The High Energy Astronomy Observatory X-ray Telescope

NASA Technical Reports Server (NTRS)

Miller, R.; Austin, G.; Koch, D.; Jagoda, N.; Kirchner, T.; Dias, R.

1978-01-01

The High Energy Astronomy Observatory-Mission B (HEAO-B) is a satellite observatory for the purpose of performing a detailed X-ray survey of the celestial sphere. Measurements will be made of stellar radiation in the range 0.2 through 20 keV. The primary viewing requirement is to provide final aspect solution and internal alignment information to correlate an observed X-ray image with the celestial sphere to within one-and-one-half arc seconds. The Observatory consists of the HEAO Spacecraft together with the X-ray Telescope. The Spacecraft provides the required attitude control and determination system, data telemetry system, space solar power system, and interface with the launch vehicle. The X-ray Telescope includes a high resolution mirror assembly, optical bench metering structure, X-ray detectors, detector positioning system, detector electronics and aspect sensing system.

X-Ray Astronomy Discovery Experiments, III*

NASA Astrophysics Data System (ADS)

Fisher, P. C.

2011-04-01

The first paper established the existence of concurrent discovery experiments by Riccardo Giacconi and myself at the start of x-ray astronomy.footnotetextR. Giacconi et al., Phys. Rev. Lett. 9, 439 (1962).^,footnotetextP. C. Fisher et al., Quasars and High Energy Astronomy including Proceedings of the 2^nd Texas Symposium on Relativistic Astrophysics 15 - 19 December 1964 (K. N. Douglas et. al., eds.) Gordon and Breach Science Publishers, New York, p. 253 (1969).^,footnotetextP. C. Fisher, BAPS 53 No. 2, 165 (2008). Paper II footnotetextP.C. Fisher, http://www.aps.org/units/fhp/index.cfm plus FHP link to April 2009 presentation H14.00006. described some acts by some individuals/institutions over four decades that may have caused the illusion that I had not made a discovery. Some additional data about this illusion, and the first possible measurement of x-ray emission from a black hole, will be presented. This paper's primary goal is for the American Physical Society to have Giacconi comment on several questions of a historical nature. [4pt] *Work supported by NASA contracts NAS5-1174 and NASw-909, the Lockheed Independent Research Program, and Ruffner Associates.

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.

My 35 Years in X-ray Astronomy (Not)

NASA Astrophysics Data System (ADS)

Urry, C. M.

2013-01-01

My contact with X-ray astronomy started with HEAO-1, just before launch, when I was a summer student at the Harvard/Smithsonian Center for Astrophysics. Another summer position followed at NASA’s Goddard Space Flight Center, where I later did my PhD thesis on HEAO1 and HEAO2 (and IUE) data. Next I was a postdoc at MIT working with Einstein and Ginga observations, and I then continued observing blazars and other AGN with ASCA, Exosat, RXTE, Chandra, XMM, Swift, Suzaku, and Fermi. I have also witnessed or participated in many proposals for future X-ray missions. Fortunately for the audience, I will not recall all these times... So many photons, so little time! But this long history does mean I met most of the great figures in X-ray astronomy when they were young and I probably have embarrassing stories to tell about many of them. For my 2-minute vignette in a panel discussion, I will entertain you with one of the more interesting (and pertinent) memories. Acknowledgement: Thank you to all my high-energy astrophysics colleagues, who taught me a great deal, and to NASA for the hit parade of high-energy missions.

Next-Generation X-Ray Astronomy

NASA Technical Reports Server (NTRS)

White, Nicholas E.

2011-01-01

The future timing capabilities in X-ray astronomy will be reviewed. This will include reviewing the missions in implementation: Astro-H, GEMS, SRG, and ASTROSAT; those under study: currently ATHENA and LOFT; and new technologies that may enable future missions e.g. Lobster eye optics. These missions and technologies will bring exciting new capabilities across the entire time spectrum from micro-seconds to years that e.g. will allow us to probe close to the event horizon of black holes and constrain the equation of state of neutron stars.

Recommended Priorities for NASA's Gamma Ray Astronomy Program 1999-2013

NASA Technical Reports Server (NTRS)

Carol, Ladd

1999-01-01

The Gamma-Ray Astronomy Program Working Group (GRAPWG) recommends priorities for the NASA Gamma-Ray Astronomy Program. The highest priority science topic is nuclear astrophysics and sites of gamma ray line emission. Other high priority topics are gamma ray bursts, hard x-ray emission from accreting black holes and neutron stars, the Advanced Compton Telescope (ACT), the High-resolution Spectroscopic Imager (HSI), and the Energetic X-ray Imaging Survey Telescope (EXIST). The recommendations include special consideration for technology development, TeV astronomy, the ultra-long duration balloon (ULDB) program, the International Space Station, optical telescope support, and data analysis and theory.

Data needs for X-ray astronomy satellites

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

Kallman, T.

I review the current status of atomic data for X-ray astronomy satellites. This includes some of the astrophysical issues which can be addressed, current modeling and analysis techniques, computational tools, the limitations imposed by currently available atomic data, and the validity of standard assumptions. I also discuss the future: challenges associated with future missions and goals for atomic data collection.

Research in space science and technology. [including X-ray astronomy and interplanetary plasma physics

NASA Technical Reports Server (NTRS)

Beckley, L. E.

1977-01-01

Progress in various space flight research programs is reported. Emphasis is placed on X-ray astronomy and interplanetary plasma physics. Topics covered include: infrared astronomy, long base line interferometry, geological spectroscopy, space life science experiments, atmospheric physics, and space based materials and structures research. Analysis of galactic and extra-galactic X-ray data from the Small Astronomy Satellite (SAS-3) and HEAO-A and interplanetary plasma data for Mariner 10, Explorers 47 and 50, and Solrad is discussed.

Research in X-ray Astronomy

NASA Technical Reports Server (NTRS)

1997-01-01

This research grant supported an active sounding rocket program at Penn State University over a period of over 10 years. During this period, the grant supported at least 8 graduate students in Astronomy & Astrophysics for at least a portion of their research. During the same period, our group was involved in seven sounding rocket flights, launched from White Sands, New Mexico, and from Woomera, Australia. Most of these rocket flights, and most of the work supported by this grant, involved the use of X-ray CCD cameras. The first X-ray CCD camera ever flown in space was our sounding rocket observation of SN1987A (flight 36.030 in 1987). Subsequent flights utilized improved CCD detectors, culminating in the'state-of-the-art EEV detector developed for our CUBIC mission, which was flown on 36.093 last May. Data from the last three flights, which observed the diffuse X-ray background with CCDS, include detection of the OVII He(alpha) line in the high latitude diffuse background and detection of the Mg XI He(alpha) line in the North Polar Spur. These results have been reported at meetings of the American Astronomical Society and the SPIE. The analysis of flights 36.092 and 36.106 is part of Jeff Mendenhall's PhD thesis and will be published in the Astrophysical Journal next year. The 36.093 data are currently being analyzed by PhD student Laura Cawley. From 1990 to 1996 this grant supported our development and launch of the CUBIC instrument on the SAC-B satellite, which was designed to measure the spectrum of the soft X-ray diffuse background with moderate energy resolution and high S/N ratio. Unfortunately, this mission terminated shortly after launch due to a failure of the Pegasus XL launch vehicle. This work resulted in publication of 4 papers in the SPIE Proceedings and four others in refereed journals, in addition to several other conference proceedings and contributed papers. In addition to the CCD flights described above, this grant has supported preliminary

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 emergence of x-ray astronomy, neutron stars and black holes

NASA Astrophysics Data System (ADS)

Gursky, H.

2003-10-01

Remo Ruffini's professional career began just as X-ray astronomy began its second decade. His paper on the maximum mass of cold stars was instrumental in establishing Cygnus X-1 as a black hole. The idea of black holes and neutron stars had originated more than 40 years earlier based on considerations of white dwarfs. It was not until the explosion of technology that emerged after World War II that the observational evidence developed which enabled establishing the existence of these objects. The discovery of X-ray sources in 1962 and the subsequent maturing of that discipline and of radio astronomy were the key elements. By now a large number of stellar objects are found to be neutron stars and black holes.

Resolve Instrument on X-ray Astronomy Recovery Mission (XARM)

NASA Astrophysics Data System (ADS)

Ishisaki, Y.; Ezoe, Y.; Yamada, S.; Ichinohe, Y.; Fujimoto, R.; Takei, Y.; Yasuda, S.; Ishida, M.; Yamasaki, N. Y.; Maeda, Y.; Tsujimoto, M.; Iizuka, R.; Koyama, S.; Noda, H.; Tamagawa, T.; Sawada, M.; Sato, K.; Kitamoto, S.; Hoshino, A.; Brown, G. V.; Eckart, M. E.; Hayashi, T.; Kelley, R. L.; Kilbourne, C. A.; Leutenegger, M. A.; Mori, H.; Okajima, T.; Porter, F. S.; Soong, Y.; McCammon, D.; Szymkowiak, A. E.

2018-04-01

The X-ray Astronomy Recovery Mission (XARM) is a recovery mission of ASTRO-H/Hitomi, which is expected to be launched in Japanese Fiscal Year of 2020 at the earliest. The Resolve instrument on XARM consists of an array of 6 × 6 silicon-thermistor microcalorimeters cooled down to 50 mK and a high-throughput X-ray mirror assembly with the focal length of 5.6 m. Hitomi was launched into orbit in February 2016 and observed several celestial objects, although the operation of Hitomi was terminated in April 2016. The soft X-ray spectrometer (SXS) on Hitomi demonstrated high-resolution X-ray spectroscopy of 5 eV FWHM in orbit for most of the pixels. The Resolve instrument is planned to mostly be a copy of the Hitomi SXS and soft X-ray telescope designs, though several changes are planned based on the lessons learned from Hitomi. We report a brief summary of the SXS performance and the status of the Resolve instrument.

Soft X-ray astronomy using grazing incidence optics

NASA Technical Reports Server (NTRS)

Davis, John M.

1989-01-01

The instrumental background of X-ray astronomy with an emphasis on high resolution imagery is outlined. Optical and system performance, in terms of resolution, are compared and methods for improving the latter in finite length instruments described. The method of analysis of broadband images to obtain diagnostic information is described and is applied to the analysis of coronal structures.

X-Ray Astronomy

NASA Technical Reports Server (NTRS)

Wu, S. T.

2000-01-01

Dr. S. N. Zhang has lead a seven member group (Dr. Yuxin Feng, Mr. XuejunSun, Mr. Yongzhong Chen, Mr. Jun Lin, Mr. Yangsen Yao, and Ms. Xiaoling Zhang). This group has carried out the following activities: continued data analysis from space astrophysical missions CGRO, RXTE, ASCA and Chandra. Significant scientific results have been produced as results of their work. They discovered the three-layered accretion disk structure around black holes in X-ray binaries; their paper on this discovery is to appear in the prestigious Science magazine. They have also developed a new method for energy spectral analysis of black hole X-ray binaries; four papers on this topics were presented at the most recent Atlanta AAS meeting. They have also carried Monte-Carlo simulations of X-ray detectors, in support to the hardware development efforts at Marshall Space Flight Center (MSFC). These computation-intensive simulations have been carried out entirely on the computers at UAH. They have also carried out extensive simulations for astrophysical applications, taking advantage of the Monte-Carlo simulation codes developed previously at MSFC and further improved at UAH for detector simulations. One refereed paper and one contribution to conference proceedings have been resulted from this effort.

