensive X-ray source catalog produced to date. Early in the development of the CSC it was recognized that the ability to estimate local background levels in an automated fashion would be critical for essential CSC tasks such as source detection, photometry, sensitivity estimates, and source characterization. We present a discussion of how such background maps are created directly from the Chandra data and how they are used in source detection. The general background for Chandra observations is rather smoothly varying, containing only low spatial frequency components. However, in the case of ACIS data, a high spatial frequency component is added that is due to the readout streaks of the CCD chips. We discuss how these components can be estimated reliably using the Chandra data and what limitations and caveats should be considered in their use. We will discuss the source detection algorithm used for the CSC and the effects of the background images on the detection results. We will also touch on some the Catalog Inclusion and Quality Assurance criteria applied to the source detection results. This work is supported by NASA contract NAS8-03060 (CXC).

Chandra Source Catalog: Background Determination and Source Detection

NASA Astrophysics Data System (ADS)

McCollough, Michael L.; Rots, A. H.; Primini, F. A.; Evans, I. N.; Glotfelty, K. J.; Hain, R.; Anderson, C. S.; Bonaventura, N. R.; Chen, J. C.; Davis, J. E.; Doe, S. M.; Evans, J. D.; Fabbiano, G.; Galle, E.; Gibbs, D. G.; Grier, J. D.; Hall, D. M.; Harbo, P. N.; He, X.; Houck, J. C.; Karovska, M.; Lauer, J.; McDowell, J. C.; Miller, J. B.; Mitschang, A. W.; Morgan, D. L.; Nichols, J. S.; Nowak, M. A.; Plummer, D. A.; Refsdal, B. L.; Siemiginowska, A. L.; Sundheim, B. A.; Tibbetts, M. S.; Van Stone, D. W.; Winkelman, S. L.; Zografou, P.

2009-01-01

The Chandra Source Catalog (CSC) is a major project in which all of the pointed imaging observations taken by the Chandra X-Ray Observatory will used to generate the most extensive X-ray source catalog produced to date. Early in the development of the CSC it was recognized that the ability to estimate local background levels in an automated fashion would be critical for essential CSC tasks such as source detection, photometry, sensitivity estimates, and source characterization. We present a discussion of how such background maps are created directly from the Chandra data and how they are used in source detection. The general background for Chandra observations is rather smoothly varying, containing only low spatial frequency components. However, in the case of ACIS data, a high spatial frequency component is added that is due to the readout streaks of the CCD chips. We discuss how these components can be estimated reliably using the Chandra data and what limitations and caveats should be considered in their use. We will discuss the source detection algorithm used for the CSC and the effects of the background images on the detection results. We will also touch on some the Catalog Inclusion and Quality Assurance criteria applied to the source detection results. This work is supported by NASA contract NAS8-03060 (CXC).

The unique, optically-dominated quasar jet of PKS 1421-490

NASA Astrophysics Data System (ADS)

Gelbord, J. M.; Marshall, H. L.; Worrall, D. M.; Birkinshaw, M.; Lovell, J. E. J.; Ojha, R.; Godfrey, L.; Schwartz, D. A.; Perlman, E. S.; Georganopoulos, M.; Murphy, D. W.; Jauncey, D. L.

2004-12-01

The unique, optically-dominated quasar jet of PKS 1421-490 We report the discovery of extremely strong optical and X-ray emission associated with a knot in the radio jet of PKS 1421-490. The SDSS g' = 17.8 magnitude makes this the second-brightest optical jet known. The jet-to-core flux ratio in the X-ray band is unusually large (3.7), and the optical flux ratio ( ˜300) is unprecedented. The broad-band spectrum of the knot is flat from the radio through the optical bands, and has a similar slope with a lower normalization in the X-ray band. This emission is difficult to interpret without resorting to extreme model parameters or physically unlikely scenarios (flat electron distributions, non-equipartition magnetic fields, huge Doppler factors, etc.). We discuss several alternative models for the radio-to-X-ray continuum, including pure synchrotron, synchrotron plus inverse Compton scattering of cosmic microwave background photons, and a decelerating jet. JMG was supported under Chandra grant GO4-5124X to MIT from the CXC. HLM was supported under NASA contract SAO SV1-61010 for the Chandra X-Ray Center (CXC).

Cold Probes of the Hot Universe

NASA Technical Reports Server (NTRS)

Kilbourne, Caroline

2017-01-01

In this image, data from NASA's Spitzer, Hubble, and Chandra satellites are combined. Optical light from stars (yellow-greenHubble) shows the disk of an apparently normal galaxy. Another Hubble observation designed to image 10,000 K hydrogen gas (orange) reveals matter blasting out of the galaxy. The Spitzer infrared image (red) shows that cool gas and dust are also being ejected. Chandra's X-ray image (blue) reveals gas that has been heated to millions of degrees by the violent outflow.

Kodak Mirror Assembly Tested at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

2003-01-01

The Eastman-Kodak mirror assembly is being tested for the James Webb Space Telescope (JWST) project at the X-Ray Calibration Facility at Marshall Space Flight Center (MSFC). In this photo, an MSFC employee is inspecting one of many segments of the mirror assembly for flaws. MSFC is supporting Goddard Space Flight Center (GSFC) in developing the JWST by taking numerous measurements to predict its future performance. The tests are conducted in a vacuum chamber cooled to approximate the super cold temperatures found in space. During its 27 years of operation, the facility has performed testing in support of a wide array of projects, including the Hubble Space Telescope (HST), Solar A, Chandra technology development, Chandra High Resolution Mirror Assembly and science instruments, Constellation X-Ray Mission, and Solar X-Ray Imager, currently operating on a Geostationary Operational Environment Satellite. The JWST is NASA's next generation space telescope, a successor to the Hubble Space Telescope, named in honor of NASA's second administrator, James E. Webb. It is scheduled for launch in 2010 aboard an expendable launch vehicle. It will take about 3 months for the spacecraft to reach its destination, an orbit of 940,000 miles in space.

Kodak Mirror Assembly Tested at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

2003-01-01

This photo (a frontal view) is of one of many segments of the Eastman-Kodak mirror assembly being tested for the James Webb Space Telescope (JWST) project at the X-Ray Calibration Facility at Marshall Space Flight Center (MSFC). MSFC is supporting Goddard Space Flight Center (GSFC) in developing the JWST by taking numerous measurements to predict its future performance. The tests are conducted in a vacuum chamber cooled to approximate the super cold temperatures found in space. During its 27 years of operation, the facility has performed testing in support of a wide array of projects, including the Hubble Space Telescope (HST), Solar A, Chandra technology development, Chandra High Resolution Mirror Assembly and science instruments, Constellation X-Ray Mission, and Solar X-Ray Imager, currently operating on a Geostationary Operational Environment Satellite. The JWST is NASA's next generation space telescope, a successor to the Hubble Space Telescope, named in honor of NASA's second administrator, James E. Webb. It is scheduled for launch in 2010 aboard an expendable launch vehicle. It will take about 3 months for the spacecraft to reach its destination, an orbit of 940,000 miles in space.

Kodak Mirror Assembly Tested at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

2003-01-01

This photo (a side view) is of one of many segments of the Eastman-Kodak mirror assembly being tested for the James Webb Space Telescope (JWST) project at the X-Ray Calibration Facility at Marshall Space Flight Center (MSFC). MSFC is supporting Goddard Space Flight Center (GSFC) in developing the JWST by taking numerous measurements to predict its future performance. The tests are conducted in a vacuum chamber cooled to approximate the super cold temperatures found in space. During its 27 years of operation, the facility has performed testing in support of a wide array of projects, including the Hubble Space Telescope (HST), Solar A, Chandra technology development, Chandra High Resolution Mirror Assembly and science instruments, Constellation X-Ray Mission, and Solar X-Ray Imager, currently operating on a Geostationary Operational Environment Satellite. The JWST is NASA's next generation space telescope, a successor to the Hubble Space Telescope, named in honor of NASA's second administrator, James E. Webb. It is scheduled for launch in 2010 aboard an expendable launch vehicle. It will take about 3 months for the spacecraft to reach its destination, an orbit of 940,000 miles in space.

Space Science

NASA Image and Video Library

2003-04-09

The Eastman-Kodak mirror assembly is being tested for the James Webb Space Telescope (JWST) project at the X-Ray Calibration Facility at Marshall Space Flight Center (MSFC). In this photo, an MSFC employee is inspecting one of many segments of the mirror assembly for flaws. MSFC is supporting Goddard Space Flight Center (GSFC) in developing the JWST by taking numerous measurements to predict its future performance. The tests are conducted in a vacuum chamber cooled to approximate the super cold temperatures found in space. During its 27 years of operation, the facility has performed testing in support of a wide array of projects, including the Hubble Space Telescope (HST), Solar A, Chandra technology development, Chandra High Resolution Mirror Assembly and science instruments, Constellation X-Ray Mission, and Solar X-Ray Imager, currently operating on a Geostationary Operational Environment Satellite. The JWST is NASA's next generation space telescope, a successor to the Hubble Space Telescope, named in honor of NASA's second administrator, James E. Webb. It is scheduled for launch in 2010 aboard an expendable launch vehicle. It will take about 3 months for the spacecraft to reach its destination, an orbit of 940,000 miles in space.

Chandra Finds Oxygen and Neon Ring in Ashes of Exploded Star

NASA Astrophysics Data System (ADS)

2000-01-01

NASA's Chandra X-ray Observatory has revealed an expanding ring-like structure of oxygen and neon that was hurled into space by the explosion of a massive star. The image of E0102-72 provides unprecedented details about the creation and dispersal of heavy elements necessary to form planets like Earth. The results were reported by Professor Claude Canizares of the Massachusetts Institute of Technology (MIT), Cambridge, at the 195th national meeting of the American Astronomical Society in Atlanta, Ga. Drs. Kathryn Flanagan, David Davis, and John Houck of MIT collaborated with Canizares in this investigation. E0102-72 is the remnant of a supernova explosion located in our neighbor galaxy, the Small Magellanic Cloud, nearly 200,000 light years away. It was created by the explosion of a star that was more than ten times as massive as our Sun. We are seeing the aftermath of the explosion a thousand or more years after the outburst. Shock waves are heating gas to temperatures of nearly 10 million degrees, so it glows with X-rays that are detected by Chandra's instruments. By using the High Energy Transmission Grating Spectrometer (HETG), astronomers were able to pinpoint the distribution of each chemical element individually and measure the velocities of different parts of the expanding ring. They also show the shock wave in a kind of "freeze-frame," revealing the progressive heating of the stellar matter as it plows into the surrounding gas. This is the first time such detailed X-ray information has ever been obtained for a supernova remnant, and should provide critical clues to the nature of supernovas. The grating spectrometer, which was built by an MIT team led by Canizares, spreads the X-rays according to their wavelength, giving distinct images of the object at specific wavelengths characteristic of each chemical element. Small wavelength shifts caused by the Doppler effect are used to measure the expansion velocities of each element independently. "We've been studying these supernova remnants for decades, but now we're getting the kind of information we need to really test the theories," said Canizares. "Understanding supernovas helps us to learn about the processes that formed chemical elements like those which are found on Earth and are necessary for life," said Flanagan. Most of the oxygen in the universe, for example, is synthesized in the interiors of relatively few massive stars like the one being studied here. When they explode, they expel the newly manufactured elements which become part of the raw material for new stars and planets. The amount of oxygen in the E0102-72 ring is enough for thousands of solar systems. By measuring the expansion velocity of the ring, the team can estimate the amount of energy liberated in the explosion. The expansion energy would be enough to power the Sun for 3 billion years. The ring has more complex structure and motion than can be explained by current simplified theories, suggesting complexity in the explosion itself or in the surrounding interstellar matter. The supernova remnant also provides a laboratory for atomic physics. The observations show how the atoms in the expelled matter behave when heated to such high temperatures. The images reveal the progressive stripping of electrons from the atoms after the super-sonic shock wave has passed. The Chandra observation was taken using the HETG in conjunction with the Advanced CCD Imaging Spectrometer (ACIS) on September 28 and October 10, 1999. ACIS was built by Pennsylvania State University, University Park, and the Massachusetts Institute of Technology, Cambridge. To follow Chandra's progress or download images visit the Chandra sites at http://chandra.harvard.edu/photo/2000/0015/index.html AND http://chandra.nasa.gov NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program. TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass. High resolution digital versions of the X-ray image (JPG, 300 dpi TIFF ) and other information associated with this release are available on the Internet at: http://chandra.harvard.edu Further information on the HETG may be found at: http://space.mit.edu/CSR/hetg_info.html

Current Technology Development Efforts on the International X-Ray Observatory

NASA Technical Reports Server (NTRS)

Robinson, David

2011-01-01

The International X-ray Observatory (IXO) is a collaboration between NASA, ESA, and JAXA which is under study for launch in 2021. IXO will be a large 6600 kilogram Great Observatory-class mission which will build upon the legacies of the Chandra and XMM-Newton X-ray observatories. There is an extensive ongoing effort to raise the technology readiness level of the X-ray mirror from TRL 3 to TRL 6 in the next decade. Improvements have recently been made in the area of positioning and bonding mirrors on the nanometer scale and developing metals and composites with a matching coefficient of thermal expansion to the glass X-ray mirrors. On the mission systems side, the NASA reference design has been through a preliminary coupled loads analysis and a STOP analysis of the flight mirror assembly has been initiated. An impact study was performed comparing launching IXO on an Ariane 5 or a U.S. EELV. This paper will provide a snapshot of NASA's current observatory configuration and summarize the progress of these various technology and design efforts.

NASA Observatory Confirms Black Hole Limits

NASA Astrophysics Data System (ADS)

2005-02-01

The very largest black holes reach a certain point and then grow no more, according to the best survey to date of black holes made with NASA's Chandra X-ray Observatory. Scientists have also discovered many previously hidden black holes that are well below their weight limit. These new results corroborate recent theoretical work about how black holes and galaxies grow. The biggest black holes, those with at least 100 million times the mass of the Sun, ate voraciously during the early Universe. Nearly all of them ran out of 'food' billions of years ago and went onto a forced starvation diet. Focus on Black Holes in the Chandra Deep Field North Focus on Black Holes in the Chandra Deep Field North On the other hand, black holes between about 10 and 100 million solar masses followed a more controlled eating plan. Because they took smaller portions of their meals of gas and dust, they continue growing today. "Our data show that some supermassive black holes seem to binge, while others prefer to graze", said Amy Barger of the University of Wisconsin in Madison and the University of Hawaii, lead author of the paper describing the results in the latest issue of The Astronomical Journal (Feb 2005). "We now understand better than ever before how supermassive black holes grow." One revelation is that there is a strong connection between the growth of black holes and the birth of stars. Previously, astronomers had done careful studies of the birthrate of stars in galaxies, but didn't know as much about the black holes at their centers. DSS Optical Image of Lockman Hole DSS Optical Image of Lockman Hole "These galaxies lose material into their central black holes at the same time that they make their stars," said Barger. "So whatever mechanism governs star formation in galaxies also governs black hole growth." Astronomers have made an accurate census of both the biggest, active black holes in the distance, and the relatively smaller, calmer ones closer by. Now, for the first time, the ones in between have been counted properly. Growth of the Biggest Black Holes Illustrated Growth of the Biggest Black Holes Illustrated "We need to have an accurate head count over time of all growing black holes if we ever hope to understand their habits, so to speak," co-author Richard Mushotzky of NASA's Goddard Space Flight Center in Greenbelt, Md. Supermassive black holes themselves are invisible, but heated gas around them -- some of which will eventually fall into the black hole - produces copious amounts of radiation in the centers of galaxies as the black holes grow. Growth of the Biggest Black Holes Illustrated Growth of Smaller Black Holes Illustrated This study relied on the deepest X-ray images ever obtained, the Chandra Deep Fields North and South, plus a key wider-area survey of an area called the "Lockman Hole". The distances to the X-ray sources were determined by optical spectroscopic follow-up at the Keck 10-meter telescope on Mauna Kea in Hawaii, and show the black holes range from less than a billion to 12 billion light years away. Since X-rays can penetrate the gas and dust that block optical and ultraviolet emission, the very long-exposure X-ray images are crucial to find black holes that otherwise would go unnoticed. Black Hole Animation Black Hole Animation Chandra found that many of the black holes smaller than about 100 million Suns are buried under large amounts of dust and gas, which prevents detection of the optical light from the heated material near the black hole. The X-rays are more energetic and are able to burrow through this dust and gas. However, the largest of the black holes show little sign of obscuration by dust or gas. In a form of weight self-control, powerful winds generated by the black hole's feeding frenzy may have cleared out the remaining dust and gas. Other aspects of black hole growth were uncovered. For example, the typical size of the galaxies undergoing supermassive black hole formation reduces with cosmic time. Such "cosmic downsizing" was previously observed for galaxies undergoing star formation. These results connect well with the observations of nearby galaxies, which find that the mass of a supermassive black hole is proportional to the mass of the central region of its host galaxy. The other co-authors on the paper in the February 2005 issue of The Astronomical Journal were Len Cowie, Wei-Hao Wang, and Peter Capak (Institute for Astronomy, Univ. of Hawaii), Yuxuan Yang (GSFC and the Univ. of Maryland, College Park), and Aaron Steffen (Univ. of Wisconsin, Madison). NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for NASA's Space Mission Directorate, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

An In-depth Chandra ACIS View Of The Circumnuclear Region Of NGC 4151: The Jet, The Biconical Outflow, And A Leaky Torus

NASA Astrophysics Data System (ADS)

Wang, Junfeng; Fabbiano, G.; Elvis, M.; Risaliti, G.; Karovska, M.; Zezas, A.; Mundell, C. G.

2011-05-01

We report on the imaging analysis of 200 ks Chandra ACIS-S observations of the nearby Seyfert 1 galaxy NGC 4151. Structured soft X-ray emission is observed to extend from 30 pc to 1.5 kpc. We find strong evidence for jet-gas cloud interaction in the inner 150 pc region, confirming our previous HRC results. Self-consistent photoionization models provide good descriptions of the spectra of the optical bi-cone, supporting the dominant role of nuclear photoionization. Presence of both low and high ionization spectral components and extended emission in the X-ray image perpendicular to the bi-cone indicates leakage of nuclear ionization. Using spatially resolved features, we estimate the kinematic power of the outflow in NGC 4151 to be 0.3% of its bolometric luminosity. This work is supported by NASA grant GO8-9101X and GO1-12009X.

Doing Science with the Chandra Source Catalog

NASA Astrophysics Data System (ADS)

Evans, Ian N.; Chandra Source Catalog Team

2018-01-01

The excellent spatial resolution (~1 arcsecond on-axis) of the Chandra X-ray Observatory, combined with a reasonable field of view and low instrumental backgrounds, allow detection of serendipitous X-ray sources with a high detectable-source density with low confusion. The aim of the Chandra Source Catalog (CSC) is to disseminate this wealth of information to the user community in a form that is immediately usable for scientific investigation, and the catalog is intended to satisfy the needs of a broad- based group of scientists, including those who may be less familiar with astronomical data analysis in the X-ray regime.The second major release of the catalog, CSC 2.0, will be made available to the user community in early 2018, and preliminary lists of detections and sources are available now. CSC 2.0 will roughly triple the size of the current version of the catalog to an estimated 375,000 detections, corresponding to ~315,000 unique X-ray sources on the sky. For each detected X-ray source, the catalog provides a detailed set of properties including the source position and associated position error ellipse, source extent, multi-band aperture photometry probability density functions, spectral fits using several source models, hardness ratios, and intra- and inter-observation temporal variability measures. All numerical measures have associated two-sided confidence intervals. In addition to tabular data, the catalog provides FITS data products that are immediately suitable for further user analysis, including per-field and per-source images, photon event lists, responses, spectra, and light curves.We describe the content and organization of the catalog in more detail, discuss the analyses that were performed to extract the measured source properties, and demonstrate how the catalog content can be immediately and effectively utilized for scientific investigations. This work has been supported by NASA under contract NAS 8-03060 to the Smithsonian Astrophysical Observatory for operation of the Chandra X-ray Center.

The Chandra Deep Field-North Survey and the cosmic X-ray background.

PubMed

Brandt, W Nielsen; Alexander, David M; Bauer, Franz E; Hornschemeier, Ann E

2002-09-15

Chandra has performed a 1.4 Ms survey centred on the Hubble Deep Field-North (HDF-N), probing the X-ray Universe 55-550 times deeper than was possible with pre-Chandra missions. We describe the detected point and extended X-ray sources and discuss their overall multi-wavelength (optical, infrared, submillimetre and radio) properties. Special attention is paid to the HDF-N X-ray sources, luminous infrared starburst galaxies, optically faint X-ray sources and high-to-extreme redshift active galactic nuclei. We also describe how stacking analyses have been used to probe the average X-ray-emission properties of normal and starburst galaxies at cosmologically interesting distances. Finally, we discuss plans to extend the survey and argue that a 5-10 Ms Chandra survey would lay key groundwork for future missions such as XEUS and Generation-X.

KSC-99pp0977

NASA Image and Video Library

1999-07-19

KENNEDY SPACE CENTER, FLA. -- Mrs. Lalitha Chandrasekhar (right), wife of the late Indian-American Nobel Laureate Subrahmanyan Chandrasekhar, addresses the media and other invited guests in the TRW Media Hospitality Tent at the NASA Press Site at KSC as Dr. Alan Bunner, Science Program Director, Structure and Evolution of the Universe, Office of Space Science, NASA Headquarters, Washington, D.C., looks on. The name "Chandra," a shortened version of her husband's name which he preferred among friends and colleagues, was chosen in a contest to rename the Advanced X-ray Astrophysics Facility. "Chandra" also means "Moon" or "luminous" in Sanskrit. The observatory is scheduled to be launched aboard Columbia on Space Shuttle mission STS-93

New Panorama Reveals More Than a Thousand Black Holes

NASA Astrophysics Data System (ADS)

2007-03-01

By casting a wide net, astronomers have captured an image of more than a thousand supermassive black holes. These results give astronomers a snapshot of a crucial period when these monster black holes are growing, and provide insight into the environments in which they occur. The new black hole panorama was made with data from NASA's Chandra X-ray Observatory, the Spitzer Space Telescope and ground-based optical telescopes. The black holes in the image are hundreds of millions to several billion times more massive than the sun and lie in the centers of galaxies. X-ray, IR & Optical Composites of Obscured & Unobscured AGN in Bootes Field X-ray, IR & Optical Composites of Obscured & Unobscured AGN in Bootes Field Material falling into these black holes at high rates generates huge amounts of light that can be detected in different wavelengths. These systems are known as active galactic nuclei, or AGN. "We're trying to get a complete census across the Universe of black holes and their habits," said Ryan Hickox of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass. "We used special tactics to hunt down the very biggest black holes." Instead of staring at one relatively small part of the sky for a long time, as with the Chandra Deep Fields -- two of the longest exposures obtained with the observatory -- and other concentrated surveys, this team scanned a much bigger portion with shorter exposures. Since the biggest black holes power the brightest AGN, they can be spotted at vast distances, even with short exposures. Scale Chandra Images to Full Moon Scale Chandra Images to Full Moon "With this approach, we found well over a thousand of these monsters, and have started using them to test our understanding of these powerful objects," said co-investigator Christine Jones, also of the CfA. The new survey raises doubts about a popular current model in which a supermassive black hole is surrounded by a doughnut-shaped region, or torus, of gas. An observer from Earth would have their view blocked by this torus by different amounts, depending on the orientation of the torus. According to this model, astronomers would expect a large sample of black holes to show a range of absorption of the radiation from the nuclei. This absorption should range from completely exposed to completely obscured, with most in-between. Nuclei that are completely obscured are not detectable, but heavily obscured ones are. "Instead of finding a whole range, we found nearly all of the black holes are either naked or covered by a dense veil of gas," said Hickox. "Very few are in between, which makes us question how well we know the environment around these black holes." This study found more than 600 obscured and 700 unobscured AGN, located between about six to 11 billion light years from Earth. They were found using an early application of a new search method. By looking at the infrared colors of objects with Spitzer, AGN can be separated from stars and galaxies. The Chandra and optical observations then verify these objects are AGN. This multi-wavelength method is especially efficient at finding obscured AGN. "These results are very exciting, using two NASA Great Observatories to find and understand the largest sample of obscured supermassive black holes ever found in the distant universe", said co-investigator Daniel Stern, of NASA's Jet Propulsion Laboratory in Pasadena, Calif. The Chandra image is the largest contiguous field ever obtained by the observatory. At 9.3 square degrees, it is over 40 times larger than the full moon seen on the night sky and over 80 times larger than either of the Chandra Deep Fields. This survey, taken in a region of the Bootes constellation, involved 126 separate pointings of 5,000-second Chandra exposures each. The researchers combined this with data obtained from Spitzer, and Kitt Peak's 4-meter Mayall and the MMT 6.5-meter optical telescopes, both located outside Tuscon, Ariz., from the same patch of sky. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center, Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

When Worlds Collide: Chandra Observes Titanic Merger

NASA Astrophysics Data System (ADS)

2002-04-01

NASA's Chandra X-ray Observatory has provided the best X-ray image yet of two Milky Way-like galaxies in the midst of a head-on collision. Since all galaxies - including our own - may have undergone mergers, this provides insight into how the universe came to look as it does today. Astronomers believe the mega-merger in the galaxy known as Arp 220 triggered the formation of huge numbers of new stars, sent shock waves rumbling through intergalactic space, and could possibly lead to the formation of a supermassive black hole in the center of the new conglomerate galaxy. The Chandra data also suggest that merger of these two galaxies began only 10 million years ago, a short time in astronomical terms. "The Chandra observations show that things really get messed up when two galaxies run into each other at full speed," said David Clements of the Imperial College, London, one of the team members involved in the study. "The event affects everything from the formation of massive black holes to the dispersal of heavy elements into the universe." Arp 220 is considered to be a prototype for understanding what conditions were like in the early universe, when massive galaxies and supermassive black holes were presumably formed by numerous galaxy collisions. At a relatively nearby distance of about 250 million light years, Arp 220 is the closest example of an "ultra-luminous" galaxy, one that gives off a trillion times as much radiation as our Sun. The Chandra image shows a bright central region at the waist of a glowing, hour-glass-shaped cloud of multimillion-degree gas. Rushing out of the galaxy at hundreds of thousands of miles per hour, the super-heated as forms a "superwind," thought to be due to explosive activity generated by the formation of hundreds of millions of new stars. Farther out, spanning a distance of 75,000 light years, are giant lobes of hot gas that could be galactic remnants flung into intergalactic space by the early impact of the collision. Whether the lobes will continue to expand into space or fall back into Arp 220 is unknown. The center of Arp 220 is of particular interest. Chandra observations allowed astronomers to pinpoint an X-ray source at the exact location of the nucleus of one of the pre-merger galaxies. Another fainter X-ray source nearby may coincide with the nucleus of the other galaxy remnant. The X-ray power output of these point-like sources is greater than expected for stellar black holes accreting from companion stars. The authors suggest that these sources could be due to supermassive black holes at the centers of the merging galaxies. These two remnant sources are relatively weak, and provide strong evidence to support the theory that the extraordinary luminosity of Arp 220 - about a hundred times that of our Milky Way galaxy - is due to the rapid rate of star formation and not to an active, supermassive black hole in the center. However, in a few hundred million years, this balance of power may change. The two massive black holes could merge to produce a central supermassive black hole. This new arrangement could cause much more gas to fall into the central black hole, creating a power source equal to or greater than that due to star formation. "The unusual concentration of X-ray sources in the very center of Arp 220 suggests that we could be observing the early stages of the creation of a supermassive black hole and the eventual rise to power of an active galactic nucleus," said Jonathan McDowell of the Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, another member of the team studying Arp 220. Clements and McDowell were joined on this research by an international group of researchers from the United States, United Kingdom and Spain. Chandra observed Arp 220 on June 24, 2000, for approximately 56,000 seconds using the Advanced CCD Imaging Spectrometer (ACIS) instrument. ACIS was developed for NASA by Pennsylvania State University, University Park, PA, and the Massachusetts Institute of Technology, Cambridge, MA. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program, and TRW, Inc., Redondo Beach, Calif., is the prime contractor. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass.

Laboratory Measurements of the K-Shell Transition Energies in L-Shell Ions of Si and S

NASA Technical Reports Server (NTRS)

Hell, N.; Brown, G.V.; Wilms, J.; Grinberg, V.; Clementson, J.; Liedahl, D.; Porter, F. S.; Kelley, R. L.; Kilbourne, C. A.; Beiersrdorfer, P.

2016-01-01

We have measured the energies of the strongest 1s-2 l (azimuthal quantum number) (l = s, p (s, p are angular momentum states)) transitions in He- through Ne-like silicon and sulfur ions to an accuracy of less than 1 electronvolt using the Lawrence Livermore National Laboratory's electron beam ion traps, EBIT-I and SuperEBIT, and the NASA/GSFC EBIT Calorimeter Spectrometer (ECS). We identify and measure the energies of 18 and 21 X-ray features from silicon and sulfur, respectively. The results are compared to new Flexible Atomic Code calculations and to semi-relativistic Hartree-Fock calculations by Palmeri et al. (2008). These results will be especially useful for wind diagnostics in high-mass X-ray binaries, such as Vela X-1 and Cygnus X-1, where high-resolution spectral measurements using Chandra's high-energy transmission grating has made it possible to measure Doppler shifts of 100 kilometers per second. The accuracy of our measurements is consistent with that needed to analyze Chandra observations, exceeding Chandra's 100 kilometers per second limit. Hence, the results presented here not only provide benchmarks for theory, but also accurate rest energies that can be used to determine the bulk motion of material in astrophysical sources. We show the usefulness of our results by applying them to redetermine Doppler shifts from Chandra observations of Vela X-1.

Galaxy Centaurus A

NASA Image and Video Library

2003-07-25

This image of the active galaxy Centaurus A was taken by NASA's Galaxy Evolution Explorer on June 7, 2003. The galaxy is located 30 million light-years from Earth and is seen edge on, with a prominent dust lane across the major axis. In this image the near ultraviolet emission is represented as green, and the far ultraviolet emission as blue. The galaxy exhibits jets of high energy particles, which were traced by the X-ray emission and measured by NASA's Chandra X-ray Observatory. These X-ray emissions are seen as red in the image. Several regions of ultraviolet emission can be seen where the jets of high energy particles intersect with hydrogen clouds in the upper left corner of the image. The emission shown may be the result of recent star formation triggered by the compression of gas by the jet. http://photojournal.jpl.nasa.gov/catalog/PIA04624

Planning for future X-ray astronomy missions .

NASA Astrophysics Data System (ADS)

Urry, C. M.

Space science has become an international business. Cutting-edge missions are too expensive and too complex for any one country to have the means and expertise to construct. The next big X-ray mission, Astro-H, led by Japan, has significant participation by Europe and the U.S. The two premier missions currently operating, Chandra and XMM-Newton, led by NASA and ESA, respectively, are thoroughly international. The science teams are international and the user community is International. It makes sense that planning for future X-ray astronomy missions -- and the eventual missions themselves -- be fully integrated on an international level.

Winds of Change

NASA Image and Video Library

2010-03-05

Observation Date: 1 pointing on Dec 4, 2000 and 9 pointings between Nov 18 and Dec 5, 2008. Distance Estimate: About 50 million light years away. This is a composite image of NGC 1068, one of the nearest and brightest galaxies containing a rapidly growing supermassive black hole. The X-ray images and spectra obtained using Chandra's High Energy Transmission Grating Spectrometer show that a strong wind is being driven away from the center of NGC 1068 at a rate of about a million miles per hour. This wind is likely generated as surrounding gas is accelerated and heated as it swirls toward the black hole. A portion of the gas is pulled into the black hole, but some of it is blown away. High energy X-rays produced by the gas near the black hole heat the ouflowing gas, causing it to glow at lower X-ray energies. X-ray data from the Chandra X-ray Observatory are shown in red, optical data from the Hubble Space Telescope in green and radio data from the Very Large Array in blue. The spiral structure of NGC 1068 is shown by the X-ray and optical data, and a jet powered by the central supermassive black hole is shown by the radio data. This Chandra study is much deeper than previous X-ray observations. Using this data, researchers believe that each year several times the mass of our sun is being deposited out to large distances, about 3,000 light years from the black hole. The wind likely carries enough energy to heat the surrounding gas and suppress extra star formation. These results help explain how a supermassive black hole can alter the evolution of its host galaxy. It has long been suspected that material blown away from a black hole can affect its environment, but a key question has been whether such "black hole blowback" typically delivers enough power to have a significant impact. NGC 1068 is located about 50 million light years from Earth and contains a supermassive black hole about twice as massive as the one in the middle of the Milky Way Galaxy. Image Credit: X-ray (NASA/CXC/ MIT/C.Canizares, D.Evans et al), Optical (NASA/STScI), Radio (NSF/ NRAO/VLA)

Cosmic Pressure Fronts Mapped by Chandra

NASA Astrophysics Data System (ADS)

2000-03-01

A colossal cosmic "weather system" produced by the collision of two giant clusters of galaxies has been imaged by NASA's Chandra X-ray Observatory. For the first time, the pressure fronts in the system can be traced in detail, and they show a bright, but relatively cool 50 million degree Celsius central region embedded in large elongated cloud of 70 million degree Celsius gas, all of which is roiling in a faint "atmosphere"of 100 million degree Celsius gas. "We can compare this to an intergalactic cold front," said Maxim Markevitch of the Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass. and leader of the international team involved in the analysis of the observations. "A major difference is that in this case, cold means 70 million degree Celsius." The gas clouds are in the core of a galaxy cluster known as Abell 2142. The cluster is six million light years across and contains hundreds of galaxies and enough gas to make a thousand more. It is one of the most massive objects in the universe. Galaxy clusters grow to vast sizes as smaller clusters are pulled inward under the influence of gravity. They collide and merge over the course of billions of years, releasing tremendous amounts of energy that heats the cluster gas to 100 million degrees Celsius. The Chandra data provides the first detailed look at the late stages of this merger process. Previously, scientists had used the German-US Roentgensatellite to produce a broad brush picture of the cluster. The elongated shape of the bright cloud suggested that two clouds were in the process of coalescing into one, but the details remained unclear. Chandra is able to measure variations of temperature, density, and pressure with unprecedented resolution. "Now we can begin to understand the physics of these mergers, which are among the most energetic events in the universe," said Markevitch. "The pressure and density maps of the cluster show a sharp boundary that can only exist in the moving environment of a merger." With this information scientists can make a comparison with computer simulations of cosmic mergers. This comparison, which is in the early stages, shows that this merger has progressed to an advanced stage. Strong shock waves predicted by the theory for the initial collision of clusters are not observed. It appears likely that these sub-clusters have collided two or three times in a billion years or more, and have nearly completed their merger. The observations were made on August 20, 1999 using the Advanced CCD Imaging Spectrometer (ACIS). The team involved scientists from Harvard-Smithsonian; the Massachusetts Institute of Technology, Cambridge; NASA's Marshall Space Flight Center, Huntsville, Ala.; the University of Hawaii, Honolulu; the University of Birmingham, U.K.; the University of Wollongong, Australia; the Space Research Organization Netherlands; the University of Rome, Italy; and the Russian Academy of Sciences. The results will be published in an upcoming issue of the Astrophysical Journal. The ACIS instrument was built for NASA by the Massachusetts Institute of Technology, Cambridge, and Pennsylvania State University, University Park. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program. TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass. For images connected to this release, and to follow Chandra's progress, visit the Chandra site at: http://chandra.harvard.edu/photo/2000/a2142/index.html AND http://chandra.nasa.gov High resolution digital versions of the X-ray image (JPG, 300 dpi TIFF) are available at the Internet sites listed above. This image will be available on NASA Video File which airs at noon, 3:00 p.m., 6:00 p.m., 9:00 p.m. and midnight Eastern Time. NASA Television is available on GE-2, transponder 9C at 85 degrees West longitude, with vertical polarization. Frequency is on 3880.0 megahertz, with audio on 6.8 megahertz.

Gigantic Wave Discovered in Perseus Galaxy Cluster

NASA Image and Video Library

2017-12-08

Combining data from NASA's Chandra X-ray Observatory with radio observations and computer simulations, an international team of scientists has discovered a vast wave of hot gas in the nearby Perseus galaxy cluster. Spanning some 200,000 light-years, the wave is about twice the size of our own Milky Way galaxy. The researchers say the wave formed billions of years ago, after a small galaxy cluster grazed Perseus and caused its vast supply of gas to slosh around an enormous volume of space. "Perseus is one of the most massive nearby clusters and the brightest one in X-rays, so Chandra data provide us with unparalleled detail," said lead scientist Stephen Walker at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "The wave we've identified is associated with the flyby of a smaller cluster, which shows that the merger activity that produced these giant structures is still ongoing." Read more at nasa.gov Credit: NASA's Goddard Space Flight Center/Stephen Walker href="http://www.nasa.gov/audience/formedia/features/MP_Photo_Guidelines.html" rel="nofollow">NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

The Stability of Chandra Telescope Pointing and Spacial Resolution

NASA Astrophysics Data System (ADS)

Zhao, Ping

2018-01-01

Chandra X-ray Observatory revolutionized the X-ray astronomy as being the first, and so far the only, X-ray telescope achieving sub-arcsecond spacial resolution. Chandra is comprised of three principal elements: the High Resolution Mirror Assembly (HRMA), Pointing Control and Aspect Determination (PCAD) system, and the Science Instrument Module (SIM), which is where the X-ray detectors mounted and is connected to the HRMA by a 10-meter long Optical Bench Assembly. To achieve and retain the unprecedented imaging quality, it is critical that these three principal elements to stay rigid and stable for the entire life time of the Chandra operation. I will review the issues of telescope pointing stability, optical Axis, aimpoint and their impacts to the Chandra operation, and evaluate the integrity and stability of the telescope. I will show images taken from all four detectors since launch to demonstrate the quality and stability of the Chandra spacial resolution.

The Quality and Stability of Chandra Telescope Spacial Resolution

NASA Astrophysics Data System (ADS)

Zhao, Ping

2017-08-01

Chandra X-ray Observatory revolutionized the X-ray astronomy as being the first, and so far the only, X-ray telescope achieving sub-arcsecond spacial resolution. Chandra is comprised of three principal elements: the High Resolution Mirror Assembly (HRMA), Pointing Control and Aspect Determination (PCAD) system, and the Science Instrument Module (SIM), which is where the X-ray detectors mounted and is connected to the HRMA by a 10-meter long Optical Bench Assembly. To achieve and retain the unprecedented imaging quality, it is critical that these three principal elements to stay rigid and stable for the entire life time of the Chandra operation. I will review the issues of telescope pointing stability, optical Axis, aimpoint and their impacts to the Chandra operation, and evaluate the integrity and stability of the telescope. I will show images taken from all four detectors since launch to demonstrate the quality and stability of the Chandra spacial resolution.

Science & Art in Motion: Visualizing the X-ray Universe

NASA Astrophysics Data System (ADS)

Hobart, A. J.; Arcand, K. K.; Edmonds, P. D.; Tucker, W. H.

2005-12-01

Since its launch in 1999, the Chandra X-ray Observatory has probed regions around black holes, traced the debris of exploded stars, and helped to elucidate the formation of galaxy clusters, the largest bound structures in the Universe. Conveying Chandra's exciting, though often complicated, high-energy results to the public and the media poses certain visual challenges, such as photon-starved observational data, spectra, and esoteric concepts. This poster will demonstrate some of the techniques developed to present visuals by way of motion graphics in X-ray astronomy. Some tricks of the trade will be highlighted, including establishing texture libraries, using particle or paint effects, and modeling stock objects. Topics unique to animating scientific concepts for public consumption will also be discussed, such as addressing public perception versus scientists' findings, keeping a high standard of accuracy while leaving room for visual excitement, communicating with scientists for revisions, and creative ways to interact with and educate the public. Developed with funding from NASA under Contract NAS8-39073.

X-Ray Emission from the MUSCLES Exoplanet Host Stars

NASA Astrophysics Data System (ADS)

Brown, Alexander; Schneider, P. Christian; France, Kevin; Loyd, Parke; MUSCLES Team

2016-07-01

The MUSCLES (Measurements of the Ultraviolet Spectral Characteristics of Low-mass Exoplanetary Systems) project is a multi-spectral-region investigation of the high-energy (UV/X-ray) radiation fields of K dwarf / M dwarf exoplanet host stars and how this radiation will influence the evolution of the exoplanet atmospheres. As part of this project we have used Chandra and XMM-Newton to study the X-ray emission from ten (7 M dwarf and 3 K dwarf), nearby (within 15 pc), low mass exoplanet hosts. Typically, we have coordinated the X-ray observations with HST-COS FUV and ground-based optical spectroscopy of the same targets. Even though these stars are generally considered to be inactive we find evidence for significant X-ray variability for many of the M dwarfs observed. In this poster we illustrate the coronal properties of the stars using example light-curves and spectral analyses. The UV and X-ray data are crucial input to the modeling the complete spectral energy distributions for exoplanet studies.This work was supported by Chandra grants GO4-15041X and GO5-16155X and NASA XMM grant NNX16AC09G to the University of Colorado at Boulder. The overall MUSCLES project was undertaken by HST GO programs 12464 and 13650 and supported by STScI grants HST-GO-12464.01 and HST-GO-13650.01 . P.C.S. is supported by an ESA Research Fellowship.

Managing Radiation Degradation of CCDs on the Chandra X-ray Observatory

NASA Technical Reports Server (NTRS)

ODell, Stephen L.; Blackwell, William C.; Minow, Joseph I.; Cameron, Robert A.; Morris, David C.; Virani, Shanil N.; Six, N. Frank (Technical Monitor)

2002-01-01

The CCDs on the Chandra X ray Observatory are sensitive to radiation damage particularly from low-energy protons scattering off the telescope's mirrors onto the focal plane. In its highly elliptical orbit, Chandra passes through a spatially and temporally varying radiation environment, ranging from the radiation belts to the solar wind. Translating thc Advanced CCD Imaging Spectrometer (ACIS) out of the focal position during radiation-belt passages has prevented loss of scientific utility and eventually functionality. However, carefully managing the radiation damage during the remainder of the orbit, without unnecessarily sacrificing observing time, is essential to optimizing the scientific value of this exceptional observatory throughout its planned 10-year mission. In working toward this optimization, the Chandra team developed aid applied radiation-management strategies. These strategies include autonomous instrument safing triggered by the on-board radiation monitor, as well as monitoring, alerts, and intervention based upon real-time space-environment data from NOAA and NASA spacecraft. Furthermore, because Chandra often spends much of its orbit out of the solar wind (in the Earth's outer magnetosphere and magnetosheath), the team developed the Chandra Radiation Model to describe the complete low-energy-proton environment. Management of the radiation damage has thus far succeeded in limiting degradation of the charge-transfer inefficiency (CTI) to less than 4.4*10^-6 and 1.4*10^-6 per year for the front-illuminated and back-illuminated CCDs, respectively.

Chandra Reveals Nest of Tight Binaries in Dense Cluster

NASA Astrophysics Data System (ADS)

2001-05-01

Scientists have gazed into an incredibly dense star cluster with NASA's Chandra X-ray Observatory and identified a surprising bonanza of binary stars, including a large number of rapidly rotating neutron stars. The discovery may help explain how one of the oldest structures in our Galaxy evolved over its lifetime. By combining Chandra, Hubble Space Telescope, and ground-based radio data, the researchers conducted an important survey of the binary systems that dominate the dynamics of 47 Tucanae, a globular cluster about 12 billion years old located in our Milky Way galaxy. Most of the binaries in 47 Tucanae are systems in which a normal, Sun-like companion orbits a collapsed star, either a white dwarf or a neutron star. White dwarf stars are dense, burnt-out remnants of stars like the Sun, while neutron stars are even denser remains of a more massive star. When matter from a nearby star falls onto either a white dwarf or a neutron star, as in the case with the binaries in 47 Tucanae, X-rays are produced. 47 Tuc This composite image shows relation of the Chandra image of 47 Tucanae to ground-based, optical observations. "This Chandra image provides the first complete census of compact binaries in the core of a globular cluster," said Josh Grindlay of the Harvard-Smithsonian Center for Astrophysics (CfA) and lead author of the report that appears in the May 18 issue of Science. "The relative number of neutron stars versus white dwarfs in these binaries tell us about the development of the first stars in the cluster, and the binaries themselves are key to the evolution of the entire cluster core." Many of the binaries in 47 Tucanae are exotic systems never before seen in such large quantities. Perhaps the most intriguing are the "millisecond pulsars", which contain neutron stars that are rotating extremely rapidly, between 100 to nearly 1000 times a second. "The Chandra data, in conjunction with radio observations, indicate that there are many more millisecond pulsars than we would expect based on the number of their likely progenitors we found," said co-author Peter Edmonds, also of the CfA. "While there is a general consensus on how some of the millisecond pulsars form, these new data suggest that there need to be other methods to create them." In addition to the millisecond pulsars, Chandra also detected other important populations of binary systems, including those with white dwarf stars and normal stars, and others where pairs of normal stars undergo large flares induced by their close proximity. The Chandra data also indicate an apparent absence of a central black hole. Stellar-sized mass black holes -- those about five to ten times as massive as the Sun -- have apparently not coalesced to the center of the star cluster. All or most stellar-sized black holes that formed over the lifetime of the cluster have likely been ejected by their slingshot encounters with binaries deep in the cluster core. "These results show that binary star systems are a source of gravitational energy which ejects stellar mass black holes and prevents the collapse of the cluster’s core to a more massive, central black hole," said the CfA's Craig Heinke. "In other words, binary systems - not black holes - are the dynamical heat engines that drive the evolution of globular clusters." Chandra observed 47 Tucanae on March 16-17, 2000, for a period of 74,000 seconds with the Advanced CCD Imaging Spectrometer (ACIS). The ACIS X-ray camera was developed for NASA by Penn State and the Massachusetts Institute of Technology. The High Energy Transmission Grating Spectrometer was built by MIT. NASA's Marshall Space Flight Center in Huntsville, AL, manages the Chandra program. TRW, Inc., Redondo Beach, California, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, MA. Images associated with this release are available on the World Wide Web at: http://chandra.harvard.edu AND http://chandra.nasa.gov

Never Before Seen: Two Supermassive Black Holes in Same Galaxy

NASA Astrophysics Data System (ADS)

2002-11-01

For the first time, scientists have proof two supermassive black holes exist together in the same galaxy, thanks to data from NASA's Chandra X-ray Observatory. These black holes are orbiting each other and will merge several hundred million years from now, to create an even larger black hole resulting in a catastrophic event that will unleash intense radiation and gravitational waves. The Chandra image reveals that the nucleus of an extraordinarily bright galaxy, known as NGC 6240, contains not one, but two giant black holes, actively accreting material from their surroundings. This discovery shows that massive black holes can grow through mergers in the centers of galaxies, and that these enigmatic events will be detectable with future space-borne gravitational wave observatories. "The breakthrough came with Chandra's ability to clearly distinguish the two nuclei, and measure the details of the X-radiation from each nucleus," said Guenther Hasinger, of the Max Planck Institute for Extraterrestrial Physics in Germany, a coauthor of an upcoming Astrophysical Journal Letters paper describing the research. "These cosmic fingerprints revealed features characteristic of supermassive black holes -- an excess of high-energy photons from gas swirling around a black hole, and X-rays from fluorescing iron atoms in gas near black holes," he said. Previous X-ray observatories had shown that the central region produces X-rays, while radio, infrared and optical observations had detected two bright nuclei, but the nature of this region remained a mystery. Astronomers did not know the location of the X-ray source, or the nature of the two bright nuclei. "With Chandra, we hoped to determine which one, if either, of the nuclei was an active supermassive black hole," said Stefanie Komossa, also of the Max Planck Institute, lead author of the paper on NGC 6240. "Much to our surprise, we found that both were active black holes!" At a distance of about 400 million light years, NGC 6240 is a prime example of a massive galaxy in which stars are forming at an exceptionally rapid rate due to a recent collision and subsequent merger of two smaller galaxies. Because of the large amount of dust and gas in such galaxies, it is difficult to peer deep into their central regions with optical telescopes. However, X-rays emanating from the galactic core can penetrate the veil of gas and dust. NGC 6240 Optical & X-ray Comparison of NGC 6240 "The detection of a binary black hole supports the idea that black holes can grow to enormous masses in the centers of galaxies by merging with other black holes," said Komossa. "This is important for understanding how galaxies form and evolve," she said. Over the course of the next few hundred million years, the two black holes in NGC 6240, which are about 3000 light years apart, will drift toward one another and merge to form an even larger supermassive black hole. Toward the end of this process an enormous burst of gravitational waves will be produced several hundred million years from now. These gravitational waves will spread through the universe and produce ripples in the fabric of space, which would appear as minute changes in the distance between any two points. NASA's planned space-based detector, LISA (Laser Interferometer Space Antenna), will search for gravitational waves from massive black-hole mergers. These events are estimated to occur several times each year in the observable universe. "This is the first time we see a binary black hole in action, the smoking gun for something that will become a major gravitational wave burst in the future," said Hasinger. Chandra observed NGC 6240 for 10.3 hours with the Advanced CCD Imaging Spectrometer (ACIS). Other members of the team are Vadim Burwitz and Peter Predehl of the Max Planck Institute, Jelle Kaastra of the Space Research Organization Netherlands and Yasushi Ikebe of the University of Maryland in Baltimore. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for the Office of Space Science, Washington, and TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass. Press Kit: NGC 6240 Press Kit

NASA's Chandra Sees Brightest Supernova Ever

NASA Astrophysics Data System (ADS)

2007-05-01

WASHINGTON - The brightest stellar explosion ever recorded may be a long-sought new type of supernova, according to observations by NASA's Chandra X-ray Observatory and ground-based optical telescopes. This discovery indicates that violent explosions of extremely massive stars were relatively common in the early universe, and that a similar explosion may be ready to go off in our own galaxy. "This was a truly monstrous explosion, a hundred times more energetic than a typical supernova," said Nathan Smith of the University of California at Berkeley, who led a team of astronomers from California and the University of Texas in Austin. "That means the star that exploded might have been as massive as a star can get, about 150 times that of our sun. We've never seen that before." Chandra X-ray Image of SN 2006gy Chandra X-ray Image of SN 2006gy Astronomers think many of the first generation of stars were this massive, and this new supernova may thus provide a rare glimpse of how the first stars died. It is unprecedented, however, to find such a massive star and witness its death. The discovery of the supernova, known as SN 2006gy, provides evidence that the death of such massive stars is fundamentally different from theoretical predictions. "Of all exploding stars ever observed, this was the king," said Alex Filippenko, leader of the ground-based observations at the Lick Observatory at Mt. Hamilton, Calif., and the Keck Observatory in Mauna Kea, Hawaii. "We were astonished to see how bright it got, and how long it lasted." The Chandra observation allowed the team to rule out the most likely alternative explanation for the supernova: that a white dwarf star with a mass only slightly higher than the sun exploded into a dense, hydrogen-rich environment. In that event, SN 2006gy should have been 1,000 times brighter in X-rays than what Chandra detected. Animation of SN 2006gy Animation of SN 2006gy "This provides strong evidence that SN 2006gy was, in fact, the death of an extremely massive star," said Dave Pooley of the University of California at Berkeley, who led the Chandra observations. The star that produced SN 2006gy apparently expelled a large amount of mass prior to exploding. This large mass loss is similar to that seen from Eta Carinae, a massive star in our galaxy, raising suspicion that Eta Carinae may be poised to explode as a supernova. Although SN 2006gy is intrinsically the brightest supernova ever, it is in the galaxy NGC 1260, some 240 million light years away. However, Eta Carinae is only about 7,500 light years away in our own Milky Way galaxy. "We don't know for sure if Eta Carinae will explode soon, but we had better keep a close eye on it just in case," said Mario Livio of the Space Telescope Science Institute in Baltimore, who was not involved in the research. "Eta Carinae's explosion could be the best star-show in the history of modern civilization." A New Line of Stellar Evolution A New Line of Stellar Evolution Supernovas usually occur when massive stars exhaust their fuel and collapse under their own gravity. In the case of SN 2006gy, astronomers think that a very different effect may have triggered the explosion. Under some conditions, the core of a massive star produces so much gamma ray radiation that some of the energy from the radiation converts into particle and anti-particle pairs. The resulting drop in energy causes the star to collapse under its own huge gravity. After this violent collapse, runaway thermonuclear reactions ensue and the star explodes, spewing the remains into space. The SN 2006gy data suggest that spectacular supernovas from the first stars - rather than completely collapsing to a black hole as theorized - may be more common than previously believed. "In terms of the effect on the early universe, there's a huge difference between these two possibilities," said Smith. "One pollutes the galaxy with large quantities of newly made elements and the other locks them up forever in a black hole." The results from Smith and his colleagues will appear in The Astrophysical Journal. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

RCW 108: Massive Young Stars Trigger Stellar Birth

NASA Technical Reports Server (NTRS)

2008-01-01

RCW 108 is a region where stars are actively forming within the Milky Way galaxy about 4,000 light years from Earth. This is a complicated region that contains young star clusters, including one that is deeply embedded in a cloud of molecular hydrogen. By using data from different telescopes, astronomers determined that star birth in this region is being triggered by the effect of nearby, massive young stars.

This image is a composite of X-ray data from NASA's Chandra X-ray Observatory (blue) and infrared emission detected by NASA's Spitzer Space Telescope (red and orange). More than 400 X-ray sources were identified in Chandra's observations of RCW 108. About 90 percent of these X-ray sources are thought to be part of the cluster and not stars that lie in the field-of-view either behind or in front of it. Many of the stars in RCW 108 are experiencing the violent flaring seen in other young star-forming regions such as the Orion nebula. Gas and dust blocks much of the X-rays from the juvenile stars located in the center of the image, explaining the relative dearth of Chandra sources in this part of the image.

The Spitzer data show the location of the embedded star cluster, which appears as the bright knot of red and orange just to the left of the center of the image. Some stars from a larger cluster, known as NGC 6193, are also visible on the left side of the image. Astronomers think that the dense clouds within RCW 108 are in the process of being destroyed by intense radiation emanating from hot and massive stars in NGC 6193.

Taken together, the Chandra and Spitzer data indicate that there are more massive star candidates than expected in several areas of this image. This suggests that pockets within RCW 108 underwent localized episodes of star formation. Scientists predict that this type of star formation is triggered by the effects of radiation from bright, massive stars such as those in NGC 6193. This radiation may cause the interior of gas clouds in RCW 108 to be compressed, leading to gravitational collapse and the formation of new stars.

Geriatric Pulsar Still Kicking

NASA Astrophysics Data System (ADS)

2009-02-01

The oldest isolated pulsar ever detected in X-rays has been found with NASA's Chandra X-ray Observatory. This very old and exotic object turns out to be surprisingly active. The pulsar, PSR J0108-1431 (J0108 for short) is about 200 million years old. Among isolated pulsars -- ones that have not been spun-up in a binary system -- it is over 10 times older than the previous record holder with an X-ray detection. At a distance of 770 light years, it is one of the nearest pulsars known. Pulsars are born when stars that are much more massive than the Sun collapse in supernova explosions, leaving behind a small, incredibly weighty core, known as a neutron star. At birth, these neutron stars, which contain the densest material known in the Universe, are spinning rapidly, up to a hundred revolutions per second. As the rotating beams of their radiation are seen as pulses by distant observers, similar to a lighthouse beam, astronomers call them "pulsars". Astronomers observe a gradual slowing of the rotation of the pulsars as they radiate energy away. Radio observations of J0108 show it to be one of the oldest and faintest pulsars known, spinning only slightly faster than one revolution per second. The surprise came when a team of astronomers led by George Pavlov of Penn State University observed J0108 in X-rays with Chandra. They found that it glows much brighter in X-rays than was expected for a pulsar of such advanced years. People Who Read This Also Read... Chandra Data Reveal Rapidly Whirling Black Holes Milky Way’s Giant Black Hole Awoke from Slumber 300 Years Ago Erratic Black Hole Regulates Itself Celebrate the International Year of Astronomy Some of the energy that J0108 is losing as it spins more slowly is converted into X-ray radiation. The efficiency of this process for J0108 is found to be higher than for any other known pulsar. "This pulsar is pumping out high-energy radiation much more efficiently than its younger cousins," said Pavlov. "So, although it's clearly fading as it ages, it is still more than holding its own with the younger generations." It's likely that two forms of X-ray emission are produced in J0108: emission from particles spiraling around magnetic fields, and emission from heated areas around the neutron star's magnetic poles. Measuring the temperature and size of these heated regions can provide valuable insight into the extraordinary properties of the neutron star surface and the process by which charged particles are accelerated by the pulsar. The younger, bright pulsars commonly detected by radio and X-ray telescopes are not representative of the full population of objects, so observing objects like J0108 helps astronomers see a more complete range of behavior. At its advanced age, J0108 is close to the so-called "pulsar death line," where its pulsed radiation is expected to switch off and it will become much harder, if not impossible, to observe. "We can now explore the properties of this pulsar in a regime where no other pulsar has been detected outside the radio range," said co-author Oleg Kargaltsev of the University of Florida. "To understand the properties of 'dying pulsars,' it is important to study their radiation in X-rays. Our finding that a very old pulsar can be such an efficient X-ray emitter gives us hope to discover new nearby pulsars of this class via their X-ray emission." The Chandra observations were reported by Pavlov and colleagues in the January 20, 2009, issue of The Astrophysical Journal. However, the extreme nature of J0108 was not fully apparent until a new distance to it was reported on February 6 in the PhD thesis of Adam Deller from Swinburne University in Australia. The new distance is both larger and more accurate than the distance used in the Chandra paper, showing that J0108 was brighter in X-rays than previously thought. "Suddenly this pulsar became the record holder for its ability to make X-rays," said Pavlov, "and our result became even more interesting without us doing much extra work." PSR J0108-1431 Chandra X-ray Image of PSR J0108-1431 The position of the pulsar seen by Chandra in X-rays in early 2007 is slightly different from the radio position observed in early 2001. This implies that the pulsar is moving at a velocity of about 440,000 miles per hour, close to a typical value for pulsars. Currently the pulsar is moving south from the plane of the Milky Way galaxy, but because it is moving more slowly than the escape velocity of the Galaxy, it will eventually curve back towards the plane of the Galaxy in the opposite direction. The detection of this motion has allowed Roberto Mignani of University College London, in collaboration with Pavlov and Kargaltsev, to possibly detect J0108 in optical light, using estimates of where it should be found in an image taken in 2000. Such a multi-wavelength study of old pulsars is critical for understanding the long-term evolution of neutron stars, such as how they cool with time, and how their powerful magnetic fields evolve. The team of astronomers that worked with Pavlov also included Gordon Garmire and Jared Wong at Penn State. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass.

NASA Find Clues that May Help Identify Dark Matter

NASA Image and Video Library

2015-03-26

Using observations from NASA’s Hubble Space Telescope and Chandra X-ray Observatory, astronomers have found that dark matter does not slow down when colliding with itself, meaning it interacts with itself less than previously thought. Researchers say this finding narrows down the options for what this mysterious substance might be. Dark matter is an invisible matter that makes up most of the mass of the universe. Because dark matter does not reflect, absorb or emit light, it can only be traced indirectly by, such as by measuring how it warps space through gravitational lensing, during which the light from a distant source is magnified and distorted by the gravity of dark matter. Read more: 1.usa.gov/1E5LcpO Caption: Here are images of six different galaxy clusters taken with NASA's Hubble Space Telescope (blue) and Chandra X-ray Observatory (pink) in a study of how dark matter in clusters of galaxies behaves when the clusters collide. A total of 72 large cluster collisions were studied. Credit: NASA and ESA mage Credit: NASA and ESA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

STS-93/ Chandra Science Briefing

NASA Technical Reports Server (NTRS)

1999-01-01

This video shows a press briefing, reviewing the type of information which scientist hope to get from the Chandra X-ray Telescope. The telescope is scheduled to be launched during the STS-93 flight. The participants in the briefing are: Don Savage, of NASA Headquarters; Ed Weiler, Associate Administrator for Space Sciences; Alan Bunner, Chandra Project Scientist and Michael Turner, an astrophysicist at the University of Chicago. After the introduction by Mr. Savage, the broad scientific goals of the Chandra mission are reviewed by Dr. Weiler. This is followed by an acknowledgement of many of the people who participated in the development of the Chandra Telescope. This is followed by a discussion of the astrophysics and the information which the telescope should provide. Mrs. Chandrasekhar, the widow of Subrahmanyan Chandrasekhar, was in the audience. She was introduced and spoke briefly about the late Nobel Laureate astrophysicist.

Time-domain Astronomy with the Advanced X-ray Imaging Satellite

NASA Astrophysics Data System (ADS)

Winter, Lisa M.; Vestrand, Tom; Smith, Karl; Kippen, Marc; Schirato, Richard

2018-01-01

The Advanced X-ray Imaging Satellite (AXIS) is a concept NASA Probe class mission that will enable time-domain X-ray observations after the conclusion of the successful Swift Gamma-ray burst mission. AXIS will achieve rapid response, like Swift, with an improved X-ray monitoring capability through high angular resolution (similar to the 0.5 arc sec resolution of the Chandra X-ray Observatory) and high sensitivity (ten times the Chandra count rate) observations in the 0.3-10 keV band. In the up-coming decades, AXIS’s fast slew rate will provide the only rapid X-ray capability to study explosive transient events. Increased ground-based monitoring with next-generation survey telescopes like the Large Synoptic Survey Telescope will provide a revolution in transient science through the discovery of many new known and unknown phenomena – requiring AXIS follow-ups to establish the highest energy emission from these events. This synergy between AXIS and ground-based detections will constrain the rapid rise through decline in energetic emission from numerous transients including: supernova shock breakout winds, gamma-ray burst X-ray afterglows, ionized gas resulting from the activation of a hidden massive black hole in tidal disruption events, and intense flares from magnetic reconnection processes in stellar coronae. Additionally, the combination of high sensitivity and angular resolution will allow deeper and more precise monitoring for prompt X-ray signatures associated with gravitational wave detections. We present a summary of time-domain science with AXIS, highlighting its capabilities and expected scientific gains from rapid high quality X-ray imaging of transient phenomena.

X-Ray Astronomy Research at the Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Austin, Robert A.

1999-01-01

For at least twenty years, NASA's Marshall Space Flight Center (MSFC) has played a major role in the development of X-ray astronomy in the United States. MSFC scientists and engineers are currently involved in a wide range of programs which will contribute to the growth of X-ray astronomy well into the next century. Areas of activity include calibration of X-ray astronomy instrumentation using Marshall's world-class X-ray Calibration Facility (XRCF), development of high-throughput, replicated X-ray optics, X-ray detector development, balloon-based X-ray astronomy, and analysis of Active Galactic Nuclei (AGNs) and clusters of galaxies. Recent milestones include the successful calibration of NASA's premier X-ray Astronomy Satellite - AXAF (recently renamed Chandra), a balloon flight of a large area (1000 sq cm) micro-strip proportional counter, and work on a hard X-ray (30-100 keV) telescope called HERO, capable of high quality spectroscopy and imaging through the use of grazing incidence optics and an Imaging Gas Scintillation Proportional Counter (IGSPC). In my presentation, I will provide a general overview of our research and facilities. I will conclude with a more detailed discussion of our High Energy Replicated Optics (HERO) program and plans for long duration (>100 days) balloon flights which will take place in the near future.

Mrs. Chandrasekhar addresses the media in TRW Media Hospitality Tent

NASA Technical Reports Server (NTRS)

1999-01-01

Mrs. Lalitha Chandrasekhar (right), wife of the late Indian- American Nobel Laureate Subrahmanyan Chandrasekhar, addresses the media and other invited guests in the TRW Media Hospitality Tent at the NASA Press Site at KSC as Dr. Alan Bunner, Science Program Director, Structure and Evolution of the Universe, Office of Space Science, NASA Headquarters, Washington, D.C., looks on. The name 'Chandra,' a shortened version of her husband's name which he preferred among friends and colleagues, was chosen in a contest to rename the Advanced X-ray Astrophysics Facility. 'Chandra' also means 'Moon' or 'luminous' in Sanskrit. The observatory is scheduled to be launched aboard Columbia on Space Shuttle mission STS-93.

The Chandra X-ray Observatory removed from its container in the Vertical Processing Facility

NASA Technical Reports Server (NTRS)

1999-01-01

Inside the Vertical Processing Facility (VPF), the overhead crane lifts Chandra X-ray Observatory completely out of its protective container. While in the VPF, the telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe.

The Chandra X-ray Observatory removed from its container in the Vertical Processing Facility

NASA Technical Reports Server (NTRS)

1999-01-01

Inside the Vertical Processing Facility (VPF), workers begin lifting the Chandra X-ray Observatory out of its protective container. While in the VPF, the telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe.

Chandra enables study of x-ray jets

PubMed Central

Schwartz, Daniel

2010-01-01

The exquisite angular resolution of the Chandra x-ray telescope has enabled the detection and study of resolved x-ray jets in a wide variety of astronomical systems. Chandra has detected extended jets in our galaxy from protostars, symbiotic binaries, neutron star pulsars, black hole binaries, extragalactic jets in radio sources, and quasars. The x-ray data play an essential role in deducing the emission mechanism of the jets, in revealing the interaction of jets with the intergalactic or intracluster media, and in studying the energy generation budget of black holes. PMID:20378839

The Generation-X X-ray Observatory Vision Mission and Technology Study

NASA Technical Reports Server (NTRS)

Figueroa-Feliciano, Enectali

2004-01-01

The new frontier in astrophysics is the study of the birth and evolution of the first stars, galaxies and black holes in the early Universe. X-ray astronomy opens a window into these objects by studying the emission from black holes, supernova explosions and the gamma-ray burst afterglows of massive stars. However, such objects are beyond the grasp of current or near-future observatories. X-ray imaging and spectroscopy of such distant objects will require an X-ray telescope with large collecting area and high angular resolution. Our team has conceived the Generation-X Vision Mission based on an X-ray observatory with 100 sq m collecting area at 1 keV (1000 times larger than Chandra) and 0.1 arcsecond angular resolution (several times better than Chandra and 50 times better than the Constellation-X resolution goal). Such an observatory would be capable of detecting the earliest black holes and galaxies in the Universe, and will also study extremes of density, gravity, magnetic fields, and kinetic energy which cannot be created in laboratories. NASA has selected the Generation-X mission for study under its Vision Mission Program. We describe the studies being performed to develop the mission concept and define candidate technologies and performance requirements for Generation-X. The baseline Generation-X mission involves four 8m diameter X-ray telescopes operating at Sun-Earth L2. We trade against an alternate concept of a single 26m diameter telescope with focal plane instruments on a separate spacecraft. A telescope of this size will require either robotic or human-assisted in-flight assembly. The required effective area implies that extremely lightweight grazing incidence X-ray optics must be developed. To achieve the required aerial density of at least 100 times lower than in Chandra, we will study 0.1mm thick mirrors which have active on-orbit figure control. We discuss the suite of required detectors, including a large FOV high angular resolution imager, a cryogenic imaging spectrometer and a grating spectrometer. We outline the development roadmap to confront the many technological challenges far implementing the Generation-X mission.

Probing the X-ray Emission from the Massive Star Cluster Westerlund 2

NASA Astrophysics Data System (ADS)

Lopez, Laura

2017-09-01

We propose a 300 ks Chandra ACIS-I observation of the massive star cluster Westerlund 2 (Wd2). This region is teeming with high-energy emission from a variety of sources: colliding wind binaries, OB and Wolf-Rayet stars, two young pulsars, and an unidentified source of very high-energy (VHE) gamma-rays. Our Chandra program is designed to achieve several goals: 1) to take a complete census of Wd2 X-ray point sources and monitor variability; 2) to probe the conditions of the colliding winds in the binary WR 20a; 3) to search for an X-ray counterpart of the VHE gamma-rays; 4) to identify diffuse X-ray emission; 5) to compare results to other massive star clusters observed by Chandra. Only Chandra has the spatial resolution and sensitivity necessary for our proposed analyses.

Why do we see Broad Lines in X-ray Absorbed, Red AGN?

NASA Astrophysics Data System (ADS)

Wilkes, B. J.; Ghosh, Himel; Cutri, R.; Hines, D.; Nelson, B.; Schmidt, G. D.; Smith, P. S.

2003-05-01

The Two Micron All-Sky Survey (2MASS) red AGN catalog has revealed a previously unknown population whose number density rivals that of optically-selected AGN as found in the many, relatively shallow surveys (e.g. PG, Hamburg). The Chandra X-ray spectra of these red, mostly broad-line AGN are hard. This, combined with their unusually high optical polarization, suggests substantial obscuration (log NH = 21-23 cm-2) toward the nuclear energy source, despite a clear view of the broad emission line region. We have expanded our Chandra-observed sub-sample to include 20 more 2MASS AGN yielding a set of 46 which includes all available optical classes. This sample is thus pre-selected for complex absorption and sufficient to study the relative X-ray and optical obscuration for each AGN class. Those observed to date continue the lack of a relation between the X-ray hardness ratio and optical class noted in our earlier sample. Combining this with X-ray spectral fits where we have sufficient counts and with our multi-wavelength data, we compare the spectral energy distributions with those of normal and other red AGN and investigate possible scenarios for the absorbing material. We gratefully ackowledge the financial support of NASA grant: GO1-2112A

Laboratory measurements of the K-shell transition energies in L-shell ions of Si and S [Energy measurements of K-shell transitions in L-shell ions of Si and S

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hell, Natalie; Brown, G. V.; Wilms, J.

We have measured the energies of the strongest 1s–2more » $${\\ell }\\ ({\\ell }={\\rm{s}},{\\rm{p}})$$ transitions in He- through Ne-like silicon and sulfur ions to an accuracy of $$\\lt 1\\,\\mathrm{eV}$$ using the Lawrence Livermore National Laboratory's electron beam ion traps, EBIT-I and SuperEBIT, and the NASA/GSFC EBIT Calorimeter Spectrometer (ECS). We identify and measure the energies of 18 and 21 X-ray features from silicon and sulfur, respectively. The results are compared to new Flexible Atomic Code calculations and to semi-relativistic Hartree–Fock calculations by Palmeri et al. (2008). These results will be especially useful for wind diagnostics in high-mass X-ray binaries, such as Vela X-1 and Cygnus X-1, where high-resolution spectral measurements using Chandra's high-energy transmission grating has made it possible to measure Doppler shifts of $$100\\,\\mathrm{km}\\,{{\\rm{s}}}^{-1}$$. The accuracy of our measurements is consistent with that needed to analyze Chandra observations, exceeding Chandra's $$100\\,\\mathrm{km}\\,{{\\rm{s}}}^{-1}$$ limit. Hence, the results presented here not only provide benchmarks for theory, but also accurate rest energies that can be used to determine the bulk motion of material in astrophysical sources. Finally, we show the usefulness of our results by applying them to redetermine Doppler shifts from Chandra observations of Vela X-1.« less

Laboratory measurements of the K-shell transition energies in L-shell ions of Si and S [Energy measurements of K-shell transitions in L-shell ions of Si and S

DOE PAGES

Hell, Natalie; Brown, G. V.; Wilms, J.; ...

2016-10-04

We have measured the energies of the strongest 1s–2more » $${\\ell }\\ ({\\ell }={\\rm{s}},{\\rm{p}})$$ transitions in He- through Ne-like silicon and sulfur ions to an accuracy of $$\\lt 1\\,\\mathrm{eV}$$ using the Lawrence Livermore National Laboratory's electron beam ion traps, EBIT-I and SuperEBIT, and the NASA/GSFC EBIT Calorimeter Spectrometer (ECS). We identify and measure the energies of 18 and 21 X-ray features from silicon and sulfur, respectively. The results are compared to new Flexible Atomic Code calculations and to semi-relativistic Hartree–Fock calculations by Palmeri et al. (2008). These results will be especially useful for wind diagnostics in high-mass X-ray binaries, such as Vela X-1 and Cygnus X-1, where high-resolution spectral measurements using Chandra's high-energy transmission grating has made it possible to measure Doppler shifts of $$100\\,\\mathrm{km}\\,{{\\rm{s}}}^{-1}$$. The accuracy of our measurements is consistent with that needed to analyze Chandra observations, exceeding Chandra's $$100\\,\\mathrm{km}\\,{{\\rm{s}}}^{-1}$$ limit. Hence, the results presented here not only provide benchmarks for theory, but also accurate rest energies that can be used to determine the bulk motion of material in astrophysical sources. Finally, we show the usefulness of our results by applying them to redetermine Doppler shifts from Chandra observations of Vela X-1.« less

NASA Space Observatories Glimpse Faint Afterglow of Nearby Stellar Explosion

NASA Astrophysics Data System (ADS)

2005-10-01

Intricate wisps of glowing gas float amid a myriad of stars in this image created by combining data from NASA's Hubble Space Telescope and Chandra X-ray Observatory. The gas is a supernova remnant, cataloged as N132D, ejected from the explosion of a massive star that occurred some 3,000 years ago. This titanic explosion took place in the Large Magellanic Cloud, a nearby neighbor galaxy of our own Milky Way. The complex structure of N132D is due to the expanding supersonic shock wave from the explosion impacting the interstellar gas of the LMC. Deep within the remnant, the Hubble visible light image reveals a crescent-shaped cloud of pink emission from hydrogen gas, and soft purple wisps that correspond to regions of glowing oxygen emission. A dense background of colorful stars in the LMC is also shown in the Hubble image. The large horseshoe-shaped gas cloud on the left-hand side of the remnant is glowing in X-rays, as imaged by Chandra. In order to emit X-rays, the gas must have been heated to a temperature of about 18 million degrees Fahrenheit (10 million degrees Celsius). A supernova-generated shock wave traveling at a velocity of more than four million miles per hour (2,000 kilometers per second) is continuing to propagate through the low-density medium today. The shock front where the material from the supernova collides with ambient interstellar material in the LMC is responsible for these high temperatures. Chandra image of N132D Chandra image of N132D, 2002 It is estimated that the star that exploded as a supernova to produce the N132D remnant was 10 to 15 times more massive than our own Sun. As fast-moving ejecta from the explosion slam into the cool, dense interstellar clouds in the LMC, complex shock fronts are created. A supernova remnant like N132D provides a rare opportunity for direct observation of stellar material, because it is made of gas that was recently hidden deep inside a star. Thus it provides information on stellar evolution and the creation of chemical elements such as oxygen through nuclear reactions in their cores. Such observations also help reveal how the interstellar medium (the gas that occupies the vast spaces between the stars) is enriched with chemical elements because of supernova explosions. Later on, these elements are incorporated into new generations of stars and their accompanying planets. Visible only from Earth's southern hemisphere, the LMC is an irregular galaxy lying about 160,000 light-years from the Milky Way. The supernova remnant appears to be about 3,000 years old, but since its light took 160,000 years to reach us, the explosion actually occurred some 163,000 years ago. This composite image of N132D was created by the Hubble Heritage team from visible-light data taken in January 2004 with Hubble's Advanced Camera for Surveys, and X-ray images obtained in July 2000 by Chandra's Advanced CCD Imaging Spectrometer. This marks the first Hubble Heritage image that combines pictures taken by two separate space observatories. The Hubble data include color filters that sample starlight in the blue, green, and red portions of the spectrum, as well as the pink emission from glowing hydrogen gas. The Chandra data are assigned blue in the color composite, in accordance with the much higher energy of the X-rays, emitted from extremely hot gas. This gas does not emit a significant amount of optical light, and was only detected by Chandra. Image Credit: NASA, ESA, and The Hubble Heritage Team (STScI/AURA) Acknowledgment: J.C. Green (Univ. of Colorado) and the Cosmic Origins Spectrograph (COS) GTO team; NASA/CXO/SAO Electronic image files, video, illustrations and additional information are available at: http://hubblesite.org/news/2005/30 http://heritage.stsci.edu/2005/30 The Space Telescope Science Institute (STScI) is operated by the Association of Universities for Research in Astronomy, Inc. (AURA), for NASA, under contract with the Goddard Space Flight Center, Greenbelt, Md. The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency (ESA).

Black Hole Paradox Solved By NASA's Chandra

NASA Astrophysics Data System (ADS)

2006-06-01

Black holes are lighting up the Universe, and now astronomers may finally know how. New data from NASA's Chandra X-ray Observatory show for the first time that powerful magnetic fields are the key to these brilliant and startling light shows. It is estimated that up to a quarter of the total radiation in the Universe emitted since the Big Bang comes from material falling towards supermassive black holes, including those powering quasars, the brightest known objects. For decades, scientists have struggled to understand how black holes, the darkest objects in the Universe, can be responsible for such prodigious amounts of radiation. Animation of a Black Hole Pulling Matter from Companion Star Animation of a Black Hole Pulling Matter from Companion Star New X-ray data from Chandra give the first clear explanation for what drives this process: magnetic fields. Chandra observed a black hole system in our galaxy, known as GRO J1655-40 (J1655, for short), where a black hole was pulling material from a companion star into a disk. "By intergalactic standards J1655 is in our backyard, so we can use it as a scale model to understand how all black holes work, including the monsters found in quasars," said Jon M. Miller of the University of Michigan, Ann Arbor, whose paper on these results appears in this week's issue of Nature. Gravity alone is not enough to cause gas in a disk around a black hole to lose energy and fall onto the black hole at the rates required by observations. The gas must lose some of its orbital angular momentum, either through friction or a wind, before it can spiral inward. Without such effects, matter could remain in orbit around a black hole for a very long time. Illustration of Magnetic Fields in GRO J1655-40 Illustration of Magnetic Fields in GRO J1655-40 Scientists have long thought that magnetic turbulence could generate friction in a gaseous disk and drive a wind from the disk that carries angular momentum outward allowing the gas to fall inward. Using Chandra, Miller and his team provided crucial evidence for the role of magnetic forces in the black hole accretion process. The X-ray spectrum, the number of X-rays at different energies, showed that the speed and density of the wind from J1655's disk corresponded to computer simulation predictions for magnetically-driven winds. The spectral fingerprint also ruled out the two other major competing theories to winds driven by magnetic fields. "In 1973, theorists came up with the idea that magnetic fields could drive the generation of light by gas falling onto black holes," said co-author John Raymond of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. "Now, over 30 years later, we finally may have convincing evidence." Evidence for Wind in the GRO J1655-40 Spectrum Evidence for Wind in the GRO J1655-40 Spectrum This deeper understanding of how black holes accrete matter also teaches astronomers about other properties of black holes, including how they grow. "Just as a doctor wants to understand the causes of an illness and not merely the symptoms, astronomers try to understand what causes phenomena they see in the Universe," said co-author Danny Steeghs also of the Harvard-Smithsonian Center for Astrophysics. "By understanding what makes material release energy as it falls onto black holes, we may also learn how matter falls onto other important objects." In addition to accretion disks around black holes, magnetic fields may play an important role in disks detected around young sun-like stars where planets are forming, as well as ultra-dense objects called neutron stars. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center, Cambridge, Mass. Additional information and images can be found at: http://chandra.harvard.edu and http://chandra.nasa.gov

STS-93 Crew Interview: Michel Tognini

NASA Technical Reports Server (NTRS)

1999-01-01

This NASA Johnson Space Center (JSC) video release presents a one-on-one interview with Mission Specialist 3, Michel Tognini (Col., French Air Force and Centre Nacional Etudes Spatiales (CNES) Astronaut). Subjects discussed include early influences that made Michel want to be a pilot and astronaut, his experience as a French military pilot and his flying history. Also discussed were French participation in building the International Space Station (ISS), the STS-93 primary mission objective, X-ray observation using the Advanced X-ray Astrophysics Facility (AXAF), and failure scenarios associated with AXAF deployment. The STS-93 mission objective was to deploy the Advanced X-ray Astrophysics Facility (AXAF), later renamed the Chandra X-Ray Observatory in honor of the late Indian-American Nobel Laureate Subrahmanyan Chandrasekhar.

Active x-ray optics for high resolution space telescopes

NASA Astrophysics Data System (ADS)

Doel, Peter; Atkins, Carolyn; Brooks, D.; Feldman, Charlotte; Willingale, Richard; Button, Tim; Rodriguez Sanmartin, Daniel; Meggs, Carl; James, Ady; Willis, Graham; Smith, Andy

2017-11-01

The Smart X-ray Optics (SXO) Basic Technology project started in April 2006 and will end in October 2010. The aim is to develop new technologies in the field of X-ray focusing, in particular the application of active and adaptive optics. While very major advances have been made in active/adaptive astronomical optics for visible light, little was previously achieved for X-ray optics where the technological challenges differ because of the much shorter wavelengths involved. The field of X-ray astronomy has been characterized by the development and launch of ever larger observatories with the culmination in the European Space Agency's XMM-Newton and NASA's Chandra missions which are currently operational. XMM-Newton uses a multi-nested structure to provide modest angular resolution ( 10 arcsec) but large effective area, while Chandra sacrifices effective area to achieve the optical stability necessary to provide sub-arc second resolution. Currently the European Space Agency (ESA) is engaged in studies of the next generation of X-ray space observatories, with the aim of producing telescopes with increased sensitivity and resolution. To achieve these aims several telescopes have been proposed, for example ESA and NASA's combined International X-ray Observatory (IXO), aimed at spectroscopy, and NASA's Generation-X. In the field of X-ray astronomy sub 0.2 arcsecond resolution with high efficiency would be very exciting. Such resolution is unlikely to be achieved by anything other than an active system. The benefits of a such a high resolution would be important for a range of astrophysics subjects, for example the potential angular resolution offered by active X-ray optics could provide unprecedented structural imaging detail of the Solar Wind bowshock interaction of comets, planets and similar objects and auroral phenomena throughout the Solar system using an observing platform in low Earth orbit. A major aim of the SXO project was to investigate the production of thin actively controlled grazing incident optics for the next generation of X-ray space telescopes. Currently telescope systems are limited in the resolution and sensitivity by the optical quality of the thin shell optics used. As part of its research programme an actively controlled prototype X-ray thin shell telescope optic of dimensions 30x10cm has been developed to bench test the technology. The design is based on thin nickel shells bonded to shaped piezo-electric unimorph actuators made from lead zirconate titanate (PZT).

Smoking Gun Found for Gamma-Ray Burst in Milky Way

NASA Astrophysics Data System (ADS)

2004-06-01

Combined data from NASA's Chandra X-ray Observatory and infrared observations with the Palomar 200-inch telescope have uncovered evidence that a gamma-ray burst, one of nature's most catastrophic explosions, occurred in our Galaxy a few thousand years ago. The supernova remnant, W49B, may also be the first remnant of a gamma-ray burst discovered in the Milky Way. W49B is a barrel-shaped nebula located about 35,000 light years from Earth. The new data reveal bright infrared rings, like hoops around a barrel, and intense X-radiation from iron and nickel along the axis of the barrel. "These results provide intriguing evidence that an extremely massive star exploded in two powerful, oppositely directed jets that were rich in iron," said Jonathan Keohane of NASA's Jet Propulsion Laboratory at a press conference at the American Astronomical Society meeting in Denver. "This makes W49B a prime candidate for being the remnant of a gamma ray burst involving a black hole collapsar." "The nearest known gamma-ray burst to Earth is several million light years away - most are billions of light years distant - so the detection of the remnant of one in our galaxy would be a major breakthrough," said William Reach, one of Keohane's collaborators from the California Institute of Technology. According to the collapsar theory, gamma-ray bursts are produced when a massive star runs out of nuclear fuel and the star's core collapses to form a black hole surrounded by a disk of extremely hot, rapidly rotating, magnetized gas. Much of this gas is pulled into the black hole, but some is flung away in oppositely directed jets of gas traveling at near the speed of light. An observer aligned with one these jets would see a gamma-ray burst, a blinding flash in which the concentrated power equals that of ten quadrillion Suns for a minute or so. The view perpendicular to the jets is a less astonishing, although nonetheless spectacular supernova explosion. For W49B, the jet is tilted out of the plane of the sky by about 20 degrees. W49B Chandra Fe K-line Image of W49B Four rings about 25 light years in diameter can be identified in the infrared image. These rings, which are due to warm gas, were presumably flung out by the rapid rotation of the massive star a few hundred thousand years before the star exploded. The rings were pushed outward by a hot wind from the star a few thousand years before it exploded. Chandra's image and spectral data show that the jets of multimillion-degree-Celsius gas extending along the axis of the barrel are rich in iron and nickel ions, consistent with their being ejected from the center of the star. This distinguishes the explosion from a conventional type II supernova in which most of the Fe and Ni goes into making the neutron star, and the outer part of the star is what is flung out. In contrast, in the collapsar model of gamma ray bursts iron and nickel from the center is ejected along the jet. At the ends of the barrel, the X-ray emission flares out to make a hot cap. The X-ray cap is surrounded by a flattened cloud of hydrogen molecules detected in the infrared. These features indicate that the shock wave produced by the explosion has encountered a large, dense cloud of gas and dust. The scenario that emerges is one in which a massive star formed from a dense cloud of dust, shone brightly for a few million years while spinning off rings of gas and pushing them away, forming a nearly empty cavity around the star. The star then underwent a collapsar-type supernova explosion that resulted in a gamma-ray burst. The observations of W49B may help to resolve a problem that has bedeviled the collapsar model for gamma-ray bursts. On the one hand, the model is based on the collapse of a massive star, which is normally formed from a dense cloud. On the other hand, observations of the afterglow of many gamma-ray bursts indicate that the explosion occurred in a low-density gas. Based on the W49B data, the resolution proposed by Keohane and colleagues is that the star had carved out an extensive low-density cavity in which the explosion subsequently occurred. "This star appears to have exploded inside a bubble it had created," said Keohane. "In a sense, it dug its own grave." NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the Office of Space Science, NASA Headquarters, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. The image and additional information are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

ASA's Chandra Neon Discovery Solves Solar Paradox

NASA Astrophysics Data System (ADS)

2005-07-01

NASA's Chandra X-ray Observatory survey of nearby sun-like stars suggests there is nearly three times more neon in the sun and local universe than previously believed. If true, this would solve a critical problem with understanding how the sun works. "We use the sun to test how well we understand stars and, to some extent, the rest of the universe," said Jeremy Drake of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. "But in order to understand the sun, we need to know exactly what it is made of," he added. It is not well known how much neon the sun contains. This is critical information for creating theoretical models of the sun. Neon atoms, along with carbon, oxygen and nitrogen, play an important role in how quickly energy flows from nuclear reactions in the sun's core to its edge, where it then radiates into space. Chandra X-ray Spectrum of II Pegasi Chandra X-ray Spectrum of II Pegasi The rate of this energy flow determines the location and size of a crucial stellar region called the convection zone. The zone extends from near the sun's surface inward approximately 125,000 miles. The zone is where the gas undergoes a rolling, convective motion much like the unstable air in a thunderstorm. "This turbulent gas has an extremely important job, because nearly all of the energy emitted at the surface of the sun is transported there by convection," Drake said. The accepted amount of neon in the sun has led to a paradox. The predicted location and size of the solar convection zone disagree with those deduced from solar oscillations. Solar oscillations is a technique astronomers previously relied on to probe the sun's interior. Several scientists have noted the problem could be fixed if the abundance of neon is in fact about three times larger than currently accepted. Attempts to measure the precise amount of neon in the Sun have been frustrated by a quirk of nature; neon atoms in the Sun give off no signatures in visible light. However, in a gas heated to millions of degrees, neon shines brightly in X-rays. Stars like the sun are covered in this super-heated gas that is betrayed by the white corona around them during solar eclipses. However, observations of the sun's corona are very difficult to analyze. Labeled Illustration of Convection in Sun-like Star Labeled Illustration of Convection in Sun-like Star To probe the neon content, Drake and his colleague Paola Testa of the Massachusetts Institute of Technology in Cambridge, Mass., observed 21 sun-like stars within a distance of 400 light years from Earth. These local stars and the sun should contain about the same amount of neon when compared to oxygen. However, these close stellar kin were found to contain on average almost three times more neon than is believed for the sun. "Either the sun is a freak in its stellar neighborhood, or it contains a lot more neon than we think," Testa said. These Chandra results reassured astronomers the detailed physical theory behind the solar model is secure. Scientists use the model of the sun as a basis for understanding the structure and evolution of other stars, as well as many other areas of astrophysics. "If the higher neon abundance measured by Drake and Testa is right, then it is a simultaneous triumph for Chandra and for the theory of how stars shine," said John Bahcall of the Institute for Advanced Study, Princeton, N.J. Bahcall is an expert in the field who was not involved in the Chandra study. Drake is lead author of the study published in this week's issue of the journal Nature. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Chandra X-ray Observations of Jovian Low-latitude Emissions: Morphological, Temporal, and Spectral Characteristics

NASA Technical Reports Server (NTRS)

Bhardwaj, Anil; Elsner, Ronald F.; Gladstone, G. Randall; Cravens, Thomas E.; Waiate J. Hunter, Jr.; Branduardi-Raymont, Graziella; Ford, Peter

2004-01-01

Chandra observed X-rays from Jupiter during 24-26 February 2003 for about 40 hours with the ACIS-S and HRC-I instruments. The analysis of Jovian low-latitude "disk" Xray emissions are presented and compared with the high-latitude "auroral" emissions. We report the first Chandra ACIS-S measured X-ray spectrum (0.3-2 keV) of Jupiter's low-latitude disk The disk X-ray emission is harder and extends to higher energies than the auroral spectrum. The temporal variation in the Jovian disk X-rays is on an average consistent with those in the solar X-rays observed by GOES, and TIMED/SSE. Contrary to the auroral X-rays, the disk emissions are uniformly distributed over Jupiter; no indication of longitudinal dependence or correlation with surface magneh field strength is visible. Also, unlike the approx. 40 +/- 20 min periodic oscillations seen in the auroral X-ray emissions, the disk emissions do not show any periodic oscillations. The disk spectrum seems to be consistent with resonant and fluorescent scattering of solar X-rays by the Jovian upper atmosphere. Jupiter's disk is found to be about 50% dimmer in soft X-rays in February 2003 compared that in December 2000, which is consistent with the decrease in solar activity. No evidence of lightning-induced X-rays is seen in the Chandra X-ray data. The Jovian disk spectra observed with Chandra-ACIS is stronger than that observed with XMM-Newton two months later during April 28-29, 2003. The XMM-Newton Xray image of Jupiter shows evidence of limb darkening on the anti-sunward side as seen from Earth, as well as an asymmetry with respect to the subsolar point: suggesting a solar driven process.

The Chandra X-ray Observatory prepped for removal from its container in the Vertical Processing Faci

NASA Technical Reports Server (NTRS)

1999-01-01

Inside the Vertical Processing Facility (VPF), workers check the overhead cable that will lift the Chandra X-ray Observatory out of its protective container. While in the VPF, the telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe.

The Chandra X-ray Observatory prepped for removal from its container in the Vertical Processing Faci

NASA Technical Reports Server (NTRS)

1999-01-01

Inside the Vertical Processing Facility (VPF), the Chandra X-ray Observatory (top) lies in its protective container while workers on the floor prepare the overhead cable that will remove it. In the VPF, the telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe.

The Chandra X-ray Observatory prepped for removal from its container in the Vertical Processing Faci

NASA Technical Reports Server (NTRS)

1999-01-01

Inside the Vertical Processing Facility (VPF), workers attach the overhead cable to the Chandra X-ray Observatory to lift it out of its protective container. While in the VPF, the telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe.

Galaxy IC 3639 with Obscured Active Galactic Nucleus

NASA Image and Video Library

2017-01-07

IC 3639, a galaxy with an active galactic nucleus, is seen in this image combining data from the Hubble Space Telescope and the European Southern Observatory. This galaxy contains an example of a supermassive black hole hidden by gas and dust. Researchers analyzed NuSTAR data from this object and compared them with previous observations from NASA's Chandra X-Ray Observatory and the Japanese-led Suzaku satellite. The findings from NuSTAR, which is more sensitive to higher energy X-rays than these observatories, confirm the nature of IC 3639 as an active galactic nucleus that is heavily obscured, and intrinsically much brighter than observed. http://photojournal.jpl.nasa.gov/catalog/PIA21087

Chandra Observations of SN 1987A: The Soft X-Ray Light Curve Revisited

NASA Technical Reports Server (NTRS)

Helder, E. A.; Broos, P. S.; Dewey, D.; Dwek, E.; McCray, R.; Park, S.; Racusin, J. L.; Zhekov, S. A.; Burrows, D. N.

2013-01-01

We report on the present stage of SN 1987A as observed by the Chandra X-Ray Observatory. We reanalyze published Chandra observations and add three more epochs of Chandra data to get a consistent picture of the evolution of the X-ray fluxes in several energy bands. We discuss the implications of several calibration issues for Chandra data. Using the most recent Chandra calibration files, we find that the 0.5-2.0 keV band fluxes of SN 1987A have increased by approximately 6 x 10(exp-13) erg s(exp-1)cm(exp-2) per year since 2009. This is in contrast with our previous result that the 0.5-2.0 keV light curve showed a sudden flattening in 2009. Based on our new analysis, we conclude that the forward shock is still in full interaction with the equatorial ring.

KSC-99pp0354

NASA Image and Video Library

1999-03-26

Viewed from above in the Vertical Processing Facility, the Chandra X-ray Observatory is seen with one of its solar panel arrays attached, at right. Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93

KSC-99pp0356

NASA Image and Video Library

1999-03-25

In the Vertical Processing Facility, TRW workers continue checking the deployment of the solar panel array (right) after attaching it to the Chandra X-ray Observatory (left). Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93

KSC-99pp0352

NASA Image and Video Library

1999-03-26

TRW technicians in the Vertical Processing Facility check the fitting of the solar panel array being attached to the Chandra X-ray Observatory. Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93

KSC-99pp0363

NASA Image and Video Library

1999-03-26

TRW workers in the Vertical Processing Facility check equipment after deployment of the solar panel array above them, attached to the Chandra X-ray Observatory. Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93

KSC-99pp0362

NASA Image and Video Library

1999-03-26

In the Vertical Processing Facility, the Chandra X-ray Observatory is observed after deployment of the solar panel array (near the bottom and to the right). Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93

Characterizing Intermediate-Mass, Pre-Main-Sequence Stars via X-Ray Emision

NASA Astrophysics Data System (ADS)

Haze Nunez, Evan; Povich, Matthew Samuel; Binder, Breanna Arlene; Broos, Patrick; Townsley, Leisa K.

2018-01-01

The X-ray emission from intermediate-mass, pre-main-sequence stars (IMPS) can provide useful constraints on the ages of very young (${<}5$~Myr) massive star forming regions. IMPS have masses between 2 and 8 $M_{\\odot}$ and are getting power from the gravitational contraction of the star. Main-sequence late-B and A-type stars are not expected to be strong X-ray emitters, because they lack the both strong winds of more massive stars and the magneto-coronal activity of lower-mass stars. There is, however, mounting evidence that IMPS are powerful intrinsic x-ray emitters during their convection-dominated early evolution, before the development and rapid growth of a radiation zone. We present our prime candidates for intrinsic, coronal X-ray emission from IMPS identified in the Chandra Carina Complex Project. The Carina massive star-forming complex is of special interest due to the wide variation of star formation stages within the region. Candidate IMPS were identified using infrared spectral energy distribution (SED) models. X-ray properties, including thermal plasma temperatures and absorption-corrected fluxes, were derived from XSPEC fits performed using absorption ($N_{H}$) constrained by the extinction values returned by the infrared SED fits. We find that IMPS have systematically higher X-ray luminosities compared to their lower-mass cousins, the TTauri stars.This work is supported by the National Science Foundation under grant CAREER-1454334 and by NASA through Chandra Award 18200040.

NASA astronomical findings highlighted on This Week @NASA – January 8, 2016

NASA Image and Video Library

2016-01-08

New NASA astrophysics findings were highlighted at the 227th American Astronomical Society meeting, Jan. 4-8 in Kissimmee, Florida. The findings, which ranged from runaway stars to a burping galaxy, were made with the help of several NASA observation instruments, including the Spitzer Space Telescope, the Wide-field Infrared Survey Explorer, the Chandra X-ray Observatory, the Nuclear Spectroscopic Telescope Array and others. Also, Next space station crew preparing for mission, Economical new era of aviation, A new level of coral reef studies and more!

Searching for Primordial Antimatter

NASA Astrophysics Data System (ADS)

2008-10-01

Scientists are on the hunt for evidence of antimatter - matter's arch nemesis - leftover from the very early Universe. New results using data from NASA's Chandra X-ray Observatory and Compton Gamma Ray Observatory suggest the search may have just become even more difficult. Antimatter is made up of elementary particles, each of which has the same mass as their corresponding matter counterparts --protons, neutrons and electrons -- but the opposite charges and magnetic properties. When matter and antimatter particles collide, they annihilate each other and produce energy according to Einstein's famous equation, E=mc2. According to the Big Bang model, the Universe was awash in particles of both matter and antimatter shortly after the Big Bang. Most of this material annihilated, but because there was slightly more matter than antimatter - less than one part per billion - only matter was left behind, at least in the local Universe. Trace amounts of antimatter are believed to be produced by powerful phenomena such as relativistic jets powered by black holes and pulsars, but no evidence has yet been found for antimatter remaining from the infant Universe. How could any primordial antimatter have survived? Just after the Big Bang there was believed to be an extraordinary period, called inflation, when the Universe expanded exponentially in just a fraction of a second. "If clumps of matter and antimatter existed next to each other before inflation, they may now be separated by more than the scale of the observable Universe, so we would never see them meet," said Gary Steigman of The Ohio State University, who conducted the study. "But, they might be separated on smaller scales, such as those of superclusters or clusters, which is a much more interesting possibility." X-rayChandra X-ray Image In that case, collisions between two galaxy clusters, the largest gravitationally-bound structures in the Universe, might show evidence for antimatter. X-ray emission shows how much hot gas is involved in such a collision. If some of the gas from either cluster has particles of antimatter, then there will be annihilation and the X-rays will be accompanied by gamma rays. Steigman used data obtained by Chandra and Compton to study the so-called Bullet Cluster, where two large clusters of galaxies have crashed into one another at extremely high velocities. At a relatively close distance and with a favorable side-on orientation as viewed from Earth, the Bullet Cluster provides an excellent test site to search for the signal for antimatter. People Who Read This Also Read... Jet Power and Black Hole Assortment Revealed in New Chandra Image Chandra Data Reveal Rapidly Whirling Black Holes Black Holes Have Simple Feeding Habits Galaxies Coming of Age in Cosmic Blobs "This is the largest scale over which this test for antimatter has ever been done," said Steigman, whose paper was published in the Journal of Cosmology and Astroparticle Physics. "I'm looking to see if there could be any clusters of galaxies which are made of large amounts of antimatter." The observed amount of X-rays from Chandra and the non-detection of gamma rays from the Compton data show that the antimatter fraction in the Bullet Cluster is less than three parts per million. Moreover, simulations of the Bullet Cluster merger show that these results rule out any significant amounts of antimatter over scales of about 65 million light years, an estimate of the original separation of the two colliding clusters. "The collision of matter and antimatter is the most efficient process for generating energy in the Universe, but it just may not happen on very large scales," said Steigman. "But, I'm not giving up yet as I'm planning to look at other colliding galaxy clusters that have recently been discovered." Finding antimatter in the Universe might tell scientists about how long the period of inflation lasted. "Success in this experiment, although a long shot, would teach us a lot about the earliest stages of the Universe," said Steigman. Tighter constraints have been placed by Steigman on the presence of antimatter on smaller scales by looking at single galaxy clusters that do not involve such large, recent collisions. The Compton Gamma Ray Observatory was in orbit from 1991 until 2000 when it was safely de-orbited. The data used in this result came from Compton's Energetic Gamma Ray Telescope, or EGRET, instrument. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1977-06-01

This photograph is of the High Energy Astronomy Observatory (HEAO)-2 telescope being checked by engineers in the X-Ray Calibration Facility at the Marshall Space Flight Center (MSFC). The MSFC was heavily engaged in the technical and scientific aspects, testing and calibration, of the HEAO-2 telescope. The HEAO-2 was the first imaging and largest x-ray telescope built to date. The X-Ray Calibration Facility was built in 1976 for testing MSFC's HEAO-2. The facility is the world's largest, most advanced laboratory for simulating x-ray emissions from distant celestial objects. It produced a space-like environment in which components related to x-ray telescope imaging are tested and the quality of their performance in space is predicted. The original facility contained a 1,000-foot long by 3-foot diameter vacuum tube (for the x-ray path) cornecting an x-ray generator and an instrument test chamber. Recently, the facility was upgraded to evaluate the optical elements of NASA's Hubble Space Telescope, Chandra X-Ray Observatory and Compton Gamma-Ray Observatory.

Six Years of Science with the Chandra X-Ray Observatory

NASA Technical Reports Server (NTRS)

Weisskopf, Martin

2005-01-01

The Chandra X-ray Observatory had its origins in a 1963 proposal led by Riccardo Giacconi that called for a 1-meter diameter, 1-arcsecond class X-Ray telescope for studying the Universe in X-rays. We will briefly discuss the history of the mission, the development of the hardware, its testing, and the launch on 1999, July 23. The remainder of the talk will be an admittedly eclectic review of some of the most exciting scientific highlights. These include the detection and identification of the first source seen with Chandra - an unusual Seyfert 1 we nicknamed Leon X-1, the detailed study of the Crab Nebula and its pulsar, and spectacular images of other supernova remnants including a 1-Million second exposure on Cas A. We also will summarize some of the major Chandra findings for normal and active galaxies and we will illustrate the breadth of science enabled by Chandra observations of clusters of galaxies and their implications for cosmology.

Chandra Interactive Analysis of Observations (CIAO)

NASA Technical Reports Server (NTRS)

Dobrzycki, Adam

2000-01-01

The Chandra (formerly AXAF) telescope, launched on July 23, 1999, provides X-rays data with unprecedented spatial and spectral resolution. As part of the Chandra scientific support, the Chandra X-ray Observatory Center provides a new data analysis system, CIAO ("Chandra Interactive Analysis of Observations"). We will present the main components of the system: "First Look" analysis; SHERPA: a multi-dimensional, multi-mission modeling and fitting application; Chandra Imaging and Plotting System; Detect package-source detection algorithms; and DM package generic data manipulation tools, We will set up a demonstration of the portable version of the system and show examples of Chandra Data Analysis.