X-ray astronomical spectroscopy

NASA Technical Reports Server (NTRS)

Holt, Stephen S.

1987-01-01

The contributions of the Goddard group to the history of X-ray astronomy are numerous and varied. One role that the group has continued to play involves the pursuit of techniques for the measurement and interpretation of the X-ray spectra of cosmic sources. The latest development is the selection of the X-ray microcalorimeter for the Advanced X-ray Astrophysics Facility (AXAF) study payload. This technology is likely to revolutionize the study of cosmic X-ray spectra.

The Fabrication of Replicated Optics for Hard X-Ray Astronomy

NASA Technical Reports Server (NTRS)

Speegle, C. O.; Ramsey, B. D.; Engelhaupt, D.

2000-01-01

We describe the fabrication process for producing shallow-graze-angle mirrors for hard x-ray astronomy. This presentation includes the generation of the necessary super-polished mandrels, their metrology, and the subsequent mirror shell electroforming and testing.

Design and modeling of an additive manufactured thin shell for x-ray astronomy

NASA Astrophysics Data System (ADS)

Feldman, Charlotte; Atkins, Carolyn; Brooks, David; Watson, Stephen; Cochrane, William; Roulet, Melanie; Willingale, Richard; Doel, Peter

2017-09-01

Future X-ray astronomy missions require light-weight thin shells to provide large collecting areas within the weight limits of launch vehicles, whilst still delivering angular resolutions close to that of Chandra (0.5 arc seconds). Additive manufacturing (AM), also known as 3D printing, is a well-established technology with the ability to construct or `print' intricate support structures, which can be both integral and light-weight, and is therefore a candidate technique for producing shells for space-based X-ray telescopes. The work described here is a feasibility study into this technology for precision X-ray optics for astronomy and has been sponsored by the UK Space Agency's National Space Technology Programme. The goal of the project is to use a series of test samples to trial different materials and processes with the aim of developing a viable path for the production of an X-ray reflecting prototype for astronomical applications. The initial design of an AM prototype X-ray shell is presented with ray-trace modelling and analysis of the X-ray performance. The polishing process may cause print-through from the light-weight support structure on to the reflecting surface. Investigations in to the effect of the print-through on the X-ray performance of the shell are also presented.

[Development of Nanotechnology for X-Ray Astronomy Instrumentation

NASA Technical Reports Server (NTRS)

Schattenburg, Mark L.

2004-01-01

This Research Grant provides support for development of nanotechnology for x-ray astronomy instrumentation. MIT has made significant progress in several development areas. In the last year we have made considerable progress in demonstrating the high-fidelity patterning and replication of x-ray reflection gratings. We developed a process for fabricating blazed gratings in silicon with extremely smooth and sharp sawtooth profiles, and developed a nanoimprint process for replication. We also developed sophisticated new fixturing for holding thin optics during metrology without causing distortion. We developed a new image processing algorithm for our Shack-Hartmann tool that uses Zernike polynomials. This has resulted in much more accurate and repeatable measurements on thin optics.

UNDERSTANDING X-RAY STARS:. The Discovery of Binary X-ray Sources

NASA Astrophysics Data System (ADS)

Schreier, E. J.; Tananbaum, H.

2000-09-01

The discovery of binary X-ray sources with UHURU introduced many new concepts to astronomy. It provided the canonical model which explained X-ray emission from a large class of galactic X-ray sources: it confirmed the existence of collapsed objects as the source of intense X-ray emission; showed that such collapsed objects existed in binary systems, with mass accretion as the energy source for the X-ray emission; and provided compelling evidence for the existence of black holes. This model also provided the basis for explaining the power source of AGNs and QSOs. The process of discovery and interpretation also established X-ray astronomy as an essential sub-discipline of astronomy, beginning its incorporation into the mainstream of astronomy.

The ASTRO-H (Hitomi) X-Ray Astronomy Satellite

NASA Technical Reports Server (NTRS)

Takahashi, Tadayuki; Kokubun, Motohide; Mitsuda, Kazuhisa; Kelley, Richard; Ohashi, Takaya; Aharonian, Felix; Akamatsu, Hiroki; Akimoto, Fumie; Allen, Steve; Anabuki, Naohisa;

The ASTRO-H (Hitomi) x-ray astronomy satellite

NASA Astrophysics Data System (ADS)

Takahashi, Tadayuki; Kokubun, Motohide; Mitsuda, Kazuhisa; Kelley, Richard; Ohashi, Takaya; Aharonian, Felix; Akamatsu, Hiroki; Akimoto, Fumie; Allen, Steve; Anabuki, Naohisa; Angelini, Lorella; Arnaud, Keith; Asai, Makoto; Audard, Marc; Awaki, Hisamitsu; Axelsson, Magnus; Azzarello, Philipp; Baluta, Chris; Bamba, Aya; Bando, Nobutaka; Bautz, Marshall; Bialas, Thomas; Blandford, Roger; Boyce, Kevin; Brenneman, Laura; Brown, Greg; Bulbul, Esra; Cackett, Edward; Canavan, Edgar; Chernyakova, Maria; Chiao, Meng; Coppi, Paolo; Costantini, Elisa; de Plaa, Jelle; den Herder, Jan-Willem; DiPirro, Michael; Done, Chris; Dotani, Tadayasu; Doty, John; Ebisawa, Ken; Eckart, Megan; Enoto, Teruaki; Ezoe, Yuichiro; Fabian, Andrew; Ferrigno, Carlo; Foster, Adam; Fujimoto, Ryuichi; Fukazawa, Yasushi; Furuzawa, Akihiro; Galeazzi, Massimiliano; Gallo, Luigi; Gandhi, Poshak; Gilmore, Kirk; Giustini, Margherita; Goldwurm, Andrea; Gu, Liyi; Guainazzi, Matteo; Haas, Daniel; Haba, Yoshito; Hagino, Kouichi; Hamaguchi, Kenji; Harayama, Atsushi; Harrus, Ilana; Hatsukade, Isamu; Hayashi, Takayuki; Hayashi, Katsuhiro; Hayashida, Kiyoshi; Hiraga, Junko; Hirose, Kazuyuki; Hornschemeier, Ann; Hoshino, Akio; Hughes, John; Ichinohe, Yuto; Iizuka, Ryo; Inoue, Yoshiyuki; Inoue, Hajime; Ishibashi, Kazunori; Ishida, Manabu; Ishikawa, Kumi; Ishimura, Kosei; Ishisaki, Yoshitaka; Itoh, Masayuki; Iwata, Naoko; Iyomoto, Naoko; Jewell, Chris; Kaastra, Jelle; Kallman, Timothy; Kamae, Tuneyoshi; Kara, Erin; Kataoka, Jun; Katsuda, Satoru; Katsuta, Junichiro; Kawaharada, Madoka; Kawai, Nobuyuki; Kawano, Taro; Kawasaki, Shigeo; Khangulyan, Dmitry; Kilbourne, Caroline; Kimball, Mark; King, Ashley; Kitaguchi, Takao; Kitamoto, Shunji; Kitayama, Tetsu; Kohmura, Takayoshi; Kosaka, Tatsuro; Koujelev, Alex; Koyama, Katsuji; Koyama, Shu; Kretschmar, Peter; Krimm, Hans; Kubota, Aya; Kunieda, Hideyo; Laurent, Philippe; Lebrun, François; Lee, Shiu-Huang; Leutenegger, Maurice; Limousin, Olivier; Loewenstein, Michael; Long, Knox; Lumb, David; Madejski, Grzegorz; Maeda, Yoshitomo; Maier, Daniel; Makishima, Kazuo; Markevitch, Maxim; Masters, Candace; Matsumoto, Hironori; Matsushita, Kyoko; McCammon, Dan; McGuinness, Daniel; McNamara, Brian; Mehdipour, Missagh; Miko, Joseph; Miller, Jon; Miller, Eric; Mineshige, Shin; Minesugi, Kenji; Mitsuishi, Ikuyuki; Miyazawa, Takuya; Mizuno, Tsunefumi; Mori, Koji; Mori, Hideyuki; Moroso, Franco; Moseley, Harvey; Muench, Theodore; Mukai, Koji; Murakami, Hiroshi; Murakami, Toshio; Mushotzky, Richard; Nagano, Housei; Nagino, Ryo; Nakagawa, Takao; Nakajima, Hiroshi; Nakamori, Takeshi; Nakano, Toshio; Nakashima, Shinya; Nakazawa, Kazuhiro; Namba, Yoshiharu; Natsukari, Chikara; Nishioka, Yusuke; Nobukawa, Masayoshi; Nobukawa, Kumiko; Noda, Hirofumi; Nomachi, Masaharu; O'Dell, Steve; Odaka, Hirokazu; Ogawa, Hiroyuki; Ogawa, Mina; Ogi, Keiji; Ohno, Masanori; Ohta, Masayuki; Okajima, Takashi; Okamoto, Atsushi; Okazaki, Tsuyoshi; Ota, Naomi; Ozaki, Masanobu; Paerels, Frederik; Paltani, Stéphane; Parmar, Arvind; Petre, Robert; Pinto, Ciro; Pohl, Martin; Pontius, James; Porter, F. Scott; Pottschmidt, Katja; Ramsey, Brian; Reynolds, Christopher; Russell, Helen; Safi-Harb, Samar; Saito, Shinya; Sakai, Shin-ichiro; Sakai, Kazuhiro; Sameshima, Hiroaki; Sasaki, Toru; Sato, Goro; Sato, Yoichi; Sato, Kosuke; Sato, Rie; Sawada, Makoto; Schartel, Norbert; Serlemitsos, Peter; Seta, Hiromi; Shibano, Yasuko; Shida, Maki; Shidatsu, Megumi; Shimada, Takanobu; Shinozaki, Keisuke; Shirron, Peter; Simionescu, Aurora; Simmons, Cynthia; Smith, Randall; Sneiderman, Gary; Soong, Yang; Stawarz, Łukasz; Sugawara, Yasuharu; Sugita, Hiroyuki; Sugita, Satoshi; Szymkowiak, Andrew; Tajima, Hiroyasu; Takahashi, Hiromitsu; Takeda, Shin'ichiro; Takei, Yoh; Tamagawa, Toru; Tamura, Takayuki; Tamura, Keisuke; Tanaka, Takaaki; Tanaka, Yasuo; Tanaka, Yasuyuki; Tashiro, Makoto; Tawara, Yuzuru; Terada, Yukikatsu; Terashima, Yuichi; Tombesi, Francesco; Tomida, Hiroshi; Tsuboi, Yohko; Tsujimoto, Masahiro; Tsunemi, Hiroshi; Tsuru, Takeshi; Uchida, Hiroyuki; Uchiyama, Yasunobu; Uchiyama, Hideki; Ueda, Yoshihiro; Ueda, Shutaro; Ueno, Shiro; Uno, Shin'ichiro; Urry, Meg; Ursino, Eugenio; de Vries, Cor; Wada, Atsushi; Watanabe, Shin; Watanabe, Tomomi; Werner, Norbert; Wik, Daniel; Wilkins, Dan; Williams, Brian; Yamada, Takahiro; Yamada, Shinya; Yamaguchi, Hiroya; Yamaoka, Kazutaka; Yamasaki, Noriko; Yamauchi, Makoto; Yamauchi, Shigeo; Yaqoob, Tahir; Yatsu, Yoichi; Yonetoku, Daisuke; Yoshida, Atsumasa; Yuasa, Takayuki; Zhuravleva, Irina; Zoghbi, Abderahmen

2016-07-01

The Hitomi (ASTRO-H) mission is the sixth Japanese X-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E > 2 keV, using a microcalorimeter instrument, and to cover a wide energy range spanning four decades in energy from soft X-rays to gamma-rays. After a successful launch on 2016 February 17, the spacecraft lost its function on 2016 March 26, but the commissioning phase for about a month provided valuable information on the on-board instruments and the spacecraft system, including astrophysical results obtained from first light observations. The paper describes the Hitomi (ASTRO-H) mission, its capabilities, the initial operation, and the instruments/spacecraft performances confirmed during the commissioning operations for about a month.

Prototyping iridium coated mirrors for x-ray astronomy

NASA Astrophysics Data System (ADS)

Döhring, Thorsten; Probst, Anne-Catherine; Stollenwerk, Manfred; Emmerich, Florian; Stehlíková, Veronika; Inneman, Adolf

2017-05-01

X-ray astronomy uses space-based telescopes to overcome the disturbing absorption of the Earth's atmosphere. The telescope mirrors are operating at grazing incidence angles and are coated with thin metal films of high-Z materials to get sufficient reflectivity for the high-energy radiation to be observed. In addition the optical payload needs to be light-weighted for launcher mass constrains. Within the project JEUMICO, an acronym for "Joint European Mirror Competence", the Aschaffenburg University of Applied Sciences and the Czech Technical University in Prague started a collaboration to develop mirrors for X-ray telescopes. The X-ray telescopes currently developed within this Bavarian- Czech project are of Lobster eye type optical design. Corresponding mirror segments use substrates of flat silicon wafers which are coated with thin iridium films, as this material is promising high reflectivity in the X-ray range of interest. The deposition of the iridium films is based on a magnetron sputtering process. Sputtering with different parameters, especially by variation of the argon gas pressure, leads to iridium films with different properties. In addition to investigations of the uncoated mirror substrates the achieved surface roughness has been studied. Occasional delamination of the iridium films due to high stress levels is prevented by chromium sublayers. Thereby the sputtering parameters are optimized in the context of the expected reflectivity of the coated X-ray mirrors. In near future measurements of the assembled mirror modules optical performances are planned at an X-ray test facility.

Fifty years of X-ray astronomy: A look back and into the (near) future

NASA Astrophysics Data System (ADS)

Santangelo, Andrea; Madonia, Rosalia

2014-01-01

In this article we review the history of X-ray astronomy from the pioneering years to the age of the great observatories. We will try to show how new discoveries have been linked to technological breakthroughs, to science policy achievements and have been always supported by the passion of scientists who dedicated their life to the exploration of the Universe at the high energies. We will also briefly review the current challenges of X-ray astronomy (and astrophysics) and the missions already planned or that are being designed to address these challenges.

Chandra X-ray Observatory - NASA's flagship X-ray telescope

Science.gov Websites

astronomy, taking its place in the fleet of "Great Observatories." Who we are NASA's Chandra X-ray astronomy, distances are measured in units of light years, where one light year is the distance that light gravity? The answer is still out there. By studying clusters of galaxies, X-ray astronomy is tackling this

Astronomy and Cancer Research: X-Rays and Nanotechnology from Black Holes to Cancer Therapy

NASA Astrophysics Data System (ADS)

Pradhan, Anil K.; Nahar, Sultana N.

It seems highly unlikely that any connection is to be found between astronomy and medicine. But then it also appears to be obvious: X-rays. However, that is quite superficial because the nature of X-rays in the two disciplines is quite different. Nevertheless, we describe recent research on exactly that kind of link. Furthermore, the linkage lies in atomic physics, and via spectroscopy which is a vital tool in astronomy and may also be equally valuable in biomedical research. This review begins with the physics of black hole environments as viewed through X-ray spectroscopy. It is then shown that similar physics can be applied to spectroscopic imaging and therapeutics using heavy-element (high-Z) moieties designed to target cancerous tumors. X-ray irradiation of high-Z nanomaterials as radiosensitizing agents should be extremely efficient for therapy and diagnostics (theranostics). However, broadband radiation from conventional X-ray sources (such as CT scanners) results in vast and unnecessary radiation exposure. Monochromatic X-ray sources are expected to be considerably more efficient. We have developed a new and comprehensive methodology—Resonant Nano-Plasma Theranostics (RNPT)—that encompasses the use of monochromatic X-ray sources and high-Z nanoparticles. Ongoing research entails theoretical computations, numerical simulations, and in vitro and in vivo biomedical experiments. Stemming from basic theoretical studies of Kα resonant photoabsorption and fluorescence in all elements of the Periodic Table, we have established a comprehensive multi-disciplinary program involving researchers from physics, chemistry, astronomy, pathology, radiation oncology and radiology. Large-scale calculations necessary for theory and modeling are done at a variety of computational platforms at the Ohio Supercomputer Center. The final goal is the implementation of RNPT for clinical applications.

Quest for ultrahigh resolution in X-ray optics. [for solar astronomy

NASA Technical Reports Server (NTRS)

Davis, J. M.; Krieger, A. S.; Silk, J. K.; Chase, R. C.

1979-01-01

A program of solar X-ray astronomy using grazing incidence optics has culminated in X-ray images of the corona having one arc second spatial resolution. These images have demonstrated that, in general, X-ray optics can be fabricated to their specifications and can provide the level of resolution for which they are designed. Several aspects of these programs relating to the performance of X-ray optics in regard to resolution, including the point response function, the variation of resolution with off-axis position and the recognition that nearly all solar X-ray images have been film limited, are discussed. By extending the experience gained on this and other programs it is clearly possible to design and fabricate X-ray optics with sub arc sec resolution. The performance required to meet the scientific objectives for the remainder of the century are discussed in relation to AXIO, an Advanced X-Ray Imaging Observatory for solar observations which is proposed for flight on the Space Shuttle. Several configurations of AXIO are described, each of which would be a major step in the quest for ultrahigh-resolution observations.

A cosmic X-ray astronomy bibliography: The Astrophysical Journal, 1962 to 1972

NASA Technical Reports Server (NTRS)

Wilson, R. M.

1972-01-01

The results are presented of a survey of the Astrophysical Journal for the period January 1962 through March 1972 (volumes 135-172). Some 395 references are contained within this document related to cosmic X-ray astronomy.

Additive manufactured x-ray optics for astronomy

NASA Astrophysics Data System (ADS)

Atkins, Carolyn; Feldman, Charlotte; Brooks, David; Watson, Stephen; Cochrane, William; Roulet, Melanie; Doel, Peter; Willingale, Richard; Hugot, Emmanuel

2017-08-01

Additive manufacturing, more commonly known as 3D printing, has become a commercially established technology for rapid prototyping and the fabrication of bespoke intricate parts. Optical components, such as mirrors and lenses, are now being fabricated via additive manufacturing, where the printed substrate is polished in a post-processing step. One application of additively manufactured optics could be within the astronomical X-ray community, where there is a growing need to demonstrate thin, lightweight, high precision optics for a beyond Chandra style mission. This paper will follow a proof-of-concept investigation, sponsored by the UK Space Agency's National Space Technology Programme, into the feasibility of applying additive manufacturing in the production of thin, lightweight, precision X-ray optics for astronomy. One of the benefits of additive manufacturing is the ability to construct intricate lightweighting, which can be optimised to minimise weight while ensuring rigidity. This concept of optimised lightweighting will be applied to a series of polished additively manufactured test samples and experimental data from these samples, including an assessment of the optical quality and the magnitude of any print-through, will be presented. In addition, the finite element analysis optimisations of the lightweighting development will be discussed.

Novel Hybrid CMOS X-ray Detector Developments for Future Large Area and High Resolution X-ray Astronomy Missions

NASA Astrophysics Data System (ADS)

Falcone, Abe

In the coming years, X-ray astronomy will require new soft X-ray detectors that can be read very quickly with low noise and can achieve small pixel sizes over a moderately large focal plane area. These requirements will be present for a variety of X-ray missions that will attempt to address science that was highly ranked by the Decadal Review, including missions with science that over-laps with that of IXO and ATHENA, as well as other missions addressing science topics beyond those of IXO and ATHENA. An X-ray Surveyor mission was recently endorsed by the NASA long term planning document entitled "Enduring Quests, Daring Visions," and a detailed description of one possible realization of such a mission has been referred to as SMART-X, which was described in a recent NASA RFI response. This provides an example of a future mission concept with these requirements since it has high X-ray throughput and excellent spatial resolution. We propose to continue to modify current active pixel sensor designs, in particular the hybrid CMOS detectors that we have been working with for several years, and implement new in-pixel technologies that will allow us to achieve these ambitious and realistic requirements on a timeline that will make them available to upcoming X-ray missions. This proposal is a continuation of our program that has been working on these developments for the past several years.

Ray-tracing of shape metrology data of grazing incidence x-ray astronomy mirrors

NASA Astrophysics Data System (ADS)

Zocchi, Fabio E.; Vernani, Dervis

2008-07-01

A number of future X-ray astronomy missions (e.g. Simbol-X, eROSITA) plan to utilize high throughput grazing incidence optics with very lightweight mirrors. The severe mass specifications require a further optimization of the existing technology with the consequent need of proper optical numerical modeling capabilities for both the masters and the mirrors. A ray tracing code has been developed for the simulation of the optical performance of type I Wolter masters and mirrors starting from 2D and 3D metrology data. In particular, in the case of 2D measurements, a 3D data set is reconstructed on the basis of dimensional references and used for the optical analysis by ray tracing. In this approach, the actual 3D shape is used for the optical analysis, thus avoiding the need of combining the separate contributions of different 2D measurements that require the knowledge of their interactions which is not normally available. The paper describes the proposed approach and presents examples of application on a prototype engineering master in the frame of ongoing activities carried out for present and future X-ray missions.

Future Hard X-ray and Gamma-Ray Missions

NASA Astrophysics Data System (ADS)

Krawczynski, Henric; Physics of the Cosmos (PCOS) Gamma Ray Science Interest Group (GammaSIG) Team

2017-01-01

With four major NASA and ESA hard X-ray and gamma-ray missions in orbit (Swift, NuSTAR, INTEGRAL, and Fermi) hard X-ray and gamma-ray astronomy is making major contributions to our understanding of the cosmos. In this talk, I will summarize the current and upcoming activities of the Physics of the Cosmos Gamma Ray Science Interest Group and highlight a few of the future hard X-ray and gamma-ray mission discussed by the community. HK thanks NASA for the support through the awards NNX14AD19G and NNX16AC42G and for PCOS travel support.