M31 in the Chandra Era: A High Definition Movie of a Nearby Galaxy

NASA Astrophysics Data System (ADS)

Kong, Albert; di Stefano, Rosanne

2009-09-01

M31 has been a prime targets for all X-ray missions since the first detection in 1974. With its superb spatial resolution, Chandra is unique in resolving dense source regions and detecting faint sources. Since the launch of Chandra, M31 has been regularly observed. It is perhaps the only nearby galaxy which is observed by an X-ray telescope regularly throughout operation. With 10 years of observations, the center of M31 has been observed with Chandra for nearly 1 Msec. The X-ray skies of M31 not only consist of many transients and variables, globular cluster X-ray sources in M31 are also different from our Milky Way. They are in general more luminous and one of them may even host an intermediate-mass black hole. Supersoft and quasi-soft X-ray sources in M31 are the best kept secret to unlock the nature of the progenitor of Type Ia supernova. In this talk, I will review some of the important Chandra discoveries in M31 in the past 10 years.

The CHANDRA HETGS X-ray Grating Spectrum of Eta Carinae

NASA Technical Reports Server (NTRS)

Corcoran, M. F.; Swank, J. H.; Petre, R.; Ishibashi, K.; Davidson, K.; Townsley, L.; Smith, R.; White, S.; Viotti, R.; Damineli, A.;

Monitoring the Health and Safety of the ACIS Instrument On-Board the Chandra X-ray Observatory

NASA Astrophysics Data System (ADS)

Virani, Shanil N.; Ford, Peter G.; DePasquale, Joseph M.; Plucinsky, Paul P.

2002-12-01

The Chandra X-ray Observatory (CXO), NASA's latest "Great Observatory", was launched on July 23, 1999 and reached its final orbit on August 7, 1999. The CXO is in a highly elliptical orbit, approximately 140,000 km × 10,000 km, and has a period of approximately 63.5 hours (≍2.65 days). Communication with the CXO nominally consists of 1-hour contacts spaced 8-hours apart. Thus, once a communication link has been established, it is very important that the health and safety status of the scientific instruments as well as the Observatory itself be determined as quickly as possible. In this paper, we focus exclusively on the automated health and safety monitoring scripts developed for the Advanced CCD Imaging Spectrometer (ACIS) during those 1-hour contacts. ACIS is one of the two focal plane instruments on-board the CXO. We present an overview of the real-time ACIS Engineering Data Web Page and the alert schemes developed for monitoring the instrument status during each communication contact. A suite of HTML and PERL scripts monitors the instrument hardware house-keeping electronics (i.e., voltages and currents) and temperatures during each contact. If a particular instrument component is performing either above or below pre- established operating parameters, a sequence of email and alert pages are spawned to the Science Operations Team of the Chandra X-ray Observatory Center so that the anomaly can be quickly investigated and corrective actions taken if necessary. We also briefly discuss the tools used to monitor the real-time science telemetry reported by the ACIS flight software. The authors acknowledge support for this research from NASA contract NAS8-39073.

VizieR Online Data Catalog: MYStIX: the Chandra X-ray sources (Kuhn+, 2013)

NASA Astrophysics Data System (ADS)

Kuhn, M. A.; Getman, K. V.; Broos, P. S.; Townsley, L. K.; Feigelson, E. D.

2013-11-01

X-ray observations were made with the imaging array on the Advanced CCD Imaging Spectrometer (ACIS-I) on board the Chandra X-Ray Observatory. This array of four CCD detectors subtends 17'x17' on the sky. Data were acquired from the Chandra Data Archive from 2001 Jan to Mar 2008 for 10 MYStIX fields (Flame Nebula, RCW 36, NGC 2264, Rosette Nebula, Lagoon Nebula, NGC 2362, DR 21, RCW 38, Trifid Nebula and NGC 1893); see table1. (2 data files).

A Comparative View of X-rays from the Solar System

NASA Technical Reports Server (NTRS)

Bhardwaj, Anil; Elsner, Ron; Gladstone, Randy; Cravens, Tom; Waite, Hunter; Branduardi-Raymont, Graziella; Ostgaard, Nikolai; Dennerl, Konrad; Lisse, Carey; Kharchenko, Vasili

2005-01-01

With the advent of sophisticated X-ray observatories, viz., Chandra and XMM-Newton, the field of planetary X-ray astronomy is advancing at a faster pace. Several new solar system objects are now know to shine in X-rays at energies generally below 2 keV. Jupiter, Saturn, and Earth, all three magnetized planets, have been observed by Chandra and XMM-Newton. At Jupiter, both auroral and non-auroral disk X-ray emissions have been observed. The first soft X-ray observation of Earth's aurora by Chandra shows that it is highly variable. X-rays have been detected from Saturn's disk, but no convincing evidence of X-ray aurora has been seen. Several comets have been observed in X-rays by Chandra and XMM-Newton. Cometary X-rays are produced due to change exchange of solar wind ions with cold cometary neutrals. Soft X-rays have also been observed from Venus, Mars, Moon, Io, Europa, Io plasma torus, and heliosphere. The non-auroral X-ray emissions from Jupiter, Saturn, and Earth, and those from sunlit disk of Mars, Venus, and Moon are produced due to scattering of solar X-rays. The spectral characteristics of X-ray emission from comets, heliosphere, darkside of Moon, and Martian halo are quite similar, but they appear to be quite different from those of Jovian auroral X-rays. The X- ray aurora on Earth is generated by electron bremsstrahlung and on Jupiter by precipitation of highly-ionized energetic heavy ions. In this paper we will present a comparative overview of X-ray emission from different solar system objects and make an attempt to synthesize a coherent picture.

Chandra X-Ray Observatory Pointing Control System Performance During Transfer Orbit and Initial On-Orbit Operations

NASA Technical Reports Server (NTRS)

Quast, Peter; Tung, Frank; West, Mark; Wider, John

2000-01-01

The Chandra X-ray Observatory (CXO, formerly AXAF) is the third of the four NASA great observatories. It was launched from Kennedy Space Flight Center on 23 July 1999 aboard the Space Shuttle Columbia and was successfully inserted in a 330 x 72,000 km orbit by the Inertial Upper Stage (IUS). Through a series of five Integral Propulsion System burns, CXO was placed in a 10,000 x 139,000 km orbit. After initial on-orbit checkout, Chandra's first light images were unveiled to the public on 26 August, 1999. The CXO Pointing Control and Aspect Determination (PCAD) subsystem is designed to perform attitude control and determination functions in support of transfer orbit operations and on-orbit science mission. After a brief description of the PCAD subsystem, the paper highlights the PCAD activities during the transfer orbit and initial on-orbit operations. These activities include: CXO/IUS separation, attitude and gyro bias estimation with earth sensor and sun sensor, attitude control and disturbance torque estimation for delta-v burns, momentum build-up due to gravity gradient and solar pressure, momentum unloading with thrusters, attitude initialization with star measurements, gyro alignment calibration, maneuvering and transition to normal pointing, and PCAD pointing and stability performance.

The Chandra X-ray Observatory PSF Library

NASA Astrophysics Data System (ADS)

Karovska, M.; Beikman, S. J.; Elvis, M. S.; Flanagan, J. M.; Gaetz, T.; Glotfelty, K. J.; Jerius, D.; McDowell, J. C.; Rots, A. H.

Pre-flight and on-orbit calibration of the Chandra X-Ray Observatory provided a unique base for developing detailed models of the optics and detectors. Using these models we have produced a set of simulations of the Chandra point spread function (PSF) which is available to the users via PSF library files. We describe here how the PSF models are generated and the design and content of the Chandra PSF library files.

History of Chandra X-Ray Observatory

NASA Image and Video Library

2001-07-04

Giving scientists their first look, Chandra observed x-rays produced by fluorescent radiation from oxygen atoms of the Sun in the sparse upper atmosphere of Mars, about 120 kilometers (75 miles) above its surface. The x-ray power detected from the Martian atmosphere is very small, amounting to only 4 megawatts, comparable to the x-ray power of about ten thousand medical x-ray machines. At the time of the Chandra observation, a huge dust storm developed on Mars that covered about one hemisphere, later to cover the entire planet. This hemisphere rotated out of view over the 9-hour observation, but no change was observed in the x-ray intensity indicating that the dust storm did not affect the upper atmosphere. Scientists also observed a halo of x-rays extending out to 7,000 kilometers above the surface of Mars believed to be produced by collisions of ions racing away from the Sun (the solar wind).

Chandra Image Gives First Look at Mars Emitted X-Rays

NASA Technical Reports Server (NTRS)

2001-01-01

Giving scientists their first look, Chandra observed x-rays produced by fluorescent radiation from oxygen atoms of the Sun in the sparse upper atmosphere of Mars, about 120 kilometers (75 miles) above its surface. The x-ray power detected from the Martian atmosphere is very small, amounting to only 4 megawatts, comparable to the x-ray power of about ten thousand medical x-ray machines. At the time of the Chandra observation, a huge dust storm developed on Mars that covered about one hemisphere, later to cover the entire planet. This hemisphere rotated out of view over the 9-hour observation, but no change was observed in the x-ray intensity indicating that the dust storm did not affect the upper atmosphere. Scientists also observed a halo of x-rays extending out to 7,000 kilometers above the surface of Mars believed to be produced by collisions of ions racing away from the Sun (the solar wind).

KSC-99pp0350

NASA Image and Video Library

1999-03-26

In the Vertical Processing Facility, TRW technicians get ready to attach and deploy a solar panel array on the Chandra X-ray Observatory, which is sitting on a workstand. The panel is to the right. Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93

KSC-99pp0353

NASA Image and Video Library

1999-03-26

In the Vertical Processing Facility, a TRW technician checks the attachment of the solar panel array (out of sight to the right) to the Chandra X-ray Observatory, at left. Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93

Chandra Opens New Line of Investigation on Dark Energy

NASA Astrophysics Data System (ADS)

2004-05-01

Astronomers have detected and probed dark energy by applying a powerful, new method that uses images of galaxy clusters made by NASA's Chandra X-ray Observatory. The results trace the transition of the expansion of the Universe from a decelerating to an accelerating phase several billion years ago, and give intriguing clues about the nature of dark energy and the fate of the Universe. "Dark energy is perhaps the biggest mystery in physics," said Steve Allen of the Institute of Astronomy (IoA) at the University of Cambridge in England, and leader of the study. "As such, it is extremely important to make an independent test of its existence and properties." Abell 2029 Chandra X-ray Image of Abell 2029 Allen and his colleagues used Chandra to study 26 clusters of galaxies at distances corresponding to light travel times of between one and eight billion years. These data span the time when the Universe slowed from its original expansion, before speeding up again because of the repulsive effect of dark energy. "We're directly seeing that the expansion of the Universe is accelerating by measuring the distances to these galaxy clusters," said Andy Fabian also of the IoA, a co-author on the study. The new Chandra results suggest that the dark energy density does not change quickly with time and may even be constant, consistent with the "cosmological constant" concept first introduced by Albert Einstein. If so, the Universe is expected to continue expanding forever, so that in many billions of years only a tiny fraction of the known galaxies will be observable. More Animations Animation of the "Big Rip" If the dark energy density is constant, more dramatic fates for the Universe would be avoided. These include the "Big Rip," where dark energy increases until galaxies, stars, planets and eventually atoms are eventually torn apart. The "Big Crunch," where the Universe eventually collapses on itself, would also be ruled out. Chandra's probe of dark energy relies on the unique ability of X-ray observations to detect and study the hot gas in galaxy clusters. From these data, the ratio of the mass of the hot gas and the mass of the dark matter in a cluster can be determined. The observed values of the gas fraction depend on the assumed distance to the cluster, which in turn depends on the curvature of space and the amount of dark energy in the universe. Galaxy Cluster Animation Galaxy Cluster Animation Because galaxy clusters are so large, they are thought to represent a fair sample of the matter content in the universe. If so, then relative amounts of hot gas and dark matter should be the same for every cluster. Using this assumption, Allen and colleagues adjusted the distance scale to determine which one fit the data best. These distances show that the expansion of the Universe was first decelerating and then began to accelerate about six billion years ago. Chandra's observations agree with supernova results including those from the Hubble Space Telescope (HST), which first showed dark energy's effect on the acceleration of the Universe. Chandra's results are completely independent of the supernova technique - both in wavelength and the objects observed. Such independent verification is a cornerstone of science. In this case it helps to dispel any remaining doubts that the supernova technique is flawed. "Our Chandra method has nothing to do with other techniques, so they're definitely not comparing notes, so to speak," said Robert Schmidt of University of Potsdam in Germany, another coauthor on the study. Energy Distribution of the Universe Energy Distribution of the Universe Better limits on the amount of dark energy and how it varies with time are obtained by combining the X-ray results with data from NASA's Wilkinson Microwave Anisotropy Probe (WMAP), which used observations of the cosmic microwave background radiation to discover evidence for dark energy in the very early Universe. Using the combined data, Allen and his colleagues found that dark energy makes up about 75% of the Universe, dark matter about 21%, and visible matter about 4%. Allen and his colleagues stress that the uncertainties in the measurements are such that the data are consistent with dark energy having a constant value. The present Chandra data do, however, allow for the possibility that the dark energy density is increasing with time. More detailed studies with Chandra, HST, WMAP and with the future mission Constellation-X should provide much more precise constraints on dark energy. Expansion of the Universe Expansion of the Universe at Constant Acceleration "Until we better understand cosmic acceleration and the nature of the dark energy we cannot hope to understand the destiny of the Universe," said independent commentator Michael Turner, of the University of Chicago. The team conducting the research also included Harald Ebeling of the University of Hawaii and the late Leon van Speybroeck of the Harvard-Smithsonian Center for Astrophysics. These results will appear in an upcoming issue of the Monthly Notices of the Royal Astronomy Society. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for NASA's Office of Space Science, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Press Kit: Galaxy Clusters and Dark Energy Press Kit Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

SST and the Milky Way, an Artist's Concept

NASA Technical Reports Server (NTRS)

2003-01-01

The Spitzer Space Telescope whizzes in front of a brilliant, infrared view of the Milky Way galaxy's plane in this artistic depiction.

The mission marks the last of NASA's Great Observatories, a program that includes the Hubble Space Telescope, the Chandra X-Ray Observatory and the Compton Gamma-Ray Observatory.

In addition to studying many of the coldest, oldest and most dust-enshrouded objects and processes in the universe, the mission will also be an important part of NASA's Origins Program, which seeks to answer the questions: Where did we come from? Are we alone?

The Chandra Source Catalog 2.0: Early Cross-matches

NASA Astrophysics Data System (ADS)

Rots, Arnold H.; Allen, Christopher E.; Anderson, Craig S.; Budynkiewicz, Jamie A.; Burke, Douglas; Chen, Judy C.; Civano, Francesca Maria; D'Abrusco, Raffaele; Doe, Stephen M.; Evans, Ian N.; Evans, Janet D.; Fabbiano, Giuseppina; Gibbs, Danny G., II; Glotfelty, Kenny J.; Graessle, Dale E.; Grier, John D.; Hain, Roger; Hall, Diane M.; Harbo, Peter N.; Houck, John C.; Lauer, Jennifer L.; Laurino, Omar; Lee, Nicholas P.; Martínez-Galarza, Rafael; McCollough, Michael L.; McDowell, Jonathan C.; Miller, Joseph; McLaughlin, Warren; Morgan, Douglas L.; Mossman, Amy E.; Nguyen, Dan T.; Nichols, Joy S.; Nowak, Michael A.; Paxson, Charles; Plummer, David A.; Primini, Francis Anthony; Siemiginowska, Aneta; Sundheim, Beth A.; Tibbetts, Michael; Van Stone, David W.; Zografou, Panagoula

2018-01-01

Cross-matching the Chandra Source Catalog (CSC) with other catalogs presents considerable challenges, since the Point Spread Function (PSF) of the Chandra X-ray Observatory varies significantly over the field of view. For the second release of the CSC (CSC2) we have been developing a cross-match tool that is based on the Bayesian algorithms by Budavari, Heinis, and Szalay (ApJ 679, 301 and 705, 739), making use of the error ellipses for the derived positions of the sources.However, calculating match probabilities only on the basis of error ellipses breaks down when the PSFs are significantly different. Not only can bonafide matches easily be missed, but the scene is also muddied by ambiguous multiple matches. These are issues that are not commonly addressed in cross-match tools. We have applied a satisfactory modification to the algorithm that, although not perfect, ameliorates the problems for the vast majority of such cases.We will present some early cross-matches of the CSC2 catalog with obvious candidate catalogs and report on the determination of the absolute astrometric error of the CSC2 based on such cross-matches.This work has been supported by NASA under contract NAS 8-03060 to the Smithsonian Astrophysical Observatory for operation of the Chandra X-ray Center.

The Chandra Multi-Wavelength Project (ChaMP): A Serendipitous X-Ray Survey Using Chandra Archival Data

NASA Technical Reports Server (NTRS)

Wilkes, Belinda; Lavoie, Anthony R. (Technical Monitor)

2000-01-01

The launch of the Chandra X-ray Observatory in July 2000 opened a new era in X-ray astronomy. Its unprecedented, < 1" spatial resolution and low background is providing views of the X-ray sky 10-100 times fainter than previously possible. We have begun to carry out a serendipitous survey of the X-ray sky using Chandra archival data to flux limits covering the range between those reached by current satellites and those of the small area Chandra deep surveys. We estimate the survey will cover about 8 sq.deg. per year to X-ray fluxes (2-10 keV) in the range 10(exp -13) - 6(exp -16) erg cm2/s and include about 3000 sources per year, roughly two thirds of which are expected to be active galactic nuclei (AGN). Optical imaging of the ChaMP fields is underway at NOAO and SAO telescopes using g',r',z' colors with which we will be able to classify the X-ray sources into object types and, in some cases, estimate their redshifts. We are also planning to obtain optical spectroscopy of a well-defined subset to allow confirmation of classification and redshift determination. All X-ray and optical results and supporting optical data will be place in the ChaMP archive within a year of the completion of our data analysis. Over the five years of Chandra operations, ChaMP will provide both a major resource for Chandra observers and a key research tool for the study of the cosmic X-ray background and the individual source populations which comprise it. ChaMP promises profoundly new science return on a number of key questions at the current frontier of many areas of astronomy including solving the spectral paradox by resolving the CXRB, locating and studying high redshift clusters and so constraining cosmological parameters, defining the true, possibly absorbed, population of quasars and studying coronal emission from late-type stars as their cores become fully convective. The current status and initial results from the ChaMP will be presented.

Chandra Discovers Cosmic Cannonball

NASA Astrophysics Data System (ADS)

2007-11-01

One of the fastest moving stars ever seen has been discovered with NASA's Chandra X-ray Observatory. This cosmic cannonball is challenging theories to explain its blistering speed. Astronomers used Chandra to observe a neutron star, known as RX J0822-4300, over a period of about five years. During that span, three Chandra observations clearly show the neutron star moving away from the center of the Puppis A supernova remnant. This remnant is the stellar debris field created during the same explosion in which the neutron star was created about 3700 years ago. Chandra X-ray Image of RX J0822-4300 in Puppis A Chandra X-ray Image of RX J0822-4300 in Puppis A By combining how far it has moved across the sky with its distance from Earth, astronomers determined the neutron star is moving at over 3 million miles per hour. At this rate, RX J0822-4300 is destined to escape from the Milky Way after millions of years, even though it has only traveled about 20 light years so far. "This star is moving at 3 million miles an hour, but it's so far away that the apparent motion we see in five years is less than the height of the numerals in the date on a penny, seen from the length of a football field," said Frank Winkler of Middlebury College in Vermont. "It's remarkable, and a real testament to the power of Chandra, that such a tiny motion can be measured." Labeled Image of RX J0822-4300 in Puppis A Labeled Image of RX J0822-4300 in Puppis A "Just after it was born, this neutron star got a one-way ticket out of the Galaxy," said co-author Robert Petre of NASA's Goddard Space Flight Center in Greenbelt, Md. "Astronomers have seen other stars being flung out of the Milky Way, but few as fast as this." So-called hypervelocity stars have been previously discovered shooting out of the Milky Way with speeds around one million miles per hour. One key difference between RX J0822-4300 and these other reported galactic escapees is the source of their speed. The hypervelocity stars are thought to have been ejected by interactions with the supermassive black hole in the Galaxy's center. CTIO Optical Images of Puppis A CTIO Optical Images of Puppis A This neutron star, by contrast, was flung into motion by the supernova that created Puppis A. The data suggest the explosion was lop-sided, kicking the neutron star in one direction and the debris from the explosion in the other. The supernova was precipitated when the core of a massive star imploded to form a neutron star. Computer simulations show that the infall of the outer layers of the star onto a neutron star releases an enormous amount of energy. As this energy propagates outward, it can reverse the infall and eject the outer layers of the star at speeds of millions of miles per hour. Due to the complexity of the flow, the ejection is not symmetric, leading to a rocket effect that propels the neutron star in the opposite direction. ROSAT X-ray ROSAT X-ray The breakneck speed of the Puppis A neutron star, plus an apparent lack of pulsations from it, is not easily explained by even the most sophisticated supernova explosion models. "The problem with discovering this cosmic cannonball is we aren't sure how to make the cannon powerful enough." said Winkler. "The high speed might be explained by an unusually energetic explosion, but the models are complicated and hard to apply to real explosions." Other recent work on RX J0822-4300 was published by C.Y. Hui and Wolfgang Becker, both from the Max Planck Institute for Extraterrestrial Physics in Munich, in the journal Astronomy and Astrophysics in late 2006. Using two of the three Chandra observations reported in the Winkler paper and a different analysis technique, the Hui group found a speed for RX J0822-4300 that is about two-thirds as fast, but with larger reported margins of error. The research by Winkler and Petre was published in the November 20 issue of The Astrophysical Journal. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass.

Mrs. Chandrasekhar poses with contest winners

NASA Technical Reports Server (NTRS)

1999-01-01

Mrs. Lalitha Chandrasekhar (left), wife of the late Indian- American Nobel Laureate Subrahmanyan Chandrasekhar, poses with a model of the Chandra X-ray Observatory and the winners of the contest to rename the telescope in the TRW Media Hospitality Tent at the NASA Press Site at KSC. The winners of the contest are Jatila van der Veen (center), academic coordinator and lecturer, Physics Dept., University of Santa Barbara, Calif., and Tyrel Johnson (right), high school student, Laclede, Idaho. The name 'Chandra,' a shortened version of Chandrasekhar's name which he preferred among friends and colleagues, was chosen to honor the Nobel Laureate. 'Chandra' also means 'Moon' or 'luminous' in Sanskrit. The observatory is scheduled to be launched aboard Columbia on Space Shuttle mission STS-93.

KSC-99pp0975

NASA Image and Video Library

1999-07-19

KENNEDY SPACE CENTER, FLA. -- Mrs. Lalitha Chandrasekhar (left), wife of the late Indian-American Nobel Laureate Subrahmanyan Chandrasekhar, poses with a model of the Chandra X-ray Observatory and the winners of the contest to rename the telescope in the TRW Media Hospitality Tent at the NASA Press Site at KSC. The winners of the contest are Jatila van der Veen (center), academic coordinator and lecturer, Physics Dept., University of Santa Barbara, Calif., and Tyrel Johnson (right), high school student, Laclede, Idaho. The name "Chandra," a shortened version of Chandrasekhar's name which he preferred among friends and colleagues, was chosen to honor the Nobel Laureate. "Chandra" also means "Moon" or "luminous" in Sanskrit. The observatory is scheduled to be launched aboard Columbia on Space Shuttle mission STS-93

Workers in the VPF observe the lower end of the IUS to be mated to the Chandra X-ray Observatory

NASA Technical Reports Server (NTRS)

1999-01-01

Workers in the Vertical Processing Facility observe the lower end of the Inertial Upper Stage (IUS) that will be mated with the Chandra X-ray Observatory (out of sight above it). After the two components are mated, they will undergo testing to validate the IUS/Chandra connections and to check the orbiter avionics interfaces. Following that, an end-to-end test (ETE) will be conducted to verify the communications path to Chandra, commanding it as if it were in space. With the world's most powerful X-ray telescope, Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Chandra is scheduled for launch July 22 aboard Space Shuttle Columbia, on mission STS-93.

Chandra/ACIS Observations of Rosette: Diffuse X-rays Discovered in a Galactic H II Region

NASA Astrophysics Data System (ADS)

Townsley, L. K.; Feigelson, E. D.; Broos, P. S.; Chu, Y.-H.; Montmerle, T.

2001-12-01

We present the first high-spatial-resolution X-ray images of the Rosette Nebula and Rosette Molecular Cloud (RMC), obtained in a series of 4 20-ksec snapshots with the Advanced CCD Imaging Spectrometer aboard the Chandra X-ray Observatory in January 2001. These images form a striking 1-degree X-ray panorama of a rich high-mass star formation region. The OB association is resolved at the arcsecond level into >300 sources. The other 3 pointings step across the RMC, with >100 X-ray sources in each. Soft diffuse emission is seen at the center of the H II region and is resolved from the point source population. This extended emission is most likely from the fast O-star winds, which thermalize and shock the surrounding media. Support for this effort was provided by the Chandra X-ray Observatory GO2 grant G01-2008X.

X-Ray Snapshots Capture the First Cries of Baby Stars

NASA Astrophysics Data System (ADS)

2000-11-01

CXC PR: 00-27 Stars, like babies, make quite a fuss in their first days after birth. Astronomers using the Chandra X-ray Observatory have discovered that protostars--stars in their youngest, "neonatal" stage--are marked by powerful X rays from plasma ten times hotter and 100 to 100,000 times brighter than the flares on our Sun. This is all long before their nuclear furnaces of hydrogen even ignite, the mark of stellar maturity. The X-ray flares have also provided the closest look yet at the youngest stars in the universe, never before detected because they are hidden within dust and molecular clouds that filter all other types of light. Yohko Tsuboi of the Pennsylvania State University (Penn State) presents these findings today in a press conference at the meeting of the High Energy Astrophysics Division of the American Astronomical Society in Honolulu, Hawaii. "We peered at newborn stars deeply embedded in their cradle and found that their crying is much more tumultuous than we expected," said Tsuboi. "With Chandra, we now have a new tool to examine protostars, which have been impossible to gain access to in any other wavelength." Protostars located in the rho-Ophiuchi molecular cloud Protostars located in the rho-Ophiuchi molecular cloud 1 square light years field X-ray image around rho Ophiuchi molecular cloud core. Red colorrepresents less absorbed X rays, while blue represents absorbed X rays. Lightcurves for each sources are also shown. Tsuboi and her collaborators looked at the two youngest types of protostars: Class-0 (zero) protostars, about 10,000 years old; and Class-I protostars, about 100,000 years old. In human terms, these protostars are like one-hour-old and 10-hour-old babies, respectively. The transition from one class to another is marked by changes in the protostar's infrared spectrum as the gas and dust envelope diminishes. The envelope has been well studied by infrared and radio astronomers. Protostars themselves and their most extreme activities, however, have remained hidden until now, embedded in the dense envelopes. Previous X-ray telescopes--namely the Japan-U.S. Advanced Satellite for Cosmology and Astrophysics and the German-UK-US Roentgen Satellite--discovered sporadic X rays from several Class-I protostars. These satellites did not have enough spatial resolution nor sensitivity, however, to resolve the large percentage of protostars deep inside crowded cloud cores. Movie in X-ray band of rho Ophiuchi molecular cloud core F Movie in X-ray band of rho Ophiuchi molecular cloud core F. The green bar indicates the time from 0 hours to 27 hours by the length. (Click Image to View Movie) With Chandra, astronomers from Penn State and Kyoto University in Japan have detected X rays from 17 Class-I protostars in a region with 22 known "infrared" Class-I sources. These protostars are located in the rho Ophiuchi molecular cloud 500 light years from Earth in constellation Ophiuchi. The astronomers also saw nearly a dozen X-ray flares over a 27-hour period (*see figure 1 and movie). "Virtually all the Class I protostars in the rho molecular cloud may emit X rays with extremely violent and frequent flare activity," said Kensuke Imanishi of Kyoto University, lead investigator of the rho Ophiuchi observation. "The X-ray fluxes in the flares we saw were up to 10,000 to 100,000 brighter than those in our Sun's flares." Probing deeply with Chandra into a different star-formation region, 1400 light years from Earth in constellation Orion, a second team of astronomers led by Tsuboi observed for the first time activity from Class-0 protostars. Up until now, only the protostar envelope had been seen. In the Class-0 phase, a dense molecular cloud and heavy accretion of gas onto the newly forming star enshroud the region and attenuate even the most penetrating X rays. Chandra, however, had the sensitivity to detect X-ray activity. "The X rays are heavily absorbed, possibly by a large amount of cloud gas," said Tsuboi. "It proves that the X rays come really from the center of the cloud core, from the protostar itself. We therefore discovered X rays even in the Class-0 phase." "Far beyond our imagination, a star immediately after the birth at the center of a cold molecular core at temperatures of only a few tens of Kelvin [-400 degrees Fahrenheit] frequently generates very hot plasma with 10 to 100 million Kelvin," said Katsuji Koyama of Kyoto University, director of these two observations. Koyama said that the violent X-ray flares on protostars may be generated by a coupled action of stellar spin and convection. These become less active as a star condenses to ignite the hydrogen burning and finally settles to a quiet phase like the Sun. In fact, our Sun was born about five billion years ago in a molecular cloud core, which also created the rest of the solar system, including the Earth. The infant Sun may have also been prone to fierce X-ray tantrums. Once the Sun's core was hot and dense enough to initiate hydrogen fusion, after about a few million years, the Sun became a steadier source of energy. This steadiness could have been what allowed life to develop on Earth. The research team for the Orion Molecular Clouds also includes Kenji Hamaguchi at Kyoto University; Ken'ichi Tatematsu and Yutaro Sekimoto at Nobeyama Radio Observatory, National Astronomical Observatory of Japan; and John Bally and Bo Reipurth at University of Colorado. The Chandra observations were made using the Advanced CCD Imaging Spectrometer (ACIS), conceived and developed for NASA by Penn State and Massachusetts Institute of Technology under the leadership of Penn State Professor Gordon Garmire. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program. TRW, Inc., Redondo Beach, California, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass. Rho Ophiuchi Handout Constellation Ophiuchus Note to media: The press room phone number at the High Energy Astrophysics Division meeting, which will be open from November 6-10, is 808-944-6390. MEDIA CONTACTS Megan Watzke Chandra X-ray Observatory Center, CfA, Cambridge, MA Phone: 617-496-7998 Steve Roy Marshall Space Flight Center, Huntsville, AL Phone: 256-544-6535 Barbara Kennedy Penn State PIO, University Park, PA. Phone: 814-863-4682

Observatories Combine to Crack Open the Crab Nebula

NASA Image and Video Library

2017-12-08

Astronomers have produced a highly detailed image of the Crab Nebula, by combining data from telescopes spanning nearly the entire breadth of the electromagnetic spectrum, from radio waves seen by the Karl G. Jansky Very Large Array (VLA) to the powerful X-ray glow as seen by the orbiting Chandra X-ray Observatory. And, in between that range of wavelengths, the Hubble Space Telescope's crisp visible-light view, and the infrared perspective of the Spitzer Space Telescope. This video starts with a composite image of the Crab Nebula, a supernova remnant that was assembled by combining data from five telescopes spanning nearly the entire breadth of the electromagnetic spectrum: the Very Large Array, the Spitzer Space Telescope, the Hubble Space Telescope, the XMM-Newton Observatory, and the Chandra X-ray Observatory. The video dissolves to the red-colored radio-light view that shows how a neutron star’s fierce “wind” of charged particles from the central neutron star energized the nebula, causing it to emit the radio waves. The yellow-colored infrared image includes the glow of dust particles absorbing ultraviolet and visible light. The green-colored Hubble visible-light image offers a very sharp view of hot filamentary structures that permeate this nebula. The blue-colored ultraviolet image and the purple-colored X-ray image shows the effect of an energetic cloud of electrons driven by a rapidly rotating neutron star at the center of the nebula. Read more: go.nasa.gov/2r0s8VC Credits: NASA, ESA, J. DePasquale (STScI)

History of Chandra X-Ray Observatory

NASA Image and Video Library

1999-01-01

In this photograph, the Chandra X-Ray Observatory (CXO) was installed and mated to the Inertial Upper Stage (IUS) inside the Shuttle Columbia's cargo bay at the Kennedy Space Center. The CXO will help astronomers world-wide better understand the structure and evolution of the universe by studying powerful sources of x-rays such as exploding stars, matter falling into black holes, and other exotic celestial objects. X-ray astronomy can only be done from space because Earth's atmosphere blocks x-rays from reaching the surface. The Observatory provides images that are 50 times more detailed than previous x-ray missions. At more than 45 feet in length and weighing more than 5 tons, the CXO was carried into low-Earth orbit by the Space Shuttle Columbia (STS-93 mission) on July 22, 1999. The Observatory was deployed from the Shuttle's cargo bay at 155 miles above the Earth. Two firings of an attached IUS rocket, and several firings of its own onboard rocket motors, after separating from the IUS, placed the Observatory into its working orbit. The IUS is a solid rocket used to place spacecraft into orbit or boost them away from the Earth on interplanetary missions. Since its first use by NASA in 1983, the IUS has supported a variety of important missions, such as the Tracking and Data Relay Satellite, Galileo spacecraft, Magellan spacecraft, and Ulysses spacecraft. The IUS was built by the Boeing Aerospace Co., at Seattle, Washington and managed by the Marshall Space Flight Center.

Why Space Telescopes Are Amazing

NASA Technical Reports Server (NTRS)

Rigby, Jane R.

2012-01-01

One of humanity's best ideas has been to put telescopes in space. The dark stillness of space allows telescopes to perform much better than they can on even the darkest and clearest of Earth's mountaintops. In addition, from space we can detect colors of light, like X-rays and gamma rays, that are blocked by the Earth's atmosphere I'll talk about NASA's team of great observatories: the Hubble Space Telescope, Spitzer Space Telescope, and Chandra X-ray Observatory} and how they've worked together to answer key questions: When did the stars form? Is there really dark matter? Is the universe really expanding ever faster and faster?

Most Distant X-Ray Jet Yet Discovered Provides Clues To Big Bang

NASA Astrophysics Data System (ADS)

2003-11-01

The most distant jet ever observed was discovered in an image of a quasar made by NASA's Chandra X-ray Observatory. Extending more than 100,000 light years from the supermassive black hole powering the quasar, the jet of high-energy particles provides astronomers with information about the intensity of the cosmic microwave background radiation 12 billion years ago. The discovery of this jet was a surprise to the astronomers, according to team members. Astronomers had previously known the distant quasar GB1508+5714 to be a powerful X-ray source, but there had been no indication of any complex structure or a jet. "This jet is especially significant because it allows us to probe the cosmic background radiation 1.4 billion years after the Big Bang," said Aneta Siemiginowska of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., lead author of a report on this research in the November 20th Astrophysical Journal Letters. Prior to this discovery, the most distant confirmed X-ray jet corresponded to a time about 3 billion years after the Big Bang. Quasars are thought to be galaxies that harbor an active central supermassive black hole fueled by infalling gas and stars. This accretion process is often observed to be accompanied by the generation of powerful high-energy jets. Radio image of GB1508 Radio Image of GB1508 As the electrons in the jet fly away from the quasar at near the speed of light, they move through the sea of cosmic background radiation left over from the hot early phase of the universe. When a fast-moving electron collides with one of these background photons, it can boost the photon's energy up into the X-ray band. The X-ray brightness of the jet depends on the power in the electron beam and the intensity of the background radiation. "Everyone assumes that the background radiation will change in a predictable way with time, but it is important to have this check on the predictions," said Siemiginowska. "This jet is hopefully just the first in a large sample of these distant objects that can be used to tell us how the intensity of the cosmic microwave background changed over time." "In fact, if this interpretation is correct, then discovery of this jet is consistent with our previous prediction that X-ray jets can be detected at arbitrarily large distances!" said team member Dan Schwartz, also of the Harvard-Smithsonian Center for Astrophysics. Chandra originally observed GB1508+5714 with the purpose of studying the X-ray emission from the dust located between the Earth and the far-flung quasar. The jet was found by Siemiginowska and her colleagues when they examined the data once it became available publicly in the Chandra archive. This led another astronomer to then carefully look at radio observations of the object. Indeed, archived Very Large Array data confirmed the existence of the jet associated with the quasar GB1508+5714. A paper on the radio observations of GB1508+5714 has been accepted by Astrophysical Journal Letters from Teddy Cheung of Brandeis University in Waltham, Mass. Another group of astronomers led by Weimin Yuan of the University of Cambridge, UK independently reported the discovery of the extended emission in GB1508+5714 in X-rays. In a paper to be published in an upcoming issue of the Monthly Notices of the Royal Astronomical Society, the authors note that significant energy is being deposited in the outer regions of the host galaxy at a very early stage. This energy input could have a profound effect on the evolution of the galaxy by triggering the formation of stars, or inhibiting the growth of the galaxy through accretion of matter from intergalactic space. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the Office of Space Science, NASA Headquarters, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass.

Simultaneous Chandra/Swift Observations of the RT Cru Symbiotic System

NASA Astrophysics Data System (ADS)

Kashyap, Vinay; Kennea, J. A.; Karovska, M.; Calibration, Chandra

2013-04-01

The symbiotic star RT Cru was observed simultaneously by the Chandra/HRC-I and Swift/XRT in Dec 2012. The observations were carried out as part of a program to calibrate the Chandra PSF. The Chandra light curve shows a number of brightenings by factors of 2, with strong indications of a softening of the spectrum at these times. Swift observations cover a brief part of the Chandra light curve, and the intensities over this duration are tightly correlated. The Swift spectral data confirm the anticorrelation between intensity and spectral hardness. However, there are differences in the correlations at different periods that are not understood. We report on our analysis of the data, with emphasis on the spectral modeling at different times and intensity levels, and discuss the implications of the results on the emission mechanisms on symbiotic stars. We also report our inferences on the structure and energy dependence of the Chandra PSF anomaly, and on the high-energy cross-calibration between the HRC-I and XRT. This work is supported by the NASA contract NAS8-03060 to the Chandra X-ray Center.

KSC-99pp0351

NASA Image and Video Library

1999-03-26

In the Vertical Processing Facility, TRW technicians look at the point of attachment on the Chandra X-ray Observatory, at left, for the solar panel array (behind them). They are getting ready to attach and deploy the solar panel. Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93

X-ray Discovery Points to Location of Missing Matter

NASA Astrophysics Data System (ADS)

2010-05-01

Using observations with NASA's Chandra X-ray Observatory and ESA's XMM-Newton, astronomers have announced a robust detection of a vast reservoir of intergalactic gas about 400 million light years from Earth. This discovery is the strongest evidence yet that the "missing matter" in the nearby Universe is located in an enormous web of hot, diffuse gas. This missing matter — which is different from dark matter -- is composed of baryons, the particles, such as protons and neutrons, that are found on the Earth, in stars, gas, galaxies, and so on. A variety of measurements of distant gas clouds and galaxies have provided a good estimate of the amount of this "normal matter" present when the universe was only a few billion years old. However, an inventory of the much older, nearby universe has turned up only about half as much normal matter, an embarrassingly large shortfall. The mystery then is where does this missing matter reside in the nearby Universe? This latest work supports predictions that it is mostly found in a web of hot, diffuse gas known as the Warm-Hot Intergalactic Medium (WHIM). Scientists think the WHIM is material left over after the formation of galaxies, which was later enriched by elements blown out of galaxies. "Evidence for the WHIM is really difficult to find because this stuff is so diffuse and easy to see right through," said Taotao Fang of the University of California at Irvine and lead author of the latest study. "This differs from many areas of astronomy where we struggle to see through obscuring material." To look for the WHIM, the researchers examined X-ray observations of a rapidly growing supermassive black hole known as an active galactic nucleus, or AGN. This AGN, which is about two billion light years away, generates immense amounts of X-ray light as it pulls matter inwards. Lying along the line of sight to this AGN, at a distance of about 400 million light years, is the so-called Sculptor Wall. This "wall", which is a large diffuse structure stretching across tens of millions of light years, contains thousands of galaxies and potentially a significant reservoir of the WHIM if the theoretical simulations are correct. The WHIM in the wall should absorb some of the X-rays from the AGN as they make their journey across intergalactic space to Earth. Using new data from Chandra and previous observations with both Chandra and XMM-Newton, absorption of X-rays by oxygen atoms in the WHIM has clearly been detected by Fang and his colleagues. The characteristics of the absorption are consistent with the distance of the Sculptor Wall as well as the predicted temperature and density of the WHIM. This result gives scientists confidence that the WHIM will also be found in other large-scale structures. Several previous claimed detections of the hot component of the WHIM have been controversial because the detections had been made with only one X-ray telescope and the statistical significance of many of the results had been questioned. "Having good detections of the WHIM with two different telescopes is really a big deal," said co-author David Buote, also from the University of California at Irvine. "This gives us a lot of confidence that we have truly found this missing matter." In addition to having corroborating data from both Chandra and XMM-Newton, the new study also removes another uncertainty from previous claims. Because the distance of the Sculptor Wall is already known, the statistical significance of the absorption detection is greatly enhanced over previous "blind" searches. These earlier searches attempted to find the WHIM by observing bright AGN at random directions on the sky, in the hope that their line of sight intersects a previously undiscovered large-scale structure. Confirmed detections of the WHIM have been made difficult because of its extremely low density. Using observations and simulations, scientists calculate the WHIM has a density equivalent to only 6 protons per cubic meter. For comparison, the interstellar medium -- the very diffuse gas in between stars in our galaxy -- typically has about a million hydrogen atoms per cubic meter. "Evidence for the WHIM has even been much harder to find than evidence for dark matter, which is invisible but can be detected because of its gravitational effects on stars and galaxies," said Fang. There have been important detections of possible WHIM in the nearby Universe with relatively low temperatures of about 100,000 degrees using ultraviolet observations and relatively high temperature WHIM of about 10 million degrees using observations of X-ray emission in galaxy clusters. However, these are expected to account for only a relatively small fraction of the WHIM. The X-ray absorption studies reported here probe temperatures of about a million degrees where most of the WHIM is predicted to be found. These results appear in the May 10th issue of The Astrophysical Journal. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass. More information, including images and other multimedia, can be found at: http://chandra.harvard.edu and http://chandra.nasa.gov

Taking the Pulse of a Black Hole System

NASA Astrophysics Data System (ADS)

2011-01-01

Using two NASA X-ray satellites, astronomers have discovered what drives the "heartbeats" seen in the light from an unusual black hole system. These results give new insight into the ways that black holes can regulate their intake and severely curtail their growth. This study examined GRS 1915+105 (GRS 1915 for short), a binary system in the Milky Way galaxy containing a black hole about 14 times more massive than the Sun that is feeding off material from a companion star. As this material falls towards the black hole, it forms a swirling disk that emits X-rays. The black hole in GRS 1915 has been estimated to rotate at the maximum possible rate, allowing material in the inner disk to orbit very close to the black hole, at a radius only 20% larger than the event horizon, where the material travels at 50% the speed of light. Using the Chandra X-ray Observatory and the Rossi X-ray Timing Explorer (RXTE), researchers monitored this black hole system over a period of eight hours. As they watched, GRS 1915 gave off a short, bright pulse of X-ray light approximately every 50 seconds, varying in brightness by a factor of about three. This type of rhythmic cycle closely resembles an electrocardiogram of a human heart -- though at a slower pace. "Trying to understand the physics of this 'heartbeat state' is a little like trying to understand how a person's heart beats by watching changes in the blood flow through their veins," said Joey Neilsen, a graduate student at Harvard University, who presented these results from his dissertation at the American Astronomical Society (AAS) meeting in Seattle, Wash. It was previously known that GRS 1915 can develop such heartbeats when its mass consumption rate is very high. After monitoring it with the special combination of Chandra and RXTE, Neilsen and his collaborators realized that they could use the pulses to figure out what controls how much material the black hole consumes. "With each beat, the black hole pumps an enormous amount of energy into its surroundings," said Neilsen. "All that energy has profound consequences for the disk, even very far from the black hole." Changes in the X-ray spectrum observed by RXTE during each heartbeat reveal that the inner region of the disk, at only a few times the radius of the black hole's event horizon, emits enough radiation to push material away from the black hole. Eventually the disk gets so bright and so hot that it essentially disintegrates and plunges towards the black hole. Then the cycle begins again. "This behavior is a clear and startling demonstration of the power of radiation in the fight against gravity," said co-author Ron Remillard of the Massachusetts Institute of Technology. "During the heartbeat state, radiation prevents the black hole from ingesting as much material as it would otherwise." Neilsen and his colleagues estimated that the rate at which material falls onto the black hole changes by about a factor of ten during each cycle, with the maximum rate coinciding with the X-ray pulse. Between pulses, the inner part of the disk refills from material farther away from the black hole. The astronomers also used Chandra's high-resolution spectrograph to study the effects of this heartbeat variation on regions of the disk very far from the black hole, at distances of about 100,000 to a million times the radius of the event horizon. By analyzing the Chandra spectrum, they found a very strong wind being driven away from the outer parts of the disk. The wind changed significantly in just 5 seconds, nearly 100 times faster than has ever been seen in a wind from a stellar-mass black hole. The researchers concluded that the strong X-ray pulse from the inner disk must heat the outer disk. This heating process launches a wind, so that each new pulse drives more wind from the disk. The rate of mass expelled in this wind is remarkably high, as much as 25 times the maximum rate at which matter falls onto the black hole. "All that energy blows away an enormous amount of matter, equivalent to one third the mass of the Moon per day! This effectively forces the black hole onto a severe diet, and we think it eventually has real consequences for the system's heartbeat," said co-author Julia Lee, associate professor in the Astronomy department at Harvard and Neilsen's thesis advisor. This massive wind drains material from the outer disk and after a couple weeks, this depletion affects the inner disk, causing the black hole to feed much more slowly and its X-ray brightness to decrease substantially. Unable to power such strong variations in the disk and the wind, GRS 1915's 'heart' ceases to beat. This remarkable system then likely begins one of its 13 other known patterns of variation. Neilsen is a winner of the Roger Doxsey Travel Prize, which provides graduate students within one year of receiving or receipt of their PhD a monetary prize to enable the oral presentation of their dissertation research at an AAS meeting. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass. More information, including images and other multimedia, can be found at: http://chandra.harvard.edu and http://chandra.nasa.gov

Chandra Pilot Survey of Extrasolar Planet Candidates

NASA Astrophysics Data System (ADS)

Tsuboi, Yohko

2012-09-01

We propose to detect planetary-mass companion around young nearby stars by X-ray direct imaging observations with Chandra. Our goals are to determine I. if the X-ray band can be a new probe to the exo-planet search, and II. if a planet emit detectable X-rays with a magnetic origin at a young age. This should be a challenging observation but a brand-new discovery space unique to Chandra. The abundant population of YSOs in the same field of view will enable us to obtain complete X-ray catalogues of YSOs with all categories of masses. We will also execute simultaneous deep NIR observations with IRSF/SIRIUS and Nishiharima 2m telescope to search for the other X-ray-emitting very low-mass objects near our aiming planet candidates.

Invited Review Article: The Chandra X-ray Observatory

NASA Astrophysics Data System (ADS)

Schwartz, Daniel A.

2014-06-01

The Chandra X-ray Observatory is an orbiting x-ray telescope facility. It is one of the National Aeronautics and Space Administration's four "Great Observatories" that collectively have carried out astronomical observations covering the infrared through gamma-ray portion of the electromagnetic spectrum. Chandra is used by astronomers world-wide to acquire imaging and spectroscopic data over a nominal 0.1-10 keV (124-1.24 Å) range. We describe the three major parts of the observatory: the telescope, the spacecraft systems, and the science instruments. This article will emphasize features of the design and development driven by some of the experimental considerations unique to x-ray astronomy. We will update the on-orbit performance and present examples of the scientific highlights.

Invited review article: The Chandra X-ray Observatory.

PubMed

Schwartz, Daniel A

2014-06-01

The Chandra X-ray Observatory is an orbiting x-ray telescope facility. It is one of the National Aeronautics and Space Administration's four "Great Observatories" that collectively have carried out astronomical observations covering the infrared through gamma-ray portion of the electromagnetic spectrum. Chandra is used by astronomers world-wide to acquire imaging and spectroscopic data over a nominal 0.1-10 keV (124-1.24 Å) range. We describe the three major parts of the observatory: the telescope, the spacecraft systems, and the science instruments. This article will emphasize features of the design and development driven by some of the experimental considerations unique to x-ray astronomy. We will update the on-orbit performance and present examples of the scientific highlights.

Studies in the X-Ray Emission of Clusters of Galaxies and Other Topics

NASA Technical Reports Server (NTRS)

Vrtilek, Jan; Thronson, Harley (Technical Monitor)

2001-01-01

The paper discusses the following: (1) X-ray study of groups of galaxies with Chandra and XMM. (2) X-ray properties of point sources in Chandra deep fields. (3) Study of cluster substructure using wavelet techniques. (4) Combined study of galaxy clusters with X-ray and the S-Z effect. Groups of galaxies are the fundamental building blocks of large scale structure in the Universe. X-ray study of the intragroup medium offers a powerful approach to addressing some of the major questions that still remain about almost all aspects of groups: their ages, origins, importance of composition of various galaxy types, relations to clusters, and origin and enrichment of the intragroup gas. Long exposures with Chandra have opened new opportunities for the study of X-ray background. The presence of substructure within clusters of galaxies has substantial implications for our understanding of cluster evolution as well as fundamental questions in cosmology.

High Energy Studies of Astrophysical Dust

NASA Astrophysics Data System (ADS)

Corrales, Lia Racquel

Astrophysical dust---any condensed matter ranging from tens of atoms to micron sized grains---accounts for about one third of the heavy elements produced in stars and disseminated into space. These tiny pollutants are responsible for producing the mottled appearance in the spray of light we call the "Milky Way." However these seemingly inert particles play a strong role in the physics of the interstellar medium, aiding star and planet formation, and perhaps helping to guide galaxy evolution. Most dust grains are transparent to X-ray light, leaving a signature of atomic absorption, but also scattering the light over small angles. Bright X-ray objects serendipitously situated behind large columns of dust and gas provide a unique opportunity to study the dust along the line of sight. I focus primarily on X-ray scattering through dust, which produces a diffuse halo image around a central point source. Such objects have been observed around X-ray bright Galactic binaries and extragalactic objects that happen to shine through the plane of the Milky Way. I use the Chandra X-ray Observatory, a space-based laboratory operated by NASA, which has imaging resolution ideal for studying X-ray scattering halos. I examine several bright X-ray objects with dust-free sight lines to test their viability as templates and develop a parametric model for the Chandra HETG point spread function (PSF). The PSF describes the instrument's imaging response to a point source, an understanding of which is necessary for properly measuring the surface brightness of X-ray scattering halos. I use an HETG observation of Cygnus X-3, one of the brightest objects available in the Chandra archive, to derive a dust grain size distribution. There exist degenerate solutions for the dust scattering halo, but with the aid of Bayesian analytics I am able to apply prior knowledge about the Cyg X-3 sight line to measure the relative abundance of dust in intervening Milky Way spiral arms. I also demonstrate how information from a single scattering halo can be used in conjunction with X-ray spectroscopy to directly measure the dust-to-gas mass ratio, laying the groundwork for future scattering halo surveys. Distant quasars also produce X-rays that pierce the intergalactic medium. These sources invite the unique opportunity to search for extragalactic dust, whether distributed diffusely throughout intergalactic space, surrounding other galaxies, or occupying reservoirs of cool intergalactic gas. I review X-ray scattering in a cosmological context, examining the range and sensitivity of Chandra to detect the low surface brightness levels of intergalactic scattering. Of particular interest is large "grey" dust, which would cause systematic errors in precision cosmology experiments at a level comparable to the size of the error bars sought. This requires using the more exact Mie scattering treatment, which reduces the scattering cross-section for soft X-rays by a factor of about ten, compared to the Rayleigh-Gans approximation used for interstellar X-ray scattering studies. This allows me to relax the limit on intergalactic dust imposed by previous X-ray imaging of a z=4.3 quasar, QSO 1508+5714, which overestimated the scattering intensity. After implementing the Mie solution with the cosmological integral for scattering halo intensity, I found that intergalactic dust will scatter 1-3% of soft X-ray light. Unfortunately the wings of the Chandra PSF are brighter than the surface brightness expected for these intergalactic scattering halos. The X-ray signatures of intergalactic dust may only be visible if a distant quasar suddenly dimmed by a factor of 1000 or more, leaving behind an X-ray scattering echo, or "ghost" halo.