The Origin of the UCSD X-ray Astronomy Program - A Personal Perspective

NASA Astrophysics Data System (ADS)

Peterson, Laurence E.

2013-01-01

I was a graduate student in the late 1950’s at the University of Minnesota in the Cosmic Ray Group under Prof. John R. Winckler. He had a project monitoring Cosmic ray time variations from an extensive series of balloon flights using simple detectors during the International Geophysical Year 1957-58. During the 20 March 1958 flight, a short 18 sec. burst of high energy radiation was observed simultaneously with a class II Solar flare. From the ratio of the Geiger counter rate to the energy loss in the ionization chamber, it was determined this radiation was likely hard X-rays or low-energy gamma rays and not energetic particles. Further analysis using information from other concurrent observations indicated the X-rays were likely due to Bremsstrahlung from energetic electrons accelerated in the solar flare magnetic field; these same electrons produced radio emissions. This first detection of extra-terrestrial X- or gamma rays showed the importance of non-thermal processes in Astrophysical phenomena. Winckler and I were interested by the possibility of non-solar hard X-rays. While completing my thesis on a Cosmic ray topic, I initiated a balloon program to develop more sensitive collimated low-background scintillation counters. This led to a proposal to the newly formed NASA to place an exploratory instrument on the 1st Orbiting Solar Observatory launched 7 March 1962. In August that year, I assumed a tenure-track position at UCSD; the data analysis of OSO-1 and the balloon program were transferred to UCSD to initiate the X-ray Astronomy program. The discovery of Cosmic X-ray sources in the 1-10 Kev range on a rocket flight in June 1962 by Giacconi and colleagues gave impetus to the UCSD activities. It seemed evident cosmic X-ray sources could be detected above 20 Kev using high-flying balloons. Early results included measurements of the 50 million K gas in SCO X-1, and the X-ray continuum from the Crab Nebula characterized by a power-law dN/dE ~ E-2.2. The

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.

Time Domain X-ray Astronomy with "All-Sky" Focusing Telescopes

NASA Astrophysics Data System (ADS)

Gorenstein, Paul

2016-04-01

The largest and most diverse types of temporal variations in all of astronomy occur in the soft, i.e. 0.5 to 10 keV, X-ray band. They range from millisecond QPO’s in compact binaries to year long flares from AGNs due to the absorption of a star by a SMBH, and the appearance of transient sources at decadal intervals. Models predict that at least some gravitational waves will be accompanied by an X-ray flare. A typical GRB produces more photons/sq. cm. in the soft band than it does in the Swift BAT 15 to 150 keV band. In addition the GRB X-ray fluence and knowledge of the details of the onset of the X-ray afterglow is obtained by observing the seamless transition from the active burst phase that has been attributed to internal shocks to the afterglow phases that has been attributed to external shocks. Detecting orphan X-ray afterglows will augment the event rate. With high sensitivity detectors some GRB identifications are likely to be with the youngest, most distant galaxies in the universe. Previous all-sky X-ray monitors have been non focusing limited field of view scanning instruments. An “All-Sky” (actually several ster FOV), focusing lobster-eye X-ray telescope will have much more grasp than the previous instruments and will allow a wide range of topics to be studied simultaneously. Two types of lobster-eye telescopes have been proposed. One type focuses in one dimension and uses a coded mask for resolution in the second. The other type focuses in two dimensions but has less effective area and less bandwidth. Both types are compatible with a Probe mission.

Multi-Absorber Transition-Edge Sensors for X-Ray Astronomy Applications

NASA Technical Reports Server (NTRS)

Smith, S. J.; Adams, J. S.; Bandler, S. R.; Busch, S. E.; Chervenak, J. A.; Eckart, M. E.; Ewin, A. J.; Finkbeiner, F. M.; Kelley, R. L.; Kelly, D. P.;

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.

High energy gamma ray astronomy

NASA Technical Reports Server (NTRS)

Fichtel, Carl E.

1987-01-01

High energy gamma ray astronomy has evolved with the space age. Nonexistent twenty-five years ago, there is now a general sketch of the gamma ray sky which should develop into a detailed picture with the results expected to be forthcoming over the next decade. The galactic plane is the dominant feature of the gamma ray sky, the longitude and latitude distribution being generally correlated with galactic structural features including the spiral arms. Two molecular clouds were already seen. Two of the three strongest gamma ray sources are pulsars. The highly variable X-ray source Cygnus X-3 was seen at one time, but not another in the 100 MeV region, and it was also observed at very high energies. Beyond the Milky Way Galaxy, there is seen a diffuse radiation, whose origin remains uncertain, as well as at least one quasar, 3C 273. Looking to the future, the satellite opportunities for high energy gamma ray astronomy in the near term are the GAMMA-I planned to be launched in late 1987 and the Gamma Ray Observatory, scheduled for launch in 1990. The Gamma Ray Observatory will carry a total of four instruments covering the entire energy range from 30,000 eV to 3 x 10 to the 10th eV with over an order of magnitude increase in sensitivity relative to previous satellite instruments.

Advances in solar and cosmic X-ray astronomy - A survey of experimental techniques and observational results.

NASA Technical Reports Server (NTRS)

Hoover, R. B.; Thomas, R. J.; Underwood, J. H.

1972-01-01

The current status of X-ray astronomy is surveyed by reviewing observational results and theoretical conclusions gained within the past two years in areas dealing with the quiet-sun, slowly-varying, and burst components of solar X-radiation and with the features of cosmic X-ray sources. Thermal and nonthermal processes responsible for a wide variety of X-ray emission mechanisms in nature are explained, and characteristics of X radiation from specific solar structures are described. Attention is given to the effects of interstellar and intergalactic matter on cosmic X-rays; the properties of galactic and extragalactic X-ray sources; and the specifications of such instruments as gas-filled ionization detectors, proportional counters, Geiger counters, scintillation detectors, photoelectric detectors, polarimeters, collimators, spectrometers, and imaging systems.

Focusing X-Ray Telescopes

NASA Technical Reports Server (NTRS)

O'Dell, Stephen; Brissenden, Roger; Davis, William; Elsner, Ronald; Elvis, Martin; Freeman, Mark; Gaetz, Terrance; Gorenstein, Paul; Gubarev, Mikhall; Jerlus, Diab;

Advanced X-ray Astrophysics Facility (AXAF): Science working group report. [space shuttle payload

NASA Technical Reports Server (NTRS)

1980-01-01

The Advanced X-Ray Astrophysics Facility (AXAF) mission concept is examined from a scientific viewpoint. A brief description of the development of X-ray astronomy and a summary description of AXAF, the scientific objectives of the facility, a description of representative scientific instruments, requirements for X-ray ground testing, and a summary of studies related to spacecraft and support subsystems, are included.

Innovative space x-ray telescopes

NASA Astrophysics Data System (ADS)

Hudec, R.; Inneman, A.; Pina, L.; Sveda, L.; Ticha, H.; Brozek, V.

2017-11-01

We report on the progress in innovative X-ray mirror development with focus on requirements of future X-ray astronomy space projects. Various future projects in X-ray astronomy and astrophysics will require large lightweight but highly accurate segments with multiple thin shells or foils. The large Wolter 1 grazing incidence multiple mirror arrays, the Kirkpatrick-Baez modules, as well as the large Lobster-Eye X-ray telescope modules in Schmidt arrangement may serve as examples. All these space projects will require high quality and light segmented shells (shaped, bent or flat foils) with high X-ray reflectivity and excellent mechanical stability.

Development of observational and instrumental techniques in hard X-ray and medium energy gamma-ray astronomy

NASA Technical Reports Server (NTRS)

Pelling, M.

1985-01-01

The technical activities, scientific results, related space hardware projects and personnel of the high energy astrophysics program are reported. The development of observational and instrumental techniques in hard X-ray (0.001 to 100 keV) and medium energy gamma-ray (0.1 to 10 MeV) astronomy are examined. Many of these techniques were developed explicitly for use on high altitude balloons where most of the scientific results were obtained. The extensive observational activity using balloons are tabulated. Virtually every research activity will eventually result in a major space hardware development effort.

Multimessenger astronomy with pulsar timing and X-ray observations of massive black hole binaries

NASA Astrophysics Data System (ADS)

Sesana, A.; Roedig, C.; Reynolds, M. T.; Dotti, M.

2012-02-01

In the decade of the dawn of gravitational wave astronomy, the concept of multimessenger astronomy, combining gravitational wave signals to conventional electromagnetic observation, has attracted the attention of the astrophysical community. So far, most of the effort has been focused on ground- and space-based laser interferometer sources, with little attention devoted to the ongoing and upcoming pulsar timing arrays (PTAs). We argue in this paper that PTA sources, being very massive (>108 M⊙) cosmologically nearby (z < 1) black hole binaries (MBHBs), are particularly appealing multimessenger carriers. According to current models for massive black hole formation and evolution, the planned Square Kilometre Array will observe thousands of such massive systems, being able to individually resolve and locate in the sky several of them (maybe up to a hundred). MBHBs form in galaxy mergers, which are usually accompanied by strong inflows of gas in the centre of the merger remnant. By employing a standard model for the evolution of MBHBs in circumbinary discs, with the aid of dedicated numerical simulations, we characterize the gas-binary interplay, identifying possible electromagnetic signatures of the PTA sources. We concentrate our investigation on two particularly promising scenarios in the high-energy domain, namely the detection of X-ray periodic variability and double broad Kα iron lines. Up to several hundreds of periodic X-ray sources with a flux >10-13 erg s-1 cm-2 will be in the reach of upcoming X-ray observatories; in the most optimistic case, a few of them may be already being observed by the MAXI detector placed on the International Space Station. Double relativistic Kα lines may be observable in a handful of low-redshift (z < 0.3) sources by proposed deep X-ray probes, such as Athena. The exact figures depend on the details of the adopted MBHB population and on the properties of the circumbinary discs, but the existence of a sizeable population of

Gamma Ray Astronomy

NASA Technical Reports Server (NTRS)

Wu, S. T.

2000-01-01

The project has progressed successfully during this period of performance. The highlights of the Gamma Ray Astronomy teams efforts are: (1) Support daily BATSE data operations, including receipt, archival and dissemination of data, quick-look science analysis, rapid gamma-ray burst and transient monitoring and response efforts, instrument state-of-health monitoring, and instrument commanding and configuration; (2) On-going scientific analysis, including production and maintenance of gamma-ray burst, pulsed source and occultation source catalogs, gamma-ray burst spectroscopy, studies of the properties of pulsars and black holes, and long-term monitoring of hard x-ray sources; (3) Maintenance and continuous improvement of BATSE instrument response and calibration data bases; (4) Investigation of the use of solid state detectors for eventual application and instrument to perform all sky monitoring of X-Ray and Gamma sources with high sensitivity; and (5) Support of BATSE outreach activities, including seminars, colloquia and World Wide Web pages. The highlights of this efforts can be summarized in the publications and presentation list.

Position-Sensitive CZT Detectors for High Energy X-Ray Astronomy

NASA Astrophysics Data System (ADS)

Matteson, J.; Coburn, W.; Heindl, W.; Peterson, L.; Pelling, M.; Rothschild, R.; Skelton, R.; Hink, P.; Slavis, K.

1998-05-01

We report recent progress on CZT (Cadmium Zinc Telluride) detectors by the UCSD/WU collaboration. CZT, a room- temperature semiconductor, is a very promising detector material for high energy X-ray astronomy. It can operate from <10 keV to >200 keV, and give sub-keV energy resolution and sub-mm spatial resolution. We have developed an advanced CZT detector that uses two innovations to improve spectral response, give it 3-D localization of energy loss events, and reduce background at high altitudes and in space. The detector measures 12 x 12 x 2 mm(3) and was manufactured by eV Products. Each face has a strip readouts with 500 micron pitch electrodes. The 2 faces' strips are orthogonal, which provides x-y localization into 500 micron pixels. One innovation is "steering electrodes", which are located between the anode strips. They improve the anode charge collection and energy resolution, and tailing due to hole trapping is nearly totally eliminated. The energy resolution at 60 keV is 4 keV and the peak to valley ratio is 50. The other innovation is 3-D localization of energy losses. This is done by comparing the signals from the anode strips, cathode strips, and steering electrodes. There is a strong depth of interaction signature, which can be used to accept events which interact close to the cathode strips (where X-rays of interest are incident) and reject deeper interactions (which are likely to be background). The detector was tested in a balloon flight at 108,000 feet in October 1997. Background was reduced by passive shielding, consisting of lead graded with tin and copper. The lead thickness was changed by command during the flight, and was 7, 2, and 0 mm thick. With the 2 mm thickness the 20 - 40 keV background for the central 30 pixels was 8x10(-4) c/cm(2) -s-keV when the depth of interaction signature was used to reject background, and 7 times greater when this information was not used. The lower background is 12 times less than other workers have obtained

Recent Progress in Adjustable X-ray Optics for Astronomy

NASA Technical Reports Server (NTRS)

Reid, Paul B.; Allured, Ryan; Cotroneo, Vincenzo; McMuldroch, Stuart; Marquez, Vanessa; Schwartz, Daniel A.; Vikhlinin, Alexey; ODell, Stephen L.; Ramsey, Brian; Trolier-McKinstry, Susan;

A Saturn launched X-ray astronomy experiment. Volume 1: S-027

NASA Technical Reports Server (NTRS)

1971-01-01

The S-027 X-Ray Astronomy Experiment originally proposed in early 1966, was developed to detect X-rays in the 2 keV to 10 keV range. Both a prototype unit and flight unit were constructed with the prototype unit also serving as the engineering model, the qualification test unit, and after refurbishment, as the back-up flight unit. Two Ground Support Equipment consoles were built to verify the experiment operation. A photograph of one experiment package with its Ground Support Equipment is shown. The S-027 experiment was scheduled for launch in 1968/69 and although both units were completed and tested to the extent that either would be ready for the scheduled launch, delays in the space program resulted in a launch date slip of several years. When the 1968/69 launch delay became official, provisions were made for storage of the two experiment packages at SCI Electronics in Huntsville, Alabama until a new launch date could be established.

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.

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

Novel Hybrid CMOS X-ray Detector Developments for Future Large Area and High Resolution X-ray Astronomy Missions

NASA Astrophysics Data System (ADS)

Falcone, Abe

In the coming years, X-ray astronomy will require new soft X-ray detectors that can be read very quickly with low noise and can achieve small pixel sizes over a moderately large focal plane area. These requirements will be present for a variety of X-ray missions that will attempt to address science that was highly ranked by the 2010 Decadal Survey, including missions with science that overlaps with that of IXO and Athena, as well as other missions addressing science topics beyond those of IXO and Athena. An X-ray Surveyor mission was recently chosen by NASA for study by a Science & Technology Definition Team (STDT) so it can be considered as an option for an upcom-ing flagship mission. A mission such as this was endorsed by the NASA long term planning document entitled "Enduring Quests, Daring Visions," and a detailed description of one possible reali-zation of such a mission has been referred to as SMART-X, which was described in a recent NASA RFI response. This provides an example of a future mission concept with these requirements since it has high X-ray throughput and excellent spatial resolution. We propose to continue to modify current active pixel sensor designs, in particular the hybrid CMOS detectors that we have been working with for several years, and implement new in-pixel technologies that will allow us to achieve these ambitious and realistic requirements on a timeline that will make them available to upcoming X-ray missions. This proposal is a continuation of our program that has been work-ing on these developments for the past several years. The first 3 years of the program led to the development of a new circuit design for each pixel, which has now been shown to be suitable for a larger detector array. The proposed activity for the next four years will be to incorporate this pixel design into a new design of a full detector array (2k×2k pixels with digital output) and to fabricate this full-sized device so it can be thoroughly tested and

Toward Adaptive X-Ray Telescopes

NASA Technical Reports Server (NTRS)

O'Dell, Stephen L.; Atkins, Carolyn; Button, Tim W.; Cotroneo, Vincenzo; Davis, William N.; Doel, Peer; Feldman, Charlotte H.; Freeman, Mark D.; Gubarev, Mikhail V.; Kolodziejczak, Jeffrey J.;

Toward active x-ray telescopes

NASA Astrophysics Data System (ADS)

O'Dell, Stephen L.; Atkins, Carolyn; Button, Timothy W.; Cotroneo, Vincenzo; Davis, William N.; Doel, Peter; Feldman, Charlotte H.; Freeman, Mark D.; Gubarev, Mikhail V.; Kolodziejczak, Jeffery J.; Michette, Alan G.; Ramsey, Brian D.; Reid, Paul B.; Rodriguez Sanmartin, Daniel; Saha, Timo T.; Schwartz, Daniel A.; Trolier-McKinstry, Susan; Wilke, Rudeger H. T.; Willingale, Richard; Zhang, William W.

2011-09-01

Future x-ray observatories will require high-resolution (< 1") optics with very-large-aperture (> 25 m2) areas. Even with the next generation of heavy-lift launch vehicles, launch-mass constraints and aperture-area requirements will limit the areal density of the grazing-incidence mirrors to about 1 kg/m2 or less. Achieving sub-arcsecond x-ray imaging with such lightweight mirrors will require excellent mirror surfaces, precise and stable alignment, and exceptional stiffness or deformation compensation. Attaining and maintaining alignment and figure control will likely involve active (in-space adjustable) x-ray optics. In contrast with infrared and visible astronomy, active optics for x-ray astronomy is in its infancy. In the middle of the past decade, two efforts began to advance technologies for adaptive x-ray telescopes: The Smart X-ray Optics (SXO) Basic Technology project in the United Kingdom (UK) and the Generation-X (Gen-X) concept studies in the United States (US). This paper discusses relevant technological issues and summarizes progress toward active x-ray telescopes.

Solar x ray astronomy rocket program

NASA Technical Reports Server (NTRS)

1990-01-01

The dynamics were studied of the solar corona through the imaging of large scale coronal structures with AS&E High Resolution Soft X ray Imaging Solar Sounding Rocket Payload. The proposal for this program outlined a plan of research based on the construction of a high sensitivity X ray telescope from the optical and electronic components of the previous flight of this payload (36.038CS). Specifically, the X ray sensitive CCD camera was to be placed in the prime focus of the grazing incidence X ray mirror. The improved quantum efficiency of the CCD detector (over the film which had previously been used) allows quantitative measurements of temperature and emission measure in regions of low x ray emission such as helmet streamers beyond 1.2 solar radii or coronal holes. Furthermore, the improved sensitivity of the CCD allows short exposures of bright objects to study unexplored temporal regimes of active region loop evolution.

X-Ray Optics: Past, Present, and Future

NASA Technical Reports Server (NTRS)

Zhang, William W.

2010-01-01

X-ray astronomy started with a small collimated proportional counter atop a rocket in the early 1960s. It was immediately recognized that focusing X-ray optics would drastically improve both source location accuracy and source detection sensitivity. In the past 5 decades, X-ray astronomy has made significant strides in achieving better angular resolution, large photon collection area, and better spectral and timing resolutions, culminating in the three currently operating X-ray observatories: Chandra, XMM/Newton, and Suzaku. In this talk I will give a brief history of X-ray optics, concentrating on the characteristics of the optics of these three observatories. Then I will discuss current X-ray mirror technologies being developed in several institutions. I will end with a discussion of the optics for the International X-ray Observatory that I have been developing at Goddard Space Flight Center.

Processings of the Workshop on Electron Contamination in X-Ray Astronomy Experiments. [proceedings of conference on effects of extraterrestrial radiation

NASA Technical Reports Server (NTRS)

Holt, S. S. (Editor)

1974-01-01

The proceedings of a conference to investigate the effects of extraterrestrial radiation and particle contamination of X-ray astronomical data are presented. The subjects discussed include the following: (1) electrons at low altitudes which affect soft X-ray astronomy, (2) the geographical distribution of 100 keV electrons above the earth's atmosphere, (3) midlatitude electron precipitation, (4) particle background observed by X-ray detectors on board Copernicus satellite, and (5) a survey of trapped low energy electrons near the inner boundary of the inner radiation zone as determined by OSO-7.

X-ray astronomy in the laboratory with a miniature compact object produced by laser-driven implosion

NASA Astrophysics Data System (ADS)

Fujioka, Shinsuke; Takabe, Hideaki; Yamamoto, Norimasa; Salzmann, David; Wang, Feilu; Nishimura, Hiroaki; Li, Yutong; Dong, Quanli; Wang, Shoujun; Zhang, Yi; Rhee, Yong-Joo; Lee, Yong-Woo; Han, Jae-Min; Tanabe, Minoru; Fujiwara, Takashi; Nakabayashi, Yuto; Zhao, Gang; Zhang, Jie; Mima, Kunioki

2009-11-01

X-ray spectroscopy is an important tool for understanding the extreme photoionization processes that drive the behaviour of non-thermal equilibrium plasmas in compact astrophysical objects such as black holes. Even so, the distance of these objects from the Earth and the inability to control or accurately ascertain the conditions that govern their behaviour makes it difficult to interpret the origin of the features in astronomical X-ray measurements. Here, we describe an experiment that uses the implosion driven by a 3TW, 4kJ laser system to produce a 0.5keV blackbody radiator that mimics the conditions that exist in the neighbourhood of a black hole. The X-ray spectra emitted from photoionized silicon plasmas resemble those observed from the binary stars Cygnus X-3 (refs 7, 8) and Vela X-1 (refs 9, 10 11) with the Chandra X-ray satellite. As well as demonstrating the ability to create extreme radiation fields in a laboratory plasma, our theoretical interpretation of these laboratory spectra contrasts starkly with the generally accepted explanation for the origin of similar features in astronomical observations. Our experimental approach offers a powerful means to test and validate the computer codes used in X-ray astronomy.