Giant Black Hole Rips Apart Star

NASA Astrophysics Data System (ADS)

2004-02-01

Thanks to two orbiting X-ray observatories, astronomers have the first strong evidence of a supermassive black hole ripping apart a star and consuming a portion of it. The event, captured by NASA's Chandra and ESA's XMM-Newton X-ray Observatories, had long been predicted by theory, but never confirmed. Astronomers believe a doomed star came too close to a giant black hole after being thrown off course by a close encounter with another star. As it neared the enormous gravity of the black hole, the star was stretched by tidal forces until it was torn apart. This discovery provides crucial information about how these black holes grow and affect surrounding stars and gas. "Stars can survive being stretched a small amount, as they are in binary star systems, but this star was stretched beyond its breaking point," said Stefanie Komossa of the Max Planck Institute for Extraterrestrial Physics (MPE) in Germany, leader of the international team of researchers. "This unlucky star just wandered into the wrong neighborhood." While other observations have hinted stars are destroyed by black holes (events known as "stellar tidal disruptions"), these new results are the first strong evidence. Evidence already exists for supermassive black holes in many galaxies, but looking for tidal disruptions represents a completely independent way to search for black holes. Observations like these are urgently needed to determine how quickly black holes can grow by swallowing neighboring stars. Animation of Star Ripped Apart by Giant Black Hole Star Ripped Apart by Giant Black Hole Observations with Chandra and XMM-Newton, combined with earlier images from the German Roentgen satellite, detected a powerful X-ray outburst from the center of the galaxy RX J1242-11. This outburst, one of the most extreme ever detected in a galaxy, was caused by gas from the destroyed star that was heated to millions of degrees Celsius before being swallowed by the black hole. The energy liberated in the process was equivalent to a supernova. "Now, with all the data in hand, we have the smoking gun proof that this spectacular event has occurred," said coauthor Günther Hasinger, also of MPE. The black hole in the center of RX J1242-11 is estimated to have a mass of about 100 million times Earth's Sun. By contrast, the destroyed star probably had a mass about equal to the Sun, making it a lopsided battle of gravity. "This is the ultimate David versus Goliath battle, but here David loses," said Hasinger. The astronomers estimated about one percent of the star's mass was ultimately consumed, or accreted, by the black hole. This small amount is consistent with predictions that the momentum and energy of the accretion process will cause most of the destroyed star's gas to be flung away from the black hole. XMM-Newton Spectrum &Illustration of RX J1242-11 XMM-Newton Spectrum & Illustration of RX J1242-11 The force that disrupted the star in RX J1242-11 is an extreme example of the tidal force caused by differences in gravity acting on the front and back of an object. The tidal force from the Moon causes tides in Earth's oceans. A tidal force from Jupiter pulled Comet Shoemaker-Levy apart, before it plunged into the giant planet. The odds stellar tidal disruption will happen in a typical galaxy are low, about one in 10,000 annually. If it happened at the center of the Milky Way Galaxy, 26,000 light-years from Earth, the resulting X-ray outburst would be about 50,000 times brighter than the brightest X-ray source in our galaxy, beside the Sun, but it would not pose a threat to Earth. Other dramatic flares have been seen from galaxies, but this is the first studied with the high-spatial resolution of Chandra and the high-spectral resolution of XMM-Newton. Both instruments made a critical advance. Chandra showed the RX J1242-11 event occurred in the center of a galaxy, where the black hole lurks. The XMM-Newton spectrum revealed the fingerprints expected for the surroundings of a black hole, ruling out other possible astronomical explanations. In the future, searches using Chandra, XMM-Newton and survey instruments should find many other tidal disruptions. Detailed studies with future observatories like Constellation-X should teach us about the extreme physics around supermassive black holes. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the Office of Space Science, NASA Headquarters, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. XMM-Newton is an ESA science mission managed at the European Space Research and Technology Centre (ESTEC) in the Netherlands for the Directorate of the Scientific Programme. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Chandra Provides New View of Biggest Construction Sites in Universe

NASA Astrophysics Data System (ADS)

2003-05-01

Images made by NASA's Chandra X-ray Observatory have revealed two distant cosmic construction sites buzzing with activity. This discovery shows how super massive black holes control the growth of massive galaxies in the distant universe. X-rays were detected from vast clouds of high-energy particles around the galaxies 3C294 and 4C41.17, which are 10 and 12 billion light years from Earth, respectively. The energetic particles were left over from past explosive events that can be traced through the X-ray and radio jets back to the super massive black holes located in the centers of the galaxies. "These galaxies are revealing an energetic phase in which a super massive black hole transfers considerable energy into the gas surrounding the galaxies," said Andrew Fabian of England's Cambridge University, lead author of a paper on 3C294 to appear in an upcoming issue of the Monthly Notices of the Royal Astronomical Society. "This appears to be crucial in explaining the puzzling properties of present-day galaxies, especially those that group together in large clusters," he said. The picture that is emerging is of a grand cosmic cycle. A dense region of intergalactic gas cools to form several smaller galaxies, which merge to form a larger galaxy with a super massive black hole. The galaxy and its central black hole continue to grow until the energy generated by jets from the vicinity of the voracious black hole stops the fall of matter into the black hole. Millions of years after the jet activity subsides, matter will resume falling into the black hole and the cycle begins anew. 4C41.17 and 3C294 4C41.17 Both 3C294 and 4C41.17 reside in regions of space containing unusually high numbers of galaxies. The gas and galaxies surrounding these galaxies will eventually collapse to form galaxy clusters, some of the most massive objects in the universe. Although 3C294 and 4C41.17 will grow to gargantuan sizes, through the accumulation of surrounding matter that forms hundreds of billions of stars, their growth does not go unchecked. "It's as if nature tries to impose a weight limit on the size of the most massive galaxies," said Caleb Scharf of Columbia University, N.Y., and lead author of a paper on 4C41.17 to be published in The Astrophysical Journal. "The Chandra observations have given us an important clue as to how this occurs. The high energy jets give the super massive black holes an extended reach to regulate the growth of these galaxies," he said. In 3C294 and 4C41.17, the hot swirling infernos around their super massive black holes have launched magnetized jets of high energy particles first identified by radio telescopes. These jets, which were also detected by Chandra, have swept up clouds of dust and gas and have helped trigger the formation of billions of new stars. The dusty, star-forming clouds of 4C41.17, the most powerful source of infrared radiation ever observed, are embedded in even larger clouds of gas. Astronomers recently used the Keck Observatory to observe these larger clouds, which have a temperature of 10,000 degree Celsius gas. These clouds are leftover material from the galaxy's formation and should have cooled rapidly by radiation in the absence of a heat source. Animation of How Supermassive Black Holes Affect the Formation of Massive Galaxies Animation of How Supermassive Black Holes Affect the Formation of Massive Galaxies "Significantly, the warm gas clouds coincide closely with the largest extent of the X-ray emission," said Michiel Reuland of Lawrence Livermore National Laboratory, Livermore, Calif., a coauthor on the 4C41.17 paper and a paper describing Keck Observatory work. "The Chandra results show that high energy particles or radiation can supply the necessary energy to light up these clouds," he said. Most of the X-rays from 4C41.17 and 3C294 are due to collisions of energetic electrons with the cosmic background of photons produced in the hot early universe. Because these galaxies are far away, their observed radiation originated when the universe was younger and the background was more intense. This effect enhances the X-radiation and helps astronomers to study extremely distant galaxies. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program, and TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass., for the Office of Space Science, NASA Headquarters, Washington. Images and additional information about this result are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

The Chandra X-Ray Observatory: Progress Report and Highlights

NASA Technical Reports Server (NTRS)

Weisskopf, Martin C.

2012-01-01

Over the past 13 years, the Chandra X-ray Observatory's ability to provide high resolution X-ray images and spectra have established it as one of the most versatile and powerful tools for astrophysical research in the 21st century. Chandra explores the hot, high-energy regions of the universe, observing X-ray sources with fluxes spanning more than 10 orders of magnitude, from the X-ray brightest, Sco X-1, to the faintest sources in the Chandra Deep Field South survey. Thanks to its continuing operational life, the Chandra mission now also provides a long observing baseline which, in and of itself, is opening new research opportunities. Observations in the past few years alone have deepened our understanding of the co-evolution of supermassive black holes and galaxies, the details of black hole accretion, the nature of dark energy and dark matter, the details of supernovae and their progenitors, the interiors of neutron stars, the evolution of massive stars, and the high-energy environment of protoplanetary nebulae and the interaction of an exo-planet with its star. Here we update the technical status, highlight some of the scientific results, and very briefly discuss future prospects. We fully expect that the Observatory will continue to provide outstanding scientific results for many years to come.

Breaking Self-Similarity in Poor Clusters of Galaxies

NASA Astrophysics Data System (ADS)

Kempner, J. C.; David, L. P.

2005-12-01

The large scatter in the LX--TX relation among poor clusters in the ˜2--4 keV range indicates that the self-similarity seen among hotter clusters does not apply to their cooler siblings. Many forms of non-gravitational heating have been proposed to break this self-similarity, including cluster mergers, AGN heating, and supernova ``pre-heating.'' We present an analysis of a sample of poor clusters from the Chandra and XMM archives that suggests a cycle of heating and cooling in the cores of these clusters is responsible for the departures from self-similarity. That these differences exist only in the core is strongly suggestive of AGN heating as the dominant mechanism. Support for this work was provided by the National Aeronautics and Space Administration through Chandra Award Number G05-5138A issued by the Chandra X-ray Observatory Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of NASA under contract NAS8-39073, and by NASA contract NAG5-12933.

The 3 megasecond Chandra campaign on Sgr A*: a census of x-ray flaring activity from the galactic center

NASA Astrophysics Data System (ADS)

Neilsen, Joey

Over the last decade, X-ray observations of Sgr A* have revealed a black hole in a deep sleep, punctuated roughly once per day by brief flares. The extreme X-ray faintness of this supermassive black hole has been a long-standing puzzle in black hole accretion. To study the accretion processes in the Galactic Center, Chandra (in concert with numerous ground- and space-based observatories) undertook a 3 Ms campaign on Sgr A* in 2012. With its excellent observing cadence, sensitivity, and spectral resolution, this Chandra X-ray Visionary Project (XVP) provides an unprecedented opportunity to study the behavior of our closest supermassive black hole. We present a progress report from our ongoing study of X-ray flares, including the brightest flare ever seen from Sgr A*. Focusing on the statistics of the flares, the quiescent emission, and the relationship between the X-ray and the infrared, we discuss the physical implications of X-ray variability in the Galactic Center.

Monitoring variable X-ray sources in nearby galaxies

NASA Astrophysics Data System (ADS)

Kong, A. K. H.

2010-12-01

In the last decade, it has been possible to monitor variable X-ray sources in nearby galaxies. In particular, since the launch of Chandra, M31 has been regularly observed. It is perhaps the only nearby galaxy which is observed by an X-ray telescope regularly throughout operation. With 10 years of observations, the center of M31 has been observed with Chandra for nearly 1 Msec and the X-ray skies of M31 consist of many transients and variables. Furthermore, the X-ray Telescope of Swift has been monitoring several ultraluminous X-ray sources in nearby galaxies regularly. Not only can we detect long-term X-ray variability, we can also find spectral variation as well as possible orbital period. In this talk, I will review some of the important Chandra and Swift monitoring observations of nearby galaxies in the past 10 years. I will also present a "high-definition" movie of M31 and discuss the possibility of detecting luminous transients in M31 with MAXI.

The 3 Megasecond Chandra Campaign on Sgr A*: A Census of X-ray Flaring Activity from the Galactic Center

NASA Astrophysics Data System (ADS)

Neilsen, Joseph; Nowak, Michael; Gammie, Charles F.; Dexter, Jason; Markoff, Sera; Haggard, Daryl; Nayakshin, Sergei; Wang, Q. Daniel; Grosso, N.; Porquet, D.; Tomsick, John; Degenaar, Nathalie; Fragile, P. Christopher; Houck, John C.; Wijnands, Rudy; Miller, Jon M.; Baganoff, Frederick K.

2014-08-01

Over the last decade, X-ray observations of Sgr A* have revealed a black hole in a deep sleep, punctuated roughly once per day by brief ares. The extreme X-ray faintness of this supermassive black hole has been a long-standing puzzle in black hole accretion. To study the accretion processes in the Galactic Center, Chandra (in concert with numerous ground- and space-based observatories) undertook a 3 Ms campaign on Sgr A* in 2012. With its excellent observing cadence, sensitivity, and spectral resolution, this Chandra X-ray Visionary Project (XVP) provides an unprecedented opportunity to study the behavior of our closest supermassive black hole. We present a progress report from our ongoing study of X-ray flares, including one of the brightest flares ever seen from Sgr A*. Focusing on the statistics of the flares, the quiescent emission, and the relationship between the X-ray and the infrared, we discuss the physical implications of X-ray variability in the Galactic Center.

Galaxy Cluster Takes It to the Extreme

NASA Astrophysics Data System (ADS)

2007-05-01

Evidence for an awesome upheaval in a massive galaxy cluster was discovered in an image made by NASA's Chandra X-ray Observatory. The origin of a bright arc of ferociously hot gas extending over two million light years requires one of the most energetic events ever detected. The cluster of galaxies is filled with tenuous gas at 170 million degree Celsius that is bound by the mass equivalent of a quadrillion, or 1,000 trillion, suns. The temperature and mass make this cluster a giant among giants. VLA Radio Image of 3C438 VLA Radio Image of 3C438 "The huge feature detected in the cluster, combined with the high temperature, points to an exceptionally dramatic event in the nearby Universe," said Ralph Kraft of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass., and leader of a team of astronomers involved in this research. "While we're not sure what caused it, we've narrowed it down to a couple of exciting possibilities." The favored explanation for the bright X-ray arc is that two massive galaxy clusters are undergoing a collision at about 4 million miles per hour. Shock waves generated by the violent encounter of the clusters' hot gas clouds could produce a sharp change in pressure along the boundary where the collision is occurring, giving rise to the observed arc-shaped structure which resembles a titanic weather front. "Although this would be an extreme collision, one of the most powerful ever seen, we think this may be what is going on," said team member Martin Hardcastle, of the University of Hertfordshire, United Kingdom. Images of 3C438 and Surrounding Galaxy Cluster Images of 3C438 and Surrounding Galaxy Cluster A problem with the collision theory is that only one peak in the X-ray emission is seen, whereas two are expected. Longer observations with Chandra and the XMM-Newton X-ray observatories should help determine how serious this problem is for the collision hypothesis. Another possible explanation is that the disturbance was caused by an outburst generated by the infall of matter into a supermassive black hole located in a central galaxy. The black hole inhales much of the matter but expels some of it outward in a pair of high-speed jets, heating and pushing aside the surrounding gas. Such events are known to occur in this cluster. The galaxy 3C438 in the central region of the cluster is known to be a powerful source of explosive activity, which is presumably due to a central supermassive black hole. But the energy in these outbursts is not nearly large enough to explain the Chandra data. "If this event was an outburst from a supermassive black hole, then it's by far the most powerful one ever seen," said team member Bill Forman, also of CfA. The phenomenal amount of energy involved implies a very large amount of mass would have been swallowed by the black hole, about 30 billion times the Sun's mass over a period of 200 million years. The authors consider this rate of black hole growth implausible. "These values have never been seen before and, truthfully, are hard to believe," said Kraft. These results were presented at the American Astronomical Society meeting in Honolulu, HI, and will appear in an upcoming issue of The Astrophysical Journal. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1977-01-01

This photograph is of the High Energy Astronomy Observatory (HEAO)-2 telescope being evaluated by engineers in the clean room of the X-Ray Calibration Facility at the Marshall Space Flight Center (MSFC). The MSFC was heavily engaged in the technical and scientific aspects, testing and calibration, of the HEAO-2 telescope The HEAO-2 was the first imaging and largest x-ray telescope built to date. The X-Ray Calibration Facility was built in 1976 for testing MSFC's HEAO-2. The facility is the world's largest, most advanced laboratory for simulating x-ray emissions from distant celestial objects. It produced a space-like environment in which components related to x-ray telescope imaging are tested and the quality of their performance in space is predicted. The original facility contained a 1,000-foot long by 3-foot diameter vacuum tube (for the x-ray path) cornecting an x-ray generator and an instrument test chamber. Recently, the facility was upgraded to evaluate the optical elements of NASA's Hubble Space Telescope, Chandra X-Ray Observatory and Compton Gamma-Ray Observatory.

Chandra Takes In The Bright Lights, Big City Of The Milky Way

NASA Astrophysics Data System (ADS)

2002-01-01

NASA's Chandra X-ray Observatory has made a stunning, high-energy panorama of the central regions of our Milky Way galaxy. The findings are an important step toward understanding the most active area of the Milky Way as well as other galaxies throughout the universe. Like a sprawling megalopolis, the new Chandra images show hundreds of white dwarf stars, neutron stars and black holes bathed in an incandescent fog of multimillion-degree gas around a supermassive black hole. "The center of the galaxy is where the action is," said Q. Daniel Wang of the University of Massachusetts, Amherst. "With these images, we get a new perspective of the interplay between stars, gas and dust, as well as the magnetic fields and gravity in the region. We can see how such forces affect the immediate vicinity and may influence other aspects of the galaxy." Wang presented the montage of 30 separate Chandra images today at the American Astronomical Society meeting in Washington, and in a paper published in the Jan. 10, 2002, issue of the journal Nature. The images, made with the Advanced CCD Imaging Spectrometer (ACIS) July 16-21, 2001, covered a 400- by 900-light-year swath of the center of the galaxy. One immediate result was that the team could separate out the individual X-ray sources from the diffuse glow produced by hot gas. "We can now see that the sources are responsible for most of the X-rays from highly ionized iron previously attributed to the diffuse glow," said Eric Gotthelf, of Columbia University in New York, a co-author. "So we must now revise our notion of the hot gas, which appears to be about 10 times cooler than previously thought. It's only a relatively mild 10 million degrees!" The diffuse X-ray emission seems to be related to the turmoil and density of matter in the inner Milky Way. Stars are forming there at a much more rapid rate than in the galactic "suburbs." Many of the most massive stars in the galaxy are located in the galactic center and are furiously boiling off their outer layers in searing stellar winds. Supernova explosions are far more common in the region and send shock waves booming through the inner galaxy. And then there is the three-million-solar-mass black hole at the epicenter. Although Chandra recently observed a small flare from the vicinity of the central supermassive black hole, the power output near the black hole remains relatively low. However, an unexplained fluorescence of iron atoms, observed by the team to be associated with molecular clouds a few hundred light years away, may indicate that the supermassive black hole was hundreds of times brighter in the past. Alternatively, the fluorescence could be due to high-energy particles called cosmic rays produced by supernovas or bygone eruptions from the supermassive black hole. "The galactic center is dominated by very high pressures due to the hot gas component and the strong magnetic fields," said Cornelia Lang, also of the University of Massachusetts, and a co-author. "It's a nice place to visit with a telescope but I wouldn't want to live there." The Chandra map shows that the high-pressure and high-temperature gas is apparently escaping from the center into the halo of the galaxy. "A galaxy is a sort of ecosystem, and the activity in the center can seriously affect the evolution of the galaxy as a whole," said Wang. "Astronomically, the center of the Milky Way is really in our backyard, and, therefore, provides an excellent laboratory to learn about the cores of other galaxies." The ACIS instrument was developed for NASA by Pennsylvania State University, University Park, and Massachusetts Institute of Technology, Cambridge. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program, and TRW, Inc., Redondo Beach, Calif., is the prime contractor. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass.

Chandra reveals a black hole X-ray binary within the ultraluminous supernova remnant MF 16

NASA Astrophysics Data System (ADS)

Roberts, T. P.; Colbert, E. J. M.

2003-06-01

We present evidence, based on Chandra ACIS-S observations of the nearby spiral galaxy NGC 6946, that the extraordinary X-ray luminosity of the MF 16 supernova remnant actually arises in a black hole X-ray binary. This conclusion is drawn from the point-like nature of the X-ray source, its X-ray spectrum closely resembling the spectrum of other ultraluminous X-ray sources thought to be black hole X-ray binary systems, and the detection of rapid hard X-ray variability from the source. We briefly discuss the nature of the hard X-ray variability, and the origin of the extreme radio and optical luminosity of MF 16 in light of this identification.

Banging Galaxy Clusters: High Fidelity X-ray Temperature and Radio Maps to Probe the Physics of Merging Clusters

NASA Astrophysics Data System (ADS)

Burns, Jack O.; Hallman, Eric J.; Alden, Brian; Datta, Abhirup; Rapetti, David

2017-06-01

We present early results from an X-ray/Radio study of a sample of merging galaxy clusters. Using a novel X-ray pipeline, we have generated high-fidelity temperature maps from existing long-integration Chandra data for a set of clusters including Abell 115, A520, and MACSJ0717.5+3745. Our pipeline, written in python and operating on the NASA ARC high performance supercomputer Pleiades, generates temperature maps with minimal user interaction. This code will be released, with full documentation, on GitHub in beta to the community later this year. We have identified a population of observable shocks in the X-ray data that allow us to characterize the merging activity. In addition, we have compared the X-ray emission and properties to the radio data from observations with the JVLA and GMRT. These merging clusters contain radio relics and/or radio halos in each case. These data products illuminate the merger process, and how the energy of the merger is dissipated into thermal and non-thermal forms. This research was supported by NASA ADAP grant NNX15AE17G.

Improving the Multi-Wavelength Capability of Chandra Large Programs

NASA Astrophysics Data System (ADS)

Pacucci, Fabio

2017-09-01

In order to fully exploit the joint Chandra/JWST/HST ventures to detect faint sources, we urgently need an advanced matching algorithm between optical/NIR and X-ray catalogs/images. This will be of paramount importance in bridging the gap between upcoming optical/NIR facilities (JWST) and later X-ray ones (Athena, Lynx). We propose to develop an advanced and automated tool to improve the identification of Chandra X-ray counterparts detected in deep optical/NIR fields based on T-PHOT, a software widely used in the community. The developed code will include more than 20 years in advancements of X-ray data analysis and will be released to the public. Finally, we will release an updated catalog of X-ray sources in the CANDELS regions: a leap forward in our endeavor of charting the Universe.

AEGIS-X: Deep Chandra Imaging of the Central Groth Strip

NASA Astrophysics Data System (ADS)

Nandra, K.; Laird, E. S.; Aird, J. A.; Salvato, M.; Georgakakis, A.; Barro, G.; Perez-Gonzalez, P. G.; Barmby, P.; Chary, R.-R.; Coil, A.; Cooper, M. C.; Davis, M.; Dickinson, M.; Faber, S. M.; Fazio, G. G.; Guhathakurta, P.; Gwyn, S.; Hsu, L.-T.; Huang, J.-S.; Ivison, R. J.; Koo, D. C.; Newman, J. A.; Rangel, C.; Yamada, T.; Willmer, C.

2015-09-01

We present the results of deep Chandra imaging of the central region of the Extended Groth Strip, the AEGIS-X Deep (AEGIS-XD) survey. When combined with previous Chandra observations of a wider area of the strip, AEGIS-X Wide (AEGIS-XW), these provide data to a nominal exposure depth of 800 ks in the three central ACIS-I fields, a region of approximately 0.29 deg2. This is currently the third deepest X-ray survey in existence; a factor ∼ 2-3 shallower than the Chandra Deep Fields (CDFs), but over an area ∼3 times greater than each CDF. We present a catalog of 937 point sources detected in the deep Chandra observations, along with identifications of our X-ray sources from deep ground-based, Spitzer, GALEX, and Hubble Space Telescope imaging. Using a likelihood ratio analysis, we associate multiband counterparts for 929/937 of our X-ray sources, with an estimated 95% reliability, making the identification completeness approximately 94% in a statistical sense. Reliable spectroscopic redshifts for 353 of our X-ray sources are available predominantly from Keck (DEEP2/3) and MMT Hectospec, so the current spectroscopic completeness is ∼38%. For the remainder of the X-ray sources, we compute photometric redshifts based on multiband photometry in up to 35 bands from the UV to mid-IR. Particular attention is given to the fact that the vast majority the X-ray sources are active galactic nuclei and require hybrid templates. Our photometric redshifts have mean accuracy of σ =0.04 and an outlier fraction of approximately 5%, reaching σ =0.03 with less than 4% outliers in the area covered by CANDELS . The X-ray, multiwavelength photometry, and redshift catalogs are made publicly available.

Chandra High Resolution Imaging of NGC 1365 and NGC 4151

NASA Astrophysics Data System (ADS)

Wang, Junfeng; Fabbiano, G.; Elvis, M.; Risaliti, G.; Karovska, M.; Zezas, A.; Mazzarella, J. M.; Lord, S.; Howell, J. H.; Mundell, C. G.

2010-07-01

We present Chandra high resolution imaging of the circumnuclear regions of two nearby active galaxies, namely the starburst/AGN composite Seyfert 1.8 NGC 1365 and the archetypal Seyfert 1 NGC 4151. In NGC 1365, the X-ray morphology shows a biconical soft X-ray-emission region extending ~5 kpc in projection from the nucleus, coincident with the optical high-excitation outflows. Chandra HRC imaging of the NGC 4151 nucleus resolves X-ray emission from the 4 arcsec radio jet and the narrow line region (NLR) clouds. Our results demonstrate the unique power of spatially resolved spectroscopy with Chandra, and support previous claims that frequent jet-ISM interaction may explain why jets in Seyfert galaxies appear small, slow, and thermally dominated.

KSC-99pc0191

NASA Image and Video Library

1999-02-10

In the Vertical Processing Facility (VPF), workers prepare the shrouded Chandra X-ray Observatory for its lift to a vertical position. The telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

KSC-99pc0195

NASA Image and Video Library

1999-02-10

In the Vertical Processing Facility (VPF), the shrouded Chandra X-ray Observatory achieves a vertical position via the overhead crane. The telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

"Survivor" Black Holes May Be Mid-Sized

NASA Astrophysics Data System (ADS)

2010-04-01

New evidence from NASA's Chandra X-ray Observatory and ESA's XMM-Newton strengthens the case that two mid-sized black holes exist close to the center of a nearby starburst galaxy. These "survivor" black holes avoided falling into the center of the galaxy and could be examples of the seeds required for the growth of supermassive black holes in galaxies, including the one in the Milky Way. For several decades, scientists have had strong evidence for two distinct classes of black hole: the stellar-mass variety with masses about ten times that of the Sun, and the supermassive ones, located at the center of galaxies, that range from hundreds of thousands to billions of solar masses. But a mystery has remained: what about black holes that are in between? Evidence for these objects has remained controversial, and until now there were no strong claims of more than one such black hole in a single galaxy. Recently, a team of researchers has found signatures in X-ray data of two mid-sized black holes in the starburst galaxy M82 located 12 million light years from Earth. "This is the first time that good evidence for two mid-sized black holes has been found in one galaxy," said Hua Feng of the Tsinghua University in China, who led two papers describing the results. "Their location near the center of the galaxy might provide clues about the origin of the Universe's largest black holes - supermassive black holes found in the centers of most galaxies." One possible mechanism for the formation of supermassive black holes involves a chain reaction of collisions of stars in compact star clusters that results in the buildup of extremely massive stars, which then collapse to form intermediate-mass black holes. The star clusters then sink to the center of the galaxy, where the intermediate-mass black holes merge to form a supermassive black hole. In this picture, clusters that were not massive enough or close enough to the center of the galaxy to fall in would survive, as would any black holes they contain. "We can't say whether this process actually occurred in M82, but we do know that both of these possible mid-sized black holes are located in or near star clusters," said Phil Kaaret from the University of Iowa, who co-authored both papers. "Also, M82 is the nearest place to us where the conditions are similar to those in the early Universe, with lots of stars forming." The evidence for these two "survivor" black holes comes from how their X-ray emission varies over time and analysis of their X-ray brightness and spectra, i.e., the distribution of X-rays with energy. Chandra and XMM-Newton data show that the X-ray emission for one of these objects changes in a distinctive manner similar to stellar-mass black holes found in the Milky Way. Using this information and theoretical models, the team estimated this black hole's mass is between 12,000 and 43,000 times the mass of the Sun. This mass is large enough for the black hole to generate copious X-rays by pulling gas directly from its surroundings, rather than from a binary companion, like with stellar-mass black holes. The black hole is located at a projected distance of 290 light years from the center of M82. The authors estimate that, at this close distance, if the black hole was born at the same time as the galaxy and its mass was more than about 30,000 solar masses it would have been pulled into the center of the galaxy. That is, it may have just escaped falling into the supermassive black hole that is presumably located in the center of M82. The second object, located 600 light years in projection away from the center of M82, was observed by both Chandra and XMM-Newton. During X-ray outbursts, periodic and random variations normally present in the X-ray emission disappear, a strong indication that a disk of hot gas dominates the X-ray emission. A detailed fit of the X-ray data indicates that the disk extends all the way to the innermost stable orbit around the black hole. Similar behavior has been seen from stellar-mass black holes in our Galaxy, but this is the first likely detection in a candidate intermediate-mass black hole. The radius of the innermost stable orbit depends only on the mass and spin of the black hole. The best model for the X-ray emission implies a rapidly spinning black hole with mass in the range 200 to 800 times the mass of the Sun. The mass agrees with theoretical estimates for a black hole created in a star cluster by runaway collisions of stars. "This result is one of the strongest pieces of evidence to date for the existence of an intermediate-mass black hole," said Feng. "This looks just like well-studied examples of stellar-mass black holes, except for being more than 20 times as massive." The two papers describing these results recently appeared in The Astrophysical Journal. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass. The XMM-Newton spacecraft is controlled by the European Space Operations Center. The XMM-Newton Science Operations Center situated at ESAC in Villafranca, Spain, manages observation requests and receives XMM-Newton data. The XMM-Newton Survey Science Centre at Leicester University, UK, processes and correlates all XMM-Newton observations with existing sky data held elsewhere in the world. More information, including images and other multimedia, can be found at: http://chandra.harvard.edu and http://chandra.nasa.gov and http://www.esa.int/esaSC/

Stars Form Surprisingly Close to Milky Way's Black Hole

NASA Astrophysics Data System (ADS)

2005-10-01

The supermassive black hole at the center of the Milky Way has surprisingly helped spawn a new generation of stars, according to observations from NASA's Chandra X-ray Observatory. This novel mode of star formation may solve several mysteries about the supermassive black holes that reside at the centers of nearly all galaxies. "Massive black holes are usually known for violence and destruction," said Sergei Nayakshin of the University of Leicester, United Kingdom, and coauthor of a paper on this research in an upcoming issue of the Monthly Notices of the Royal Astronomical Society. "So it's remarkable that this black hole helped create new stars, not just destroy them." Black holes have earned their fearsome reputation because any material -- including stars -- that falls within the so-called event horizon is never seen again. However, these new results indicate that the immense disks of gas known to orbit many black holes at a "safe" distance from the event horizon can help nurture the formation of new stars. Animation of Stars Forming Around Black Hole Animation of Stars Forming Around Black Hole This conclusion came from new clues that could only be revealed in X-rays. Until the latest Chandra results, astronomers have disagreed about the origin of a mysterious group of massive stars discovered by infrared astronomers to be orbiting less than a light year from the Milky Way's central black hole, a.k.a. Sagittarius A*, or Sgr A*. At such close distances to Sgr A*, the standard model for star formation predicts that gas clouds from which stars form should have been ripped apart by tidal forces from the black hole. Two models to explain this puzzle have been proposed. In the disk model, the gravity of a dense disk of gas around Sgr A* offsets the tidal forces and allows stars to form; in the migration model, the stars formed in a star cluster far away from the black hole and migrated in to form the ring of massive stars. The migration scenario predicts about a million low mass, sun-like stars in and around the ring, whereas in the disk model, the number of low mass stars could be much less. Nayakshin and his coauthor, Rashid Sunyaev of the Max Plank Institute for Physics in Garching, Germany, used Chandra observations to compare the X-ray glow from the region around Sgr A* to the X-ray emission from thousands of young stars in the Orion Nebula star cluster. They found that the Sgr A* star cluster contains only about 10,000 low mass stars, thereby ruling out the migration model. "We can now say that the stars around Sgr A* were not deposited there by some passing star cluster, rather they were born there," said Sunyaev . "There have been theories that this was possible, but this is the first real evidence. Many scientists are going to be very surprised by these results." Because the Galactic Center is shrouded in dust and gas, it has not been possible to look for the low-mass stars in optical observations. In contrast, X-ray data have allowed astronomers to penetrate the veil of gas and dust and look for these low mass stars. Scenario Dismissed by Chandra Results Scenario Dismissed by Chandra Results "In one of the most inhospitable places in our Galaxy, stars have prevailed," said Nayakshin. "It appears that star formation is much more tenacious than we previously believed." The results suggest that the "rules" of star formation change when stars form in the disk of a giant black hole. Because this environment is very different from typical star formation regions, there is a change in the proportion of stars that form. For example, there is a much higher percentage of massive stars in the disks around black holes. And, when these massive stars explode as supernovae, they will "fertilize" the region with heavy elements such as oxygen. This may explain the large amounts of such elements observed in the disks of young supermassive black holes. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

The Chandra Source Catalog: X-ray Aperture Photometry

NASA Astrophysics Data System (ADS)

Kashyap, Vinay; Primini, F. A.; Glotfelty, K. J.; Anderson, C. S.; Bonaventura, N. R.; Chen, J. C.; Davis, J. E.; Doe, S. M.; Evans, I. N.; Evans, J. D.; Fabbiano, G.; Galle, E.; Gibbs, D. G.; Grier, J. D.; Hain, R.; Hall, D. M.; Harbo, P. N.; He, X.; Houck, J. C.; Karovska, M.; Lauer, J.; McCollough, M. L.; McDowell, J. C.; Miller, J. B.; Mitschang, A. W.; Morgan, D. L.; Nichols, J. S.; Nowak, M. A.; Plummer, D. A.; Refsdal, B. L.; Rots, A. H.; Siemiginowska, A. L.; Sundheim, B. A.; Tibbetts, M. S.; Van Stone, D. W.; Winkelman, S. L.; Zografou, P.

2009-01-01

The Chandra Source Catalog represents a reanalysis of the entire ACIS and HRC imaging observations over the 9-year Chandra mission. Source detection is carried out on a uniform basis, using the CIAO tool wavdetect, and source fluxes are estimated post-facto using a Bayesian method that accounts for background, spatial resolution effects, and contamination from nearby sources. We use gamma-function prior distributions, which could be either non-informative, or in case there exist previous observations of the same source, strongly informative. The resulting posterior probability density functions allow us to report the flux and a robust credible range on it. We also determine limiting sensitivities at arbitrary locations in the field using the same formulation. This work was supported by CXC NASA contracts NAS8-39073 (VK) and NAS8-03060 (CSC).

Firework Nova

NASA Image and Video Library

2017-12-08

Nova Stars are essentially giant fusion reactions occurring in the vacuum of space. Because stars have so much mass, they possess powerful gravitational force—but they don’t collapse because of the outward force generated by nuclear fusion, continually converting hydrogen atoms to helium. Sometimes stars begin orbiting each other, forming a binary star system. Typically this involves a white dwarf star and a red giant. Orbiting the red giant like a moon, the dwarf star rips matter from its companion until it essentially gags on the excess, coughing hot gas and radiation into space. This dramatic phenomenon is relatively common, and the white dwarf is not destroyed in the resulting nova. To learn more about x-ray emissions, read about NASA’s Chandra mission: www.nasa.gov/mission_pages/chandra/main/ --- Original caption: In Hollywood blockbusters, explosions are often among the stars of the show. In space, explosions of actual stars are a focus for scientists who hope to better understand their births, lives, and deaths and how they interact with their surroundings. Using NASA’s Chandra X-ray Observatory, astronomers have studied one particular explosion that may provide clues to the dynamics of other, much larger stellar eruptions. A team of researchers pointed the telescope at GK Persei, an object that became a sensation in the astronomical world in 1901 when it suddenly appeared as one of the brightest stars in the sky for a few days, before gradually fading away in brightness. Today, astronomers cite GK Persei as an example of a “classical nova,” an outburst produced by a thermonuclear explosion on the surface of a white dwarf star, the dense remnant of a Sun-like star. Read Full Article: www.nasa.gov/mission_pages/chandra/mini-supernova-explosi... NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Carbon Atmosphere Discovered On Neutron Star

NASA Astrophysics Data System (ADS)

2009-11-01

Evidence for a thin veil of carbon has been found on the neutron star in the Cassiopeia A supernova remnant. This discovery, made with NASA's Chandra X-ray Observatory, resolves a ten-year mystery surrounding this object. "The compact star at the center of this famous supernova remnant has been an enigma since its discovery," said Wynn Ho of the University of Southampton and lead author of a paper that appears in the latest issue of Nature. "Now we finally understand that it can be produced by a hot neutron star with a carbon atmosphere." By analyzing Chandra's X-ray spectrum - akin to a fingerprint of energy - and applying it to theoretical models, Ho and his colleague Craig Heinke, from the University of Alberta, determined that the neutron star in Cassiopeia A, or Cas A for short, has an ultra-thin coating of carbon. This is the first time the composition of an atmosphere of an isolated neutron star has been confirmed. The Chandra "First Light" image of Cas A in 1999 revealed a previously undetected point-like source of X-rays at the center. This object was presumed to be a neutron star, the typical remnant of an exploded star, but researchers were unable to understand its properties. Defying astronomers' expectations, this object did not show any X-ray or radio pulsations or any signs of radio pulsar activity. By applying a model of a neutron star with a carbon atmosphere to this object, Ho and Heinke found that the region emitting X-rays would uniformly cover a typical neutron star. This would explain the lack of X-ray pulsations because -- like a lightbulb that shines consistently in all directions -- this neutron star would be unlikely to display any changes in its intensity as it rotates. Scientists previously have used a neutron star model with a hydrogen atmosphere giving a much smaller emission area, corresponding to a hot spot on a typical neutron star, which should produce X-ray pulsations as it rotates. Interpreting the hydrogen atmosphere model without pulsations would require a tiny size, consistent only with exotic stars made of strange quark matter. "Our carbon veil solves one of the big questions about the neutron star in Cas A," said Craig Heinke. "People have been willing to consider some weird explanations, so it's a relief to discover a less peculiar solution." Unlike most astronomical objects, neutron stars are small enough to understand on a human scale. For example, neutron stars typically have a diameter of about 14 miles, only slightly longer than a half-marathon. The atmosphere of a neutron star is on an even smaller scale. The researchers calculate that the carbon atmosphere is only about 4 inches thick, because it has been compressed by a surface gravity that is 100 billion times stronger than on Earth. "For people who are used to hearing about immense sizes of things in space, it might be a surprise that we can study something so small," said Ho. "It's also funny to think that such a thin veil over this star played a key role in frustrating researchers." In Earth's time frame, the estimated age of the neutron star in Cas A is only several hundred years, making it about ten times younger than other neutron stars with detected surface emission. Therefore, the Cas A neutron star gives a unique window into the early life of a cooling neutron star. The carbon itself comes from a combination of material that has fallen back after the supernova, and nuclear reactions on the hot surface of the neutron star which convert hydrogen and helium into carbon. The X-ray spectrum and lack of pulsar activity suggest that the magnetic field on the surface of this neutron star is relatively weak. Similarly low magnetic fields are implied for several other young neutron stars by study of their weak X-ray pulsations. It is not known whether these neutron stars will have low magnetic fields for their entire lives, and never become radio pulsars, or whether processes in their interior will lead to the development of stronger magnetic fields as they age. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass.

NASA Telescopes Join Forces To Observe Unprecedented Explosion

NASA Image and Video Library

2017-12-08

NASA image release April 6, 2011 Images from Swift's Ultraviolet/Optical (white, purple) and X-ray telescopes (yellow and red) were combined in this view of GRB 110328A. The blast was detected only in X-rays, which were collected over a 3.4-hour period on March 28. Credit: NASA/Swift/Stefan Immler NASA's Swift, Hubble Space Telescope and Chandra X-ray Observatory have teamed up to study one of the most puzzling cosmic blasts yet observed. More than a week later, high-energy radiation continues to brighten and fade from its location. Astronomers say they have never seen anything this bright, long-lasting and variable before. Usually, gamma-ray bursts mark the destruction of a massive star, but flaring emission from these events never lasts more than a few hours. Although research is ongoing, astronomers say that the unusual blast likely arose when a star wandered too close to its galaxy's central black hole. Intense tidal forces tore the star apart, and the infalling gas continues to stream toward the hole. According to this model, the spinning black hole formed an outflowing jet along its spin axis. A powerful blast of X- and gamma rays is seen if this jet is pointed in our direction. To read more go to: www.nasa.gov/topics/universe/features/star-disintegration... NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Join us on Facebook

KSC-99pc0165

NASA Image and Video Library

1999-02-06

Cradled in the cargo hold of a tractor-trailer rig called the Space Cargo Transportation System, the Chandra X-ray Observatory reaches the Vertical Processing Facility (VPF). Chandra arrived at the Shuttle Landing Facility on Thursday, Feb. 4, aboard an Air Force C-5 Galaxy aircraft. In the VPF, the telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

KSC-99pc0166

NASA Image and Video Library

1999-02-06

Cradled in the cargo hold of a tractor-trailer rig called the Space Cargo Transportation System, the Chandra X-ray Observatory waits to be moved inside the Vertical Processing Facility (VPF). Chandra arrived at the Shuttle Landing Facility on Thursday, Feb. 4, aboard an Air Force C-5 Galaxy aircraft. In the VPF, the telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

Three Great Eyes on Kepler's Supernova Remnant

NASA Technical Reports Server (NTRS)

2004-01-01

[figure removed for brevity, see original site] Composite

[figure removed for brevity, see original site] [figure removed for brevity, see original site] Chandra X-Ray Data (blue) Chandra X-Ray Data (green)Hubble Telescope (visible-light)Spitzer Telescope (infrared)

NASA's three Great Observatories -- the Hubble Space Telescope, the Spitzer Space Telescope, and the Chandra X-ray Observatory -- joined forces to probe the expanding remains of a supernova, called Kepler's supernova remnant, first seen 400 years ago by sky watchers, including astronomer Johannes Kepler.

The combined image unveils a bubble-shaped shroud of gas and dust that is 14 light-years wide and is expanding at 4 million miles per hour (2,000 kilometers per second). Observations from each telescope highlight distinct features of the supernova remnant, a fast-moving shell of iron-rich material from the exploded star, surrounded by an expanding shock wave that is sweeping up interstellar gas and dust.

Each color in this image represents a different region of the electromagnetic spectrum, from X-rays to infrared light. These diverse colors are shown in the panel of photographs below the composite image. The X-ray and infrared data cannot be seen with the human eye. By color-coding those data and combining them with Hubble's visible-light view, astronomers are presenting a more complete picture of the supernova remnant.

Visible-light images from the Hubble telescope (colored yellow) reveal where the supernova shock wave is slamming into the densest regions of surrounding gas. The bright glowing knots are dense clumps from instabilities that form behind the shock wave. The Hubble data also show thin filaments of gas that look like rippled sheets seen edge-on. These filaments reveal where the shock wave is encountering lower-density, more uniform interstellar material.

The Spitzer telescope shows microscopic dust particles (colored red) that have been heated by the supernova shock wave. The dust re-radiates the shock wave's energy as infrared light. The Spitzer data are brightest in the regions surrounding those seen in detail by the Hubble telescope.

The Chandra X-ray data show regions of very hot gas, and extremely high-energy particles. The hottest gas (higher-energy X-rays, colored blue) is located primarily in the regions directly behind the shock front. These regions also show up in the Hubble observations, and also align with the faint rim of glowing material seen in the Spitzer data. The X-rays from the region on the lower left (colored blue) may be dominated by extremely high-energy electrons that were produced by the shock wave and are radiating at radio through X-ray wavelengths as they spiral in the intensified magnetic field behind the shock front. Cooler X-ray gas (lower-energy X-rays, colored green) resides in a thick interior shell and marks the location of heated material expelled from the exploded star.

Kepler's supernova, the last such object seen to explode in our Milky Way galaxy, resides about 13,000 light-years away in the constellation Ophiuchus.

The Chandra observations were taken in June 2000, the Hubble in August 2003; and the Spitzer in August 2004.

VizieR Online Data Catalog: Intermediate-luminosity X-ray objects catalog (Colbert+, 2002)

NASA Astrophysics Data System (ADS)

Colbert, E. J. M.; Ptak, A. F.

2002-11-01

ROSAT, and now Chandra, X-ray images allow studies of extranuclear X-ray point sources in galaxies other than our own. X-ray observations of normal galaxies with ROSAT and Chandra have revealed that off-nuclear, compact, intermediate-luminosity (LX[2-10keV]>=1039erg/s) X-ray objects (IXOs, a.k.a. ULXs [ultraluminous X-ray sources]) are quite common. Here we present a catalog and finding charts for 87 IXOs in 54 galaxies, derived from all of the ROSAT HRI imaging data for galaxies with cz<=5000km/s from the Third Reference Catalog of Bright Galaxies. (2 data files).

THE CHANDRA X-RAY SURVEY OF PLANETARY NEBULAE (CHANPLANS): PROBING BINARITY, MAGNETIC FIELDS, AND WIND COLLISIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kastner, J. H.; Montez, R. Jr.; Rapson, V.

2012-08-15

We present an overview of the initial results from the Chandra Planetary Nebula Survey (CHANPLANS), the first systematic (volume-limited) Chandra X-Ray Observatory survey of planetary nebulae (PNe) in the solar neighborhood. The first phase of CHANPLANS targeted 21 mostly high-excitation PNe within {approx}1.5 kpc of Earth, yielding four detections of diffuse X-ray emission and nine detections of X-ray-luminous point sources at the central stars (CSPNe) of these objects. Combining these results with those obtained from Chandra archival data for all (14) other PNe within {approx}1.5 kpc that have been observed to date, we find an overall X-ray detection rate ofmore » {approx}70% for the 35 sample objects. Roughly 50% of the PNe observed by Chandra harbor X-ray-luminous CSPNe, while soft, diffuse X-ray emission tracing shocks-in most cases, 'hot bubbles'-formed by energetic wind collisions is detected in {approx}30%; five objects display both diffuse and point-like emission components. The presence (or absence) of X-ray sources appears correlated with PN density structure, in that molecule-poor, elliptical nebulae are more likely to display X-ray emission (either point-like or diffuse) than molecule-rich, bipolar, or Ring-like nebulae. All but one of the point-like CSPNe X-ray sources display X-ray spectra that are harder than expected from hot ({approx}100 kK) central stars emitting as simple blackbodies; the lone apparent exception is the central star of the Dumbbell nebula, NGC 6853. These hard X-ray excesses may suggest a high frequency of binary companions to CSPNe. Other potential explanations include self-shocking winds or PN mass fallback. Most PNe detected as diffuse X-ray sources are elliptical nebulae that display a nested shell/halo structure and bright ansae; the diffuse X-ray emission regions are confined within inner, sharp-rimmed shells. All sample PNe that display diffuse X-ray emission have inner shell dynamical ages {approx}< 5 Multiplication-Sign 10{sup 3} yr, placing firm constraints on the timescale for strong shocks due to wind interactions in PNe. The high-energy emission arising in such wind shocks may contribute to the high excitation states of certain archetypical 'hot bubble' nebulae (e.g., NGC 2392, 3242, 6826, and 7009).« less

CHANDRA Observations of the Corona of AU Mic (dM1e)

NASA Astrophysics Data System (ADS)

Linsky, J. L.; Brown, A.; Osten, R. A.

2002-05-01

The dM1e flare star AU Mic (HD 197481, Gl 803) is the most luminous flare star in X-rays within 10 pc of the Sun. We observed the star in November 2000 for 60 ks using Chandra's High Energy Transmission Grating Spectrometer and ACIS-S detector. Since the X-ray flux was remarkably constant during this interval with only one small flare, the results we present refer to the quiescent state of the stellar corona. We have analyzed the Chandra spectra using the approach described by Osten et al (2002) for the analysis of similar observations of the active binary σ 2 CrB. We used CIAO2.0 "threads" and custom IDL procedures applied to the reprocessed Level 2 file. For the spectral line identification and atomic parameters, we used the APEC v1.10 line list. We derive the coronal emission measure distribution and abundances from the emission lines and continuum in the Chandra data set and the emission lines observed by EUVE during similar quiescent periods. The coronal model is compared with the fluxes of Fe XXI 1354A observed by STIS and Fe XVIII 975A observed by FUSE and with the lower temperature emission measure distribution obtained by Pagano et al (2000) from quiescent STIS observations. We acknowledge support by NASA through grant H-04630D to NIST and the University of Colorado.

Dynamical Models for High-Energy Emission from Massive Stars

NASA Astrophysics Data System (ADS)

Owocki, Stanley %FAA(University of Delaware)

Massive stars are prominent sources of X-rays and gamma-rays detected by both targeted and survey observations from orbiting telescopes like Chandra, XMM/Newton, RXTE, and Fermi. Such high-energy emissions represent key probes of the dynamics of massive-star mass loss, and their penetration through many magnitudes of visible interstellar extinction makes them effective beacons of massive stars in distant reaches of the Galaxy, and in young, active star-forming regions. The project proposed here will develop a comprehensive theoretical framework for interpreting both surveys and targeted observations of high-energy emission from massive stars. It will build on our team's extensive experience in both theoretical models and observational analyses for three key types of emission mechanisms in the stellar wind outflows of these stars, namely: 1) Embedded Wind Shocks (EWS) arising from internal instabilities in the wind driving; 2) shocks in Colliding Wind Binary (CWB) systems; and 3) High-Mass X-ray Binaries (HMXB) systems with interaction between massive-star wind with a compact companion (neutron star or black hole). Taking advantage of commonalities in the treatment of radiative driving, hydrodynamics, shock heating and cooling, and radiation transport, we will develop radiation hydrodynamical models for the key observational signatures like energy distribution, emission line spectrum, and variability, with an emphasis on how these can be used in affiliated analyses of both surveys like the recent Chandra mapping of the Carina association, and targeted observations of galactic X-ray and gamma-ray sources associated with each of the above specific model types. The promises of new clumping-insensitive diagnostics of mass loss rates, and the connection to mass transfer and binarity, all have broad relevance for understanding the origin, evolution, and fate of massive stars, in concert with elements of NASA's Strategic Subgoal 3D. Building on our team's expertise, the project emphasizes training of a new generation of students and post-doctoral researchers to model and analyze observations by current and future NASA X-ray and gamma-ray observatories.