X-ray astronomy from Uhuru to HEAO-1

NASA Technical Reports Server (NTRS)

Clark, G. W.

1981-01-01

The nature of galactic and extragalactic X-ray sources is investigated using observations made with nine satellites and several rockets. The question of X-ray pulsars being neutron stars or white dwarfs is considered, as is the nature of Population II and low-luminosity X-ray stars, the diffuse X-ray emission from clusters of galaxies, the unidentified high-galactic-latitude (UHGL) sources, and the unresolved soft X-ray background. The types of sources examined include binary pulsars, Population II X-ray stars (both nonbursters and bursters) inside and outside globular clusters, coronal X-ray emitters, and active galactic nuclei. It is concluded that: (1) X-ray pulsars are strongly magnetized neutron stars formed in the evolution of massive close binaries; (2) all Population II X-ray stars are weakly magnetized or nonmagnetic neutron stars accreting from low-mass companions in close binary systems; (3) the diffuse emission from clusters is thermal bremsstrahlung of hot matter processed in stars and swept out by ram pressure exerted by the intergalactic gas; (4) most or all of the UHGL sources are active galactic nuclei; and (5) the soft X-ray background is emission from a hot component of the interstellar medium.

AXAF: The Advanced X-Ray Astrophysics Facility

NASA Technical Reports Server (NTRS)

Pellerin, Charles J.; Weisskopf, Martin C.; Neal, Valerie

2005-01-01

X-rays are produced by violent, energetic, and explosive phenomena in the universe. The Advanced X-Ray Astrophysics Facility (AXAF) is an orbiting observatory designed to view these X-rays. The National Academy of Sciences Survey Committee on Astronomy and Astrophysics has recommended AXAF as the #1 priority among all major new astronomy programs. The scientific importance of AXAF was also highlighted by the Academy's Survey Committee on Physics. Why has AXAF earned such enthusiastic support, not only among astronomers, but also broadly within the nation's scientific community?

Very high energy gamma ray astronomy

NASA Technical Reports Server (NTRS)

Grindlay, J. E.

1976-01-01

Recent results in ground based very high energy gamma ray astronomy are reviewed. The various modes of the atmospheric Cerenkov technique are described, and the importance of cosmic ray rejection methods is stressed. The positive detections of the Crab pulsar that suggest a very flat spectrum and time-variable pulse phase are discussed. Observations of other pulsars (particularly Vela) suggest these features may be general. Evidence that a 4.8 hr modulated effect was detected from Cyg X-3 is strengthened in that the exact period originally proposed agrees well with a recent determination of the X-ray period. The southern sky observations are reviewed, and the significance of the detection of an active galaxy (NGC 5128) is considered for source models and future observations.

Flight programs and X-ray optics development at MSFC

NASA Astrophysics Data System (ADS)

Gubarev, M.; Ramsey, B.; O'Dell, S.; Elsner, R.; Kilaru, K.; Atkins, C.; Swartz, D.; Gaskin, J.; Weisskopf, M.

The X-ray astronomy group at the Marshall Space Flight Center (MSFC) is developing electroformed nickel/cobalt x-ray optics for suborbital and orbital experiments. Suborbital instruments include the Focusing X-ray Solar Imager (FOXSI) and Micro-X sounding rocket experiments and the HEROES balloon payload. Our current orbital program is the fabrication of mirror modules for the Astronomical Roentgen Telescope (ART) to be launched on board the Russian-German Spectrum Roentgen Gamma Mission (SRG). A second component of our work is the development of fabrication techniques and optical metrology to improve the angular resolution of thin-shell optics to the arcsecond-level.

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

Ground-based very high energy gamma ray astronomy: Observational highlights

NASA Technical Reports Server (NTRS)

Turver, K. E.

1986-01-01

It is now more than 20 years since the first ground based gamma ray experiments involving atmospheric Cerenkov radiation were undertaken. The present highlights in observational ground-based very high energy (VHE) gamma ray astronomy and the optimism about an interesting future for the field follow progress in these areas: (1) the detection at increased levels of confidence of an enlarged number of sources so that at present claims were made for the detection, at the 4 to 5 sd level of significance, of 8 point sources; (2) the replication of the claimed detections with, for the first time, confirmation of the nature and detail of the emission; and (3) the extension of gamma ray astronomy to the ultra high energy (UHE) domain. The pattern, if any, to emerge from the list of sources claimed so far is that X-ray binary sources appear to be copious emitters of gamma rays over at least 4 decades of energy. These X-ray sources which behave as VHE and UHE gamma ray emitters are examined.

X-ray Interferometry with Transmissive Beam Combiners for Ultra-High Angular Resolution Astronomy

NASA Technical Reports Server (NTRS)

Skinner, G. K.; Krismanic, John F.

2009-01-01

Abstract Interferometry provides one of the possible routes to ultra-high angular resolution for X-ray and gamma-ray astronomy. Sub-micro-arc-second angular resolution, necessary to achieve objectives such as imaging the regions around the event horizon of a super-massive black hole at the center of an active galaxy, can be achieved if beams from parts of the incoming wavefront separated by 100s of meters can be stably and accurately brought together at small angles. One way of achieving this is by using grazing incidence mirrors. We here investigate an alternative approach in which the beams are recombined by optical elements working in transmission. It is shown that the use of diffractive elements is a particularly attractive option. We report experimental results from a simple 2-beam interferometer using a low-cost commercially available profiled film as the diffractive elements. A rotationally symmetric filled (or mostly filled) aperture variant of such an interferometer, equivalent to an X-ray axicon, is shown to offer a much wider bandpass than either a Phase Fresnel Lens (PFL) or a PFL with a refractive lens in an achromatic pair. Simulations of an example system are presented.

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.

X-Ray Imaging System

NASA Technical Reports Server (NTRS)

1986-01-01

The FluoroScan Imaging System is a high resolution, low radiation device for viewing stationary or moving objects. It resulted from NASA technology developed for x-ray astronomy and Goddard application to a low intensity x-ray imaging scope. FlouroScan Imaging Systems, Inc, (formerly HealthMate, Inc.), a NASA licensee, further refined the FluoroScan System. It is used for examining fractures, placement of catheters, and in veterinary medicine. Its major components include an x-ray generator, scintillator, visible light image intensifier and video display. It is small, light and maneuverable.

Flight Programs and X-ray Optics Development at MSFC

NASA Technical Reports Server (NTRS)

Gubarev, M.; Ramsey, B.; O'Dell, S. L.; Elsner, R.; Kilaru, K.; Atkins, C.; Swartz, D.; Gaskin, J.; Weisskopf, Martin

2012-01-01

The X-ray astronomy group at the Marshall Space Flight Center is developing electroformed nickel/cobalt x-ray optics for suborbital and orbital experiments. Suborbital instruments include the Focusing X-ray Solar Imager (FOXSI) and Micro-X sounding rocket experiments and the HERO balloon payload. Our current orbital program is the fabrication of a series of mirror modules for the Astronomical Roentgen Telescope (ART) to be launched on board the Russian-German Spectrum Roentgen Gamma Mission (SRG.) The details and status of these various programs are presented. A second component of our work is the development of fabrication techniques and optical metrology to improve the angular resolution of thin shell optics to the arcsecond-level. The status of these x-ray optics technology developments is also presented.

Soft X-ray astronomy proportional counter electronics

NASA Technical Reports Server (NTRS)

Gardner, W. R.

1971-01-01

The X-ray multiwire proportional counter is designed to measure cosmic X-ray fluxes at sounding rocket altitudes in the energy range of 0.1 to 10 keV. Four instruments will be launched in a Black Brant 4 rocket employing different combinations of detector windows and gas. The detector is constructed with two layers of twelve cells. A columnator is mounted on the face of one layer whose cells are wired together alternately to form two main detector sections. The electronics and gas regulation systems are mounted on the face of the second layer whose cells are wired together to form one anticoincidence detector section. Normally X-rays will have short ionization paths in only one of the main detector cells at a time and won't enter the anticoincidence detector cells. To distinguish between X-rays and charged particles, the instrument includes a coincidence discriminator, an anticoincidence discriminator, and a pulse rise time discriminator.

X-ray emission from Stephan's Quintet and other compact groups

NASA Technical Reports Server (NTRS)

Bahcall, N. A.; Harris, D. E.; Rood, H. J.

1984-01-01

A search for X-ray emission from five compact groups of galaxies with the Einstein Observatory revealed detections from three groups. Soft, extended X-ray emission was observed in Stephan's Quintet, which is most likely caused by hot intracluster gas. This provides evidence for dynamical interaction among the group galaxies. X-ray emission from the group Arp 330 may also originate in hot intracluster gas. Stephan's Quintet and Arp 330 have the largest velocity dispersions among the groups studied, suggesting a correlation between high velocity and the release (or properties) of hot gas. X-ray emission from Arp 318 may originate in its member galaxies.

Transforming Our Understanding of the X-ray Universe: The Imaging X-ray Polarimeter Explorer (IXPE)

NASA Technical Reports Server (NTRS)

Weisskopf, Martin C.; Bellazzini, Ronaldo; Costa, Enrico; Matt, Giorgio; Marshall, Herman; ODell, Stephen L.; Pavlov, George; Ramsey, Brian; Romani, Roger

2014-01-01

Accurate X-ray polarimetry can provide unique information on high-energy-astrophysical processes and sources. As there have been no meaningful X-ray polarization measurements of cosmic sources since our pioneering work in the 1970's, the time is ripe to explore this new parameter space in X-ray astronomy. To accomplish this requires a well-calibrated and well understood system that-particularly for an Explorer mission-has technical, cost, and schedule credibility. The system that we shall present satisfies these conditions, being based upon completely calibrated imaging- and polarization-sensitive detectors and proven X-ray-telescope technology.

Development of a Hybrid Gas Detector/Phoswich for Hard X-Ray Astronomy

NASA Technical Reports Server (NTRS)

Pimperl, M. M.; Ramsey, B. D.; Austin, R. A.; Minamitani, T.; Weisskopf, M. C.; Grindlay, J. E.; Lum, K. S. K.; Manandhar, R. P.

1994-01-01

A hybrid detector is under development for use as a balloon-borne instrument in hard x-ray astronomy. The detector provides broad band coverage by coupling an optical avalanche chamber to a phoswich. The optical avalanche chamber yields superior instrument response at low energies while the scintillator takes over at the higher energies where the gas becomes transparent: at 25 keV, the addition of the gas chamber improves the energy resolution by a factor of 2.5 and the spatial resolution by a factor of 10 as compared to the stand-alone response of the phoswich. A half-scale prototype instrument is being constructed for test purposes and to help resolve a number of design questions involving the coupling of the two components.

AXAF: The Advanced X-ray Astrophysics Facility

NASA Technical Reports Server (NTRS)

1988-01-01

The Advanced X-ray Astrophysics Facility (AXAF) will be the X-ray astronomy component of U.S. space exploration via Great Observatories (mostly orbital) for the remainder of the century. AXAF and the research planned for it are discussed for a lay audience.