CHANDRA AND SWIFT X-RAY OBSERVATIONS OF THE X-RAY PULSAR SMC X-2 DURING THE OUTBURST OF 2015

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, K. L.; Hu, C.-P; Lin, L. C. C.

2016-09-10

We report the Chandra /HRC-S and Swift /XRT observations for the 2015 outburst of the high-mass X-ray binary pulsar in the Small Magellanic Cloud, SMC X-2. While previous studies suggested that either an O star or a Be star in the field is the high-mass companion of SMC X-2, our Chandra /HRC-S image unambiguously confirms the O-type star as the true optical counterpart. Using the Swift /XRT observations, we extracted accurate orbital parameters of the pulsar binary through a time of arrivals analysis. In addition, there were two X-ray dips near the inferior conjunction, which are possibly caused by eclipsesmore » or an ionized high-density shadow wind near the companion’s surface. Finally, we propose that an outflow driven by the radiation pressure from day ∼10 played an important role in the X-ray/optical evolution of the outburst.« less

Galaxy Cluster IDCS J1426

NASA Image and Video Library

2016-01-07

Astronomers have made the most detailed study yet of an extremely massive young galaxy cluster using three of NASA's Great Observatories. This multi-wavelength image shows this galaxy cluster, called IDCS J1426.5+3508 (IDCS 1426 for short), in X-rays recorded by the Chandra X-ray Observatory in blue, visible light observed by the Hubble Space Telescope in green, and infrared light detected by the Spitzer Space Telescope in red. This rare galaxy cluster, which is located 10 billion light-years from Earth, is almost as massive as 500 trillion suns. This object has important implications for understanding how such megastructures formed and evolved early in the universe. The light astronomers observed from IDCS 1426 began its journey to Earth when the universe was less than a third of its current age. It is the most massive galaxy cluster detected at such an early time. First discovered by the Spitzer Space Telescope in 2012, IDCS 1426 was then observed using the Hubble Space Telescope and the Keck Observatory to determine its distance. Observations from the Combined Array for Millimeter-wave Astronomy indicated it was extremely massive. New data from the Chandra X-ray Observatory confirm the galaxy cluster's mass and show that about 90 percent of this mass is in the form of dark matter -- the mysterious substance that has so far been detected only through its gravitational pull on normal matter composed of atoms. http://photojournal.jpl.nasa.gov/catalog/PIA20063

The 3 Ms Chandra campaign on Sgr A*: a census of X-ray flaring activity from the Galactic center

NASA Astrophysics Data System (ADS)

Neilsen, J.; Nowak, M. A.; Gammie, C.; Dexter, J.; Markoff, S.; Haggard, D.; Nayakshin, S.; Wang, Q. D.; Grosso, N.; Porquet, D.; Tomsick, J. A.; Degenaar, N.; Fragile, P. C.; Houck, J. C.; Wijnands, R.; Miller, J. M.; Baganoff, F. K.

2014-05-01

Over the last decade, X-ray observations of Sgr A* have revealed a black hole in a deep sleep, punctuated roughly once per day by brief flares. The extreme X-ray faintness of this supermassive black hole has been a long-standing puzzle in black hole accretion. To study the accretion processes in the Galactic center, Chandra (in concert with numerous ground- and space-based observatories) undertook a 3 Ms campaign on Sgr A* in 2012. With its excellent observing cadence, sensitivity, and spectral resolution, this Chandra X-ray Visionary Project (XVP) provides an unprecedented opportunity to study the behavior of the closest supermassive black hole. We present a progress report from our ongoing study of X-ray flares, including the brightest flare ever seen from Sgr A*. Focusing on the statistics of the flares and the quiescent emission, we discuss the physical implications of X-ray variability in the Galactic center.

History of Chandra X-Ray Observatory

NASA Image and Video Library

1999-12-01

This Chandra image shows the central regions of two colliding galaxies known collectively as the Antennae (NGC-4038/4039). The Chandra image reveals a large population of extremely bright x-ray sources in this area of intense star formation. These x-ray sources, which emit 10 to several hundred times more x-ray power than similar sources in our own galaxy, are believed to be either massive black holes, or black holes that are beaming their energy toward Earth. In this x-ray image, red represents the low energy band, green intermediate, and blue the highest observed energies. The white and yellow sources are those that emit significant amounts of both low and high energy x-rays. About 60 million light years from Earth in the constellation Corvus, the Antennae Galaxies got their nickname from the wispy anntennae-like streams of gas as seen by optical telescopes. These ongoing wisps are believed to have been produced approximately 100 million years ago by the collision between the gala

Closed and Not Closed: Mitigating a Mystery on Chandra's Door

NASA Technical Reports Server (NTRS)

Odom, Brian

2015-01-01

The Chandra X-ray Observatory is part of NASA's fleet of "Great Observatories" along with the Hubble Space Telescope, the Spitzer Space Telescope, and the now deorbited Compton Gamma Ray Observatory. The observatory was designed to detect x-ray emissions from some of the hottest regions of the galaxy including exploded stars, clusters of galaxies, and matter around black holes. One of the observatory's key scientific instruments is the Advanced CCD Imaging Spectrometer (ACIS), which is one of four primary and two focal plane instruments. Due to the sensitivity of the charged coupled devices (CCD's), an aperture door was designed and built by Lockheed-Martin that protected the instrument during testing and the time leading up to launch. The design called for a system of wax actuators (manufactured by STARSYS Corp) to be used as components in a rotary actuator that would open and close the door during ground testing and on-orbit operations. Another feature of the design was an internal shear disc located in each actuator to prevent excessive internal pressure and to shield other components from damage.

Dead Star Creates Celestial Havoc

NASA Image and Video Library

2006-10-27

A star's spectacular death in the constellation Taurus was observed on Earth as the supernova of 1054 A.D. Now, almost a thousand years later, a superdense neutron star left behind by the stellar death is spewing out a blizzard of extremely high-energy particles into the expanding debris field known as the Crab Nebula. This composite image uses data from three of NASA's Great Observatories. The Chandra X-ray image is shown in light blue, the Hubble Space Telescope optical images are in green and dark blue, and the Spitzer Space Telescope's infrared image is in red. The size of the X-ray image is smaller than the others because ultrahigh-energy X-ray emitting electrons radiate away their energy more quickly than the lower-energy electrons emitting optical and infrared light. The neutron star, which has the mass equivalent to the sun crammed into a rapidly spinning ball of neutrons twelve miles across, is the bright white dot in the center of the image. http://photojournal.jpl.nasa.gov/catalog/PIA01320

KSC-99pc0193

NASA Image and Video Library

1999-02-10

In the Vertical Processing Facility (VPF), workers keep watch on the crane lifting the shrouded Chandra X-ray Observatory to a vertical position. The telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

KSC-99pc0172

NASA Image and Video Library

1999-02-08

Inside the Vertical Processing Facility (VPF), the overhead crane lifts Chandra X-ray Observatory completely out of its protective container. While in the VPF, the telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

KSC-99pc0194

NASA Image and Video Library

1999-02-10

In the Vertical Processing Facility (VPF), workers guide the final stages as the overhead crane lifts the shrouded Chandra X-ray Observatory to a vertical position. The telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

KSC-99pc0196

NASA Image and Video Library

1999-02-10

In the Vertical Processing Facility (VPF), workers move the shrouded Chandra X-ray Observatory on its workstand to the scaffolding behind it. The telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

KSC-99pc0170

NASA Image and Video Library

1999-02-08

Inside the Vertical Processing Facility (VPF), workers check the overhead cable that will lift the Chandra X-ray Observatory out of its protective container. While in the VPF, the telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

KSC-99pc0169

NASA Image and Video Library

1999-02-08

Inside the Vertical Processing Facility (VPF), workers attach the overhead cable to the Chandra X-ray Observatory to lift it out of its protective container. While in the VPF, the telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

KSC-99pc0192

NASA Image and Video Library

1999-02-10

In the Vertical Processing Facility (VPF), workers watch as the overhead crane starts lifting the shrouded Chandra X-ray Observatory to a vertical position. The telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

KSC-99pc0171

NASA Image and Video Library

1999-02-08

Inside the Vertical Processing Facility (VPF), workers begin lifting the Chandra X-ray Observatory out of its protective container. While in the VPF, the telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

Milky Way Monster Stars in Cosmic Reality Show

NASA Astrophysics Data System (ADS)

2003-01-01

The longest X-ray look yet at the supermassive black hole at the Milky Way's center has given astronomers unprecedented access to its life and times. The new data from NASA's Chandra X-ray Observatory revealed that our galaxy's central black hole is a frequent bad actor, prone to numerous outbursts and occasional large explosions. The observations of the black hole, a.k.a. Sagittarius A* or Sgr A*, occurred over a two-week period for a total exposure time of 164 hours. During this time Sgr A* flared up in X-ray intensity half a dozen or more times. Astronomers also found evidence that suggests it had an even more boisterous past. These discoveries will help to unlock the secrets of how Sgr A* grows and how it interacts with its environment "We are getting a look at the everyday life of a supermassive black hole like never before," said Frederick K. Baganoff of the Massachusetts Institute of Technology in Cambridge, who presented these new results on behalf of an international team at a press conference today at the American Astronomical Society meeting in Seattle. "We see it flaring on an almost daily basis." Sagittarius A* More images of Sagittarius A* The cause of the flares is not understood, but the rapidity with which they rise and fall indicates that they are occurring near the event horizon, or point of no return, around the black hole. Even when it flares, the intensity of the X-ray emission from the vicinity of the black hole is relatively weak, which suggests that Sgr A*, weighing in at 3 million times the mass of the Sun, is a starved black hole. "Although it appears to snack often, this black hole is definitely on a severe diet," says Baganoff. "This could be because explosive events in the past blew away much of the gas from the neighborhood of the black hole." Indeed, evidence for such events - which astronomers are viewing 26,000 years later due to the time it takes light to travel to Earth from the center of the Galaxy - can be found in the image. A faint streak of X-rays about 1 light-year long has been discovered 1.5 light years from Sgr A*. The streak points at Sgr A*, suggesting that it may be a jet of particles expelled at nearly the speed of light from just outside the event horizon of the black hole. The intensity and size of this jet indicate that the flaring activity has been occurring for many years. Labeled image of Sagittarius A* Jet Labeled image of Sagittarius A* Jet On a much larger scale, huge lobes of 20-million-degree-Centigrade gas extending over dozens of light years on either side of the black hole have also been discovered. "These lobes show that enormous explosions have occurred several times over the last ten thousand years," said Mark Morris of UCLA, lead author of a second paper on Sgr A*, who also participated in the press conference. Sangwook Park, of Penn State University in University Park, and Michael Muno, of MIT, were lead authors of two other papers presented at the meeting. These papers focused on the extraordinarily rich region around the central black hole, where they detected more than 2,000 X-ray sources. Other members of the team include Mark Bautz and George Ricker of MIT, Niel Brandt, Patrick Broos, George Chartas, Eric Feigelson, Gordon Garmire, and Leisa Townsley of Penn State, Yoshitomo Maeda of the Institute of Space and Astronautical Science in Japan, and Christian Howard of UCLA. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program, and TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass., for the Office of Space Science at NASA Headquarters, Washington. Images and additional information about this result are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

The making of the Chandra X-Ray Observatory: The project scientist’s perspective

PubMed Central

Weisskopf, Martin C.

2010-01-01

The history of the development of the Chandra X-Ray Observatory is reviewed from a personal perspective. This review is necessarily biased and limited by space because it attempts to cover a time span approaching five decades. PMID:20194740

How to Do Science From an Engineering Organization

NASA Technical Reports Server (NTRS)

Suggs, Robert M.

2003-01-01

MSFC's Space Environments Team performs engineering support for a number of NASA spaceflight projects by defining the space environment, developing design requirements, supporting the design process, and supporting operations. Examples of this type of support are given including meteoroid environment work for the Jovian Icy Moon Orbiter mission, ionizing radiation support for the Chandra X-Ray Observatory, and astronomicaVgeophysica1 observation planning for International Space Station.

The Loneliest Young Star (Artist Concept)

NASA Image and Video Library

2016-07-27

This artist's concept shows an unusual celestial object called CX330 was first detected as a source of X-ray light in 2009 by NASA's Chandra X-Ray Observatory while it was surveying the bulge in the central region of the Milky Way. A 2016 study in the Monthly Notices of the Royal Astronomical Society found that CX330 is the most isolated young star that has been discovered. Researchers compared NASA's Wide-field Infrared Survey Explorer (WISE) data from 2010 with NASA's Spitzer Space Telescope data from 2007 to come to this conclusion. CX330 is not near any star-forming region. As of the most recent observation, which was August 2015, this object was outbursting, meaning it was launching "jets" of material that slam into the gas and dust around it. Astronomers plan to continue studying the object, including with future telescopes that could view CX330 in other wavelengths of light. http://photojournal.jpl.nasa.gov/catalog/PIA20700

Real Time Space Weather Support for Chandra X-ray Observatory Operations

NASA Technical Reports Server (NTRS)

O'Dell, Stephen L.; Miller, J. Scott; Minow, Joseph I.; Wolk, Scott J.; Aldcroft, Thomas L.; Spitzbart, Bradley D.; Swartz, Douglas A.

2012-01-01

NASA launched the Chandra X-ray Observatory in July 1999. Soon after first light in August 1999, however, degradation in the energy resolution and charge transfer efficiency of the Advanced CCD Imaging Spectrometer (ACIS) x-ray detectors was observed. The source of the degradation was quickly identified as radiation damage in the charge-transfer channel of the front-illuminated CCDs, by weakly penetrating ("soft", 100-500 keV) protons as Chandra passed through the Earth s radiation belts and ring currents. As soft protons were not considered a risk to spacecraft health before launch, the only on-board radiation monitoring system is the Electron, Proton, and Helium Instrument (EPHIN) which was included on Chandra with the primary purpose of monitoring energetic solar particle events. Further damage to the ACIS detector has been successfully mitigated through a combination of careful mission planning, autonomous on-board radiation protection, and manual intervention based upon real-time monitoring of the soft-proton environment. The AE-8 and AP-8 trapped radiation models and Chandra Radiation Models are used to schedule science operations in regions of low proton flux. EPHIN has been used as the primary autonomous in-situ radiation trigger; but, it is not sensitive to the soft protons that damage the front-illuminated CCDs. Monitoring of near-real-time space weather data sources provides critical information on the proton environment outside the Earth's magnetosphere due to solar proton events and other phenomena. The operations team uses data from the Geostationary Operational Environmental Satellites (GOES) to provide near-real-time monitoring of the proton environment; however, these data do not give a representative measure of the soft-proton (less than 1 MeV) flux in Chandra s high elliptical orbit. The only source of relevant measurements of sub-MeV protons is the Electron, Proton, and Alpha Monitor (EPAM) aboard the Advanced Composition Explorer (ACE) satellite at L1, with real-time data provided by NOAA's Space Weather Prediction Center. This presentation will discuss radiation mitigation against proton damage, including models and real-time data sources used to protect the ACIS detector system.

Real Time Space Weather Support for Chandra X-Ray Observatory Operations

NASA Technical Reports Server (NTRS)

O'Dell, Stephen L.; Minow, Joseph I.; Miller, J. Scott; Wolk, Scott J.; Aldcroft, Thomas L.; Spitzbart, Bradley D.; Swartz. Douglas A.

2012-01-01

NASA launched the Chandra X-ray Observatory in July 1999. Soon after first light in August 1999, however, degradation in the energy resolution and charge transfer efficiency of the Advanced CCD Imaging Spectrometer (ACIS) x-ray detectors was observed. The source of the degradation was quickly identified as radiation damage in the charge-transfer channel of the front-illuminated CCDs, by weakly penetrating ( soft , 100 500 keV) protons as Chandra passed through the Earth s radiation belts and ring currents. As soft protons were not considered a risk to spacecraft health before launch, the only on-board radiation monitoring system is the Electron, Proton, and Helium Instrument (EPHIN) which was included on Chandra with the primary purpose of monitoring energetic solar particle events. Further damage to the ACIS detector has been successfully mitigated through a combination of careful mission planning, autonomous on-board radiation protection, and manual intervention based upon real-time monitoring of the soft-proton environment. The AE-8 and AP-8 trapped radiation models and Chandra Radiation Models are used to schedule science operations in regions of low proton flux. EPHIN has been used as the primary autonomous in-situ radiation trigger; but, it is not sensitive to the soft protons that damage the front-illuminated CCDs. Monitoring of near-real-time space weather data sources provides critical information on the proton environment outside the Earth s magnetosphere due to solar proton events and other phenomena. The operations team uses data from the Geostationary Operational Environmental Satellites (GOES) to provide near-real-time monitoring of the proton environment; however, these data do not give a representative measure of the soft-proton (< 1 MeV) flux in Chandra s high elliptical orbit. The only source of relevant measurements of sub-MeV protons is the Electron, Proton, and Alpha Monitor (EPAM) aboard the Advanced Composition Explorer (ACE) satellite at L1, with real-time data provided by NOAA s Space Weather Prediction Center. This presentation describes the radiation mitigation strategies to minimize the proton damage in the ACIS CCD detectors and the importance of real-time data sources that are used to protect the ACIS detector system from space weather events.

Real Time Space Weather Support for Chandra X-ray Observatory Operations

NASA Astrophysics Data System (ADS)

O'Dell, S. L.; Miller, S.; Minow, J. I.; Wolk, S.; Aldcroft, T. L.; Spitzbart, B. D.; Swartz, D. A.

2012-12-01

NASA launched the Chandra X-ray Observatory in July 1999. Soon after first light in August 1999, however, degradation in the energy resolution and charge transfer efficiency of the Advanced CCD Imaging Spectrometer (ACIS) x-ray detectors was observed. The source of the degradation was quickly identified as radiation damage in the charge-transfer channel of the front-illuminated CCDs, by weakly penetrating ("soft", 100-500 keV) protons as Chandra passed through the Earth's radiation belts and ring currents. As soft protons were not considered a risk to spacecraft health before launch, the only on-board radiation monitoring system is the Electron, Proton, and Helium Instrument (EPHIN) which was included on Chandra with the primary purpose of monitoring energetic solar particle events. Further damage to the ACIS detector has been successfully mitigated through a combination of careful mission planning, autonomous on-board radiation protection, and manual intervention based upon real-time monitoring of the soft-proton environment. The AE-8 and AP-8 trapped radiation models and Chandra Radiation Models are used to schedule science operations in regions of low proton flux. EPHIN has been used as the primary autonomous in-situ radiation trigger; but, it is not sensitive to the soft protons that damage the front-illuminated CCDs. Monitoring of near-real-time space weather data sources provides critical information on the proton environment outside the Earth's magnetosphere due to solar proton events and other phenomena. The operations team uses data from the Geostationary Operational Environmental Satellites (GOES) to provide near-real-time monitoring of the proton environment; however, these data do not give a representative measure of the soft-proton (< 1 MeV) flux in Chandra's high elliptical orbit. The only source of relevant measurements of sub-MeV protons is the Electron, Proton, and Alpha Monitor (EPAM) aboard the Advanced Composition Explorer (ACE) satellite at L1, with real-time data provided by NOAA's Space Weather Prediction Center. This presentation will discuss radiation mitigation against proton damage, including models and real-time data sources used to protect the ACIS detector system.

Three Great Eyes on Kepler Supernova Remnant

NASA Image and Video Library

2004-10-06

NASA's three Great Observatories -- the Hubble Space Telescope, the SpitzerSpace Telescope, and the Chandra X-ray Observatory -- joined forces to probe theexpanding remains of a supernova, called Kepler's supernova remnant, first seen 400 years ago by sky watchers, including astronomer Johannes Kepler. The combined image unveils a bubble-shaped shroud of gas and dust that is 14light-years wide and is expanding at 4 million miles per hour (2,000 kilometersper second). Observations from each telescope highlight distinct features of thesupernova remnant, a fast-moving shell of iron-rich material from the explodedstar, surrounded by an expanding shock wave that is sweeping up interstellar gasand dust. Each color in this image represents a different region of the electromagneticspectrum, from X-rays to infrared light. These diverse colors are shown in thepanel of photographs below the composite image. The X-ray and infrared datacannot be seen with the human eye. By color-coding those data and combining themwith Hubble's visible-light view, astronomers are presenting a more completepicture of the supernova remnant. Visible-light images from the Hubble telescope (colored yellow) reveal where the supernova shock wave is slamming into the densest regions of surrounding gas.The bright glowing knots are dense clumps from instabilities that form behindthe shock wave. The Hubble data also show thin filaments of gas that look likerippled sheets seen edge-on. These filaments reveal where the shock wave isencountering lower-density, more uniform interstellar material. The Spitzer telescope shows microscopic dust particles (colored red) that havebeen heated by the supernova shock wave. The dust re-radiates the shock wave'senergy as infrared light. The Spitzer data are brightest in the regionssurrounding those seen in detail by the Hubble telescope. The Chandra X-ray data show regions of very hot gas, and extremely high-energyparticles. The hottest gas (higher-energy X-rays, colored blue) is locatedprimarily in the regions directly behind the shock front. These regions alsoshow up in the Hubble observations, and also align with the faint rim of glowingmaterial seen in the Spitzer data. The X-rays from the region on the lower left(colored blue) may be dominated by extremely high-energy electrons that wereproduced by the shock wave and are radiating at radio through X-ray wavelengthsas they spiral in the intensified magnetic field behind the shock front. CoolerX-ray gas (lower-energy X-rays, colored green) resides in a thick interior shelland marks the location of heated material expelled from the exploded star. Kepler's supernova, the last such object seen to explode in our Milky Waygalaxy, resides about 13,000 light-years away in the constellation Ophiuchus. The Chandra observations were taken in June 2000, the Hubble in August 2003;and the Spitzer in August 2004. http://photojournal.jpl.nasa.gov/catalog/PIA06907

Seeing Red and Shooting Blanks: Study of Red Quasars and Blank X-Ray Sources

NASA Technical Reports Server (NTRS)

Oliversen, Ronald (Technical Monitor); Elvis, Martin

2005-01-01

A major paper describing the technique and providing a list of 'blanks' was published in the Astrophysical Journal (abstract below). The results revealed a fascinating trove of novel X-ray sources: high redshift clusters of galaxies found efficiently; X-ray absorbed, optically clean AGN, which may be the bright prototypes of Chandra Deep Survey sources; and several with a still unknown nature. Recent XMM-Newton results confirm the existence of this class of X-ray source with much refined positions. During the first year of this project we have made a major discovery. The second 'blanks' X-ray source observed with Chandra was found to be extended. Using Chandra data and ground-based R and K band imaging we estimated this to be a high redshift cluster of galaxies with z approx. 0.85. Spectroscopy agrees with this estimate (z=0.89). This success shows that our method of hunting down 'blank' field X-ray sources is a highly efficient method of finding the otherwise elusive high redshift clusters. With extensive follow-up we should be able to use 'blanks' to make cosmological tests. The paper is now in press in the Astrophysical Journal (abstract below.) The other Chandra source is point-like, showing that there are a variety of 'blank' source types. Other follow-up observations with XMM-Newton, and (newly approved in cycle 2) with Chandra are eagerly awaited. A follow-up paper uses a large amount of supporting data for the remaining blanks. A combination of ROSAT, Chandra and ground based data convincingly identified one of the blanks as a Ultra-luminous X-ray source (ULX) in a spiral galaxy (abstract below). This program resulted in 3 refereed papers in major journals, 4 conference proceedings and a significant fraction of the PhD thesis of Dr. Ilaria Cagnoni. Details of the publications are given.

Modeling Contamination Migration on the Chandra X-ray Observatory II

NASA Technical Reports Server (NTRS)

O'Dell, Steve; Swartz, Doug; Tice, Neil; Plucinsky, Paul; Grant, Catherine; Marshall, Herman; Vikhlinin, Alexey

2013-01-01

During its first 14 years of operation, the cold (about -60degC) optical blocking filter of the Advanced CCD Imaging Spectrometer (ACIS), aboard the Chandra X-ray Observatory, has accumulated a growing layer of molecular contamination that attenuates low-energy x rays. Over the past few years, the accumulation rate, spatial distribution, and composition may have changed, perhaps partially related to changes in the operating temperature of the ACIS housing. This evolution of the accumulation of the molecular contamination has motivated further analysis of contamination migration on the Chandra X-ray Observatory, particularly within and near the ACIS cavity. To this end, the current study employs a higher-fidelity geometric model of the ACIS cavity, detailed thermal modeling based upon monitored temperature data, and an accordingly refined model of the molecular transport.

Powerful Nearby Supernova Caught By Web

NASA Astrophysics Data System (ADS)

2008-09-01

One of the nearest supernovas in the last 25 years has been identified over a decade after it exploded. This result was made possible by combining data from the vast online archives from many of the world's premier telescopes. The supernova was first singled out in 2001 by Franz Bauer, then at Penn State and now at Columbia University, who noticed a bright, variable object in the spiral galaxy Circinus using NASA's Chandra X-ray Observatory. Though the source displayed some exceptional properties, at the time Bauer and his Penn State colleagues could not confidently identify its nature. It was not until years later that Bauer and his team were able to confirm this object was a supernova. Clues in a spectrum from the European Southern Observatory's Very Large Telescope (VLT) led the team to search through data from 18 different telescopes, both in space and on the ground, nearly all of which was from archives. Because this object was found in a nearby galaxy, making it relatively easy to study, the public archives of these telescopes contained abundant data on this galaxy. The data show that this supernova, dubbed SN 1996cr, is among the brightest supernovas ever seen in radio and X-rays. It also bears many striking similarities to the famous supernova SN 1987A, which occurred in a galaxy only 160,000 light years from Earth. "This supernova appears to be a wild cousin of SN 1987A," said Bauer. "These two look alike in many ways, except this newer supernova is intrinsically a thousand times brighter in radio and X-rays." Optical images from the archives of the Anglo-Australian Telescope in Australia show that SN 1996cr exploded between February 28, 1995 and March 15, 1996, nearly a decade after SN 1987A. SN 1996cr may not have been noticed by astronomers at the time because it was only visible in the southern hemisphere, which is not as widely monitored as the northern. Among the five nearest supernovas of the last 25 years, it is the only one that was not seen shortly after the explosion. X-rayChandra X-ray Image SN 1996cr was not detected by other major X-ray observatories in orbit - ROSAT and ASCA - around the time of explosion. Rather, it wasn't until several years later that it was detected as an X-ray source by Chandra (launched in 1999), and has become steadily brighter ever since. Previously, SN 1987A had been the only known supernova with an X-ray output observed to increase over time. "Supernovas that are close enough to be studied in detail like this are quite rare and may only appear once a decade, so we don't want to miss such an important opportunity for discovery," said Bauer. "It's a bit of a coup to find SN 1996cr like we did, and we could never have nailed it without the serendipitous data taken by all of these telescopes. We've truly entered a new era of `Internet astronomy'." People Who Read This Also Read... Chandra Data Reveal Rapidly Whirling Black Holes Dark Energy Found Stifling Growth in Universe Ghostly Glow Reveals a Hidden Class of Long-Wavelength Radio Emitters Jet Power and Black Hole Assortment Revealed in New Chandra Image The data, combined with theoretical work, has led the team to the following model. Before it exploded, the parent star cleared out a large cavity around it, either via a fast wind or an outburst from the star late in its life. Then, the blast wave from the explosion expanded relatively unimpeded into this cavity. Once the blast wave hit the dense material surrounding SN1996cr, the impact caused the system to glow brightly in X-ray and radio emission. The X-ray and radio emission from SN 1987A is fainter because the surrounding material is probably less compact. Astronomers think that both SN 1987A and SN 1996cr show evidence for these pre-explosion clear-outs by the star doomed to explode. Having two nearby examples suggests that this type of activity could be relatively common during the death of massive stars. "Not only does our work suggest that SN 1987A isn't as unusual as previously thought, but it also teaches us more about the tremendous upheavals that massive stars can undergo during their lifetime," said co-author Vikram Dwarkadas of the University of Chicago. SN 1996cr, at a distance of about 12 million light years, will be a compelling target for future work because it is nearby and so much brighter than a typical supernova. These results will appear in an upcoming issue of The Astrophysical Journal. Other co-authors on this paper include Niel Brandt (Penn State), Stefan Immler (NASA Goddard Space Flight Center), Norbert Bartel (York University, Canada), and Michael Bietenholz (York University and Hartebeesthoek Radio Observatory, South Africa). NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass.

Chandra Finds Ghosts Of Eruption In Galaxy Cluster

NASA Astrophysics Data System (ADS)

2002-01-01

"Ghostly" relics of an ancient eruption that tore through a cluster of galaxies were recently uncovered by NASA's Chandra X-ray Observatory. The discovery implies that galaxy clusters are the sites of enormously energetic and recurring explosions, and may provide an explanation why galaxy clusters behave like giant cosmic magnets. "Chandra's image revealed vast regions in the galaxy cluster Abell 2597 that contain almost no X-ray or radio emission. We call them ghost cavities," said Brian McNamara of Ohio University in Athens today during a press conference at the American Astronomical Society meeting in Washington. "They appear to be remnants of an old explosion where the radio emission has faded away over millions of years." The ghost cavities were likely created by extremely powerful explosions, due to material falling toward a black hole millions of times more massive than the Sun. As the matter swirled around the black hole, located in a galaxy near the center of the cluster, it generated enormous electromagnetic fields that expelled material from the vicinity of the black hole at high speeds. This explosive activity in Abell 2597 created jets of highly energetic particles that cleared out voids in the hot gas. Because they are lighter than the surrounding material, the cavities will eventually push their way to the edge of the cluster, just as air bubbles in water make their way to the surface. Researchers also found evidence that this explosion was not a one-time event. "We detected a small, bright radio source near the center of the cluster that indicates a new explosion has occurred recently," said team member Michael Wise of the Massachusetts Institute of Technology in Cambridge, "so the cycle of eruption is apparently continuing." Though dim, the ghost cavities are not completely empty. They contain a mixture of very hot gas, high-energy particles and magnetic fields -- otherwise the cavities would have collapsed under the pressure of the surrounding hot gas. "Ghost cavities may be the vessels that transport magnetic fields generated in a disk surrounding a giant black hole to the cluster gas that is spread over a region a billion times larger," said McNamara. If dozens of these cavities were created over the life of the cluster, they could explain the surprisingly strong magnetic field of the multimillion-degree gas that pervades the cluster. Galaxy clusters are the largest known gravitationally bound structures in the universe. Hundreds of galaxies swarm in giant reservoirs of multimillion-degree gas that radiates most of its energy in X-rays. Over the course of billions of years some of the gas should cool and sink toward a galaxy in the center of the cluster where it could trigger an outburst in the vicinity of the central massive black hole. Chandra observed Abell 2597 on July 28, 2000,for 40,000 seconds with the Advanced CCD Imaging Spectrometer (ACIS) instrument. Pennsylvania State University, University Park, and MIT developed the instrument for NASA. In addition to a group of astronomers from the Space Telescope Science Institute, Baltimore, and the University of Virginia, Charlottesville, the team included: Paul Nulsen, University of Wollagong, Australia; Larry David, Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass.; Chris Carilli, National Radio Astronomy Observatory, Socorro, N.M.; and Craig Sarazin, University of Virginia. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program, and TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass.

Chandra-SDSS Normal and Star-Forming Galaxies. I. X-Ray Source Properties of Galaxies Detected by the Chandra X-Ray Observatory in SDSS DR2

NASA Astrophysics Data System (ADS)

Hornschemeier, A. E.; Heckman, T. M.; Ptak, A. F.; Tremonti, C. A.; Colbert, E. J. M.

2005-01-01

We have cross-correlated X-ray catalogs derived from archival Chandra X-Ray Observatory ACIS observations with a Sloan Digital Sky Survey Data Release 2 (DR2) galaxy catalog to form a sample of 42 serendipitously X-ray-detected galaxies over the redshift interval 0.03

Chandra Observations of New X-ray Supernovae

NASA Astrophysics Data System (ADS)

Pooley, David

2016-09-01

We propose to continue our X-ray studies of all types of supernovae (SNe). The Swift satellite ushered in a new era of studying SNe in the X-rays, obtaining densely sampled observations for nearby SNe, both core collapse and thermonuclear (although no Type Ia has been conclusively detected in X-rays). However, the Swift XRT spatial resolution is often not good enough to definitively associate X-ray emission in the direction of the SN with the SN itself. We propose short Chandra observations to alleviate this. These observations will assess the X-ray environment of newly discovered X-ray SNe to determine any possible source confusion or contamination of the SN flux. Our strategy makes the best use of the capabilities of each observatory.

Chandra Observations of New X-ray Supernovae

NASA Astrophysics Data System (ADS)

Pooley, David

2017-09-01

We propose to continue our X-ray studies of all types of supernovae (SNe). The Swift satellite ushered in a new era of studying SNe in the X-rays, obtaining densely sampled observations for nearby SNe, both core collapse and thermonuclear (although no Type Ia has been conclusively detected in X-rays). However, the Swift XRT spatial resolution is often not good enough to definitively associate X-ray emission in the direction of the SN with the SN itself. We propose short Chandra observations to alleviate this. These observations will assess the X-ray environment of newly discovered X-ray SNe to determine any possible source confusion or contamination of the SN flux. Our strategy makes the best use of the capabilities of each observatory.

Chandra Observations of New X-ray Supernovae

NASA Astrophysics Data System (ADS)

Pooley, David

2015-09-01

We propose to continue our X-ray studies of all types of supernovae (SNe). The Swift satellite ushered in a new era of studying SNe in the X-rays, obtaining densely sampled observations for nearby SNe, both core collapse and thermonuclear (although no Type Ia has been conclusively detected in X-rays). However, the Swift XRT spatial resolution is often not good enough to definitively associate X-ray emission in the direction of the SN with the SN itself. We propose short Chandra observations to alleviate this. These observations will assess the X-ray environment of newly discovered X-ray SNe to determine any possible source confusion or contamination of the SN flux. Our strategy makes the best use of the capabilities of each observatory.

X-Ray Binary Populations in a Cosmological Context, Including NuSTAR Predictions

NASA Technical Reports Server (NTRS)

Cardiff, Ann Hornschemeier

2011-01-01

The new ultradeep 4 Ms Chandra Deep Field South has afforded the deepest view ever of X-ray binary populations. We report on the latest results on both LMXB and HMXB evolution out to redshifts of approximately four, including comparison with the latest theoretical models, using this deepest-ever view of the X-ray universe with Chandra. The upcoming NuSTAR mission will open up X-ray binary populations in the hard X-ray band, similar to the pioneering work of Fabbiano et al. in the Einstein era. We report on plans to study both Local Group and starburst galaxies as well as the implications those observations may have for X-ray binary populations in galaxies contributing to the Cosmic X-ray Background.

STS-93: Columbia / Chandra Mission Overview (from JSC)

NASA Technical Reports Server (NTRS)

1999-01-01

A press briefing held on July 7, 1999 reviews the progress of the Chandra X ray Observatory project. The tape begins with an animated view of the launch of the Chandra X ray Observatory from the shuttle, as it was planned. Next is a press briefing. Bryan Austin, the Lead Flight Director, discusses the five day mission, and the reason for the shortened length, due to the added weight from the Chandra Observatory. He also reviews the other payloads, and activities that will take place during the mission. Kenneth Ledbetter, Science Director Mission Development, discusses the 4 great observatories and the role of each. They are the Hubble, which observed visible light; Compton Gamma Ray Observatory, the Chandra, and the Space Infrared Telescope Facility. A time line of the expected operational lifetime of each of the 4 great observatories is shown. Specific information about the Chandra Telescope is reviewed. The last press briefing presenter is Fred Wojtalik, who is the Chandra Program Manager. He reviews the Chandra's components, and acknowledges a few of the many companies that contributed to its building. He also reviews the orbital activation and checkout sequences. Question that follows, center around contingency plans if some part of the planned sequence is not successful. The costs are reviewed, and concerns about the Initial Upper Stage, the propulsion unit required to take the Chandra to its high orbit are addressed. The Chandra is planned to take an eliptical orbit, which is higher than the other space telescopes, thus far launched due to the requirement to avoid Earth generated X rays.

From EXOSAT to the High Energy Astrophysics Science Archive (HEASARC): X-ray Astronomy Comes of Age

NASA Technical Reports Server (NTRS)

White, Nicholas E.

2012-01-01

In May 1983 the European Space Agency launched EXOSAT, its first X-ray astronomy observatory. Even though it lasted only 3 short years, this mission brought not only new capabilities that resulted in unexpected discoveries, but also a pioneering approach to operations and archiving that changed X-ray astronomy from observations led by small instrument teams, to an observatory approach open to the entire community through a guest observer program. The community use of the observatory was supported by a small dedicated team of scientists, the precursor to the data center activities created to support e.g. Chandra and XMM-Newton. The new science capabilities of EX OS AT included a 90 hr highly eccentric high earth orbit that allow unprecedented continuous coverage of sources as well as direct communication with the satellite that allowed real time decisions to respond to unexpected events through targets of opportunity. The advantages of this orbit demonstrated by EXOSAT resulted in Chandra and XMM-Newton selecting similar orbits. The three instruments on board the EXOSAT observatory were complementary, designed to give complete coverage over a wide energy band pass of 0.05-50 keY. An onboard processor could be programmed to give multiple data modes that could be optimized in response to science discoveries: These new capabilities resulted in many new discoveries including the first comprehensive study of AGN variability, new orbital periods in X-ray binaries and cataclysmic variables, new black holes, quasi-periodic oscillations from neutron stars and black holes and broad band X-ray spectroscopy. The EXOSAT team generated a well-organized database accessible worldwide over the nascent internet, allowing remote selection of data products, making samples and undertaking surveys from the data. The HEASARC was established by NASA at Goddard Space Flight Center in 1990 as the repository of NASA X-ray and Gamma-ray data. The proven EXOSAT database system became the core of the HEASARC infrastructure. The HEASARC pioneered many concepts now taken for granted including standardized formats using FITS files, restoring data from earlier missions, multi-mission analysis tools and a searchable archive over the world wide web.

The STS-93 crew takes part in payload familiarization of the Chandra X-ray Observatory

NASA Technical Reports Server (NTRS)

1999-01-01

A TRW technician joins STS-93 Commander Eileen Collins (center) and Pilot Jeffrey S. Ashby (right) as they observe the Chandra X- ray Observatory on its work stand inside the Vertical Processing Facility. Other members of the STS-93 crew who are at KSC for payload familiarization are Mission Specialists Catherine G. Coleman and Michel Tognini of France, who represents the Centre National d'Etudes Spatiales (CNES). Collins is the first woman to serve as a shuttle mission commander. She was the first woman pilot of a Space Shuttle, on mission STS-63, and also served as pilot on mission STS-84. The fifth member of the crew is Mission Specialist Steven A. Hawley. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe.

Young Star Cluster Found Aglow With Mysterious X-Ray Cloud

NASA Astrophysics Data System (ADS)

2002-12-01

A mysterious cloud of high-energy electrons enveloping a young cluster of stars has been discovered by astronomers using NASA's Chandra X-ray Observatory. These extremely high-energy particles could cause dramatic changes in the chemistry of the disks that will eventually form planets around stars in the cluster. Known as RCW 38, the star cluster covers a region about 5 light years across. It contains thousands of stars formed less than a million years ago and appears to be forming new stars even today. The crowded environment of a star cluster is thought to be conducive to the production of hot gas, but not high-energy particles. Such particles are typically produced by exploding stars, or in the strong magnetic fields around neutron stars or black holes, none of which is evident in RCW 38. "The RCW 38 observation doesn't agree with the conventional picture," said Scott Wolk of the Harvard-Smithsonian Center for Astrophysics in Cambridge, MA, lead author of an Astrophysical Journal Letters paper describing the Chandra observation. "The data show that somehow extremely high-energy electrons are being produced there, although it is not clear how." RCW 38 RCW 38 X-ray, Radio, Infrared Composite Electrons accelerated to energies of trillions of volts are required to account for the observed X-ray spectrum of the gas cloud surrounding the ensemble of stars, which shows an excess of high-energy X-rays. As these electrons move in the magnetic field that threads the cluster, they produce X-rays. One possible origin for the high-energy electrons is a previously undetected supernova that occurred in the cluster. Although direct evidence for the supernova could have faded away thousands of years ago, a shock wave or a rapidly rotating neutron star produced by the outburst could be acting in concert with stellar winds to produce the high-energy electrons. "Regardless of the origin of the energetic electrons," said Wolk, "their presence would change the chemistry of proto-stellar disks in ways that could still be manifest billions of years later." For example, in our own solar system, we find evidence of certain short-lived radioactive nuclides (Aluminum 26 being the most well known). This implies the existence of a high-energy process late in the evolution of our solar system. If our solar system was immersed for a time in a sea of energetic particles, this could explain the rare nuclides present in meteorites found on the Earth today. RCW 38, at a distance of 6,000 light years from Earth, is one of the nearest star-forming regions with very young, hot stars. Other authors of the paper, which appeared in the 2002 December 1 issue of the Astrophysical Journal Letters, are Tyler Bourke, Randall Smith and Bradley Spitzbart of the Harvard-Smithsonian Center for Astrophysics, and Joao Alves of the European Southern Observatory in Garching, Germany. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the Office of Space Science in Washington. TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass.

Exploding Stars and Stripes

NASA Astrophysics Data System (ADS)

2011-03-01

The discovery of a pattern of X-ray "stripes" in the remains of an exploded star may provide the first direct evidence that a cosmic event can accelerate particles to energies a hundred times higher than achieved by the most powerful particle accelerator on Earth. This result comes from a very long observation of the Tycho supernova remnant with NASA's Chandra X-ray Observatory. It could explain how some of the extremely energetic particles bombarding the Earth, called cosmic rays, are produced. "We've seen lots of intriguing structures in supernova remnants, but we've never seen stripes before," said Kristoffer Eriksen, a postdoctoral researcher at Rutgers University who led the study. "This made us think very hard about what's happening in the blast wave of this powerful explosion." This latest study from Chandra provides support for a theory about how magnetic fields can be dramatically amplified in such blast waves. In this theory, the magnetic fields become highly tangled and the motions of the particles very turbulent near the expanding supernova shock wave at the front edge of the supernova remnant. High-energy charged particles can bounce back and forth across the shock wave repeatedly, gaining energy with each crossing. Theoretical models of the motion of the most energetic particles -- which are mostly protons -- are predicted to leave a messy network of holes and dense walls corresponding to weak and strong regions of magnetic fields, respectively. The X-ray stripes discovered by the Chandra researchers are thought to be regions where the turbulence is greater and the magnetic fields more tangled than surrounding areas, and may be the walls predicted by the theory. Electrons become trapped in these regions and emit X-rays as they spiral around the magnetic field lines. However, the regular and almost periodic pattern of the X-ray stripes was not predicted by the theory. "It was a big surprise to find such a neatly arranged set of stripes," said co-author Jack Hughes, professor of physics and astronomy at Rutgers. "We were not expecting so much order to appear in so much chaos. It could mean that the theory is incomplete, or that there's something else we don't understand." Assuming that the spacing between the X-ray stripes corresponds to the radius of the spiraling motion of the highest energy protons in the supernova remnant, the spacing corresponds to energies about 100 times higher than reached in the Large Hadron Collider. These energies equal the highest energies of cosmic rays thought to be produced in our Galaxy. Because cosmic rays are composed of charged particles, like protons and electrons, their direction of motion changes when they encounter magnetic fields throughout the galaxy. So, the origin of individual cosmic rays detected on Earth cannot be determined. Supernova remnants have long been considered a good candidate for producing the most energetic cosmic rays in our Galaxy. The protons can reach energies that are hundreds of times higher than the highest energy electrons, but since they do not radiate efficiently like the electrons, direct evidence for the acceleration of cosmic ray protons in supernova remnants has been lacking. These results also support the prediction that magnetic fields in interstellar space are greatly amplified in supernova remnants, but the difference between the observed and predicted structures means that other interpretations cannot be ruled out. "We were excited to discover these stripes because they might allow us to directly track, for the first time, the origin of the most energetic particles produced in our galaxy," said Eriksen. "But, we're not claiming victory yet." The Tycho supernova remnant is named for the famous Danish astronomer Tycho Brahe, who reported observing the supernova in 1572. Scientists think the explosion occurred when a white dwarf star grew in mass and exceeded its weight limit, forming a so-called Type Ia supernova. The Tycho remnant is located in the Milky Way, about 13,000 light years from Earth. "Supernova remnants are our best cosmic laboratories for understanding how nature accelerates the highest energy cosmic rays," said Roger Blandford of Stanford University, a noted expert in this field who was not involved with these findings. "These careful measurements provide a very strong clue as to what actually happens at these giant shock fronts." These results were published in the February 20th, 2011 issue of The Astrophysical Journal Letters. The other co-authors are Carles Badenes from Tel-Aviv University and the Weizmann Institute of Science in Israel, Robert Fesen from Dartmouth College, NH, Parviz Ghavamian from Space Telescope Science Institute, Baltimore, MD, David Moffett, from Furman University, Greenville, SC, Paul Plucinsky from Harvard-Smithsonian Center for Astrophysics (CfA), Cambridge, MA, Cara Rakowski from the Naval Research Laboratory, Washington, DC, Estela M. Reynoso from the Institute of Astronomy and Space Physics and University of Buenos Aires, Argentina and Patrick Slane from CfA. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass. More information, including images and other multimedia, can be found at: http://chandra.si.edu and http://chandra.nasa.gov

"Iron-Clad" Evidence For Spinning Black Hole

NASA Astrophysics Data System (ADS)

2003-09-01

Telltale X-rays from iron may reveal if black holes are spinning or not, according to astronomers using NASA's Chandra X-ray Observatory and the European Space Agency's XMM-Newton Observatory. The gas flows and bizarre gravitational effects observed near stellar black holes are similar to those seen around supermassive black holes. Stellar black holes, in effect, are convenient `scale models' of their much larger cousins. Black holes come in at least two different sizes. Stellar black holes are between five and 20 times the mass of the Sun. At the other end of the size scale, supermassive black holes contain millions or billions times the mass of our Sun. The Milky Way contains both a supermassive black hole at its center, as well as a number of stellar black holes sprinkled throughout the Galaxy. At a press conference at the "Four Years of Chandra" symposium in Huntsville, Ala., Jon Miller of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. discussed recent results on the X-ray spectra, or distribution of X-rays with energy, from the iron atoms in gas around three stellar black holes in the Milky Way. "Discovering the high degree of correspondence between stellar and supermassive black holes is a real breakthrough," said Miller. "Because stellar black holes are smaller, everything happens about a million times faster, so they can be used as a test-bed for theories of how spinning black holes affect the space and matter around them." X-rays from a stellar black hole are produced when gas from a nearby companion star is heated to tens of millions of degrees as it swirls toward the black hole. Iron atoms in this gas produce distinctive X-ray signals that can be used to study the orbits of particles around the black hole. For example, the gravity of a black hole can shift the X-rays to lower energies. "The latest work provides the most precise measurements yet of the X-ray spectra for stellar black holes," said Miller. "These data help rule out competing explanations that do not require extreme gravitational effects, and provide the best look yet at the geometry of the space-time around a stellar black hole created by the death of a massive star." The orbit of a particle near a black hole depends on the curvature of space around the black hole, which also depends on how fast the black hole is spinning. A spinning black hole drags space around with it and allows atoms to orbit closer to the black hole than is possible for a non-spinning black hole. The latest Chandra data from Cygnus X-1, the first stellar-size black hole discovered, show that the gravitational effects on the signal from the iron atoms can only be due to relativistic effects, and that some of the atoms are no closer than 100 miles to the black hole. There was no evidence that the Cygnus X-1 black hole is spinning. The XMM-Newton data from the black hole, XTE J1650-500, show a very similar distribution of iron atom X-rays with one important exception. More low energy X-rays from iron atoms are observed, an indication that some X-rays are coming from deep in the gravitational well around the black hole, as close as 20 miles to the black hole event horizon. This black hole must be spinning rapidly. Chandra observations of a third stellar black hole, GX 339-4, have revealed that it is also spinning rapidly, and clouds of warm absorbing gas appear to be flowing away from the black hole at speeds of about three hundred thousand miles per hour. Such warm gas flows have been observed in the vicinity of supermassive black holes. Previous observations of some supermassive black holes by Japan's ASCA satellite, XMM-Newton and Chandra have indicated that they may also be rotating rapidly. The latest results presented by Miller indicate that the peculiar geometry of space around spinning stellar-mass black holes and supermassive black holes is remarkably similar. Stellar and supermassive black holes may be similar in other ways. Powerful jets of high-energy particles have been detected around both types of black holes. Why do some stellar black holes spin rapidly and others not? One possibility is that differences in spin are imparted at birth when a massive star collapses. Another possibility is that the spin rate depends on how long the black hole has been devouring matter from its companion star, a process that makes the black hole spin faster. Black holes with more rapid spin, XTE J1650-500 and GX 339-4, have low-mass companion stars. These relatively long-lived stars may have been feeding the black hole for longer, allowing it to spin up to faster rates. Cygnus X-1 with its short-lived companion star may not have not time to spin up. Miller is a National Science Foundation Astronomy & Astrophysics Postdoctoral Fellow. His primary collaborators in this work were Walter Lewin if the Massachusetts Institute of Technology in Cambridge, Andrew Fabian of the University of Cambridge, UK, and Chris Reynolds of the University of Maryland, College Park. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the Office of Space Science, NASA Headquarters, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass.

Energetic Ring Shows Way To Discovery Of Pulsar "Bulls-Eye"

NASA Astrophysics Data System (ADS)

2002-06-01

Astronomers from the University of Massachusetts and Columbia University have found the "bulls-eye" pulsar in a bright ring of high-energy particles in a distant supernova remnant. This discovery, made with NASA's Chandra X-ray Observatory and the Arecibo Radio Telescope, will help scientists better understand how neutron stars channel enormous amounts of energy into particles moving near the speed of light. Chandra's image of the supernova remnant SNR G54.1+0.3 reveals a bright, point-like central source, which is surrounded by a ring and two jet-like structures in an extended nebula of high-energy particles. The radio data show that this bright central source is a neutron star, or pulsar, that is rotating 7 times per second. "The features Chandra found appear to be due to the energetic flow of radiation and particles from a rapidly spinning neutron star formed during a supernova event," said Fangjun Lu of the University of Massachusetts at Amherst who led the X-ray research. Lu and colleagues informed Fernando Camilo of Columbia University in New York of this detection. Camilo and his collaborators then used the powerful Arecibo telescope to look for the tell-tale radio pulsations from a neutron star at the center of the ring. After a search in August 2001 was aborted by radio-frequency interference, they observed the source again in April 2002 and found a weak, pulsating radio source. Further observations indicate the pulsar (and hence the supernova remnant) has an age of approximately 3000 years. Analysis of 1997 ASCA satellite data confirmed that the source is pulsing in X-rays as well. "This discovery is an excellent example of how the superb resolution of Chandra and the improved capabilities of Arecibo worked together to quickly resolve an outstanding scientific question," said Camilo. "We look forward to continued substantial progress in understanding the properties of young neutron stars." Intense electric fields around the neutron star accelerate particles to form jets blasting away from the poles and a disk of matter and anti-matter flowing away from the equator at high speeds. As the equatorial flow rams into particles and magnetic fields in the nebula, a shock wave forms. The shock wave then boosts the particles to extremely high energies causing them to glow in X-rays and produce the bright ring. The particles continue to stream outward from the ring and the jets to supply the extended nebula, which spans approximately 6 light years. The features observed in SNR G54.1+0.3 are very similar to other "pulsar wind nebulas" found by Chandra in the Crab Nebula, the Vela supernova remnant, and B1509-58. By analyzing the similarities and differences between these objects, scientists hope to better understand the fascinating process of transforming the rotational energy of the neutron star into extremely high-energy particles with very little frictional heat loss. Chandra observed SNR G54.1+0.3 on June 6-7, 2001, using the Advanced CCD Imaging Spectrometer instrument. The radio data on the central pulsar, known as PSR J1930+1852, were gathered at Arecibo on April 29, 2002. The results from this work appear in two separate papers in the March 20 and July 20, 2002 issues of the Astrophysical Journal Letters. The Arecibo Observatory is part of the National Astronomy and Ionosphere Center (NAIC), operated by Cornell University under a cooperative agreement with the National Science Foundation (NSF). NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the Office of Space Science, Washington, DC. TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass.

The Future of X-Ray Optics

NASA Technical Reports Server (NTRS)

Weisskopf, Martin C.

2013-01-01

The most important next step is the development of X-ray optics comparable to (or better than) Chandra in angular resolution that far exceed Chandra s effective area. Use the long delay to establish an adequately funded, competitive technology program along the lines I have recommended. Don't be diverted from this objective, except for Explorer-class missions. Progress in X-ray optics, with emphasis on the angular resolution, is central to the paradigm-shifting discoveries and the contributions of X-ray astronomy to multiwavelength astrophysics over the past 51 years.

Galaxy NGC 1448 with Active Galactic Nucleus

NASA Image and Video Library

2017-01-07

NGC 1448, a galaxy with an active galactic nucleus, is seen in this image combining data from the Carnegie-Irvine Galaxy Survey in the optical range and NuSTAR in the X-ray range. This galaxy contains an example of a supermassive black hole hidden by gas and dust. X-ray emissions from NGC 1448, as seen by NuSTAR and Chandra, suggests for the first time that, like IC 3639 in PIA21087, there must be a thick layer of gas and dust hiding the active black hole in this galaxy from our line of sight. http://photojournal.jpl.nasa.gov/catalog/PIA21086

Determination of Cluster Distances from Chandra Imaging Spectroscopy and Sunyaev-Zeldovich Effect Measurements. I; Analysis Methods and Initial Results

NASA Technical Reports Server (NTRS)

Bonamente, Massimiliano; Joy, Marshall K.; Carlstrom, John E.; LaRoque, Samuel J.

2004-01-01

X-ray and Sunyaev-Zeldovich Effect data ca,n be combined to determine the distance to galaxy clusters. High-resolution X-ray data are now available from the Chandra Observatory, which provides both spatial and spectral information, and interferometric radio measurements of the Sunyam-Zeldovich Effect are available from the BIMA and 0VR.O arrays. We introduce a Monte Carlo Markov chain procedure for the joint analysis of X-ray and Sunyaev-Zeldovich Effect data. The advantages of this method are the high computational efficiency and the ability to measure the full probability distribution of all parameters of interest, such as the spatial and spectral properties of the cluster gas and the cluster distance. We apply this technique to the Chandra X-ray data and the OVRO radio data for the galaxy cluster Abell 611. Comparisons with traditional likelihood-ratio methods reveal the robustness of the method. This method will be used in a follow-up paper to determine the distance of a large sample of galaxy clusters for which high-resolution Chandra X-ray and BIMA/OVRO radio data are available.

Massive Star Burps, Then Explodes

NASA Astrophysics Data System (ADS)

2007-04-01

Berkeley -- In a galaxy far, far away, a massive star suffered a nasty double whammy. On Oct. 20, 2004, Japanese amateur astronomer Koichi Itagaki saw the star let loose an outburst so bright that it was initially mistaken for a supernova. The star survived, but for only two years. On Oct. 11, 2006, professional and amateur astronomers witnessed the star actually blowing itself to smithereens as Supernova 2006jc. Swift UVOT Image Swift UVOT Image (Credit: NASA / Swift / S.Immler) "We have never observed a stellar outburst and then later seen the star explode," says University of California, Berkeley, astronomer Ryan Foley. His group studied the event with ground-based telescopes, including the 10-meter (32.8-foot) W. M. Keck telescopes in Hawaii. Narrow helium spectral lines showed that the supernova's blast wave ran into a slow-moving shell of material, presumably the progenitor's outer layers ejected just two years earlier. If the spectral lines had been caused by the supernova's fast-moving blast wave, the lines would have been much broader. artistic rendering This artistic rendering depicts two years in the life of a massive blue supergiant star, which burped and spewed a shell of gas, then, two years later, exploded. When the supernova slammed into the shell of gas, X-rays were produced. (Credit: NASA/Sonoma State Univ./A.Simonnet) Another group, led by Stefan Immler of NASA's Goddard Space Flight Center, Greenbelt, Md., monitored SN 2006jc with NASA's Swift satellite and Chandra X-ray Observatory. By observing how the supernova brightened in X-rays, a result of the blast wave slamming into the outburst ejecta, they could measure the amount of gas blown off in the 2004 outburst: about 0.01 solar mass, the equivalent of about 10 Jupiters. "The beautiful aspect of our SN 2006jc observations is that although they were obtained in different parts of the electromagnetic spectrum, in the optical and in X-rays, they lead to the same conclusions," says Immler. "This event was a complete surprise," added Alex Filippenko, leader of the UC Berkeley/Keck supernova group and a member of NASA'S Swift team. "It opens up a fascinating new window on how some kinds of stars die." All the observations suggest that the supernova's blast wave took only a few weeks to reach the shell of material ejected two years earlier, which did not have time to drift very far from the star. As the wave smashed into the ejecta, it heated the gas to millions of degrees, hot enough to emit copious X-rays. The Swift satellite saw the supernova continue to brighten in X-rays for 100 days, something that has never been seen before in a supernova. All supernovae previously observed in X-rays have started off bright and then quickly faded to invisibility. "You don't need a lot of mass in the ejecta to produce a lot of X-rays," notes Immler. Swift's ability to monitor the supernova's X-ray rise and decline over six months was crucial to his team's mass determination. But he adds that Chandra's sharp resolution enabled his group to resolve the supernova from a bright X-ray source that appears in the field of view of Swift's X-ray Telescope. "We could not have made this measurement without Chandra," says Immler, who will submit his team's paper next week to the Astrophysical Journal. "The synergy between Swift's fast response and its ability to observe a supernova every day for a long period, and Chandra's high spatial resolution, is leading to a lot of interesting results." Foley and his colleagues, whose paper appears in the March 10 Astrophysical Journal Letters, propose that the star recently transitioned from a Luminous Blue Variable (LBV) star to a Wolf-Rayet star. An LBV is a massive star in a brief but unstable phase of stellar evolution. Similar to the 2004 eruption, LBVs are prone to blow off large amounts of mass in outbursts so extreme that they are frequently mistaken for supernovae, events dubbed "supernova impostors." Wolf-Rayet stars are hot, highly evolved stars that have shed their outer envelopes. Swift XRT Image Swift XRT Image (Credit: NASA / GSFC / CXC /S.Immler) Most astronomers did not expect that a massive star would explode so soon after a major outburst, or that a Wolf-Rayet star would produce such a luminous eruption, so SN 2006jc represents a puzzle for theorists. "It challenges some aspects of our current model of stellar evolution," says Foley. "We really don't know what caused this star to have such a large eruption so soon before it went supernova." "SN 2006jc provides us with an important clue that LBV-style eruptions may be related to the deaths of massive stars, perhaps more closely than we used to think," adds coauthor and UC Berkeley astronomer Nathan Smith. "The fact that we have no well-established theory for what actually causes these outbursts is the elephant in the living room that nobody is talking about." SN 2006jc occurred in galaxy UGC 4904, located 77 million light years from Earth in the constellation Lynx. The supernova explosion, a peculiar variant of a Type Ib, was first sighted by Itagaki, American amateur astronomer Tim Puckett and Italian amateur astronomer Roberto Gorelli. See also NASA Goddard press release at: http://www.nasa.gov/centers/goddard/news/topstory/ 2007/supernova_imposter.html

The Discovery of a Second Luminous Low Mass X-ray Binary in the Globular Cluster M15

NASA Technical Reports Server (NTRS)

White, Nicholas E.; Angelini, Lorella

2001-01-01

We report an observation by the Chandra X-ray Observatory of 4U2127+119, the X-ray source identified with the globular cluster M15. The Chandra observation reveals that 4U2127+119 is in fact two bright sources, separated by 2.7". One source is associated with AC21 1, the previously identified optical counterpart to 4U2127+119, a low mass X-ray binary (LMXB). The second source, M15-X2, is coincident with a 19th U magnitude blue star that is 3.3" from the cluster core. The Chandra count rate of M15-X2 is 2.5 times higher than that of AC211. Prior to the 0.5" imaging capability of Chandra the presence of two so closely separated bright sources would not have been resolved, The optical counterpart, X-ray luminosity and spectrum of M15-X2 are consistent with it also being an LMXB system. This is the first time that two LMXBS have been seen to be simultaneously active in a globular cluster. The discovery of a second active LMXB in M15 solves a long standing puzzle where the properties of AC211 appear consistent with it being dominated by an extended accretion disk corona, and yet 4U2127+119 also shows luminous X-ray bursts requiring that the neutron star be directly visible. The resolution of 4U2127+119 into two sources suggests that the X-ray bursts did not come from AC211, but rather from M15X2. We discuss the implications of this discovery for understanding the origin and evolution of LMXBs in GCs as well as X-ray observations of globular clusters in nearby galaxies.

The Discovery of a Second Luminous Low-Mass X-Ray Binary in the Globular Cluster M15

NASA Technical Reports Server (NTRS)

White, Nicholas E.; Angelini, Lorella

2001-01-01

We report an observation by the Chandra X-Ray Observatory of 4U 2127+119, the X-ray source identified with the globular cluster M15. The Chandra observation reveals that 4U 2127+119 is in fact two bright sources, separated by 2.7 arcsec. One source is associated with AC 211, the previously identified optical counterpart to 4U 2127+119, a low-mass X-ray binary (LMXB). The second source, M15 X-2, is coincident with a 19th U magnitude blue star that is 3.3 arcsec from the cluster core. The Chandra count rate of M15 X-2 is 2.5 times higher than that of AC 211. Prior to the 0.5 arcsec imaging capability of Chandra, the presence of two so closely separated bright sources would not have been resolved. The optical counterpart, X-ray luminosity, and spectrum of M15 X-2 are consistent with it also being an LMXB system. This is the first time that two LMXBs have been seen to be simultaneously active in a globular cluster. The discovery of a second active LMXB in M15 solves a long-standing puzzle where the properties of AC 211 appear consistent with it being dominated by an extended accretion disk corona, and yet 4U 2127+119 also shows luminous X-ray bursts requiring that the neutron star be directly visible. The resolution of 4U 2127+119 into two sources suggests that the X-ray bursts did not come from AC 211 but rather from M15 X-2. We discuss the implications of this discovery for understanding the origin and evolution of LMXBs in globular clusters as well as X-ray observations of globular clusters in nearby galaxies.

The Outer X-ray and Radio Jets in R Aquarii

NASA Technical Reports Server (NTRS)

Kellogg, E.; Anderson, C.; DePasquale, J.; Korreck, K.; Nichols, J.; Sokoloski, J.; Krauss, M.; Pedelty, J.

2007-01-01

The symbiotic star R Aquarii has been known to emit collimated outflow in the form of jets for many years. We report on five years of observations in x-rays and radio using Chandra, VLA and XMM-Newton. We discuss the evolution of the outer thermal jets, including new observations performed in June and October 2005. We see motion of the NE x-ray jet at a projected velocity of about 600 km (sup -1). The SW x-ray jet has almost disappeared between 2000.7 and 2004.0. An XMM grating spectrum of the NE jet confirms the existence of O VII He-like lines, and offers the possibility of doing plasma density diagnostics. We comment on on the physics of cooling in the SW jet and implications for the density of the x-ray emitting gas, the heating mechanism, and mass and kinetic energy in the jets and its implications for the system as a whole. This work was supported by NASA and NSF.

History of Chandra X-Ray Observatory

NASA Image and Video Library

2001-01-10

This Chandra image, the first x-ray image ever made of Venus, shows a half crescent due to the relative orientation of the Sun, Earth, and Venus. The x-rays are produced by fluorescent radiation from oxygen and other atoms in the atmosphere between 120 and 140 kilometers above the surface of the planet. In contrast, the optical light from Venus is caused by the reflection from clouds 50 to 70 kilometers above the surface.

History of Chandra X-Ray Observatory

NASA Image and Video Library

1999-07-01

A crew member of the STS-93 mission took this photograph of the Chandra X-Ray Observatory, still attached to the Inertial Upper Stage (IUS), backdropped against the darkness of space not long after its release from Orbiter Columbia. Two firings of an attached IUS rocket placed the Observatory into its working orbit. The primary duty of the crew of this mission was to deploy the 50,162-pound Observatory, the world's most powerful x-ray telescope.

Observations of the Crab Nebula with the Chandra X-Ray Observatory

NASA Technical Reports Server (NTRS)

Weisskopf, Martin C.

2012-01-01

The Crab Nebula and its pulsar has been the subject of a number of detailed observations with the Chandra X-ray Observatory. The superb angular resolution of Chandra s high-resolution telescope has made possible numerous remarkable results. Here we describe a number of specific studies of the Crab that I and my colleagues have undertaken. We discuss the geometry of the system, which indicates that the "inner X-ray ring", typically identified with the termination shock of the pulsar s particle wind, is most likely not in the equatorial plane of the pulsar. Other topics are the northern wisps and their evolution with time; the characterization of features in the jet to the southeast; pulse-phase spectroscopy and possible correlations with the features at other wavelengths, particularly the optical polarization; and a search for correlations of the X-ray flux with the recently-discovered gamma -ray flares.

Adaptive grazing incidence optics for the next generation of x-ray observatories

NASA Astrophysics Data System (ADS)

Lillie, C.; Pearson, D.; Plinta, A.; Metro, B.; Lintz, E.; Shropshire, D.; Danner, R.

2010-09-01

Advances in X-ray astronomy require high spatial resolution and large collecting area. Unfortunately, X-ray telescopes with grazing incidence mirrors require hundreds of concentric mirror pairs to obtain the necessary collecting area, and these mirrors must be thin shells packed tightly together... They must also be light enough to be placed in orbit with existing launch vehicles, and able to be fabricated by the thousands for an affordable cost. The current state of the art in X-ray observatories is represented by NASA's Chandra X-ray observatory with 0.5 arc-second resolution, but only 400 cm2 of collecting area, and by ESA's XMM-Newton observatory with 4,300 cm2 of collecting area but only 15 arc-second resolution. The joint NASA/ESA/JAXA International X-ray Observatory (IXO), with {15,000 cm2 of collecting area and 5 arc-second resolution which is currently in the early study phase, is pushing the limits of passive mirror technology. The Generation-X mission is one of the Advanced Strategic Mission Concepts that NASA is considering for development in the post-2020 period. As currently conceived, Gen-X would be a follow-on to IXO with a collecting area >= 50 m2, a 60-m focal length and 0.1 arc-second spatial resolution. Gen-X would be launched in {2030 with a heavy lift Launch Vehicle to an L2 orbit. Active figure control will be necessary to meet the challenging requirements of the Gen-X optics. In this paper we present our adaptive grazing incidence mirror design and the results from laboratory tests of a prototype mirror.

KSC-99pc0175

NASA Image and Video Library

1999-02-08

In the Vertical Processing Facility (VPF), workers check fittings and cables on the stand that will raise the Chandra X-ray Observatory to a vertical position. While in the VPF, the telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

KSC-99pc0168

NASA Image and Video Library

1999-02-08

Inside the Vertical Processing Facility (VPF), the Chandra X-ray Observatory (top) lies in its protective container while workers on the floor prepare the overhead cable that will remove it. In the VPF, the telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

KSC-99pc0173

NASA Image and Video Library

1999-02-08

In the Vertical Processing Facility (VPF), workers begin moving the overhead crane carrying the Chandra X-ray Observatory from its protective container to a stand on the floor. While in the VPF, the telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

Initial Performance of the Attitude Control and Aspect Determination Subsystems on the Chandra Observatory

NASA Technical Reports Server (NTRS)

Cameron, R.; Aldcroft, T.; Podgorski, W. A.; Freeman, M. D.

2000-01-01

The aspect determination system of the Chandra X-ray Observatory plays a key role in realizing the full potential of Chandra's X-ray optics and detectors. We review the performance of the spacecraft hardware components and sub-systems, which provide information for both real time control of the attitude and attitude stability of the Chandra Observatory and also for more accurate post-facto attitude reconstruction. These flight components are comprised of the aspect camera (star tracker) and inertial reference units (gyros), plus the fiducial lights and fiducial transfer optics which provide an alignment null reference system for the science instruments and X-ray optics, together with associated thermal and structural components. Key performance measures will be presented for aspect camera focal plane data, gyro performance both during stable pointing and during maneuvers, alignment stability and mechanism repeatability.

New insights into the X-ray properties of nearby barred spiral galaxy NGC 1672

NASA Astrophysics Data System (ADS)

Jenkins, L. P.; Brnadt, W. N.; Colbert, E. J. M.; Levan, A. J.; Roberts, T. P.; Ward, M. J.; Zezas, A.

2008-02-01

We present some preliminary results from new Chandra and XMM-Newton X-ray observations of the nearby barred spiral galaxy NGC1672. It shows dramatic nuclear and extra-nuclear star formation activity, including starburst regions located near each end of its strong bar, both of which host ultraluminous X-ray sources (ULXs). With the new high-spatial-resolution Chandra imaging, we show for the first time that NGC1672 possesses a faint ($L(X)~10^39 erg/s), hard central X-ray source surrounded by an X-ray bright circumnuclear starburst ring that dominates the X-ray emission in the region. The central source may represent low-level AGN activity, or alternatively the emission from X-ray binaries associated with star-formation in the nucleus.

The Case of the Neutron Star With a Wayward Wake

NASA Astrophysics Data System (ADS)

2006-06-01

A long observation with NASA's Chandra X-ray Observatory has revealed important new details of a neutron star that is spewing out a wake of high-energy particles as it races through space. The deduced location of the neutron star on the edge of a supernova remnant, and the peculiar orientation of the neutron star wake, pose mysteries that remain unresolved. "Like a kite flying in the wind, the behavior of this neutron star and its wake tell us what sort of gas it must be plowing through," said Bryan Gaensler of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass., and lead author of a paper accepted to The Astrophysical Journal. "Yet we're still not sure how the neutron star got to its present location." Animation: Sequence of images of J0617 in IC 443 Animation: Sequence of images of J0617 in IC 443 The neutron star, known as CXOU J061705.3+222127, or J0617 for short, appears to lie near the outer edge of an expanding bubble of hot gas associated with the supernova remnant IC 443. Presumably, J0617 was created at the time of the supernova -- approximately 30,000 years ago -- and propelled away from the site of the explosion at about 500,000 miles per hour. However, the neutron star's wake is oriented almost perpendicularly to the direction expected if the neutron star were moving away from the center of the supernova remnant. This apparent misalignment had previously raised doubts about the association of the speeding neutron star with the supernova remnant. Gaensler and his colleagues provide strong evidence that J0617 was indeed born in the same explosion that created the supernova remnant. First, the shape of the neutron star's wake indicates it is moving a little faster than the speed of sound in Composite Images of SNR IC 443 Composite Images of SNR IC 443 the remnant's multimillion-degree gas. The velocity that one can then calculate from this conclusion closely matches the predicted pace of the neutron star. In contrast, if the neutron star were outside the confines of the remnant, its inferred speed would be a sluggish 20,000 miles per hour. Also, the measured temperature of the neutron star matches that of one born at the same time of the supernova remnant. What then, could cause the misaligned, or wayward, neutron star wake? The authors speculate that perhaps the doomed progenitor star was moving at a high speed before it exploded, so that the explosion site was not at the observed center of the supernova remnant. Fast moving gusts of gas inside the supernova remnant have further pushed the neutron star's wake out of alignment. Observations of J0617 in the next 10 years should put this idea to the test. "If the neutron star was born off-center and if the wake is being pushed around by cross-winds, the neutron star should be moving close to vertically, away from the center of the supernova remnant. Now we wait and see," said Gaensler. Chandra X-ray Image of J0617 in IC 443 Chandra X-ray Image of J0617 in IC 443 Another group, led by Margarita Karovska, also of the CfA, has concentrated on other, previously unnoticed intriguing features of J0617. At a recent conference on neutron stars in London, England, they announced their findings, which include a thin filament of cooler gas that appears to extend from the neutron star along the long axis of its wake, and a second point-like feature embedded in the X-ray nebula around the neutron star. "There are a number of puzzling observational features associated with this system crying out for longer observations," said Karovska. Other members of the Gaensler team were S. Chatterjee and P. O. Slane (CfA), E. van der Swaluw (Royal Netherlands Meteorological Institute), F. Camilo (Columbia University), and J. P. Hughes (Rutgers University). Karovska's team included T. Clarke (Naval Research Laboratory), G. Pavlov (Penn State University), and M.C. Weisskopf and V. Zavlin of the Marshall Space Flight Center, Huntsville, Ala. which also manages the Chandra program for NASA's Science Mission Directorate. The Smithsonian Astrophysical Observatory provides science support and controls flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images can be found at: http://chandra.harvard.edu and http://chandra.nasa.gov For information about NASA and agency programs on the Web, visit: http://www.nasa.gov

Leon X-1, the First Chandra Source

NASA Technical Reports Server (NTRS)

Weisskopf, Martin C.; Aldcroft, Tom; Cameron, Robert A.; Gandhi, Poshak; Foellmi, Cedric; Elsner, Ronald F.; Patel, Sandeep K.; ODell, Stephen L.

2004-01-01

Here we present an analysis of the first photons detected with the Chandra X-ray Observatory and an identification of the brightest source in the field which we named Leon X-1 to honor the momentous contributions of the Chandra Telescope Scientist, Leon Van Speybroeck. The observation took place immediately following the opening of the last door protecting the X-ray telescope. We discuss the unusual operational conditions as the first extra-terrestrial X-ray photons reflected from the telescope onto the ACIS camera. One bright source was a p parent to the team at the control center and the small collection of photons that appeared on the monitor were sufficient to indicate that the telescope had survived the launch and was approximately in focus, even prior to any checks and subsequent adjustments.

Chandra X-ray Center Science Data Systems Regression Testing of CIAO

NASA Astrophysics Data System (ADS)

Lee, N. P.; Karovska, M.; Galle, E. C.; Bonaventura, N. R.

2011-07-01

The Chandra Interactive Analysis of Observations (CIAO) is a software system developed for the analysis of Chandra X-ray Observatory observations. An important component of a successful CIAO release is the repeated testing of the tools across various platforms to ensure consistent and scientifically valid results. We describe the procedures of the scientific regression testing of CIAO and the enhancements made to the testing system to increase the efficiency of run time and result validation.

KSC-99pp0772

NASA Image and Video Library

1999-06-27

In this fish-eye view, the Chandra X-ray Observatory rests inside the payload bay of the orbiter Columbia. Chandra is the primary payload on mission STS-93, scheduled to launch no earlier than July 20 aboard Space Shuttle Columbia. The world's most powerful X-ray telescope, Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

Scientists Find X Rays from Stellar Winds That May Play Significant Role in Galactic Evolution

NASA Astrophysics Data System (ADS)

2001-09-01

Colorful star-forming regions that have captivated stargazers since the advent of the telescope 400 years ago contain gas thousands of times more energetic than previously recognized, powered by colliding stellar winds. This multimillion-degree gas radiated as X rays is one of the long-sought sources of energy and elements in the Milky Way galaxy's interstellar medium. A team led by Leisa Townsley, a senior research associate in astronomy and astrophysics at Penn State University, uncovered this wind phenomenon in the Rosette Nebula, a stellar nursery. With the Chandra X-ray Observatory, the team found that the most massive stars in the nebula produce winds that slam into each other, create violent shocks, and infuse the region with 6-million-degree gas. The findings are presented in Washington, D.C., today at a conference entitled "Two Years of Science with Chandra." "A ghostly glow of diffuse X-ray emission pervades the Rosette Nebula and perhaps many other similar star-forming regions throughout the Galaxy," said Townsley. "We now have a new view of the engine lighting the beautiful Rosette Nebula and new evidence for how the interstellar medium may be energized." Townsley and her colleagues created a striking X-ray panorama of the Rosette Molecular Cloud from four images with Chandra's Advanced CCD Imaging Spectrometer. This is a swath of the sky nearly 100 light years across sprayed with hundreds of X-ray-emitting young stars. In one corner of the Rosette Molecular Cloud lies the Rosette Nebula, called an "H II region" because the hydrogen gas there has been stripped of its electrons due to the strong ultraviolet radiation from its young stars. This region, about 5,000 light years away in the constellation Monoceros, the Unicorn, has long been a favorite among amateur astronomers. The wispy, colorful display is visible with small telescopes. The Chandra survey reveals, for the first time, 6-million-degree gas at the center of the Rosette Nebula, occupying a volume of about 3,000 cubic light years. Fueling the fury are a handful of massive type-O and type-B stars at the core of the nebula, the most massive members of a populous "OB association" that also includes hundreds of lower- mass stars. Rosette Nebula Optical/X-ray Composite Press Image and Caption "Until this observation, no one really knew where the energy of the powerful OB stellar winds goes," said Eric Feigelson, professor of astronomy and astrophysics at Penn State and a co-investigator in the study. "Theorists have speculated about this for decades, and we now see with Chandra the heat from the winds slamming into the cooler gas." Earlier X-ray telescopes did not have the resolution to differentiate between point sources and diffuse emission in the Rosette Nebula to the extent that Chandra has. Chandra imaged over 300 individual young stars in the Rosette Nebula, plus hundreds more in the Rosette Molecular Cloud. "We were able to identify the faint, diffuse radiation by subtracting out these point sources and looking at what was left over," explains team member Patrick Broos, a research assistant in astronomy and astrophysics at Penn State. The diffuse emission is not likely to be from supernova remnants left over from exploded stars because the Rosette Nebula is too young to have produced these, according to You- Hua Chu, of the University of Illinois at Urbana-Champaign. Rather, the diffuse emission must be related to the way the stellar winds from OB associations dissipate their energy. Understanding the detailed processes involved will rely on front-line research done in the laboratory on energy transport in very hot gases, according to Thierry Montmerle, of the Centre d'Etudes de Saclay in France. Chu and Montmerle have joined the research team to help interpret the Chandra results. The observations were made with Chandra's Advanced CCD Imaging Spectrometer, which was conceived and developed for NASA by Penn State and Massachusetts Institute of Technology under the leadership of Gordon Garmire, the Evan Pugh Professor of Astronomy and Astrophysics at Penn State.

The 3CR Chandra Snapshot Survey: Extragalactic Radio Sources with Redshifts between 1 and 1.5

NASA Astrophysics Data System (ADS)

Stuardi, C.; Missaglia, V.; Massaro, F.; Ricci, F.; Liuzzo, E.; Paggi, A.; Kraft, R. P.; Tremblay, G. R.; Baum, S. A.; O’Dea, C. P.; Wilkes, B. J.; Kuraszkiewicz, J.; Forman, W. R.; Harris, D. E.

2018-04-01

The aim of this paper is to present an analysis of newly acquired X-ray observations of 16 extragalactic radio sources listed in the Third Cambridge Revised (3CR) catalog and not previously observed by Chandra. Observations were performed during Chandra Cycle 17, extending X-ray coverage for the 3CR extragalactic catalog up to z = 1.5. Among the 16 targets, two lie at z < 0.5 (3CR 27 at z = 0.184 and 3CR 69 at z = 0.458) all of the remaining 14 have redshifts between 1.0 and 1.5. In the current sample, there are three compact steep spectrum (CSS) sources, three quasars, and an FR I radio galaxy, while the other nine are FR II radio galaxies. All radio sources have an X-ray counterpart. We measured nuclear X-ray fluxes as well as X-ray emission associated with radio jet knots, hotspots, or lobes in three energy bands: soft (0.5–1 keV), medium (1–2 keV), and hard (2–7 keV). We also performed standard X-ray spectral analysis for the four brightest nuclei. We discovered X-ray emission associated with the radio lobe of 3CR 124, a hotspot of the quasar 3CR 220.2, another hotspot of the radio galaxy 3CR 238, and the jet knot of 3CR 297. We also detected extended X-ray emission around the nuclear region of 3CR 124 and 3CR 297 on scales of several tens of kiloparsecs. Finally, we present an update on the X-ray observations performed with Chandra and XMM-Newton on the entire 3CR extragalactic catalog.

X-ray Properties and the Environment of Compact Radio Sources.

NASA Astrophysics Data System (ADS)

Siemiginowska, Aneta; Sobolewska, Malgorzata; Guainazzi, Matteo; Hardcastle, Martin; Migliori, Giulia; Ostorero, Luisa; Stawarz, Lukasz

2018-01-01

Compact extragalactic radio sources provide important insights into the initial stages of radio source evolution and probe states of a black hole activity at the time of the formation of the relativistic outflow. Such outflows propagate out to hundreds kpc distances from the origin and impact environment on many scales, and thus influence evolution of structures in the universe. These compact sources show radio features typically observed in large-scale radio galaxies (jets, lobes, hot spots), but contained within the central 1 kpc region of the host galaxy. Compact Symmetric Objects (CSOs, a subclass of GigaHertz Peaked spectrum radio sources) are symmetric and not affected by beaming. Their linear radio size can be translated into a source age if one measures the expansion velocity of the radio structures. Such ages has been measured for a small sample of CSOs. Using the Chandra X-ray Observatory and XMM-Newton we observed a pilot samples of 16 CSOs in X-rays (6 for the first time). Our results show heterogeneous nature of the CSOs X-ray emission indicating a range of AGN luminosities and a complex environment. In particular, we identified four Compton Thick sources with a dense medium (equivalent column > 1e24 cm^-2) capable of disturbing/slowing down the jet and confining the jet to a small region. Thus for the first time we gain the observational evidence in X-ray domain in favor of the hypothesis that in a sub-population of CSOs the radio jets may be confined by the dense X-ray obscuring medium. As a consequence, the kinematic ages of these CSOs may be underestimated.. We discuss the implications of our results on the emission models of CSOs, the earliest stages of the radio source evolution, jet interactions with the ISM, diversity of the environments in which the jets expand, and jet-galaxy co-evolution.Partial support for this work was provided by the NASA grants GO1-12145X, GO4-15099X, NNX10AO60G, NNX17AC23G and XMM AO15 project 78461. This work supported in part by NASA under contract NAS 8-03060 to the Smithsonian Astrophysical Observatory for operation of the Chandra X-ray Center.

X-Ray Emission for the Saturnian System

NASA Technical Reports Server (NTRS)

Bhardwaj, Anil; Elsner, Ron F.; Waite, J. Hunter; Gladstone, G. Randall; Branduardi-Raymont, Graziella; Cravens, Tom E.; Ford, Peter G.

2005-01-01

Early attempts to detect X-ray emission from Saturn with Einstein (in December 1979) and ROSAT (in April 1992) were negative and marginal, respectively. Saturnian X-rays were unambiguously detected by XMM-Newton in September 2002 and by the Chandra X-ray Observatory in April 2003. These earlier X-ray observations of Saturn revealed emissions only from its non-auroral disk. In January 2004, Saturn was observed by the Advanced CCD Imaging Spectrometer of the Chandra observatory in two exposures on 20 and 26-27 January; each continuous observation lasted for about one full Saturn rotation. These new observations detected an X-ray flare at Saturn, and show that the Saturnian X-ray emission is highly variable - a factor of 4 variability in brightness over one week. These observations also discovered X-rays from Saturn's rings. The X-ray spectrum of the rings is dominated by emission in the 0.49-0.63 keV band with peak flux near the atomic oxygen K(lpha) fluorescence line at 525 eV. In addition, there is a hint of auroral emission from Saturn's south pole. But unlike Jupiter, X-rays from Saturn's polar region have characteristics similar to those from its disk and that they vary in brightness inversely to the FUV aurora observed by the Hubble Space Telescope. These exciting results obtained from Chandra observations will be presented and discussed.

KSC-99pp0624

NASA Image and Video Library

1999-06-01

In the Vertical Processing Facility, the Chandra X-ray Observatory is revealed with its protective cover removed. Chandra is ready for mating with the Inertial Upper Stage (IUS) beneath it, to be followed by testing to validate the IUS/Chandra connections and to check the orbiter avionics interfaces. Following that, an end-to-end test (ETE) will be conducted to verify the communications path to Chandra, commanding it as if it were in space. With the world's most powerful X-ray telescope, Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Chandra is scheduled for launch July 22 aboard Space Shuttle Columbia, on mission STS-93

X-Ray Probes of Jupiter's Auroral Zones, Galilean Moons, and the Io Plasma Torus

NASA Technical Reports Server (NTRS)

Elsner, R. F.; Ramsey, B. D.; Swartz, D. A.; Rehak, P.; Waite, J. H., Jr.; Cooper, J. F.; Johnson, R. E.

2005-01-01

Remote observations from the Earth orbiting Chandra X-ray Observatory and the XMM-Newton Observatory have shown the the Jovian system is a rich and complex source of x-ray emission. The planet's auroral zones and its disk are powerful sources of x-ray emission, though with different origins. Chandra observations discovered x-ray emission from the Io plasma torus and from the Galilean moons Io, Europa, and possibly Ganymede. The emission from the moons is due to bombardment of their surfaces by highly energetic magnetospheric protons, and oxygen and sulfur ions, producing fluorescent x-ray emission lines from the elements in their surfaces against an intense background continuum. Although very faint when observed from Earth orbit, an imaging x-ray spectrometer in orbit around the icy Galilean moons would provide a detail mapping of the elemental composition in their surfaces. Here we review the results of Chandra and XMM-Newton observations of the Jovian system and describe the characteristics of X-MIME, an imaging x-ray spectrometer undergoing study for possible application to future missions to Jupiter such as JIMO. X-MIME has the ultimate goal of providing detailed high-resolution maps of the elemental abundances of the surfaces of Jupiter's icy moons and Io, as well as detailed study of the x-ray mission from the Io plasma torus, Jupiter's auroral zones, and the planetary disk.

Preliminary Results from Recent Simultaneous Chandra/HST Observations of Jupiter Auroral Zones

NASA Technical Reports Server (NTRS)

Elsner, R.; Gladstone, R.; Waite, H.; Majeed, T.; Ford, P.; Grodent, D.; Bwardwaj, A.; Howell, R.; Cravens, T.; MacDowell, R.

2003-01-01

Jupiter was observed by the Chandra X-ray Observatory in late February, 2003, for 144 ks, using both the ACIS-S and HRC-I imaging x-ray cameras. Five orbits of HST STIS observations of the planet's northern auroral zone were obtained during the ACIS-S observations. These data are providing a wealth of information about Jupiter's auroral activity, including the first x-ray spectra from the x-ray hot spots inside the auroral ovals. We will also discuss the approximately 45 minute quasi-periodicity in the auroral x-ray emission - which correlates well with simultaneous observations of radio bursts by the Ulysses spacecraft - and a possible phase relation between the emission from the northern and southern x-ray aurora.

Chandra's Observations of Jupiter's X-Ray Aurora During Juno Upstream and Apojove Intervals

NASA Technical Reports Server (NTRS)

Jackman, C.M.; Dunn, W.; Kraft, R.; Gladstone, R.; Branduardi-Raymont, G.; Knigge, C.; Altamirano, D.; Elsner, R.

2017-01-01

The Chandra space telescope has recently conducted a number of campaigns to observe Jupiter's X-ray aurora. The first set of campaigns took place in summer 2016 while the Juno spacecraft was upstream of the planet sampling the solar wind. The second set of campaigns took place in February, June and August 2017 at times when the Juno spacecraft was at apojove (expected close to the magnetopause). We report on these upstream and apojove campaigns including intensities and periodicities of auroral X-ray emissions. This new era of jovian X-ray astronomy means we have more data than ever before, long observing windows (up to 72 kiloseconds for this Chandra set), and successive observations relatively closely spaced in time. These features combine to allow us to pursue novel methods for examining periodicities in the X-ray emission. Our work will explore significance testing of emerging periodicities, and the search for coherence in X-ray pulsing over weeks and months, seeking to understand the robustness and regularity of previously reported hot spot X-ray emissions. The periods that emerge from our analysis will be compared against those which emerge from radio and UV wavelengths.

Dynamics of the Shocked Gas in the Eta Carinae System as Seen by Chandra

NASA Technical Reports Server (NTRS)

Corcoran, M. F.; Hamaguchi, K.; Henley, D. B.; Ishibashi, K.; Gull, T.; Nielsen, K.; Pittard, J. M.

2006-01-01

We report on a series of X-ray spectra of the supermassive star Eta Carinae obtained by the High Energy Transmission Grating Spectrometer on the CHANDRA X-ray observatory before, during and after the star's X-ray minimum in the summer of 2003. The X-ray spectra show significant variations in emission measure and absorption, in the strength of the iron K edge and fluorescent iron emission, but show little change in the distribution of emission measure with temperature. The CHANDRA spectra also resolve emission from Si, S, Fe and other elements in H-like and He-like configurations. The HETGS spectra show that these lines change in centroid energy along with evidence of changes in the forbidden-to-intercombination ratios of the He-like triplets. These spectra offer strong support that the X-ray emission originates within a shock cone around an unseen, massive companion. The variations of the X-ray line spectrum provide a direct measure of the dynamics of the shocked gas in this cone and also evidence that the hottest region of the shock is not always in collisional ionization equilibrium. We discuss these results in light of the recent discovery of He II 4686 emission and the reported discovery of FUV emission from the companion star. This work was supported by SAO/Chandra grant GO3-4008A.

Absolute Effective Area of the Chandra High-Resolution Mirror Assembly

NASA Technical Reports Server (NTRS)

Schwartz, D. A.; David, L. P.; Donnelly, R. H.; Edgar, R. J.; Gaetz, T. J.; Jerius, D.; Juda, M.; Kellogg, E. M.; McNamara, B. R.; Dewey, D.

2000-01-01

The Chandra X-ray Observatory was launched in July 1999, and is returning exquisite sub-arcsecond x-ray images of star groups, supernova remnants, galaxies, quasars, and clusters of galaxies. In addition to being the premier X-ray observatory in terms of angular and spectral resolution, Chandra is the best calibrated X-ray facility ever flown. We discuss here the calibration of the effective area of the High Resolution Mirror Assembly. Because we do not know the absolute X-ray flux density of any celestial source, this must be based primarily on ground measurements and on modeling. In particular, we must remove the calibrated modeled responses of the detectors and gratings to obtain the mirror area. For celestial sources which may be assumed to have smoothly varying spectra, such as the Crab Nebula, we may verify the continuity of the area calibration as a function of energy. This is of significance in energy regions such as the Ir M-edges, or near the critical grazing angle cutoff of the various mirror shells.

X-ray Point Source Populations in Spiral and Elliptical Galaxies

NASA Astrophysics Data System (ADS)

Colbert, E.; Heckman, T.; Weaver, K.; Strickland, D.

2002-01-01

The hard-X-ray luminosity of non-active galaxies has been known to be fairly well correlated with the total blue luminosity since the days of the Einstein satellite. However, the origin of this hard component was not well understood. Some possibilities that were considered included X-ray binaries, extended upscattered far-infrared light via the inverse-Compton process, extended hot 107 K gas (especially in ellipitical galaxies), or even an active nucleus. Chandra images of normal, elliptical and starburst galaxies now show that a significant amount of the total hard X-ray emission comes from individual point sources. We present here spatial and spectral analyses of the point sources in a small sample of Chandra obervations of starburst galaxies, and compare with Chandra point source analyses from comparison galaxies (elliptical, Seyfert and normal galaxies). We discuss possible relationships between the number and total hard luminosity of the X-ray point sources and various measures of the galaxy star formation rate, and discuss possible options for the numerous compact sources that are observed.

Galaxy Centaurus A

NASA Technical Reports Server (NTRS)

2003-01-01

This image of the active galaxy Centaurus A was taken by NASA's Galaxy Evolution Explorer on June 7, 2003. The galaxy is located 30 million light-years from Earth and is seen edge on, with a prominent dust lane across the major axis. In this image the near ultraviolet emission is represented as green, and the far ultraviolet emission as blue. The galaxy exhibits jets of high energy particles, which were traced by the X-ray emission and measured by NASA's Chandra X-ray Observatory. These X-ray emissions are seen as red in the image. Several regions of ultraviolet emission can be seen where the jets of high energy particles intersect with hydrogen clouds in the upper left corner of the image. The emission shown may be the result of recent star formation triggered by the compression of gas by the jet.

The Galaxy Evolution Explorer mission is led by the California Institute of Technology, which is also responsible for the science operations and data analysis. NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of Caltech, manages the mission and built the science instrument. The mission was developed under NASA's Explorers Program, managed by the Goddard Space Flight Center, Greenbelt, Md. The mission's international partners include South Korea and France.

Astrostatistics in X-ray Astronomy: Systematics and Calibration

NASA Astrophysics Data System (ADS)

Siemiginowska, Aneta; Kashyap, Vinay; CHASC

2014-01-01

Astrostatistics has been emerging as a new field in X-ray and gamma-ray astronomy, driven by the analysis challenges arising from data collected by high performance missions since the beginning of this century. The development and implementation of new analysis methods and techniques requires a close collaboration between astronomers and statisticians, and requires support from a reliable and continuous funding source. The NASA AISR program was one such, and played a crucial part in our work. Our group (CHASC; http://heawww.harvard.edu/AstroStat/), composed of a mixture of high energy astrophysicists and statisticians, was formed ~15 years ago to address specific issues related to Chandra X-ray Observatory data (Siemiginowska et al. 1997) and was initially fully supported by Chandra. We have developed several statistical methods that have laid the foundation for extensive application of Bayesian methodologies to Poisson data in high-energy astrophysics. I will describe one such project, on dealing with systematic uncertainties (Lee et al. 2011, ApJ ), and present the implementation of the method in Sherpa, the CIAO modeling and fitting application. This algorithm propagates systematic uncertainties in instrumental responses (e.g., ARFs) through the Sherpa spectral modeling chain to obtain realistic error bars on model parameters when the data quality is high. Recent developments include the ability to narrow the space of allowed calibration and obtain better parameter estimates as well as tighter error bars. Acknowledgements: This research is funded in part by NASA contract NAS8-03060. References: Lee, H., Kashyap, V.L., van Dyk, D.A., et al. 2011, ApJ, 731, 126 Siemiginowska, A., Elvis, M., Connors, A., et al. 1997, Statistical Challenges in Modern Astronomy II, 241

The Chandra Delta Ori Large Project: Occultation Measurements of the Shocked Gas tn the Nearest Eclipsing O-Star Binary

NASA Technical Reports Server (NTRS)

Corcoran, Michael F.; Nichols, Joy; Naze, Yael; Rauw, Gregor; Pollock, Andrew; Moffat, Anthony; Richardson, Noel; Evans, Nancy; Hamaguchi, Kenji; Oskinova, Lida;

The Chandra Source Catalog: Spectral Properties

NASA Astrophysics Data System (ADS)

Doe, Stephen; Siemiginowska, Aneta L.; Refsdal, Brian L.; Evans, Ian N.; Anderson, Craig S.; Bonaventura, Nina R.; Chen, Judy C.; Davis, John E.; Evans, Janet D.; Fabbiano, Giuseppina; Galle, Elizabeth C.; Gibbs, Danny G., II; Glotfelty, Kenny J.; Grier, John D.; Hain, Roger; Hall, Diane M.; Harbo, Peter N.; He, Xiang Qun (Helen); Houck, John C.; Karovska, Margarita; Kashyap, Vinay L.; Lauer, Jennifer; McCollough, Michael L.; McDowell, Jonathan C.; Miller, Joseph B.; Mitschang, Arik W.; Morgan, Douglas L.; Mossman, Amy E.; Nichols, Joy S.; Nowak, Michael A.; Plummer, David A.; Primini, Francis A.; Rots, Arnold H.; Sundheim, Beth A.; Tibbetts, Michael S.; van Stone, David W.; Winkelman, Sherry L.; Zografou, Panagoula

2009-09-01

The first release of the Chandra Source Catalog (CSC) contains all sources identified from eight years' worth of publicly accessible observations. The vast majority of these sources have been observed with the ACIS detector and have spectral information in 0.5-7 keV energy range. Here we describe the methods used to automatically derive spectral properties for each source detected by the standard processing pipeline and included in the final CSC. Hardness ratios were calculated for each source between pairs of energy bands (soft, medium and hard) using the Bayesian algorithm (BEHR, Park et al. 2006). The sources with high signal to noise ratio (exceeding 150 net counts) were fit in Sherpa (the modeling and fitting application from the Chandra Interactive Analysis of Observations package, developed by the Chandra X-ray Center; see Freeman et al. 2001). Two models were fit to each source: an absorbed power law and a blackbody emission. The fitted parameter values for the power-law and blackbody models were included in the catalog with the calculated flux for each model. The CSC also provides the source energy flux computed from the normalizations of predefined power-law and black-body models needed to match the observed net X-ray counts. In addition, we provide access to data products for each source: a file with source spectrum, the background spectrum, and the spectral response of the detector. This work is supported by NASA contract NAS8-03060 (CXC).

The Chandra planetary nebula survey (CHANPLANS). II. X-ray emission from compact planetary nebulae

DOE Office of Scientific and Technical Information (OSTI.GOV)

Freeman, M.; Kastner, J. H.; Montez, R. Jr.

2014-10-20

We present results from the most recent set of observations obtained as part of the Chandra X-ray observatory Planetary Nebula Survey (CHANPLANS), the first comprehensive X-ray survey of planetary nebulae (PNe) in the solar neighborhood (i.e., within ∼1.5 kpc of the Sun). The survey is designed to place constraints on the frequency of appearance and range of X-ray spectral characteristics of X-ray-emitting PN central stars and the evolutionary timescales of wind-shock-heated bubbles within PNe. CHANPLANS began with a combined Cycle 12 and archive Chandra survey of 35 PNe. CHANPLANS continued via a Chandra Cycle 14 Large Program which targeted allmore » (24) remaining known compact (R {sub neb} ≲ 0.4 pc), young PNe that lie within ∼1.5 kpc. Results from these Cycle 14 observations include first-time X-ray detections of hot bubbles within NGC 1501, 3918, 6153, and 6369, and point sources in HbDs 1, NGC 6337, and Sp 1. The addition of the Cycle 14 results brings the overall CHANPLANS diffuse X-ray detection rate to ∼27% and the point source detection rate to ∼36%. It has become clearer that diffuse X-ray emission is associated with young (≲ 5 × 10{sup 3} yr), and likewise compact (R {sub neb} ≲ 0.15 pc), PNe with closed structures and high central electron densities (n{sub e} ≳ 1000 cm{sup –3}), and is rarely associated with PNe that show H{sub 2} emission and/or pronounced butterfly structures. Hb 5 is one such exception of a PN with a butterfly structure that hosts diffuse X-ray emission. Additionally, two of the five new diffuse X-ray detections (NGC 1501 and NGC 6369) host [WR]-type central stars, supporting the hypothesis that PNe with central stars of [WR]-type are likely to display diffuse X-ray emission.« less

The HEASARC in 2013 and Beyond: NuSTAR, Astro-H, NICER..

NASA Astrophysics Data System (ADS)

Drake, Stephen A.; Smale, A. P.; McGlynn, T. A.; Arnaud, K. A.

2013-04-01

The High Energy Astrophysics Archival Research Center or HEASARC (http://heasarc.gsfc.nasa.gov/) is in its third decade as the NASA astrophysics discipline node supporting multi-mission cosmic X-ray and gamma-ray astronomy research. It provides a unified archive and software structure aimed both at 'legacy' missions such as Einstein, EXOSAT, ROSAT and RXTE, contemporary missions such as Fermi, Swift, Suzaku, Chandra, etc., and upcoming missions, such as NuSTAR, Astro-H and NICER. The HEASARC's high-energy astronomy archive has grown so that it presently contains 45 TB of data from 28 orbital missions. The HEASARC is the designated archive which supports NASA's Physics of the Cosmos theme (http://pcos.gsfc.nasa.gov/). We discuss some of the upcoming new initiatives and developments for the HEASARC, including the arrival of public data from the hard X-ray imaging NuSTAR mission in the summer of 2013, and the ongoing preparations to support the JAXA/NASA Astro-H mission and the NASA MoO Neutron Star Interior Composition Explorer (NICER), which are expected to become operational in 2015-2016. We also highlight some of the new software capabilities of the HEASARC, such as Xamin, a next-generation archive interface which will eventually supersede Browse, and the latest update of XSPEC (v 12.8.0).

Chandra Observation of Luminous and Ultraluminous X-ray Binaries in M101

NASA Technical Reports Server (NTRS)

Mukai, K.; Pence, W. D.; Snowden, S. L.; Kuntz, K. D.; White, Nicholas E. (Technical Monitor)

2002-01-01

X-ray binaries in the Milky Way are among the brightest objects on the X-ray sky. With the increasing sensitivity of recent missions, it is now possible to study X-ray binaries in nearby galaxies. We present data on six ultraluminous binaries in the nearby spiral galaxy, M101, obtained with Chandra ACIS-S. Of these, five appear to be similar to ultraluminous sources in other galaxies, while the brightest source, P098, shows some unique characteristics. We present our interpretation of the data in terms of an optically thick outflow, and discuss implications.

Modeling Contamination Migration on the Chandra X-Ray Observatory - III

NASA Technical Reports Server (NTRS)

O'Dell, Stephen L.; Swartz, Douglas A.; Tice, Neil W.; Plucinsky, Paul P.; Grant, Catherine E.; Marshall, Herman L.; Vikhlinin, Alexy A.; Tennant, Allyn F.; Dahmer, Matthew T.

2015-01-01

During its first 16 years of operation, the cold (about -60 C) optical blocking filter of the Advanced CCD Imaging Spectrometer (ACIS), aboard the Chandra X-ray Observatory, has accumulated a growing layer of molecular contamination that attenuates low-energy x rays. Over the past few years, the accumulation rate, spatial distribution, and composition have changed. This evolution has motivated further analysis of contamination migration within and near the ACIS cavity, in part to evaluate potential bake-out scenarios intended to reduce the level of contamination. Keywords: X-ray astronomy, CCDs, contamination, modeling and simulation, spacecraft operations

sts093-s-013

NASA Image and Video Library

1999-06-27

STS093-S-013 (27 June 1999) --- In this fish-eye view, the Chandra X-ray Observatory rests inside the payload bay of the Space Shuttle Columbia at the Kennedy Space Center (KSC). Chandra is the primary payload on the STS-93 mission, scheduled to launch next month. The world's most powerful X-ray telescope, Chandra, will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of the universe.