Technology Needs for Gamma Ray Astronomy

NASA Technical Reports Server (NTRS)

Gehrels, Neil

2011-01-01

Gamma ray astronomy is currently in an exciting period of multiple missions and a wealth of data. Results from INTEGRAL, Fermi, AGILE, Suzaku and Swift are making large contributions to our knowledge of high energy processes in the universe. The advances are due to new detector and imaging technologies. The steps to date have been from scintillators to solid state detectors for sensors and from light buckets to coded aperture masks and pair telescopes for imagers. A key direction for the future is toward focusing telescopes pushing into the hard X-ray regime and Compton telescopes and pair telescopes with fine spatial resolution for medium and high energy gamma rays. These technologies will provide finer imaging of gamma-ray sources. Importantly, they will also enable large steps forward in sensitivity by reducing background.

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)

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.;

X-ray-selected galaxy groups in Boötes

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

Vajgel, Bruna; Lopes, Paulo A. A.; Jones, Christine

2014-10-10

We present the X-ray and optical properties of the galaxy groups selected in the Chandra X-Boötes survey. We used follow-up Chandra observations to better define the group sample and their X-ray properties. Group redshifts were measured from the AGN and Galaxy Evolution Survey spectroscopic data. We used photometric data from the NOAO Deep Wide Field Survey to estimate the group richness (N {sub gals}) and the optical luminosity (L {sub opt}). Our final sample comprises 32 systems at z < 1.75 with 14 below z = 0.35. For these 14 systems, we estimate velocity dispersions (σ {sub gr}) and performmore » a virial analysis to obtain the radii (R {sub 200} and R {sub 500}) and total masses (M {sub 200} and M {sub 500}) for groups with at least 5 galaxy members. We use the Chandra X-ray observations to derive the X-ray luminosity (L{sub X} ). We examine the performance of the group properties σ{sub gr}, L {sub opt}, and L{sub X} , as proxies for the group mass. Understanding how well these observables measure the total mass is important to estimate how precisely the cluster/group mass function is determined. Exploring the scaling relations built with the X-Boötes sample and comparing these with samples from the literature, we find a break in the L{sub X} -M {sub 500} relation at approximately M {sub 500} = 5 × 10{sup 13} M {sub ☉} (for M {sub 500} > 5 × 10{sup 13} M {sub ☉}, M{sub 500}∝L{sub X}{sup 0.61±0.02}, while for M {sub 500} ≤ 5 × 10{sup 13} M {sub ☉}, M{sub 500}∝L{sub X}{sup 0.44±0.05}). Thus, the mass-luminosity relation for galaxy groups cannot be described by the same power law as galaxy clusters. A possible explanation for this break is the dynamical friction, tidal interactions, and projection effects that reduce the velocity dispersion values of the galaxy groups. By extending the cluster luminosity function to the group regime, we predict the number of groups that new X-ray surveys, particularly eROSITA, will detect. Based on our

Alternative designs for space x-ray telescopes

NASA Astrophysics Data System (ADS)

Hudec, R.; Pína, L.; Maršíková, Veronika; Černá, Daniela; Inneman, A.; Tichý, V.

2017-11-01

The X-ray optics is a key element of space X-ray telescopes, as well as other X-ray imaging instruments. The grazing incidence X-ray lenses represent the important class of X-ray optics. Most of grazing incidence (reflective) X-ray imaging systems used in astronomy but also in other (laboratory) applications are based on the Wolter 1 (or modified) arrangement. But there are also other designs and configurations proposed, used and considered for future applications both in space and in laboratory. The Kirkpatrick-Baez (K-B) lenses as well as various types of Lobster-Eye optics and MCP/Micropore optics serve as an example. Analogously to Wolter lenses, the X-rays are mostly reflected twice in these systems to create focal images. Various future projects in X-ray astronomy and astrophysics will require large segments with multiple thin shells or foils. The large Kirkpatrick-Baez modules, as well as the large Lobster-Eye X-ray telescope modules in Schmidt arrangement may serve as examples. All related space projects will require high quality and light segmented shells (bent or flat foils) with high X-ray reflectivity and excellent mechanical stability. The Multi Foil Optics (MFO) approach represent a promising alternative for both LE and K-B X-ray optical modules. Several types of reflecting substrates may be considered for these applications, with emphasis on thin float glass sheets and, more recently, high quality silicon wafers. This confirms the importance of non-Wolter X-ray optics designs for the future. The alternative designs require novel reflective substrates which are also discussed in the paper.

High-Resolution Detector For X-Ray Diffraction

NASA Technical Reports Server (NTRS)

Carter, Daniel C.; Withrow, William K.; Pusey, Marc L.; Yost, Vaughn H.

1988-01-01

Proposed x-ray-sensitive imaging detector offers superior spatial resolution, counting-rate capacity, and dynamic range. Instrument based on laser-stimulated luminescence and reusable x-ray-sensitive film. Detector scans x-ray film line by line. Extracts latent image in film and simultaneously erases film for reuse. Used primarily for protein crystallography. Principle adapted to imaging detectors for electron microscopy and fluorescence spectroscopy and general use in astronomy, engineering, and medicine.

X-Ray Polarization from High Mass X-Ray Binaries

NASA Technical Reports Server (NTRS)

Kallman, T.; Dorodnitsyn, A.; Blondin, J.

2015-01-01

X-ray astronomy allows study of objects which may be associated with compact objects, i.e. neutron stars or black holes, and also may contain strong magnetic fields. Such objects are categorically non-spherical, and likely non-circular when projected on the sky. Polarization allows study of such geometric effects, and X-ray polarimetry is likely to become feasible for a significant number of sources in the future. A class of potential targets for future X-ray polarization observations is the high mass X-ray binaries (HMXBs), which consist of a compact object in orbit with an early type star. In this paper we show that X-ray polarization from HMXBs has a distinct signature which depends on the source inclination and orbital phase. The presence of the X-ray source displaced from the star creates linear polarization even if the primary wind is spherically symmetric whenever the system is viewed away from conjunction. Direct X-rays dilute this polarization whenever the X-ray source is not eclipsed; at mid-eclipse the net polarization is expected to be small or zero if the wind is circularly symmetric around the line of centers. Resonance line scattering increases the scattering fraction, often by large factors, over the energy band spanned by resonance lines. Real winds are not expected to be spherically symmetric, or circularly symmetric around the line of centers, owing to the combined effects of the compact object gravity and ionization on the wind hydrodynamics. A sample calculation shows that this creates polarization fractions ranging up to tens of percent at mid-eclipse.

Exploring the X-Ray Universe

NASA Astrophysics Data System (ADS)

Seward, Frederick D.; Charles, Philip A.

1995-11-01

Exploring the X-Ray Universe describes the view of the stars and galaxies that is obtained through X-ray telescopes. X-rays, which are invisible to human sight, are created in the cores of active galaxies, in cataclysmic stellar explosions, and in streams of gas expelled by the Sun and stars. The window on the heavens used by the X-ray astronomers shows the great drama of cosmic violence on the grandest scale.

A Three-Year Program of Micro- and Nano-System Technology Development for X-Ray Astronomy

NASA Technical Reports Server (NTRS)

Canizares, Claude R.

1997-01-01

For many years the work at MIT aimed at the development of new concepts and technologies for space experiments in high-energy astrophysics, but not explicitly supported by flight programs, has been supported. This work has yielded new devices and techniques for X-ray astronomy, primarily low-noise, deep-depletion charge-coupled devices (CCDS) for spectrally-resolved X-ray imaging, and high-performance transmission gratings for high-resolution X-ray spectroscopy. Among the most significant recent achievements have been the development by G. Ricker and associates of the X-ray CCD camera flying on ASCA, and currently in development for AXAF and Astro-E, and the development by C. Canizares and associates of thick, 200 nm-period transmission gratings employing the phenomenon of phase shifting for high-resolution X-ray spectroscopy up to energies of 8- 1 0 keV that is essential for the operation of the AXAF High Energy Transmission Grating Spectrometer (HETGS). Through the current SR&T grant, the latter technology is now being extended successfully to the fabrication of 100 nm-period transmission gratings, which have twice the dispersion of the AXAF gratings. We note that, among other outcomes, the modest investments of past SR&T Grants at MIT resulted in the development of the key technologies for fully one-half of the scientific instrumentation on AXAF. In addition, NASA flight programs that have benefited from previous SR&T support at MIT include the SAS 3 X-ray Observatory, which carried the first rotation modulation collimator, the Focal Plane Crystal Spectrometer (FPCS) on the Einstein Observatory, the CCD cameras on ASCA and planned for Astro-E, the High Energy Transient Experiment (HETE), the Solar EUV Monitor on the Solar and Heliospheric Observatory (SOHO), the Medium Energy Neutral Atom imager (MENA) on the Image for Magnetopause-to-aurora Global Exploration (IMAGE) mission, and the recently-approved Two Wide-Angle Imaging Neutral-atom Spectrometers (TWINS

Chi-squared and C statistic minimization for low count per bin data. [sampling in X ray astronomy

NASA Technical Reports Server (NTRS)

Nousek, John A.; Shue, David R.

1989-01-01

Results are presented from a computer simulation comparing two statistical fitting techniques on data samples with large and small counts per bin; the results are then related specifically to X-ray astronomy. The Marquardt and Powell minimization techniques are compared by using both to minimize the chi-squared statistic. In addition, Cash's C statistic is applied, with Powell's method, and it is shown that the C statistic produces better fits in the low-count regime than chi-squared.

A Weak Lensing Study of X-ray Groups in the Cosmos Survey: Form and Evolution of the Mass-Luminosity Relation

NASA Astrophysics Data System (ADS)

Leauthaud, Alexie; Finoguenov, Alexis; Kneib, Jean-Paul; Taylor, James E.; Massey, Richard; Rhodes, Jason; Ilbert, Olivier; Bundy, Kevin; Tinker, Jeremy; George, Matthew R.; Capak, Peter; Koekemoer, Anton M.; Johnston, David E.; Zhang, Yu-Ying; Cappelluti, Nico; Ellis, Richard S.; Elvis, Martin; Giodini, Stefania; Heymans, Catherine; Le Fèvre, Oliver; Lilly, Simon; McCracken, Henry J.; Mellier, Yannick; Réfrégier, Alexandre; Salvato, Mara; Scoville, Nick; Smoot, George; Tanaka, Masayuki; Van Waerbeke, Ludovic; Wolk, Melody

2010-01-01

Measurements of X-ray scaling laws are critical for improving cosmological constraints derived with the halo mass function and for understanding the physical processes that govern the heating and cooling of the intracluster medium. In this paper, we use a sample of 206 X-ray-selected galaxy groups to investigate the scaling relation between X-ray luminosity (L X) and halo mass (M 200) where M 200 is derived via stacked weak gravitational lensing. This work draws upon a broad array of multi-wavelength COSMOS observations including 1.64 degrees2 of contiguous imaging with the Advanced Camera for Surveys to a limiting magnitude of I F814W = 26.5 and deep XMM-Newton/Chandra imaging to a limiting flux of 1.0 × 10-15 erg cm-2 s-1 in the 0.5-2 keV band. The combined depth of these two data sets allows us to probe the lensing signals of X-ray-detected structures at both higher redshifts and lower masses than previously explored. Weak lensing profiles and halo masses are derived for nine sub-samples, narrowly binned in luminosity and redshift. The COSMOS data alone are well fit by a power law, M 200 vprop (L X)α, with a slope of α = 0.66 ± 0.14. These results significantly extend the dynamic range for which the halo masses of X-ray-selected structures have been measured with weak gravitational lensing. As a result, tight constraints are obtained for the slope of the M-L X relation. The combination of our group data with previously published cluster data demonstrates that the M-L X relation is well described by a single power law, α = 0.64 ± 0.03, over two decades in mass, M 200 ~ 1013.5-1015.5 h -1 72 M sun. These results are inconsistent at the 3.7σ level with the self-similar prediction of α = 0.75. We examine the redshift dependence of the M-L X relation and find little evidence for evolution beyond the rate predicted by self-similarity from z ~ 0.25 to z ~ 0.8. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope

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.