KSC-99pp0771

NASA Image and Video Library

1999-06-27

In this fish-eye view, a worker oversees the movement of the Chandra X-ray Observatory into the payload bay of the orbiter Columbia. Chandra is the primary payload on mission STS-93, scheduled to launch no earlier than July 20 aboard Space Shuttle Columbia. The world's most powerful X-ray telescope, Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

Chandra X-ray constraints on the candidate Ca-rich gap transient SN 2016hnk

NASA Astrophysics Data System (ADS)

Sell, P. H.; Arur, K.; Maccarone, T. J.; Kotak, R.; Knigge, C.; Sand, D. J.; Valenti, S.

2018-03-01

We present a Chandra observation of SN 2016hnk, a candidate Ca-rich gap transient. This observation was specifically designed to test whether or not this transient was the result of the tidal detonation of a white dwarf by an intermediate-mass black hole. Since we detect no X-ray emission 28 d after the discovery of the transient, as predicted from fall-back accretion, we rule out this model. Our upper limit of ˜10 M⊙ does not allow us to rule out a neutron star or stellar-mass black hole detonator due limits on the sensitivity of Chandra to soft X-rays and unconstrained variables tied to the structure of super-Eddington accretion discs. Together with other Chandra and multiwavelength observations, our analysis strongly argues against the intermediate-mass black hole tidal detonation scenario for Ca-rich gap transients more generally.

KSC-99pc0174

NASA Image and Video Library

1999-02-08

In the Vertical Processing Facility (VPF), workers check the placement of the Chandra X-ray Observatory on the stand on the floor. The stand will be used to raise the observatory to a vertical position. While in the VPF, the telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

A Chandra Search for Coronal X Rays from the Cool White Dwarf GD 356

NASA Technical Reports Server (NTRS)

Weisskopf, Martin C.; Wu, Kinwah; Trimble, Virginia; ODell, Stephen L.; Elsner, Ronald F.; Zavlin, Vyacheslav E.; Kouveliotou, Chryssa

2006-01-01

We report observations with the Chandra X-ray Observatory of the single, cool, magnetic white dwarf GD 356. For consistent comparison with other X-ray observations of single white dwarfs, we also re-analyzed archival ROSAT data for GD 356 (GJ 1205), G 99-47 (GR 290 = V1201 Ori), GD 90, G 195-19 (EG250 = GJ 339.1), and WD 2316+123 and archival Chandra data for LHS 1038 (GJ 1004) and GD 358 (V777 Her). Our Chandra observation detected no X rays from GD 356, setting the most restrictive upper limit to the X-ray luminosity from any cool white dwarf - Lx less than 6.0 x 10(exp 25) erg s(sup -1), at 99.7% confidence, for a 1- keV thermal-bremsstrahlung spectrum. The corresponding limit to the electron density is no less than 4.4x10(exp 11) per cubic centimeter. Our re-analysis of the archival data confirmed the non-detections reported by the original investigators. We discuss the implications of our and prior observations on models for coronal emission from white dwarfs. For magnetic white dwarfs, we emphasize the more stringent constraints imposed by cyclotron radiation. In addition, we describe (in an appendix) a statistical methodology for detecting a source and for constraining the strength of a source, which applies even when the number of source or background events is small.

CIAO: A Modern Data Analysis System for X-Ray Astronomy

NASA Astrophysics Data System (ADS)

Fruscione, Antonella

2017-08-01

It is now eighteen years after launch and Chandra continues to produce spectacular results!A portion of the success is to be attributed to the data analysis software CIAO (Chandra Interactive Analysis of Observations) that the Chandra X-Ray Center (CXC) continues to improve and release year after year.CIAO is downloaded more than 1200 times a year and it is used by a wide variety of users around the world: from novice to experienced X-ray astronomers, high school, undergraduate and graduate students, archival users (many new to X-ray or Chandra data), users with extensive resources and others from smaller countries and institutions.The scientific goals and kinds of datasets and analysis cover a wide range: observations spanning from days to years, different instrument configurations and different kinds of targets, from pointlike stars and quasars, to fuzzy galaxies and clusters, to moving solar objects. These different needs and goals require a variety of specialized software and careful and detailed documentation which is what the CIAO software provides. In general, we strive to build a software system which is easy for beginners, yet powerful for advanced users.The complexity of the Chandra data require a flexible data analysis system which provides an environment where the users can apply our tools, but can also explore and construct their own applications. The main purpose of this talk is to present CIAO as a modern data analysis system for X-ray data analysis.CIAO has grown tremendously over the years and we will highlight (a) the most recent advancements with a particular emphasis on the newly developed high-level scripts which simplify the analysis steps for the most common cases making CIAO more accessible to all users - including beginners and users who are not X-ray astronomy specialists, (b) the python-based Sherpa modelling and fitting application and the new stand-alone version openly developed and distributed on Github and (c) progress on methods to characterize the Chandra PSF.

DISCOVERY OF X-RAY EMISSION FROM SUPERNOVA 1970G WITH CHANDRA: FILLING THE VOID BETWEEN SUPERNOVAE AND SUPERNOVA REMNANTS

NASA Technical Reports Server (NTRS)

Immler, Stefan; Kuntz, K. D.

2005-01-01

We report the discovery of X-ray emission from SN 1970G in M101, 35 yr after its outburst, using deep X-ray imaging with the Chundra X-Ray Observatory. The Chandra ACIS spectrum shows that the emission is soft (52 keV) and characteristic of the reverse-shock region. The X-ray luminosity, Lo,,, = (1.1 3 0.2) x lo3# ergs s-1, is likely caused by the interaction of the supernova shock with dense circumstellar matter. If the material was deposited by the stellar wind from the progenitor, a mass-loss rate of M = (2.6 ? 0.4) x M, yr-I (v,/lO km s-I) is inferred. Utilizing the high-resolution Chandra ACIS data of SN 1970G and its environment, we reconstruct the X-ray lightcurve from previous ROSAT HRI, PSPC, and XMM-Newton EPIC observations, and find a best-fit linear rate of decline of L cc t-# with index s = 2.7 t 0.9 over a period of -20-35 yr after the outburst. As the oldest supernova detected in X-rays, SN 1970G allows, for the first time, direct observation of the transition from a supenova to its supernova remnant phase.

The Ultracompact Nature of the Black Hole Candidate X-Ray Binary 47 Tuc X9

NASA Technical Reports Server (NTRS)

Bahramian, Arash; Heinke, Craig O.; Tudor, Vlad; Miller-Jones, James C. A.; Bogdanov, Slavko; Maccarone, Thomas J.; Knigge, Christian; Sivakoff, Gregory R.; Chomiuk, Laura; Strader, J.;

Evidence for a Constant Initial Mass Function in Early-type Galaxies Based on Their X-Ray Binary Populations

NASA Astrophysics Data System (ADS)

Peacock, Mark B.; Zepf, Stephen E.; Maccarone, Thomas J.; Kundu, Arunav; Gonzalez, Anthony H.; Lehmer, Bret D.; Maraston, Claudia

2014-04-01

A number of recent studies have proposed that the stellar initial mass function (IMF) of early type galaxies varies systematically as a function of galaxy mass, with higher mass galaxies having bottom-heavy IMFs. These bottom-heavy IMFs have more low-mass stars relative to the number of high mass stars, and therefore naturally result in proportionally fewer neutron stars (NSs) and black holes (BHs). In this paper, we specifically predict the variation in the number of BHs and NSs based on the power-law IMF variation required to reproduce the observed mass-to-light ratio trends with galaxy mass. We then test whether such variations are observed by studying the field low-mass X-ray binary (LMXB) populations of nearby early-type galaxies. In these binaries, an NS or BH accretes matter from a low-mass donor star. Their number is therefore expected to scale with the number of BHs and NSs present in a galaxy. We find that the number of LMXBs per K-band light is similar among the galaxies in our sample. These data therefore demonstrate the uniformity of the slope of the IMF from massive stars down to those now dominating the K-band light and are consistent with an invariant IMF. Our results are inconsistent with an IMF which varies from a Kroupa/Chabrier like IMF for low-mass galaxies to a steep power-law IMF (with slope x = 2.8) for high mass galaxies. We discuss how these observations constrain the possible forms of the IMF variations and how future Chandra observations can enable sharper tests of the IMF. Based in part on observations made with the NASA/ESA Hubble Space Telescope, and obtained from the Hubble Legacy Archive, which is a collaboration between the Space Telescope Science Institute (STScI/NASA), the Space Telescope European Coordinating Facility (ST-ECF/ESA) and the Canadian Astronomy Data Centre (CADC/NRC/CSA). The scientific results reported in this article are based in part on data obtained from the Chandra Data Archive and observations made by the Chandra X-ray Observatory and published previously in cited articles.

Chandra X-Ray Observations of the Two Brightest Unidentified High Galactic Latitude Fermi-LAT Gamma-Ray Sources

NASA Technical Reports Server (NTRS)

Cheung, C. C.; Donato, D.; Gehrels, N.; Sokolovsky, K. V.; Giroletti, M.

2012-01-01

We present Chandra ACIS-I X-ray observations of 0FGL J1311.9-3419 and 0FGL J1653.4-0200, the two brightest high Galactic latitude (absolute value (beta) >10 deg) gamma-ray sources from the three-month Fermi Large Area Telescope (LAT) bright source list that are still unidentified. Both were also detected previously by EGRET, and despite dedicated multi-wavelength follow-up, they are still not associated with established classes of gamma-ray emitters like pulsars or radio-loud active galactic nuclei. X-ray sources found in the ACIS-I fields of view are cataloged, and their basic properties are determined. These are discussed as candidate counterparts to 0FGL J1311.9-3419 and 0FGL J1653.4-0200, with particular emphasis on the brightest of the 9 and 13 Chandra sources detected within the respective Fermi-LAT 95% confidence regions. Further follow-up studies, including optical photometric and spectroscopic observations, are necessary to identify these X-ray candidate counterparts in order to ultimately reveal the nature of these enigmatic gamma-ray objects.

Compton thick AGN in Chandra sureys

NASA Astrophysics Data System (ADS)

Brightman, Murray; Nandra, Kirpal

2014-07-01

We present the results from the X-ray spectral analysis of active galactic nuclei (AGN) in the Chandra Deep Field-South, AEGIS-XD and Chandra-COSMOS surveys, focussing on the identification and characterisation of the most heavily obscured, Compton thick (CT, N H > 104 cm-2) sources. Our sample is comprised of 3088 X-ray selected sources, which has a high rate of redshift completeness (97%). The aim is to produce the largest and cleanest uniform sample of these sources from the data as possible. We identify these sources through X-ray spectral fitting, utilising torus spectral models designed for heavily obscured AGN which self consistently include the spectral signatures of heavy absorption, being Compton scattering, photoelectric absorption and iron Kα fluorescence. We identify a total of 163 CT AGN covering an intrinsic 2-10 keV X-ray luminosity range of 102 -3 × 105 erg s-1 and from z = 0.1-7.

KSC-99pp0619

NASA Image and Video Library

1999-06-01

The Inertial Upper Stage (IUS) booster is lowered toward a workstand in Kennedy Space Center's Vertical Processing Facility. The IUS will be mated with the Chandra X-ray Observatory and then undergo testing to validate the IUS/Chandra connections and check the orbiter avionics interfaces. Following that, an end-to-end test (ETE) will be conducted to verify the communications path to Chandra, commanding it as if it were in space. With the world's most powerful X-ray telescope, Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Chandra is scheduled for launch July 22 aboard Space Shuttle Columbia, on mission STS-93

KSC-99pp0623

NASA Image and Video Library

1999-06-01

In the Vertical Processing Facility, the Chandra X-ray Observatory is lowered onto the Inertial Upper Stage (IUS) beneath it. After the two components are mated, they will undergo testing to validate the IUS/Chandra connections and to check the orbiter avionics interfaces. Following that, an end-to-end test (ETE) will be conducted to verify the communications path to Chandra, commanding it as if it were in space. With the world's most powerful X-ray telescope, Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Chandra is scheduled for launch July 22 aboard Space Shuttle Columbia, on mission STS-93

KSC-99pp0618

NASA Image and Video Library

1999-06-01

The Inertial Upper Stage (IUS) booster is moved toward a workstand in Kennedy Space Center's Vertical Processing Facility. The IUS will be mated with the Chandra X-ray Observatory and then undergo testing to validate the IUS/Chandra connections and check the orbiter avionics interfaces. Following that, an end-to-end test (ETE) will be conducted to verify the communications path to Chandra, commanding it as if it were in space. With the world's most powerful X-ray telescope, Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Chandra is scheduled for launch July 22 aboard Space Shuttle Columbia, on mission STS-93

Chandra Observations and Models of the Mixed Morphology Supernova Remnant W44: Global Trends

NASA Technical Reports Server (NTRS)

Shelton, R. L.; Kuntz, K. D.; Petre, R.

2004-01-01

We report on the Chandra observations of the archetypical mixed morphology (or thermal composite) supernova remnant, W44. As with other mixed morphology remnants, W44's projected center is bright in thermal X-rays. It has an obvious radio shell, but no discernable X-ray shell. In addition, X-ray bright knots dot W44's image. The spectral analysis of the Chandra data show that the remnant s hot, bright projected center is metal-rich and that the bright knots are regions of comparatively elevated elemental abundances. Neon is among the affected elements, suggesting that ejecta contributes to the abundance trends. Furthermore, some of the emitting iron atoms appear to be underionized with respect to the other ions, providing the first potential X-ray evidence for dust destruction in a supernova remnant. We use the Chandra data to test the following explanations for W44's X-ray bright center: 1.) entropy mixing due to bulk mixing or thermal conduction, 2.) evaporation of swept up clouds, and 3.) a metallicity gradient, possibly due to dust destruction and ejecta enrichment. In these tests, we assume that the remnant has evolved beyond the adiabatic evolutionary stage, which explains the X-ray dimness of the shell. The entropy mixed model spectrum was tested against the Chandra spectrum for the remnant's projected center and found to be a good match. The evaporating clouds model was constrained by the finding that the ionization parameters of the bright knots are similar to those of the surrounding regions. While both the entropy mixed and the evaporating clouds models are known to predict centrally bright X-ray morphologies, their predictions fall short of the observed brightness gradient. The resulting brightness gap can be largely filled in by emission from the extra metals in and near the remnant's projected center. The preponderance of evidence (including that drawn from other studies) suggests that W44's remarkable morphology can be attributed to dust destruction and ejecta enrichment within an entropy mixed, adiabatic phase supernova remnant. The Chandra data prompts a new question - by what astrophysical mechanisms are the metals distributed so inhomogeneously in the supernova remnant.

Orphan Stars Found in Long Galaxy Tail

NASA Astrophysics Data System (ADS)

2007-09-01

Astronomers have found evidence that stars have been forming in a long tail of gas that extends well outside its parent galaxy. This discovery suggests that such "orphan" stars may be much more prevalent than previously thought. The comet-like tail was observed in X-ray light with NASA's Chandra X-ray Observatory and in optical light with the Southern Astrophysical Research (SOAR) telescope in Chile. The feature extends for more than 200,000 light years and was created as gas was stripped from a galaxy called ESO 137-001 that is plunging toward the center of Abell 3627, a giant cluster of galaxies. "This is one of the longest tails like this we have ever seen," said Ming Sun of Michigan State University, who led the study. "And, it turns out that this is a giant wake of creation, not of destruction." Chandra X-ray Image of ESO 137-001 and Tail in Abell 3627 Chandra X-ray Image of ESO 137-001 and Tail in Abell 3627 The observations indicate that the gas in the tail has formed millions of stars. Because the large amounts of gas and dust needed to form stars are typically found only within galaxies, astronomers have previously thought it unlikely that large numbers of stars would form outside a galaxy. "This isn't the first time that stars have been seen to form between galaxies," said team member Megan Donahue, also of MSU. "But the number of stars forming here is unprecedented." The evidence for star formation in this tail includes 29 regions of ionized hydrogen glowing in optical light, thought to be from newly formed stars. These regions are all downstream of the galaxy, located in or near the tail. Two Chandra X-ray sources are near these regions, another indication of star formation activity. The researchers believe the orphan stars formed within the last 10 million years or so. The stars in the tail of this fast-moving galaxy, which is some 220 million light years away, would be much more isolated than the vast majority of stars in galaxies. H-alpha Image of ESO 137-001 and Tail in Abell 3627 H-alpha Image of ESO 137-001 and Tail in Abell 3627 "By our galactic standards, these are extremely lonely stars," said Mark Voit, another team member from MSU. "If life was to form out there on a planet a few billion years from now, they would have very dark skies." The gas that formed the orphan stars was stripped out of its parent galaxy by the pressure induced by the motion of the galaxy through the multimillion degree gas that pervades the intergalactic space of the galaxy cluster. Eventually most of the gas will be scoured from the galaxy, depleting the raw material for new stars, and effectively stopping further star formation in the galaxy. This process may represent an important but short-lived stage in the transformation of a galaxy. Although apparently rare in the present-day universe, galactic tails of gas and orphan stars may have been more common billions of years ago when galaxies were younger and richer in star-forming gas. These results will appear in the December 10th issue of The Astrophysical Journal. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. The SOAR (Southern Astrophysical Research Telescope) is a joint project of Michigan State University, Conselho Nacional de Pesquisas Científicas e Tecnológicas (CNPq-Brazil), The University of North Carolina at Chapel Hill, and the National Optical Astronomy Observatory.

The X-ray Spectrum and Spectral Energy Distribution of FIRST J155633.8+351758: A Beamed Radio-Quiet Quasar with a Polar Outflow

NASA Astrophysics Data System (ADS)

Berrington, Robert C.; Brotherton, M. S.; Gallagher, S. C.; Ganguly, R.; Shang, Z.; Lacy, M.; Gregg, M. D.; Hall, P. B.; Laurent-Muehleisen, S. A.

2007-12-01

We report the results of a 60 ks Chandra X-ray Observatory ACIS-S observation of the reddened, radio-selected, highly polarized "FeLoBAL" quasar FIRST J155633.8+351758. Our analyses of the 531 photon spectrum indicate that the intrinsic X-ray flux is consistent with that expected for quasars of similarly high luminosity. We cannot tightly constrain the intrinsic X-ray power-law slope, but find indications that it is flat (photon index Γ = 1.7 or flatter). No iron K-α line is detected, and the X-rays appear to be down by only an order of magnitude below their intrinsic unabsorbed levels. Absorption is present with both partially ionized models and neutral hydrogen models with partial covering providing good fits. The level of partial covering in the latter model is consistent with the rest-frame ultraviolet maximum polarization of 13%, in the sense that light scattered by electrons around the X-ray absorber could account for both results. We present the spectral energy distribution (SED) of FIRST J155633.8+351758 from radio through X-ray energies, and make corrections for Doppler beaming for the pole-on radio-quiet jet, optical dust reddening, and X-ray absorption. The corrected SED appears to be that of a luminous radio-quiet quasar deficient in the mid and far-infrared, suggesting that the dust covering fraction of the quasar is not large and that star formation is not excessive. FIRST J155633.8+351758 seems to be an intrinsically normal radio-quiet quasar with an X-ray absorber not dissimilar from that of other broad absorption line quasars studied in detail at X-ray wavelengths. We acknowledge support from Chandra Award No. GO6-7105X, from the US NSF (grant AST 05-07781), from NASA under the grant NNG05GD03G, and from the National Natural Science Foundation of China (grant 10643001). This work was performed under the auspices of the US DOE by the University of California, LLNL (Contract No. W-7405-Eng-48).

The Chandra Source Catalog 2.0: Building The Catalog

NASA Astrophysics Data System (ADS)

Grier, John D.; Plummer, David A.; Allen, Christopher E.; Anderson, Craig S.; Budynkiewicz, Jamie A.; Burke, Douglas; Chen, Judy C.; Civano, Francesca Maria; D'Abrusco, Raffaele; Doe, Stephen M.; Evans, Ian N.; Evans, Janet D.; Fabbiano, Giuseppina; Gibbs, Danny G., II; Glotfelty, Kenny J.; Graessle, Dale E.; Hain, Roger; Hall, Diane M.; Harbo, Peter N.; Houck, John C.; Lauer, Jennifer L.; Laurino, Omar; Lee, Nicholas P.; Martínez-Galarza, Juan Rafael; McCollough, Michael L.; McDowell, Jonathan C.; Miller, Joseph; McLaughlin, Warren; Morgan, Douglas L.; Mossman, Amy E.; Nguyen, Dan T.; Nichols, Joy S.; Nowak, Michael A.; Paxson, Charles; Primini, Francis Anthony; Rots, Arnold H.; Siemiginowska, Aneta; Sundheim, Beth A.; Tibbetts, Michael; Van Stone, David W.; Zografou, Panagoula

2018-01-01

To build release 2.0 of the Chandra Source Catalog (CSC2), we require scientific software tools and processing pipelines to evaluate and analyze the data. Additionally, software and hardware infrastructure is needed to coordinate and distribute pipeline execution, manage data i/o, and handle data for Quality Assurance (QA) intervention. We also provide data product staging for archive ingestion.Release 2 utilizes a database driven system used for integration and production. Included are four distinct instances of the Automatic Processing (AP) system (Source Detection, Master Match, Source Properties and Convex Hulls) and a high performance computing (HPC) cluster that is managed to provide efficient catalog processing. In this poster we highlight the internal systems developed to meet the CSC2 challenge.This work has been supported by NASA under contract NAS 8-03060 to the Smithsonian Astrophysical Observatory for operation of the Chandra X-ray Center.

The Frequency of Intrinsic X-Ray Weakness among Broad Absorption Line Quasars

NASA Astrophysics Data System (ADS)

Liu, Hezhen; Luo, B.; Brandt, W. N.; Gallagher, S. C.; Garmire, G. P.

2018-06-01

We present combined ≈14–37 ks Chandra observations of seven z = 1.6–2.7 broad absorption line (BAL) quasars selected from the Large Bright Quasar Survey (LBQS). These seven objects are high-ionization BAL (HiBAL) quasars, and they were undetected in the Chandra hard band (2–8 keV) in previous observations. The stacking analyses of previous Chandra observations suggested that these seven objects likely contain some candidates for intrinsically X-ray weak BAL quasars. With the new Chandra observations, six targets are detected. We calculate their effective power-law photon indices and hard-band flux weakness, and find that two objects, LBQS 1203+1530 and LBQS 1442–0011, show soft/steep spectral shapes ({{{Γ }}}eff}={2.2}-0.9+0.9 and {1.9}-0.8+0.9) and significant X-ray weakness in the hard band (by factors of ≈15 and 12). We conclude that the two HiBAL quasars are good candidates for intrinsically X-ray weak BAL quasars. The mid-infrared-to-ultraviolet spectral energy distributions of the two candidates are consistent with those of typical quasars. We constrain the fraction of intrinsically X-ray weak active galactic nuclei (AGNs) among HiBAL quasars to be ≈7%–10% (2/29–3/29), and we estimate it is ≈6%–23% (2/35–8/35) among the general BAL quasar population. Such a fraction is considerably larger than that among non-BAL quasars, and we suggest that intrinsically X-ray weak quasars are preferentially observed as BAL quasars. Intrinsically X-ray weak AGNs likely comprise a small minority of the luminous type 1 AGN population, and they should not affect significantly the completeness of these AGNs found in deep X-ray surveys.

KSC-99pp0626

NASA Image and Video Library

1999-06-04

STS-93 Mission Specialists Catherine Coleman (left) and Michel Tognini of France (right), representing the Centre National d'Etudes Spatiales (CNES), look over material on the mission payload behind them, the Chandra X-ray Observatory. Chandra is being mated with the Inertial Upper Stage (IUS) before testing to validate the IUS/Chandra connections and to check the orbiter avionics interfaces. Following that, an end-to-end test (ETE) will be conducted to verify the communications path to Chandra, commanding it as if it were in space. With the world's most powerful X-ray telescope, Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Chandra is scheduled for launch July 22 aboard Space Shuttle Columbia, on mission STS-93

KSC-99pp0627

NASA Image and Video Library

1999-06-04

STS-93 Mission Specialists Catherine Coleman (left) and Michel Tognini of France (right), who represents the Centre National d'Etudes Spatiales (CNES), look over the controls for the Chandra X-ray Observatory. Chandra is being mated with the Inertial Upper Stage (IUS) before testing to validate the IUS/Chandra connections and to check the orbiter avionics interfaces. Following that, an end-to-end test (ETE) will be conducted to verify the communications path to Chandra, commanding it as if it were in space. With the world's most powerful X-ray telescope, Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Chandra is scheduled for launch July 22 aboard Space Shuttle Columbia, on mission STS-93

X-ray insights into star and planet formation

PubMed Central

Feigelson, Eric D.

2010-01-01

Although stars and planets form in cold environments, X-rays are produced in abundance by young stars. This review examines the implications of stellar X-rays for star and planet formation studies, highlighting the contributions of NASA’s (National Aeronautics and Space Administration) Chandra X-ray Observatory. Seven topics are covered: X-rays from protostellar outflow shocks, X-rays from the youngest protostars, the stellar initial mass function, the structure of young stellar clusters, the fate of massive stellar winds, X-ray irradiation of protoplanetary disks, and X-ray flare effects on ancient meteorites. Chandra observations of star-forming regions often show dramatic star clusters, powerful magnetic reconnection flares, and parsec-scale diffuse plasma. X-ray selected samples of premain sequence stars significantly advance studies of star cluster formation, the stellar initial mass function, triggered star-formation processes, and protoplanetary disk evolution. Although X-rays themselves may not play a critical role in the physics of star formation, they likely have important effects on protoplanetary disks by heating and ionizing disk gases. PMID:20404197

Frontiers of X-Ray Astronomy

NASA Astrophysics Data System (ADS)

Fabian, Andrew C.; Pounds, Kenneth A.; Blandford, Roger D.

2004-07-01

Preface; 1. Forty years on from Aerobee 150: a personal perspective K. Pounds; 2. X-ray spectroscopy of astrophysical plasmas S. M. Kahn, E. Behar, A. Kinkhabwala and D. W. Savin; 3. X-rays from stars M. Gudel; 4. X-ray observations of accreting white-dwarf systems M. Cropper, G. Ramsay, C. Hellier, K. Mukai, C. Mauche and D. Pandel; 5. Accretion flows in X-ray binaries C. Done; 6. Recent X-ray observations of supernova remnants C. R. Canizares; 7. Luminous X-ray sources in spiral and star-forming galaxies M. Ward; 8. Cosmological constraints from Chandra observations of galaxy clusters S. W. Allen; 9. Clusters of galaxies: a cosmological probe R. Mushotzky; 10. Obscured active galactic nuclei: the hidden side of the X-ray Universe G. Matt; 11. The Chandra Deep Field-North Survey and the cosmic X-ray background W. N. Brandt, D. M. Alexander, F. E. Bauer and A. E. Hornschemeier; 12. Hunting the first black holes G. Hasinger; 13. X-ray astronomy in the new millennium: a summary R. D. Blandford.

Chandra observations of GW170817 260 days since merger: first statistically significant evidence for an X-ray decay

NASA Astrophysics Data System (ADS)

Hajela, A.; Alexander, K. D.; Eftekhari, T.; Margutti, R.; Fong, W.; Berger, E.

2018-05-01

The Chandra X-ray Observatory started another round of follow-up observations of GW170817. The first observation (ID 21080) was taken on May 03, 2018 at 10:41:26 UT (t 259 d after merger) for a total exposure time of 50.8 ks (PI Wilkes; program 19408644).

High School Students Discover Neutron Star Using Chandra and VLA Data

NASA Astrophysics Data System (ADS)

2000-12-01

Three high school students, using data from NASA's Chandra X-ray Observatory and the National Science Foundation's Very Large Array (VLA), have found the first evidence of a neutron star in the nearby supernova remnant IC443, a system long studied by professional astronomers. This remarkable discovery has led the team to the national finals and a 1st place finish in the team competition at the Siemens-Westinghouse Science and Technology Competition held today in Washington, DC. Charles Olbert (age 18), Christopher Clearfield (age 18), and Nikolas Williams (age 16), all of the North Carolina School for Science and Mathematics (NCSSM) in Durham, NC, found a point-like source of X rays embedded in the remains of the stellar explosion, or supernova. Based on both the X-ray and radio data, the students determined that the central object in IC443 is most likely a young and rapidly rotating neutron star -- an object known as a "pulsar." "This is a really solid scientific finding," said Bryan Gaensler of the Massachusetts Institute of Technology, a noted pulsar expert who reviewed the paper for the team. "Everyone involved should be really proud of this accomplishment." Taking advantage of Chandra's superior angular resolution, the North Carolina students found the source embedded in IC443, a region known to be emitting particularly high-energy X rays. In a highly unusual situation, the students got access to the Chandra data from their science teacher, Dr. Jonathan Keohane. Keohane applied for the observation time while still associated with NASA's Goddard Space Flight Center. "The students really went through the whole analysis process themselves," said Keohane. "And, they even lived together all summer near the school to complete the research." In order to confirm the evidence from Chandra, the students turned to the National Radio Observatory's Dale Frail who gave the student team VLA data on IC443. While the radio data did not reveal any periodicity, the VLA strengthened the team's case that a pulsar powers the supernova remnant by confirming the existence of the point-like source and discovering a cloud, or nebula, of high-energy electrons around the central object. Such nebulas are a common characteristic of pulsars. "The experience of doing new and relevant science has been one of the most rewarding experiences I have ever had," said Olbert, a senior at NCSSM and lead author on the paper submitted to the Astrophysical Journal. "I never expected to publish a scientific paper while I was still in high school." The remnant of the IC443 supernova is a well-studied object. Astronomers have searched this region (roughly 5,000 light years from Earth) for the neutron star created in the explosion that they thought should be there, judging from the size and dynamics of the supernova remnant. The comet-shaped appearance of the cloud of high-energy particles indicates that the neutron star is moving through IC 443. Like the wake of a supersonic airplane, the swept-back shape of the nebula around the neutron star allowed the students to measure the speed it is traveling away from its origin. Using this result and the apparent distance that the neutron star has traveled from the center of the supernova remnant, the students calculated that the light from the initial explosion arrived at Earth about 30,000 years ago, thus addressing an outstanding question about IC 443. Neutron stars, such as the one found by the NCSSM team, are the compact hot embers of very massive stars that have exhausted their fuel and expelled their own shells. The remaining cores, often no more than 10 miles in diameter, are very dense objects that sometimes spin and release beams of particles along their magnetic poles. Created in 1998 by the non-profit Siemens Foundation, the Siemens-Westinghouse Science & Technology Competition promotes and advances science and mathematics education in America. The Competition is open to individuals and teams of high school students who develop independent research projects in the physical or biological sciences, or mathematics. The North Carolina School of Science and Mathematics is a free statewide residential high school for students with a strong aptitude and interest in math and science. The NCSSM was founded in 1980 as part of the University of North Carolina system. About 550 high school juniors and seniors reside on the school's campus. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc. NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program. TRW, Inc., Redondo Beach, California, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Massachusetts. Images associated with this release are available on the World Wide Web at: http://chandra.harvard.edu AND http://chandra.nasa.gov

Modeling contamination migration on the Chandra X-Ray Observatory

NASA Technical Reports Server (NTRS)

O'Dell, Stephen L.; Swartz, Douglas A.; Anderson, Scot K.; Chen, Kenny C.; Giordano, Rino J.; Knollenberg, Perry J.; Morris, Peter A.; Plucinsky, Paul P.; Tice, Neil W.; Tran, Hien

2005-01-01

During its first 5 years of operation, the cold (-60 C) optical blocking filter of the Advanced CCD Imaging Spectrometer (ACIS), on board the Chandra X-ray Observatory, has accumulated a contaminating layer that attenuates the low-energy x rays. To assist in assessing the likelihood of successfully baking off the contaminant, members of the Chandra Team developed contamination-migration simulation software. The simulation follows deposition onto and (temperature-dependent) vaporization from surfaces comprising a geometrical model of the Observatory. A separate thermal analysis, augmented by on-board temperature monitoring, provides temperatures for each surface of the same geometrical model. This paper describes the physical basis for the simulations, the methodologies, and the predicted migration of the contaminant for various bake-out scenarios and assumptions.

The High Resolution Chandra X-Ray Spectrum of 3C273

NASA Technical Reports Server (NTRS)

Fruscione, Antonella; Lavoie, Anthony (Technical Monitor)

2000-01-01

The bright quasar 3C273 was observed by Chandra in January 2000 for 120 ksec as a calibration target. It was observed with all detector- plus-grating combinations (ACIS+HETG, ACIS+LETG, and HRC+LETG) yielding an X-ray spectrum across the entire 0.1-10 keV band with unprecedented spectral resolution. At about 10 arcsec from the nucleus, an X-ray jet is also clearly visible and resolved in the Oth order images. While the jet is much fainter than the nuclear source, the Chandra spatial resolution allows, for the first time, spectral analysis of both components separately. We will present detailed spectral analysis with particular emphasis on possible absorption features and comparison with simultaneous BeppoSAX data.

X-Ray Properties of AGN in Brightest Cluster Galaxies. I. A Systematic Study of the Chandra Archive in the 0.2 < z < 0.3 and 0.55 < z < 0.75 Redshift Range

NASA Astrophysics Data System (ADS)

Yang, Lilan; Tozzi, Paolo; Yu, Heng; Lusso, Elisabeta; Gaspari, Massimo; Gilli, Roberto; Nardini, Emanuele; Risaliti, Guido

2018-05-01

We present a search for nuclear X-ray emission in the brightest cluster galaxies (BCGs) of a sample of groups and clusters of galaxies extracted from the Chandra archive. The exquisite angular resolution of Chandra allows us to obtain robust photometry at the position of the BCG, and to firmly identify unresolved X-ray emission when present, thanks to an accurate characterization of the extended emission at the BCG position. We consider two redshift bins (0.2 < z < 0.3 and 0.55 < z < 0.75) and analyze all the clusters observed by Chandra with exposure time larger than 20 ks. Our samples have 81 BCGs in 73 clusters and 51 BCGs in 49 clusters in the low- and high-redshift bins, respectively. X-ray emission in the soft (0.5–2 keV) or hard (2–7 keV) band is detected only in 14 and 9 BCGs (∼18% of the total samples), respectively. The X-ray photometry shows that at least half of the BCGs have a high hardness ratio, compatible with significant intrinsic absorption. This is confirmed by the spectral analysis with a power-law model plus intrinsic absorption. We compute the fraction of X-ray bright BCGs above a given hard X-ray luminosity, considering only sources with positive photometry in the hard band (12/5 sources in the low/high-z sample).

The Chandra Source Catalog

NASA Astrophysics Data System (ADS)

Evans, Ian N.; Primini, F. A.; Glotfelty, K. J.; Anderson, C. S.; Bonaventura, N. R.; Chen, J. C.; Davis, J. E.; Doe, S. M.; Evans, J. D.; Fabbiano, G.; Galle, E. C.; Gibbs, D. G., II; Grier, J. D.; Hain, R. M.; Hall, D. M.; Harbo, P. N.; He, X.; Houck, J. C.; Karovska, M.; Kashyap, V. L.; Lauer, J.; McCollough, M. L.; McDowell, J. C.; Miller, J. B.; Mitschang, A. W.; Morgan, D. L.; Mossman, A. E.; Nichols, J. S.; Nowak, M. A.; Plummer, D. A.; Refsdal, B. L.; Rots, A. H.; Siemiginowska, A.; Sundheim, B. A.; Tibbetts, M. S.; Van Stone, D. W.; Winkelman, S. L.; Zografou, P.

2010-03-01

The Chandra Source Catalog (CSC) is a general purpose virtual X-ray astrophysics facility that provides access to a carefully selected set of generally useful quantities for individual X-ray sources, and is designed to satisfy the needs of a broad-based group of scientists, including those who may be less familiar with astronomical data analysis in the X-ray regime. The first release of the CSC includes information about 94,676 distinct X-ray sources detected in a subset of public ACIS imaging observations from roughly the first eight years of the Chandra mission. This release of the catalog includes point and compact sources with observed spatial extents < 30". The catalog (1) provides access to estimates of the X-ray source properties for detected sources with good scientific fidelity; (2) facilitates analysis of a wide range of statistical properties for classes of X-ray sources; and (3) provides efficient access to calibrated observational data and ancillary data products for individual X-ray sources. The catalog includes real X-ray sources detected with flux estimates that are at least 3 times their estimated 1σ uncertainties in at least one energy band, while maintaining the number of spurious sources at a level of < 1 false source per field for a 100 ks observation. For each detected source, the CSC provides commonly tabulated quantities, including source position, extent, multi-band fluxes, hardness ratios, and variability statistics. In addition, for each X-ray source the CSC includes an extensive set of file-based data products that can be manipulated interactively, including source images, event lists, light curves, and spectra. Support for development of the CSC is provided by the National Aeronautics and Space Administration through the Chandra X-ray Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of the National Aeronautics and Space Administration under contract NAS 8-03060.

Deep Chandra Survey of the Small Magellanic Cloud. II. Timing Analysis of X-Ray Pulsars

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hong, JaeSub; Antoniou, Vallia; Zezas, Andreas

We report the timing analysis results of X-ray pulsars from a recent deep Chandra survey of the Small Magellanic Cloud (SMC). We analyzed a total exposure of 1.4 Ms from 31 observations over a 1.2 deg{sup 2} region in the SMC under a Chandra X-ray Visionary Program. Using the Lomb–Scargle and epoch-folding techniques, we detected periodic modulations from 20 pulsars and a new candidate pulsar. The survey also covered 11 other pulsars with no clear sign of periodic modulation. The 0.5–8 keV X-ray luminosity ( L {sub X} ) of the pulsars ranges from 10{sup 34} to 10{sup 37} ergmore » s{sup −1} at 60 kpc. All of the Chandra sources with L {sub X} ≳ 4 × 10{sup 35} erg s{sup −1} exhibit X-ray pulsations. The X-ray spectra of the SMC pulsars (and high-mass X-ray binaries) are in general harder than those of the SMC field population. All but SXP 8.02 can be fitted by an absorbed power-law model with a photon index of Γ ≲ 1.5. The X-ray spectrum of the known magnetar SXP 8.02 is better fitted with a two-temperature blackbody model. Newly measured pulsation periods of SXP 51.0, SXP 214, and SXP 701, are significantly different from the previous XMM-Newton and RXTE measurements. This survey provides a rich data set for energy-dependent pulse profile modeling. Six pulsars show an almost eclipse-like dip in the pulse profile. Phase-resolved spectral analysis reveals diverse spectral variations during pulsation cycles: e.g., for an absorbed power-law model, some exhibit an (anti)-correlation between absorption and X-ray flux, while others show more intrinsic spectral variation (i.e., changes in photon indices).« less

KSC-99pc0167

NASA Image and Video Library

1999-02-06

At the Vertical Processing Facility (VPF), workers (left) drive, by remote control, the rear bogie away from the VPF. The bogie is part of the tractor-trailer rig called the Space Cargo Transportation System that helped move the Chandra X-ray Observatory (right) from the Shuttle Landing Facility into the VPF. Chandra arrived at KSC on Thursday, Feb. 4, aboard an Air Force C-5 Galaxy aircraft. In the VPF, the telescope will undergo final installation of associated electronic components; it will also be tested, fueled and mated with the Inertial Upper Stage booster. A set of integrated tests will follow. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93 . Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe

First Lady Hillary Clinton is greeted by NASA Administrator Goldin

NASA Technical Reports Server (NTRS)

1999-01-01

Upon their arrival at the Skid Strip at Cape Canaveral Air Station, First Lady Hillary Rodham Clinton and her daughter, Chelsea, are greeted by NASA Administrator Daniel S. Goldin and Mrs. Goldin. Mrs. Clinton and Chelsea are here to view the launch of Space Shuttle mission STS-93, scheduled for 12:36 a.m. EDT July 20. Much attention has been generated over the launch due to Commander Eileen M. Collins, the first woman to serve as commander of a Shuttle mission. The primary payload of the five- day mission is the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X- ray telescope and is expected to unlock the secrets of supernovae, quasars and black holes.

The Chandra Source Catalog 2.0: Interfaces

NASA Astrophysics Data System (ADS)

D'Abrusco, Raffaele; Zografou, Panagoula; Tibbetts, Michael; Allen, Christopher E.; Anderson, Craig S.; Budynkiewicz, Jamie A.; Burke, Douglas; Chen, Judy C.; Civano, Francesca Maria; Doe, Stephen M.; Evans, Ian N.; Evans, Janet D.; Fabbiano, Giuseppina; Gibbs, Danny G., II; Glotfelty, Kenny J.; Graessle, Dale E.; Grier, John D.; Hain, Roger; Hall, Diane M.; Harbo, Peter N.; Houck, John C.; Lauer, Jennifer L.; Laurino, Omar; Lee, Nicholas P.; Martínez-Galarza, Rafael; McCollough, Michael L.; McDowell, Jonathan C.; Miller, Joseph; McLaughlin, Warren; Morgan, Douglas L.; Mossman, Amy E.; Nguyen, Dan T.; Nichols, Joy S.; Nowak, Michael A.; Paxson, Charles; Plummer, David A.; Primini, Francis Anthony; Rots, Arnold H.; Siemiginowska, Aneta; Sundheim, Beth A.; Van Stone, David W.

2018-01-01

Easy-to-use, powerful public interfaces to access the wealth of information contained in any modern, complex astronomical catalog are fundamental to encourage its usage. In this poster,I present the public interfaces of the second Chandra Source Catalog (CSC2). CSC2 is the most comprehensive catalog of X-ray sources detected by Chandra, thanks to the inclusion of Chandra observations public through the end of 2014 and to methodological advancements. CSC2 provides measured properties for a large number of sources that sample the X-ray sky at fainter levels than the previous versions of the CSC, thanks to the stacking of single overlapping observations within 1’ before source detection. Sources from stacks are then crossmatched, if multiple stacks cover the same area of the sky, to create a list of unique, optimal CSC2 sources. The properties of sources detected in each single stack and each single observation are also measured. The layered structure of the CSC2 catalog is mirrored in the organization of the CSC2 database, consisting of three tables containing all properties for the unique stacked sources (“Master Source”), single stack sources (“Stack Source”) and sources in any single observation (“Observation Source”). These tables contain estimates of the position, flags, extent, significances, fluxes, spectral properties and variability (and associated errors) for all classes of sources. The CSC2 also includes source region and full-field data products for all master sources, stack sources and observation sources: images, photon event lists, light curves and spectra.CSCview, the main interface to the CSC2 source properties and data products, is a GUI tool that allows to build queries based on the values of all properties contained in CSC2 tables, query the catalog, inspect the returned table of source properties, browse and download the associated data products. I will also introduce the suite of command-line interfaces to CSC2 that can be used in alternative to CSCview, and will present the concept for an additional planned cone-search web-based interface.This work has been supported by NASA under contract NAS 8-03060 to the Smithsonian Astrophysical Observatory for operation of the Chandra X-ray Center.

VizieR Online Data Catalog: ChaMP X-ray point source catalog (Kim+, 2007)

NASA Astrophysics Data System (ADS)

Kim, M.; Kim, D.-W.; Wilkes, B. J.; Green, P. J.; Kim, E.; Anderson, C. S.; Barkhouse, W. A.; Evans, N. R.; Ivezic, Z.; Karovska, M.; Kashyap, V. L.; Lee, M. G.; Maksym, P.; Mossman, A. E.; Silverman, J. D.; Tananbaum, H. D.

2009-01-01

We present the Chandra Multiwavelength Project (ChaMP) X-ray point source catalog with ~6800 X-ray sources detected in 149 Chandra observations covering ~10deg2. The full ChaMP catalog sample is 7 times larger than the initial published ChaMP catalog. The exposure time of the fields in our sample ranges from 0.9 to 124ks, corresponding to a deepest X-ray flux limit of f0.5-8.0=9x10-16ergs/cm2/s. The ChaMP X-ray data have been uniformly reduced and analyzed with ChaMP-specific pipelines and then carefully validated by visual inspection. The ChaMP catalog includes X-ray photometric data in eight different energy bands as well as X-ray spectral hardness ratios and colors. To best utilize the ChaMP catalog, we also present the source reliability, detection probability, and positional uncertainty. (10 data files).

Galaxy Cluster Smashes Distance Record

NASA Astrophysics Data System (ADS)

2009-10-01

he most distant galaxy cluster yet has been discovered by combining data from NASA's Chandra X-ray Observatory and optical and infrared telescopes. The cluster is located about 10.2 billion light years away, and is observed as it was when the Universe was only about a quarter of its present age. The galaxy cluster, known as JKCS041, beats the previous record holder by about a billion light years. Galaxy clusters are the largest gravitationally bound objects in the Universe. Finding such a large structure at this very early epoch can reveal important information about how the Universe evolved at this crucial stage. JKCS041 is found at the cusp of when scientists think galaxy clusters can exist in the early Universe based on how long it should take for them to assemble. Therefore, studying its characteristics - such as composition, mass, and temperature - will reveal more about how the Universe took shape. "This object is close to the distance limit expected for a galaxy cluster," said Stefano Andreon of the National Institute for Astrophysics (INAF) in Milan, Italy. "We don't think gravity can work fast enough to make galaxy clusters much earlier." Distant galaxy clusters are often detected first with optical and infrared observations that reveal their component galaxies dominated by old, red stars. JKCS041 was originally detected in 2006 in a survey from the United Kingdom Infrared Telescope (UKIRT). The distance to the cluster was then determined from optical and infrared observations from UKIRT, the Canada-France-Hawaii telescope in Hawaii and NASA's Spitzer Space Telescope. Infrared observations are important because the optical light from the galaxies at large distances is shifted into infrared wavelengths because of the expansion of the universe. The Chandra data were the final - but crucial - piece of evidence as they showed that JKCS041 was, indeed, a genuine galaxy cluster. The extended X-ray emission seen by Chandra shows that hot gas has been detected between the galaxies, as expected for a true galaxy cluster rather than one that has been caught in the act of forming. Also, without the X-ray observations, the possibility remained that this object could have been a blend of different groups of galaxies along the line of sight, or a filament, a long stream of galaxies and gas, viewed front on. The mass and temperature of the hot gas detected estimated from the Chandra observations rule out both of those alternatives. The extent and shape of the X-ray emission, along with the lack of a central radio source argue against the possibility that the X-ray emission is caused by scattering of cosmic microwave background light by particles emitting radio waves. It is not yet possible, with the detection of just one extremely distant galaxy cluster, to test cosmological models, but searches are underway to find other galaxy clusters at extreme distances. "This discovery is exciting because it is like finding a Tyrannosaurus Rex fossil that is much older than any other known," said co-author Ben Maughan, from the University of Bristol in the United Kingdom. "One fossil might just fit in with our understanding of dinosaurs, but if you found many more, you would have to start rethinking how dinosaurs evolved. The same is true for galaxy clusters and our understanding of cosmology." The previous record holder for a galaxy cluster was 9.2 billion light years away, XMMXCS J2215.9-1738, discovered by ESA's XMM-Newton in 2006. This broke the previous distance record by only about 0.1 billion light years, while JKCS041 surpasses XMMXCS J2215.9 by about ten times that. "What's exciting about this discovery is the astrophysics that can be done with detailed follow-up studies," said Andreon. Among the questions scientists hope to address by further studying JKCS041 are: What is the build-up of elements (such as iron) like in such a young object? Are there signs that the cluster is still forming? Do the temperature and X-ray brightness of such a distant cluster relate to its mass in the same simple way as they do for nearby clusters? The paper describing the results on JKCS041 from Andreon and his colleagues will appear in an upcoming issue of the journal Astronomy and Astrophysics. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington, DC. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass.

Chandra Studies of Unidentified X-ray Sources in the Galactic Bulge

NASA Astrophysics Data System (ADS)

Mori, Hideyuki

2013-09-01

We propose to study a complete X-ray sample in the luminosity range of > 10^34 erg s^-1 in the Galactic bulge, including 5 unidentified sources detected in the ROSAT All Sky Survey. Our goal is to obtain a clear picture about X-ray populations in the bulge, by utilizing the excellent Chandra position accuracy leading to unique optical identification together with the X-ray spectral properties. This is a new step toward understanding the formation history of the bulge. Furthermore, because the luminosity range we observe corresponds to a ``missing link'' region ever studied for a neutron star or blackhole X-ray binary, our results are also unique to test accretion disk theories at intermediate mass accretion rates.

Studies of dark energy with X-ray observatories.

PubMed

Vikhlinin, Alexey

2010-04-20

I review the contribution of Chandra X-ray Observatory to studies of dark energy. There are two broad classes of observable effects of dark energy: evolution of the expansion rate of the Universe, and slow down in the rate of growth of cosmic structures. Chandra has detected and measured both of these effects through observations of galaxy clusters. A combination of the Chandra results with other cosmological datasets leads to 5% constraints on the dark energy equation-of-state parameter, and limits possible deviations of gravity on large scales from general relativity.

KSC-99pp0355

NASA Image and Video Library

1999-03-26

In the Vertical Processing Facility, TRW technicians check the point of attachment of the solar panel array at right. Formerly called the Advanced X-ray Astrophysics Facility, Chandra comprises three major elements: the spacecraft, the science instrument module (SIM), and the world's most powerful X-ray telescope. Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Chandra is scheduled for launch July 9 aboard Space Shuttle Columbia, on mission STS-93

Chandra X-Ray Observatory Observations of the Jovian System

NASA Technical Reports Server (NTRS)

Elsner, R. F.; Bhardwaj, A.; Gladstone, R.; Waite, J. H.; Ford, P.; Branduari-Raymont, G.

2005-01-01

Chandra X-ray Observatory (CXO) and XMM-Newton observations of x-rays from the Jovian system have answered questions that arose from early observations with the Einstein and Rosat X-ray Observatories, but in the process of vastly increasing our knowledge of x-ray emission from Jupiter and its environs they have also raised new questions and point to new opportunities for future studies. We will review recent x-ray results on the Jovian system, from the point of view of the CXO, and discuss various questions that have arisen in the course of our studies. We will discuss prospects for more observations in the immediate future, and how they might address open questions. Finally we will briefly describe ways in which an imaging x-ray spectrometer in the vicinity of the Jovian system could provide a wealth of data and results concerning Jupiter's x-ray auroral and disk emission, elemental abundance measurements for the Galilean moons, and detailed studies of x-ray emission from the Io Plasma Torus.

X-ray emission from the Wolf-Rayet bubble NGC 6888. I. Chandra ACIS-S observations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Toalá, J. A.; Guerrero, M. A.; Gruendl, R. A.

We analyze Chandra observations of the Wolf-Rayet (W-R) bubble NGC 6888. This W-R bubble presents similar spectral and morphological X-ray characteristics to those of S 308, the only other W-R bubble also showing X-ray emission. The observed spectrum is soft, peaking at the N VII line emission at 0.5 keV, with additional line emission at 0.7-0.9 keV and a weak tail of harder emission up to ∼1.5 keV. This spectrum can be described by a two-temperature optically thin plasma emission model (T {sub 1} ∼ 1.4 × 10{sup 6} K, T {sub 2} ∼ 7.4 × 10{sup 6} K). Wemore » confirm the results of previous X-ray observations that no noticeable temperature variations are detected in the nebula. The X-ray-emitting plasma is distributed in three apparent morphological components: two caps along the tips of the major axis and an extra contribution toward the northwest blowout not reported in previous analyses of the X-ray emission toward this W-R nebula. Using the plasma model fits of the Chandra ACIS spectra for the physical properties of the hot gas and the ROSAT PSPC image to account for the incomplete coverage of Chandra observations, we estimate a luminosity of L {sub X} = (7.7 ± 0.1) ×10{sup 33} erg s{sup –1} for NGC 6888 at a distance of 1.26 kpc. The average rms electron density of the X-ray-emitting gas is ≳ 0.4 cm{sup –3} for a total mass ≳ 1.2 M {sub ☉}.« less

A Catalog of Candidate Intermediate-Luminosity X-Ray Objects

NASA Astrophysics Data System (ADS)

Colbert, E. J. M.; Ptak, A. F.

2002-11-01

ROSAT, and now Chandra, X-ray images allow studies of extranuclear X-ray point sources in galaxies other than our own. X-ray observations of normal galaxies with ROSAT and Chandra have revealed that off-nuclear, compact, intermediate-luminosity (LX[2-10keV]>=1039.0 ergs s-1) X-ray objects (IXOs, a.k.a. ULXs [ultraluminous X-ray sources]) are quite common. Here we present a catalog and finding charts for 87 IXOs in 54 galaxies, derived from all of the ROSAT HRI imaging data for galaxies with cz<=5000 km s-1 from the Third Reference Catalog of Bright Galaxies. We have defined the cutoff LX for IXOs so that it is well above the Eddington luminosity of a 1.4 Msolar black hole (1038.3 ergs s-1), so as not to confuse IXOs with ``normal'' black hole X-ray binaries. This catalog is intended to provide a baseline for follow-up work with Chandra and XMM-Newton, and with space- and ground-based survey work at wavelengths other than X-ray. We demonstrate that elliptical galaxies with IXOs have a larger number of IXOs per galaxy than nonelliptical galaxies with IXOs and note that they are not likely to be merely high-mass X-ray binaries with beamed X-ray emission, as may be the case for IXOs in starburst galaxies. Approximately half of the IXOs with multiple observations show X-ray variability, and many (19) of the IXOs have faint optical counterparts in DSS optical B-band images. Follow-up observations of these objects should be helpful in identifying their nature.

KSC-99pp0617

NASA Image and Video Library

1999-06-01

The Inertial Upper Stage (IUS) booster (right) is lifted out of its container after arriving at Kennedy Space Center's Vertical Processing Facility. The IUS will be mated with the Chandra X-ray Observatory (at left) and then undergo testing to validate the IUS/Chandra connections and check the orbiter avionics interfaces. Following that, an end-to-end test (ETE) will be conducted to verify the communications path to Chandra, commanding it as if it were in space. With the world's most powerful X-ray telescope, Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Chandra is scheduled for launch July 22 aboard Space Shuttle Columbia, on mission STS-93

KSC-99pp0621

NASA Image and Video Library

1999-06-01

In the Vertical Processing Facility, the Chandra X-ray Observatory is moved toward the Inertial Upper Stage (IUS) in a workstand at right. There it will be mated with the IUS and then undergo testing to validate the IUS/Chandra connections and check the orbiter avionics interfaces. Following that, an end-to-end test (ETE) will be conducted to verify the communications path to Chandra, commanding it as if it were in space. With the world's most powerful X-ray telescope, Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Chandra is scheduled for launch July 22 aboard Space Shuttle Columbia, on mission STS-93

KSC-99pp0622

NASA Image and Video Library

1999-06-01

In the Vertical Processing Facility, the Chandra X-ray Observatory is lowered toward the Inertial Upper Stage (IUS) in a workstand beneath it. There it will be mated with the IUS and then undergo testing to validate the IUS/Chandra connections and to check the orbiter avionics interfaces. Following that, an end-to-end test (ETE) will be conducted to verify the communications path to Chandra, commanding it as if it were in space. With the world's most powerful X-ray telescope, Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Chandra is scheduled for launch July 22 aboard Space Shuttle Columbia, on mission STS-93

KSC-99pp0625

NASA Image and Video Library

1999-06-04

Workers in the Vertical Processing Facility observe the lower end of the Inertial Upper Stage (IUS) that will be mated with the Chandra X-ray Observatory (out of sight above it). After the two components are mated, they will undergo testing to validate the IUS/Chandra connections and to check the orbiter avionics interfaces. Following that, an end-to-end test (ETE) will be conducted to verify the communications path to Chandra, commanding it as if it were in space. With the world's most powerful X-ray telescope, Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Chandra is scheduled for launch July 22 aboard Space Shuttle Columbia, on mission STS-93

KSC-99pp0620

NASA Image and Video Library

1999-06-01

In the Vertical Processing Facility, the Chandra X-ray Observatory is lifted from its workstand in order to move it to the Inertial Upper Stage (IUS) nearby. After being mated, the two components will then undergo testing to validate the IUS/Chandra connections and check the orbiter avionics interfaces. Following that, an end-to-end test (ETE) will be conducted to verify the communications path to Chandra, commanding it as if it were in space. With the world's most powerful X-ray telescope, Chandra will allow scientists from around the world to see previously invisible black holes and high-temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. Chandra is scheduled for launch July 22 aboard Space Shuttle Columbia, on mission STS-93

Nustar and Chandra Insight into the Nature of the 3-40 Kev Nuclear Emission in Ngc 253

NASA Technical Reports Server (NTRS)

Lehmer, Bret D.; Wik, Daniel R.; Hornschemeier, Ann E.; Ptak, Andrew; Antoniu, V.; Argo, M.K.; Bechtol, K.; Boggs, S.; Christensen, F.E.; Craig, W.W.;

Markov Chain Monte Carlo Joint Analysis of Chandra X-Ray Imaging Spectroscopy and Sunyaev-Zel'dovich Effect Data

NASA Technical Reports Server (NTRS)

Bonamente, Massimillano; Joy, Marshall K.; Carlstrom, John E.; Reese, Erik D.; LaRoque, Samuel J.

2004-01-01

X-ray and Sunyaev-Zel'dovich effect data can be combined to determine the distance to galaxy clusters. High-resolution X-ray data are now available from Chandra, which provides both spatial and spectral information, and Sunyaev-Zel'dovich effect data were obtained from the BIMA and Owens Valley Radio Observatory (OVRO) arrays. We introduce a Markov Chain Monte Carlo procedure for the joint analysis of X-ray and Sunyaev- Zel'dovich effect data. The advantages of this method are the high computational efficiency and the ability to measure simultaneously the probability distribution of all parameters of interest, such as the spatial and spectral properties of the cluster gas and also for derivative quantities such as the distance to the cluster. We demonstrate this technique by applying it to the Chandra X-ray data and the OVRO radio data for the galaxy cluster A611. Comparisons with traditional likelihood ratio methods reveal the robustness of the method. This method will be used in follow-up paper to determine the distances to a large sample of galaxy cluster.

Chandra Observations of Magnetic White Dwarfs and their Theoretical Implications

NASA Technical Reports Server (NTRS)

Musielak, Z. E.; Noble, M.; Porter, J. G.; Winget, D. E.

2003-01-01

Observations of cool DA and DB white dwarfs have not yet been successful in detecting coronal X-ray emission, but observations of late-type dwarfs and giants show that coronae are common for these stars. To produce coronal X-rays, a star must have dynamo-generated surface magnetic fields and a well-developed convection zone. There is some observational evidence that the DA star LHS 1038 and the DB star GD 358 have weak and variable surface magnetic fields. It has been suggested that such fields can be generated by dynamo action, and since both stars have well-developed convection zones, theory predicts detectable levels of coronal X-rays from these white dwarfs. However, we present analysis of Chandra observations of both stars showing no detectable X-ray emission. The derived upper limits for the X-ray fluxes provide strong constraints on theories of formation of coronae around magnetic white dwarfs. Another important implication of our negative Chandra observations is the possibility that the magnetic fields of LHS 1038 and GD 358 are fossil fields.

Simulating 3D Stellar Winds and Diffuse X-ray Emissions from Gases in Non-equilibrium Ionization State

NASA Astrophysics Data System (ADS)

Long, Min; Sun, Wei; Niu, Shu; Zhou, Xin; Ji, Li

2017-08-01

We investigate the physical properties of stellar winds launched in super stellar clusters (SSCs). Chandra observations have detected the presence of diffuse X-ray emission caused by hot gas from such winds in SSCs, and provide the best probe for understanding interactions between the stellar winds and the complex nursery regions. However, the details of the origin of cluster winds, the mass and energy ejection, the formation of diffuse X-ray emission, the fraction of winds contribution to the distribution of diffuse X-ray emission still remain unclear. We developed a multiphysics hydrodynamic model including self-gravity, head conduction and performed 3D simulations with an unprecedented grid resolution due to adaptive mesh refinement (AMR) capability in a case study of NGC 3603, as a supplement to the analysis of the archived 500 ks Chandra observations. The synthetic emission will be computed by assuming the gas in a non-equilibrium ionization (NEI) state indicated by Chandra observation, not coronal ionization equilibrium (CIE) that most works assumed, by using a customized NEI calculation module based on AtomDB. The results will be compared to the Chandra observations.

Deconvolving the Nucleus of Centaurus A Using Chandra PSF Library

NASA Technical Reports Server (NTRS)

Karovska, Margarita

2000-01-01

Centaurus A (NGC 5128) is a giant early-type galaxy containing the nearest (at 3.5 Mpc) radio-bright Active Galactic Nucleus (AGN). Cen A was observed with the High Resolution Camera (HRC) on the Chandra X-ray Observatory on several occasions since the launch in July 1999. The high-angular resolution (less than 0.5 arcsecond) Chandra/HRC images reveal X ray multi-scale structures in this object with unprecedented detail and clarity, including the bright nucleus believed to be associated with a supermassive black hole. We explored the spatial extent of the Cen A nucleus using deconvolution techniques on the full resolution Chandra images. Model point spread functions (PSFs) were derived from the standard Chandra raytrace PSF library as well as unresolved point sources observed with Chandra. The deconvolved images show that the Cen A nucleus is resolved and asymmetric. We discuss several possible causes of this extended emission and of the asymmetries.

Managing Radiation Degradation of CCDs on the Chandra X-Ray Observatory--III

NASA Technical Reports Server (NTRS)

O'Dell, Stephen L.; Aldcroft, Thomas L.; Blackwell, William C.; Bucher, Sabina L.; Chappell, Jon H.; DePasquale, Joseph M.; Grant, Catherine E.; Juda, Michael; Martin, Eric R.; Minow, Joseph I.;

Cosmological constraints from Chandra observations of galaxy clusters.

PubMed

Allen, Steven W

2002-09-15

Chandra observations of rich, relaxed galaxy clusters allow the properties of the X-ray gas and the total gravitating mass to be determined precisely. Here, we present results for a sample of the most X-ray luminous, dynamically relaxed clusters known. We show that the Chandra data and independent gravitational lensing studies provide consistent answers on the mass distributions in the clusters. The mass profiles exhibit a form in good agreement with the predictions from numerical simulations. Combining Chandra results on the X-ray gas mass fractions in the clusters with independent measurements of the Hubble constant and the mean baryonic matter density in the Universe, we obtain a tight constraint on the mean total matter density of the Universe, Omega(m), and an interesting constraint on the cosmological constant, Omega(Lambda). We also describe the 'virial relations' linking the masses, X-ray temperatures and luminosities of galaxy clusters. These relations provide a key step in linking the observed number density and spatial distribution of clusters to the predictions from cosmological models. The Chandra data confirm the presence of a systematic offset of ca. 40% between the normalization of the observed mass-temperature relation and the predictions from standard simulations. This finding leads to a significant revision of the best-fit value of sigma(8) inferred from the observed temperature and luminosity functions of clusters.

A CHANDRA OBSERVATION OF THE ECLIPSING WOLF-RAYET BINARY CQ Cep

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skinner, Stephen L.; Zhekov, Svetozar A.; Güdel, Manuel

The short-period (1.64 d) near-contact eclipsing WN6+O9 binary system CQ Cep provides an ideal laboratory for testing the predictions of X-ray colliding wind shock theory at close separation where the winds may not have reached terminal speeds before colliding. We present results of a Chandra X-ray observation of CQ Cep spanning ∼1 day during which a simultaneous Chandra optical light curve was acquired. Our primary objective was to compare the observed X-ray properties with colliding wind shock theory, which predicts that the hottest shock plasma (T ≳ 20 MK) will form on or near the line-of-centers between the stars. The X-raymore » spectrum is strikingly similar to apparently single WN6 stars such as WR 134 and spectral lines reveal plasma over a broad range of temperatures T ∼ 4-40 MK. A deep optical eclipse was seen as the O star passed in front of the Wolf-Rayet star and we determine an orbital period P {sub orb} = 1.6412400 d. Somewhat surprisingly, no significant X-ray variability was detected. This implies that the hottest X-ray plasma is not confined to the region between the stars, at odds with the colliding wind picture and suggesting that other X-ray production mechanisms may be at work. Hydrodynamic simulations that account for such effects as radiative cooling and orbital motion will be needed to determine if the new Chandra results can be reconciled with the colliding wind picture.« less

Librarians and Scientists: Combining Forces for Better Metrics

NASA Astrophysics Data System (ADS)

Rots, Arnold H.; Winkelman, Sherry

2015-08-01

Traditionally, observatory bibliographies mainly rely on two parameters derived from the carefully compiled lists of publications associated, in a well-defined way, with the observatories contribution to the advancement of science: numbers of articles and numbers of citations - in addition to the bibliographic metadata relating to those articles. The information that can be extracted from metrics based on these parameters is limited. This is a realization that is not just typical to astronomy and astrophysics, but one that is felt across many disciplines.Relating articles with very specific datasets allows us to join those datasets' metadata with the bibliographic metadata which opens a much richer field of information to mine for knowledge concerning the performance, not only of the observatory as a whole, but also its parts: instruments, types of observations, length of observations, etc. We have experimented extensively with such new metrics in the Chandra Data Archive in the Chandra X-ray Center at SAO.The linking of articles with individual datasets requires a level of scientific expertise that is usually not in the, otherwise extensive, skill set of the librarians, but is something that is crucial on the road to more informative bibliographic metrics.This talk is a plea for librarians and research scientists to join forces to make this happen. The added benefit of such a collaboration is a powerful research tool for navigating data and literature through a single interface.This work has been supported by NASA under contract NAS 8-03060 to the Smithsonian Astrophysical Observatory for operation of the Chandra X-ray Center. It depends critically on the services provided by the ADS, which is funded by NASA Grant NNX12AG54G.

X-ray Observations of Binary and Single Wolf-Rayet Stars with XMM-Newton and Chandra

NASA Technical Reports Server (NTRS)

Skinner, Stephen; Gudel, Manuel; Schmutz, Werner; Zhekov, Svetozar

2006-01-01

We present an overview of recent X-ray observations of Wolf-Rayet (WR) stars with XMM-Newton and Chandra. These observations are aimed at determining the differences in X-ray properties between massive WR + OB binary systems and putatively single WR stars. A new XMM spectrum of the nearby WN8 + OB binary WR 147 shows hard absorbed X-ray emission (including the Fe Ka line complex), characteristic of colliding wind shock sources. In contrast, sensitive observations of four of the closest known single WC (carbon-rich) WR stars have yielded only nondetections. These results tentatively suggest that single WC stars are X-ray quiet. The presence of a companion may thus be an essential factor in elevating the X-ray emission of WC + OB stars to detectable levels.

Possible Progenitor of Special Supernova Type Detected

NASA Astrophysics Data System (ADS)

2008-04-01

Using data from NASA's Chandra X-ray Observatory, scientists have reported the possible detection of a binary star system that was later destroyed in a supernova explosion. The new method they used provides great future promise for finding the detailed origin of these important cosmic events. In an article appearing in the February 14th issue of the journal Nature, Rasmus Voss of the Max Planck Institute for Extraterrestrial Physics in Germany and Gijs Nelemans of Radboud University in the Netherlands searched Chandra images for evidence of a much sought after, but as yet unobserved binary system - one that was about to go supernova. Near the position of a recently detected supernova, they discovered an object in Chandra images taken more than four years before the explosion. Optical image of SN 2007on Optical image of SN 2007on The supernova, known as SN 2007on, was identified as a Type Ia supernova. Astronomers generally agree that Type Ia supernovas are produced by the explosion of a white dwarf star in a binary star system. However, the exact configuration and trigger for the explosion is unclear. Is the explosion caused by a collision between two white dwarfs, or because a white dwarf became unstable by pulling too much material off a companion star? Answering such questions is a high priority because Type Ia supernovas are major sources of iron in the Universe. Also, because of their nearly uniform intrinsic brightness, Type Ia supernova are used as important tools by scientists to study the nature of dark energy and other cosmological issues. People Who Read This Also Read... Oldest Known Objects Are Surprisingly Immature Black Holes Have Simple Feeding Habits Discovery of Most Recent Supernova in Our Galaxy Geriatric Pulsar Still Kicking "Right now these supernovas are used as black boxes to measure distances and derive the rate of expansion of the universe," said Nelemans. "What we're trying to do is look inside the box." If the supernova explosion is caused by material being pulled off a companion star onto the white dwarf, fusion of this material on the surface of the star should heat the star and produce a strong source of X-radiation prior to the explosion. Once the supernova explosion occurs, the white dwarf is expected to be completely destroyed and then would be undetectable in X-rays. In the merger scenario, the intensity of X-ray emission prior to the explosion is expected to be much weaker. Based on the detection of a fairly strong X-ray source at approximately the position of SN 2007on 4 years before the explosion, Voss and Nelemans conclude that the data support the scenario where matter is pulled off a companion star. The small number of X-ray sources in the field implies that there is only a small chance of an unrelated source being so close by coincidence. Also, the X-ray source has similar properties to those expected for fusion on a white dwarf, unlike most X-ray sources in the sky. However, in follow-up studies, Voss, Nelemans and colleagues Gijs Roelofs (Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass.) and Cees Bassa (McGill University, Canada) used higher-quality optical images to better determine the supernova's position. This work, which is not yet published, shows a small, but significant difference in the measured positions of the supernova and the X-ray source, suggesting the source may not be the progenitor. Follow-up Chandra observations hint that the X-ray object has disappeared, but further observations are needed to finally decide whether the source was the progenitor or not. The team is also applying this new method to other supernovas and has high hopes that they will eventually succeed in identifying the elusive cause of at least some of these explosions. "We're very excited about opening up a new way of studying supernovas, even though we're not sure that we've seen this particular stellar bomb before it exploded," said Gijs Roelofs. "We're very confident that we'll learn a lot more about these important supernovas in the future." Voss agrees that, even if the X-ray source is not found to be the progenitor of SN 2007on, the hunt is worth the effort. "Finding the progenitor to one of these Type Ia supernovas is a great chase in astronomy right now," he said. "These supernovas are great tools for studying dark energy, but if we knew more about how they form they might become even better tools." Rasmus Voss receives support from the Excellence Cluster Universe in Garching, Germany. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass

A Galactic Spectacle

NASA Image and Video Library

2017-12-08

NASA image release August 5, 2010 A beautiful new image of two colliding galaxies has been released by NASA's Great Observatories. The Antennae galaxies, located about 62 million light-years from Earth, are shown in this composite image from the Chandra X-ray Observatory (blue), the Hubble Space Telescope (gold and brown), and the Spitzer Space Telescope (red). The Antennae galaxies take their name from the long antenna-like "arms," seen in wide-angle views of the system. These features were produced by tidal forces generated in the collision. The collision, which began more than 100 million years ago and is still occurring, has triggered the formation of millions of stars in clouds of dusts and gas in the galaxies. The most massive of these young stars have already sped through their evolution in a few million years and exploded as supernovas. The X-ray image from Chandra shows huge clouds of hot, interstellar gas that have been injected with rich deposits of elements from supernova explosions. This enriched gas, which includes elements such as oxygen, iron, magnesium, and silicon, will be incorporated into new generations of stars and planets. The bright, point-like sources in the image are produced by material falling onto black holes and neutron stars that are remnants of the massive stars. Some of these black holes may have masses that are almost one hundred times that of the Sun. The Spitzer data show infrared light from warm dust clouds that have been heated by newborn stars, with the brightest clouds lying in the overlapping region between the two galaxies. The Hubble data reveal old stars and star-forming regions in gold and white, while filaments of dust appear in brown. Many of the fainter objects in the optical image are clusters containing thousands of stars. The Chandra image was taken in December 1999. The Spitzer image was taken in December 2003. The Hubble image was taken in July 2004, and February 2005. To read more go to: www.nasa.gov/mission_pages/chandra/multimedia/antennae.html NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe. Follow us on Twitter Join us on Facebook Credit: NASA, ESA, SAO, CXC, JPL-Caltech, and STScI Acknowledgment: G. Fabbiano and Z. Wang (Harvard-Smithsonian CfA), and B. Whitmore (STScI)

Toward An Understanding of Cluster Evolution: A Deep X-Ray Selected Cluster Catalog from ROSAT

NASA Technical Reports Server (NTRS)

Jones, Christine; Oliversen, Ronald (Technical Monitor)

2002-01-01

In the past year, we have focussed on studying individual clusters found in this sample with Chandra, as well as using Chandra to measure the luminosity-temperature relation for a sample of distant clusters identified through the ROSAT study, and finally we are continuing our study of fossil groups. For the luminosity-temperature study, we compared a sample of nearby clusters with a sample of distant clusters and, for the first time, measured a significant change in the relation as a function of redshift (Vikhlinin et al. in final preparation for submission to Cape). We also used our ROSAT analysis to select and propose for Chandra observations of individual clusters. We are now analyzing the Chandra observations of the distant cluster A520, which appears to have undergone a recent merger. Finally, we have completed the analysis of the fossil groups identified in ROM observations. In the past few months, we have derived X-ray fluxes and luminosities as well as X-ray extents for an initial sample of 89 objects. Based on the X-ray extents and the lack of bright galaxies, we have identified 16 fossil groups. We are comparing their X-ray and optical properties with those of optically rich groups. A paper is being readied for submission (Jones, Forman, and Vikhlinin in preparation).

X-ray microlensing in the quadruply lensed quasar Q2237+0305

NASA Astrophysics Data System (ADS)

Zimmer, F.; Schmidt, R. W.; Wambsganss, J.

2011-05-01

We use archival data of NASA's Chandra X-ray telescope to compile an X-ray light curve of all four images of the quadruply lensed quasar Q2237+0305 (zQ= 1.695) from 2006 January to 2007 January. We fit simulated point spread functions to the four individual quasar images using Cash's C-statistic to account for the Poissonian nature of the X-ray signal. The quasar images display strong flux variations up to a factor of ˜4 within one month. We can disentangle the intrinsic quasar variability from flux variations due to gravitational microlensing by looking at the flux ratios of the individual quasar images. Doing this, we find evidence for microlensing in image A. In particular, the time sequence of the flux ratio A/B in the X-ray regime correlates with the corresponding sequence in the optical monitoring by OGLE in the V band. The amplitudes in the X-ray light curve are larger. For the most prominent peak, the increase of the X-ray ratio A/B is larger by a factor of ˜1.6 compared to the signal in the optical. In agreement with theory and other observations of multiply-imaged quasars, this suggests that the X-ray emission region of this quasar is significantly smaller than the optical emission region.

Identifying the Location in the Host Galaxy of Short GRB 1111l7A with the Chandra Sub- Arcsecond Position

NASA Technical Reports Server (NTRS)

Sakamoto, Takanori; Troja, E.; Aoki, K.; Guiriec, S.; Im, M.; Leloudas, G.; Malesani, D.; Melandri, A.; deUgartePostigo, A.; Urata, Y.;

NASA Announces Contest to Name X-Ray Observatory

NASA Astrophysics Data System (ADS)

1998-04-01

NASA is searching for a new name for the Advanced X-ray Astrophysics Facility (AXAF), currently scheduled for launch Dec. 3, 1998, from the Space Shuttle Columbia. AXAF is the third of NASA's Great Observatories, after the Hubble Space Telescope and the Compton Gamma Ray Observatory. Once in orbit around Earth, it will explore hot, turbulent regions in the universe where X-rays are produced. Dr. Alan Bunner, director of NASA's Structure and Evolution of the universe science program, will announce April 18 at the National Science Teacher's Association meeting in Las Vegas, NV, the start of a contest, open to people worldwide, to find a new name for the observatory. Entries should contain the name of a person (not living), place, or thing from history, mythology, or fiction. Contestants should describe in a few sentences why this choice would be a good name for AXAF. The name must not have been used before on space missions by NASA or other organizations or countries. The grand prize will be a trip to NASA's Kennedy Space Center in Cape Canaveral, FL, to see the launch of the satellite aboard the Space Shuttle. Ten runner-up prizes will be awarded and all entrants will receive an AXAF poster. The grand prize is sponsored by TRW Inc., AXAF's prime contractor. The AXAF Science Center in Cambridge, MA, will run the contest for NASA. NASA will announce the final selection of the winning name later this year. Entries also can be mailed to: AXAF Contest, AXAF Science Center, Office of Education and Public Outreach, 60 Garden Street, MS 83, Cambridge, MA 02138. Mailed entries must be postmarked no later than June 30, 1998. All entries must state a name for the mission, along with the reason the name would make a good choice. The observatory, now in the final stages of assembly and testing at TRW's facility in Redondo Beach, CA, is more than 45 feet long and weighs 10,500 pounds. AXAF is the largest and most powerful X-ray observatory ever constructed, and its images will be more than ten times sharper than any previous X-ray telescope. This focusing power of the telescope is equivalent to the ability to read a newspaper at a distance of half a mile. Cosmic X-rays are produced by violent events, such as when stars explode or galaxies collide. X-rays also are emitted by matter heated to many millions of degrees as it swirls toward a black hole. The only way to observe these and other extremely hot astronomical sources is with a space-based X-ray telescope. Editor's Note (Dec 21, 1998): How the Chandra X-ray Observatory got its name: See the details of the contest and winning essays and the press release.

X-Ray Mosaic of Milky Way Taken by the Chandra X-Ray Observatory

NASA Technical Reports Server (NTRS)

2001-01-01

The Chandra X-Ray Observatory (CXO) has made a sturning, high-energy panorama of the central regions of our Milky Way galaxy. The findings are an important step toward understanding the most active area of the Milky Way as well as other galaxies throughout the universe. This 400 by 900-light-year mosaic of several CXO images reveals hundreds of white dwarf stars, neutron stars, and black holes bathed in an incandescent fog of miltimillion-degree gas. The diffuse x-ray emission seems to be related to the turmoil and density of matter in the inner Milky Way. Stars are forming there at a much more rapid rate than in the galactic 'suburbs.' Many of the most massive stars in the galaxy are located in the galactic center and are furiously boiling off their outer layers in searing stellar winds. Supernova explosions are far more common in the region and send shock waves booming through the inner galaxy. The super massive black hole at the center of the galaxy is located inside the bright white patch in the center of the image. The colors indicate x-ray energy bands-red (low), green (medial), and blue (high). A supernova occurs when a massive star has used up its nuclear fuel and the pressure drops in the central core of the star. The matter in the core is crushed by gravity to higher and higher densities, and temperatures reach billions of degrees. Under these extreme conditions, nuclear reactions occur violently and catastrophically reversing the collapse. A thermonuclear shock wave races through the now expanding stellar debris, fusing lighter elements into heavier ones and producing a brilliant visual outburst. (Photo credit: NASA/UMass/D. Wang et al)

A Full Year's Chandra Exposure on Sloan Digital Sky Survey Quasars from the Chandra Multiwavelength Project

NASA Astrophysics Data System (ADS)

Green, Paul J.; Aldcroft, T. L.; Richards, G. T.; Barkhouse, W. A.; Constantin, A.; Haggard, D.; Karovska, M.; Kim, D.-W.; Kim, M.; Vikhlinin, A.; Anderson, S. F.; Mossman, A.; Kashyap, V.; Myers, A. D.; Silverman, J. D.; Wilkes, B. J.; Tananbaum, H.

2009-01-01

We study the spectral energy distributions and evolution of a large sample of optically selected quasars from the Sloan Digital Sky Survey that were observed in 323 Chandra images analyzed by the Chandra Multiwavelength Project. Our highest-confidence matched sample includes 1135 X-ray detected quasars in the redshift range 0.2 < z < 5.4, representing some 36 Msec of effective exposure. We provide catalogs of QSO properties, and describe our novel method of calculating X-ray flux upper limits and effective sky coverage. Spectroscopic redshifts are available for about 1/3 of the detected sample; elsewhere, redshifts are estimated photometrically. We detect 56 QSOs with redshift z > 3, substantially expanding the known sample. We find no evidence for evolution out to z ~ 5 for either the X-ray photon index Γ or for the ratio of optical/UV to X-ray flux αox. About 10% of detected QSOs show best-fit intrinsic absorbing columns greater than 1022 cm-2, but the fraction might reach ~1/3 if most nondetections are absorbed. We confirm a significant correlation between αox and optical luminosity, but it flattens or disappears for fainter (MB gsim -23) active galactic nucleus (AGN) alone. We report significant hardening of Γ both toward higher X-ray luminosity, and for relatively X-ray loud quasars. These trends may represent a relative increase in nonthermal X-ray emission, and our findings thereby strengthen analogies between Galactic black hole binaries and AGN. For uniformly selected subsamples of narrow-line Seyfert 1s and narrow absorption line QSOs, we find no evidence for unusual distributions of either αox or Γ.

Chandra and Swift Observations of Unidentified Fermi-LAT Objects

NASA Astrophysics Data System (ADS)

Donato, Davide; Cheung, T.; Gehrels, N.

2010-03-01

In the last year we targeted some of the unidentified Fermi-LAT objects (UFOs) at high Galactic latitude with Chandra and Swift in order to determine the basic properties (positions, fluxes, hardness ratios) of all X-ray sources within the Fermi-LAT localization circles. These satellites enable us to detect the X-ray conterparts with a flux limit that is at least an order of magnitude lower than achieved in extant RASS data and to further follow-up at other wavelengths, with the ultimate goal to reveal the nature of these enigmatic gamma-ray sources. Here we present the results obtained with 5 Chandra pointings of high Galactic latitude UFOs in the Fermi-LAT 3-months bright source list. The association of detected X-ray sources within the improved 11-months Fermi-LAT localization circles with available optical and radio observations is discussed.

Probing Deep into a Young PWN: Chandra Observations of 3C 58

NASA Astrophysics Data System (ADS)

Slane, P.; Helfand, D. J.; van der Swaluw, E.; Murray, S. S.

2004-08-01

Believed to have formed in a supernova explosion in 1181 CE, the pulsar wind nebula (PWN) 3C 58 is the Medieval sibling of the Crab Nebula. Yet its size, spectrum, and luminosity all differ dramatically from those of the Crab, raising the question of just how similar these and related systems really are. Here we present an investigation of the spectral and spatial structure of the X-ray emission from 3C 58 based on a 350 ks observation with the Chandra X-ray Observatory. This deep image, obtained as part of the Chandra Large Project program, reveals new information on nearly all spatial scales in the PWN. On the smallest scales we derive an improved limit for the surface temperature of the central neutron star (NS), confirming the need for rapid, nonstandard cooling in the stellar interior. We further provide evidence consistent with detection of emission from a light element atmosphere with a slightly lower temperature. Surrounding the NS, a toroidal structure with a jet is resolved, consistent with earlier measurements and indicative of an east-west orientation for the projected rotation axis of the pulsar. A complex of loop-like X-ray filaments fills the nebula interior. Their origin is unknown, but we suggest that they may be related to kink instabilities in the inner toroidal magnetic field of the PWN. The emission from the interior of the PWN, including the pulsar, jet, and filaments, is primarily nonthermal in nature. The power law index steepens with radius, but appears to also show small azimuthal variations. The outermost regions of the nebula require a thermal emission component, confirming the presence of an ejecta-rich swept-up shell. This work was supported in part by NASA Contract NAS8-39073 and Grant GO0-1117A.

MASSIM, the Milli-Arc-Second Structure Imager

NASA Technical Reports Server (NTRS)

Skinner, Gerry

2008-01-01

The MASSIM (Milli-Arc-Second Structure Imager) mission will use a set of achromatic diffractive-refractive Fresnel lenses to achieve imaging in the X-ray band with unprecedented angular resolution. It has been proposed for study within the context of NASA's "Astrophysics Strategic Mission Concept Studies" program. Lenses on an optics spacecraft will focus 5-11 keV X-rays onto detectors on a second spacecraft flying in formation 1000 km away. It will have a point-source sensitivity comparable with that of the current generation of major X-ray observatories (Chandra, XMM-Newton) but an angular resolution some three orders of magnitude better. MASSIM is optimized for the study of jets and other phenomena that occur in the immediate vicinity of black holes and neutron stars. It can also be used for studying other phenomena on the milli-arc-second scale, such as those involving proto-stars, the surfaces and surroundings of nearby active stars and interacting winds.

Chandra Contributes to ESA's Integral Detection of Closest Gamma-Ray Burst

NASA Astrophysics Data System (ADS)

2004-08-01

A gamma-ray burst detected by ESA's Integral gamma-ray observatory on 3 December 2003 has been thoroughly studied for months by an armada of space and ground-based observatories. Astronomers have now concluded that this event, called GRB 031203, is the closest cosmic gamma-ray burst on record, and also the faintest. This also suggests that an entire population of sub-energetic gamma-ray bursts has so far gone unnoticed. Cosmic gamma-ray bursts (GRBs) are flashes of gamma rays that can last from less than a second to a few minutes and occur at random positions in the sky. A large fraction of them is thought to result when a black hole is created from a dying star in a distant galaxy. Astronomers believe that a hot disc surrounding the black hole, made of gas and matter falling onto it, somehow emits an energetic beam parallel to the axis of rotation. According to the simplest picture, all GRBs should emit similar amounts of gamma-ray energy. The fraction of it detected at Earth should then depend on the 'width' (opening angle) and orientation of the beam as well as on the distance. The energy received should be larger when the beam is narrow or points towards us and smaller when the beam is broad or points away from us. New data collected with ESA's high energy observatories, Integral and XMM-Newton, now show that this picture is not so clear-cut and that the amount of energy emitted by GRBs can vary significantly. "The idea that all GRBs spit out the same amount of gamma rays, or that they are 'standard candles' as we call them, is simply ruled out by the new data," said Dr Sergey Sazonov, from the Space Research Institute of the Russian Academy of Sciences, Moscow (Russia) and the Max-Planck Institute for Astrophysics, Garching near Munich (Germany). Sazonov and an international team of researchers studied the GRB detected by Integral on 3 December 2003 and given the code-name of GRB 031203. Within a record 18 seconds of the burst, the Integral Burst Alert System had pinpointed the approximate position of GRB 031203 in the sky and sent the information to a network of observatories around the world. A few hours later one of them, ESA's XMM-Newton, determined a much more precise position for GRB 031203 and detected a rapidly fading X-ray source, which was subsequently seen by radio and optical telescopes on the ground. This wealth of data allowed astronomers to determine that GRB 031203 went off in a galaxy less than 1300 million light years away, making it the closest GRB ever observed. Even so, the way in which GRB 031203 dimmed with time and the distribution of its energy were not different from those of distant GRBs. Then, scientists started to realise that the concept of the 'standard candle' may not hold. "Being so close should make GRB 031203 appear very bright, but the amount of gamma-rays measured by Integral is about one thousand times less than what we would normally expect from a GRB," Sazonov said. A burst of gamma rays observed in 1998 in a closer galaxy appeared even fainter, about one hundred times less bright than GRB 031203. Astronomers, however, could not conclusively tell whether that was a genuine GRB because the bulk of its energy was emitted mostly as X-rays instead of gamma-rays. The work of Sazonov's team on GRB 031203 now suggests that intrinsically fainter GRBs can indeed exist. A team of US astronomers, coordinated by Alicia Soderberg from the California Institute of Technology, Pasadena (USA), studied the 'afterglow' of GRB 031203 and gave further support to this conclusion. The afterglow, emitted when a GRB's blastwave shocks the diffuse medium around it, can last weeks or months and progressively fades away. Using NASA's Chandra X-ray Observatory, Soderberg and her team saw that the X-ray brightness of the afterglow was about one thousand times fainter than that of typical distant GRBs. The team's observations with the Very Large Array telescope of the National Radio Astronomy Observatory in Socorro (USA) also revealed a source dimmer than usual. Sazonov and Soderberg explain that their teams looked carefully for signs that GRB 031203 could be tilted in such a way that most of its energy would escape Integral's detection. However, as Sazonov said, "the fact that most of the energy that we see is emitted in the gamma-ray domain, rather than in the X-rays, means that we are seeing the beam nearly on axis." It is, therefore, unlikely that much of its energy output can go unnoticed. This discovery suggests the existence of a new population of GRBs much closer but also dimmer than the majority of those known so far, which are very energetic but distant. Objects of this type may also be very numerous and thus produce more frequent bursts. The bulk of this population has so far escaped our attention because it lies at the limit of detection with past and present instruments. Integral, however, may be just sensitive enough to reveal a few more of them in the years to come. These could be just the tip of the iceberg and future gamma-ray observatories, such as the planned NASA's Swift mission, should be able to extend this search to GRBs of much lower energy, where many more of them are expected. NASA's Marshall Space Flight Center, Huntsville, Alabama, manages the Chandra programme for the Office of Space Science, NASA Headquarters, Washington DC, USA. Northrop Grumman of Redondo Beach, California, formerly TRW Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Massachusetts. Images and additional information about this result are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Color Composite Image of the Supernova Remnant

NASA Technical Reports Server (NTRS)

2000-01-01

This image is a color composite of the supernova remnant E0102-72: x-ray (blue), optical (green), and radio (red). E0102-72 is the remnant of a star that exploded in a nearby galaxy known as the Small Magellanic Cloud. The star exploded outward at speeds in excess of 20 million kilometers per hour (12 million mph) and collided with surrounding gas. This collision produced two shock waves, or cosmic sonic booms, one traveling outward, and the other rebounding back into the material ejected by the explosion. The radio image, shown in red, was made using the Australia Telescope Compact Array. The radio waves are due to extremely high-energy electrons spiraling around magnetic field lines in the gas and trace the outward moving shock wave. The Chandra X-ray Observatory image, shown in blue, shows gas that has been heated to millions of degrees by the rebounding, or reverse shock wave. The x-ray data show that this gas is rich in oxygen and neon. These elements were created by nuclear reactions inside the star and hurled into space by the supernova. The Hubble Space Telescope optical image, shown in green, shows dense clumps of oxygen gas that have 'cooled' to about 30,000 degrees. Photo Credit: X-ray (NASA/CXC/SAO); optical (NASA/HST): radio: (ACTA)

Resolving the X-ray emission from the Lyman-continuum emitting galaxy Tol 1247-232

NASA Astrophysics Data System (ADS)

Kaaret, P.; Brorby, M.; Casella, L.; Prestwich, A. H.

2017-11-01

Chandra observations of the nearby, Lyman-continuum (LyC) emitting galaxy Tol 1247-232 resolve the X-ray emission and show that it is dominated by a point-like source with a hard spectrum (Γ = 1.6 ± 0.5) and a high luminosity [(9 ± 2) × 1040 erg s- 1]. Comparison with an earlier XMM-Newton observation shows flux variation of a factor of 2. Hence, the X-ray emission likely arises from an accreting X-ray source: a low-luminosity active galactic nucleus or one or a few X-ray binaries. The Chandra X-ray source is similar to the point-like, hard spectrum (Γ = 1.2 ± 0.2), high-luminosity (1041 erg s- 1) source seen in Haro 11, which is the only other confirmed LyC-emitting galaxy that has been resolved in X-rays. We discuss the possibility that accreting X-ray sources contribute to LyC escape.

Thin Mirror Shaping Technology for High-Throughput X-ray Telescopes

NASA Astrophysics Data System (ADS)

Schattenburg, Mark

This proposal is submitted to the NASA Research Opportunities in Space and Earth Sciences program (ROSES-2012) in response to NASA Research Announcement NNH12ZDA001N- APRA. It is targeted to the Astronomy and Astrophysics Research and Analysis (APRA) program element under the Supporting Technology category. Powerful x-ray telescope mirrors are critical components of a raft of small-to-large mission concepts under consideration by NASA. The science questions addressed by these missions have certainly never been more compelling and the need to fulfill NASA s core missions of exploring the universe and strengthening our nation s technology base has never been greater. Unfortunately, budgetary constraints are driving NASA to consider the cost/benefit and risk factors of new missions more carefully than ever. New technology for producing x-ray telescopes with increased resolution and collecting area, while holding down cost, are key to meeting these goals and sustaining a thriving high-energy astrophysics enterprise in the US. We propose to develop advanced technology which will lead to thin-shell x-ray telescope mirrors rivaling the Chandra x-ray telescope in spatial resolution but with 10-100X larger area all at significantly reduced weight, risk and cost. The proposed effort builds on previous research at MIT and complements NASA-supported research at other institutions. We are currently pursuing two thin-mirror technology development tracks which we propose to extend and accelerate with NASA support. The first research track utilizes rapidly-maturing thermal glass slumping technology which uses porous ceramic air-bearing mandrels to shape glass mirrors without touching, thus avoiding surface-induced mid-range spatial frequency ripples. A second research track seeks to remove any remaining mid- to long-range errors in mirrors by using scanning ion-beam implant to impart small, highly deterministic and very stable amounts of stress into thin glass, utilizing local bending moments to correct mirror shape. Preliminary results from our lab demonstrate the simplicity, specificity, and exquisite sensitivity of this technique on silicon and glass wafers. We believe that the combination of these new technologies has the potential to revolutionize thin mirror shaping technology and will enable a renaissance in high-energy astrophysics.

The Chandra Source Catalog 2.0: Estimating Source Fluxes

NASA Astrophysics Data System (ADS)

Primini, Francis Anthony; Allen, Christopher E.; Miller, Joseph; Anderson, Craig S.; Budynkiewicz, Jamie A.; Burke, Douglas; Chen, Judy C.; Civano, Francesca Maria; D'Abrusco, Raffaele; Doe, Stephen M.; Evans, Ian N.; Evans, Janet D.; Fabbiano, Giuseppina; Gibbs, Danny G., II; Glotfelty, Kenny J.; Graessle, Dale E.; Grier, John D.; Hain, Roger; Hall, Diane M.; Harbo, Peter N.; Houck, John C.; Lauer, Jennifer L.; Laurino, Omar; Lee, Nicholas P.; Martínez-Galarza, Juan Rafael; McCollough, Michael L.; McDowell, Jonathan C.; McLaughlin, Warren; Morgan, Douglas L.; Mossman, Amy E.; Nguyen, Dan T.; Nichols, Joy S.; Nowak, Michael A.; Paxson, Charles; Plummer, David A.; Rots, Arnold H.; Siemiginowska, Aneta; Sundheim, Beth A.; Tibbetts, Michael; Van Stone, David W.; Zografou, Panagoula

2018-01-01

The Second Chandra Source Catalog (CSC2.0) will provide information on approximately 316,000 point or compact extended x-ray sources, derived from over 10,000 ACIS and HRC-I imaging observations available in the public archive at the end of 2014. As in the previous catalog release (CSC1.1), fluxes for these sources will be determined separately from source detection, using a Bayesian formalism that accounts for background, spatial resolution effects, and contamination from nearby sources. However, the CSC2.0 procedure differs from that used in CSC1.1 in three important aspects. First, for sources in crowded regions in which photometric apertures overlap, fluxes are determined jointly, using an extension of the CSC1.1 algorithm, as discussed in Primini & Kashyap (2014ApJ...796…24P). Second, an MCMC procedure is used to estimate marginalized posterior probability distributions for source fluxes. Finally, for sources observed in multiple observations, a Bayesian Blocks algorithm (Scargle, et al. 2013ApJ...764..167S) is used to group observations into blocks of constant source flux.In this poster we present details of the CSC2.0 photometry algorithms and illustrate their performance in actual CSC2.0 datasets.This work has been supported by NASA under contract NAS 8-03060 to the Smithsonian Astrophysical Observatory for operation of the Chandra X-ray Center.

A High Definition View of AGN Feedback: Chandra Imaging of Nearby Seyfert Galaxies

NASA Astrophysics Data System (ADS)

Wang, Junfeng; Fabbiano, G.; Risaliti, G.; Elvis, M.; Karovska, M.; Zezas, A.; Mundell, C. G.

2010-03-01

To improve the physics of AGN feedback, it is crucial to evaluate the true role of outflows on galaxy evolution observationally. I will present new results from Chandra spectral imaging of nearby Seyfert galaxies, which offer unique opportunities to examine feedback in action in much greater detail than at high redshift. Exploiting Chandra's highest possible resolution, we are able to study structures in NGC 4151 on spatial scales of 0.5 arcsec (30 pc), showing an extended X-ray morphology overall consistent with the optical NLR. We find that most of the NLR clouds in NGC 4151 have [OIII] to soft X-ray ratio consistent with the values observed in NLRs of some Seyfert 2 galaxies, which indicates a uniform ionization parameter even at large radii. We examine various X-ray emission mechanisms of the radio jet and consider thermal emission from interaction between radio outflow and the NLR clouds the most probable origin for the X-ray emission associated with the jet.

PSR J2022 plus 3842: An Energetic Radio and X-Ray Pulsar Associated with SNR G76.9 plus 1.0

NASA Technical Reports Server (NTRS)

Arzoumanian, Z.; Gotthelf, E. V.; Ransom, S. M.; Kothes, R.; Landecker, T. L.

2010-01-01

We present Chandra X-ray Observatory, Robert C. Byrd Green Bank Radio Telescope (GBT), and Rossi X-ray Timing Explorer (RXTE) observations directed toward the radio supernova remnant (SNR) G76.9+1.0. The Chandra investigation reveals a hard, unresolved X-ray source coincident with the midpoint of the double-lobed radio morphology and surrounded by faint, compact X-ray nebulosity. These features suggest that an energetic neutron star is powering a pulsar wind nebula (PWN) seen in synchrotron emission. Indeed, the spatial relationship of the X-ray and radio emissions is remarkably similar to the extended emission around the Vela pulsar. A follow-up pulsation search with the GBT uncovered a highly-dispersed (DM = 427 +/- 1 pc/cu cm) and highly-scattered pulsar with a period of 24 ms. Its subsequently measured spin-down rate implies a characteristic age T(sub c) = 8.9 kyr, making PSR J2022+3842 the most rapidly rotating young radio pulsar known. With a spin-down luminosity E = 1.2 x 10(exp 38) erg/s, it is the second-most energetic Galactic pulsar known, after the Crab pulsar. The 24-ms pulsations have also been detected in the RXTE observation; the combined Chandra and RXTE spectral fit suggests that the Chandra point-source emission is virtually 100% pulsed. The 2-16 keV spectrum of the narrow (0.06 cycles FWHM) pulse is well-fitted by an absorbed power-law model with column density N(sub H) = (1.7 +/- 0.5) x 10(exp 22)/sq cm and photon index Gamma = 1.0 +/- 0.2, strongly suggestive of magnetospheric emission. For an assumed distance of 10 kpc, the 2-10 keV luminosity of L(sub X) = 6.9 x 10(exp 33) erg/s suggests one of the lowest known X-ray conversion efficiencies L(sub X)/ E = 5.8 x 10(exp -5), similar to that of the Vela pulsar. Finally, the PWN around PSR J2022+3842 revealed by Chandra is also underluminous, with F(sub PWN)/ F(sub PSR) < or approx.1 in the 2-10 keV band, a further surprise given the pulsar's high spin-down luminosity.

X-ray Optics Development at MSFC

NASA Technical Reports Server (NTRS)

Sharma, Dharma P.

2017-01-01

Development of high resolution focusing telescopes has led to a tremendous leap in sensitivity, revolutionizing observational X-ray astronomy. High sensitivity and high spatial resolution X-ray observations have been possible due to use of grazing incidence optics (paraboloid/hyperboloid) coupled with high spatial resolution and high efficiency detectors/imagers. The best X-ray telescope flown so far is mounted onboard Chandra observatory launched on July 23,1999. The telescope has a spatial resolution of 0.5 arc seconds with compatible imaging instruments in the energy range of 0.1 to 10 keV. The Chandra observatory has been responsible for a large number of discoveries and has provided X-ray insights on a large number of celestial objects including stars, supernova remnants, pulsars, magnetars, black holes, active galactic nuclei, galaxies, clusters and our own solar system.

History of Chandra X-Ray Observatory

NASA Image and Video Library

2000-12-04

Chandra X-Ray Observatory provided this composite X-ray (blue and green) and optical (red) image of the active galaxy NGC 1068 showing gas blowing away in a high-speed wind from the vicinity of a central supermassive black hole. Regions of intense star formation in the irner spiral arms of the galaxy are highlighted by both optical and x-ray emissions. A doughnut shaped cloud of cool gas and dust surrounding the black hole, known as the torus, appears as the elongated white spot . It has has a mass of about 5 million suns and is estimated to extend from within a few light years of the black hole out to about 300 light years.

A Search for the Location of the Gamma-ray Flares

NASA Technical Reports Server (NTRS)

Weisskopf, Martin

2012-01-01

Subsequent to announcements by the AGILE and by the Fermi-LAT teams of the discovery of gamma-ray flares from the Crab Nebula in the fall of 2010, an international collaboration has been monitoring X-Ray emission from the Crab on a regular basis using the Chandra X-Ray Observatory. Observations occurred typically once per month when viewing constraints allow. A notable exception occurred in 2011 April, when we triggered a set of Chandra Target-of-Opportunity observations in conjunction with the brightest -ray flare yet observed. The aim of the program is to characterize in depth the X-Ray variations within the Nebula, and, if possible, to much more precisely locate the origin of the -ray flares. We briefly summarize the April X-ray observations and the information we have gleaned to date.

A Magnetron Sputter Deposition System for the Development of X-Ray Multilayer Optics

NASA Technical Reports Server (NTRS)

Broadway, David

2015-01-01

The project objective is to establish the capability to deposit multilayer structures for x-ray, neutron, and extreme ultraviolet (EUV) optic applications through the development of a magnetron sputtering deposition system. A specific goal of this endeavor is to combine multilayer deposition technology with the replication process in order to enhance NASA Marshall Space Flight Center's (MSFC's) position as a world leader in the design of innovative x-ray instrumentation through the development of full shell replicated multilayer optics. The development of multilayer structures are absolutely necessary in order to advance the field of x-ray astronomy by pushing the limit for observing the universe to ever-increasing photon energies (i.e., up to 200 keV or higher), well beyond Chandra's (approx.10 keV) and NuStar's (approx.75 keV) capability. The addition of multilayer technology would significantly enhance the x-ray optics capability at MSFC and allow NASA to maintain its world leadership position in the development, fabrication, and design of innovative x-ray instrumentation, which would be the first of its kind by combining multilayer technology with the mirror replication process. This marriage of these technologies would allow astronomers to see the universe in a new light by pushing to higher energies that are out of reach with today's instruments. To this aim, a magnetron vacuum sputter deposition system for the deposition of novel multilayer thin film x-ray optics is proposed. A significant secondary use of the vacuum deposition system includes the capability to fabricate multilayers for applications in the field of EUV optics for solar physics, neutron optics, and x-ray optics for a broad range of applications including medical imaging.