The ASTRO-H X-ray astronomy satellite

NASA Astrophysics Data System (ADS)

Takahashi, Tadayuki; Mitsuda, Kazuhisa; Kelley, Richard; Aharonian, Felix; Akamatsu, Hiroki; Akimoto, Fumie; Allen, Steve; Anabuki, Naohisa; Angelini, Lorella; Arnaud, Keith; Asai, Makoto; Audard, Marc; Awaki, Hisamitsu; Azzarello, Philipp; Baluta, Chris; Bamba, Aya; Bando, Nobutaka; Bautz, Marshall; Bialas, Thomas; Blandford, Roger D.; Boyce, Kevin; Brenneman, Laura; Brown, Gregory; Cackett, Ed; Canavan, Edgar; Chernyakova, Maria; Chiao, Meng; Coppi, Paolo; Costantini, Elisa; de Plaa, Jelle; den Herder, Jan-Willem; DiPirro, Michael; Done, Chris; Dotani, Tadayasu; Doty, John; Ebisawa, Ken; Enoto, Teruaki; Ezoe, Yuichiro; Fabian, Andrew; Ferrigno, Carlo; Foster, Adam; Fujimoto, Ryuichi; Fukazawa, Yasushi; Funk, Stefan; Furuzawa, Akihiro; Galeazzi, Massimiliano; Gallo, Luigi; Gandhi, Poshak; Gilmore, Kirk; Guainazzi, Matteo; Haas, Daniel; Haba, Yoshito; Hamaguchi, Kenji; Harayama, Atsushi; Hatsukade, Isamu; Hayashi, Katsuhiro; Hayashi, Takayuki; Hayashida, Kiyoshi; Hiraga, Junko; Hirose, Kazuyuki; Hornschemeier, Ann; Hoshino, Akio; Hughes, John; Hwang, Una; Iizuka, Ryo; Inoue, Yoshiyuki; Ishibashi, Kazunori; Ishida, Manabu; Ishikawa, Kumi; Ishimura, Kosei; Ishisaki, Yoshitaka; Itoh, Masayuki; Iwata, Naoko; Iyomoto, Naoko; Jewell, Chris; Kaastra, Jelle; Kallman, Timothy; Kamae, Tuneyoshi; Kataoka, Jun; Katsuda, Satoru; Katsuta, Junichiro; Kawaharada, Madoka; Kawai, Nobuyuki; Kawano, Taro; Kawasaki, Shigeo; Khangaluyan, Dmitry; Kilbourne, Caroline; Kimball, Mark; Kimura, Masashi; Kitamoto, Shunji; Kitayama, Tetsu; Kohmura, Takayoshi; Kokubun, Motohide; Konami, Saori; Kosaka, Tatsuro; Koujelev, Alexander; Koyama, Katsuji; Krimm, Hans; Kubota, Aya; Kunieda, Hideyo; LaMassa, Stephanie; Laurent, Philippe; Lebrun, François; Leutenegger, Maurice; Limousin, Olivier; Loewenstein, Michael; Long, Knox; Lumb, David; Madejski, Grzegorz; Maeda, Yoshitomo; Makishima, Kazuo; Markevitch, Maxim; Masters, Candace; Matsumoto, Hironori; Matsushita, Kyoko; McCammon, Dan; McGuinness, Daniel; McNamara, Brian; Miko, Joseph; Miller, Jon; Miller, Eric; Mineshige, Shin; Minesugi, Kenji; Mitsuishi, Ikuyuki; Miyazawa, Takuya; Mizuno, Tsunefumi; Mori, Koji; Mori, Hideyuki; Moroso, Franco; Muench, Theodore; Mukai, Koji; Murakami, Hiroshi; Murakami, Toshio; Mushotzky, Richard; Nagano, Housei; Nagino, Ryo; Nakagawa, Takao; Nakajima, Hiroshi; Nakamori, Takeshi; Nakashima, Shinya; Nakazawa, Kazuhiro; Namba, Yoshiharu; Natsukari, Chikara; Nishioka, Yusuke; Nobukawa, Masayoshi; Noda, Hirofumi; Nomachi, Masaharu; O'Dell, Steve; Odaka, Hirokazu; Ogawa, Hiroyuki; Ogawa, Mina; Ogi, Keiji; Ohashi, Takaya; Ohno, Masanori; Ohta, Masayuki; Okajima, Takashi; Okazaki, Tsuyoshi; Ota, Naomi; Ozaki, Masanobu; Paerels, Frits; Paltani, Stéphane; Parmar, Arvind; Petre, Robert; Pinto, Ciro; Pohl, Martin; Pontius, James; Porter, F. S.; Pottschmidt, Katja; Ramsey, Brian; Reis, Rubens; Reynolds, Christopher; Ricci, Claudio; Russell, Helena; Safi-Harb, Samar; Saito, Shinya; Sakai, Shin-ichiro; Sameshima, Hiroaki; Sato, Kosuke; Sato, Rie; Sato, Goro; Sawada, Makoto; Serlemitsos, Peter; Seta, Hiromi; Shibano, Yasuko; Shida, Maki; Shimada, Takanobu; Shirron, Peter; Simionescu, Aurora; Simmons, Cynthia; Smith, Randall; Sneiderman, Gary; Soong, Yang; Stawarz, Lukasz; Sugawara, Yasuharu; Sugita, Satoshi; Szymkowiak, Andrew; Tajima, Hiroyasu; Takahashi, Hiroaki; Takahashi, Hiromitsu; Takeda, Shin-ichiro; Takei, Yoh; Tamagawa, Toru; Tamura, Keisuke; Tamura, Takayuki; Tanaka, Takaaki; Tanaka, Yasuyuki; Tanaka, Yasuo; Tashiro, Makoto; Tawara, Yuzuru; Terada, Yukikatsu; Terashima, Yuichi; Tombesi, Francesco; Tomida, Hiroshi; Tsuboi, Yoko; Tsujimoto, Masahiro; Tsunemi, Hiroshi; Tsuru, Takeshi; Uchida, Hiroyuki; Uchiyama, Hideki; Uchiyama, Yasunobu; Ueda, Yoshihiro; Ueda, Shutaro; Ueno, Shiro; Uno, Shinichiro; Urry, Meg; Ursino, Eugenio; de Vries, Cor; Wada, Atsushi; Watanabe, Shin; Watanabe, Tomomi; Werner, Norbert; White, Nicholas; Wilkins, Dan; Yamada, Shinya; Yamada, Takahiro; Yamaguchi, Hiroya; Yamaoka, Kazutaka; Yamasaki, Noriko; Yamauchi, Makoto; Yamauchi, Shigeo; Yaqoob, Tahir; Yatsu, Yoichi; Yonetoku, Daisuke; Yoshida, Atsumasa; Yuasa, Takayuki; Zhuravleva, Irina; Zoghbi, Abderahmen; ZuHone, John

2014-07-01

The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions developed by the Institute of Space and Astronautical Science (ISAS), with a planned launch in 2015. The ASTRO-H mission is equipped with a suite of sensitive instruments with the highest energy resolution ever achieved at E > 3 keV and a wide energy range spanning four decades in energy from soft X-rays to gamma-rays. The simultaneous broad band pass, coupled with the high spectral resolution of ΔE <= 7 eV of the micro-calorimeter, will enable a wide variety of important science themes to be pursued. ASTRO-H is expected to provide breakthrough results in scientific areas as diverse as the large-scale structure of the Universe and its evolution, the behavior of matter in the gravitational strong field regime, the physical conditions in sites of cosmic-ray acceleration, and the distribution of dark matter in galaxy clusters at different redshifts.

NASA and Japanese X-ray observatories Clarify Origin of Cosmic Rays

NASA Technical Reports Server (NTRS)

2005-01-01

Recent observations from NASA and Japanese X-ray observatories have helped clarify one of the long-standing mysteries in astronomy -- the origin of cosmic rays. This image from Japan's Suzaku X-ray observatory shows RXJ1713.7-3946. This supernova remnant is the gaseous remnant of a massive star that exploded. The remnant is about 1,600 years old. The contour lines show where gamma-ray intensity is highest, as measured by the High Energy Stereoscopic System (HESS) in Namibia.

Active x-ray optics for Generation-X, the next high resolution x-ray observatory

NASA Astrophysics Data System (ADS)

Elvis, Martin; Brissenden, R. J.; Fabbiano, G.; Schwartz, D. A.; Reid, P.; Podgorski, W.; Eisenhower, M.; Juda, M.; Phillips, J.; Cohen, L.; Wolk, S.

2006-06-01

X-rays provide one of the few bands through which we can study the epoch of reionization, when the first galaxies, black holes and stars were born. To reach the sensitivity required to image these first discrete objects in the universe needs a major advance in X-ray optics. Generation-X (Gen-X) is currently the only X-ray astronomy mission concept that addresses this goal. Gen-X aims to improve substantially on the Chandra angular resolution and to do so with substantially larger effective area. These two goals can only be met if a mirror technology can be developed that yields high angular resolution at much lower mass/unit area than the Chandra optics, matching that of Constellation-X (Con-X). We describe an approach to this goal based on active X-ray optics that correct the mid-frequency departures from an ideal Wolter optic on-orbit. We concentrate on the problems of sensing figure errors, calculating the corrections required, and applying those corrections. The time needed to make this in-flight calibration is reasonable. A laboratory version of these optics has already been developed by others and is successfully operating at synchrotron light sources. With only a moderate investment in these optics the goals of Gen-X resolution can be realized.

X-ray Reflection

NASA Astrophysics Data System (ADS)

Fabian, A. C.; Ross, R. R.

2010-12-01

Material irradiated by X-rays produces backscattered radiation which is commonly known as the Reflection Spectrum. It consists of a structured continuum, due at high energies to the competition between photoelectric absorption and electron scattering enhanced at low energies by emission from the material itself, together with a complex line spectrum. We briefly review the history of X-ray reflection in astronomy and discuss various methods for computing the reflection spectrum from cold and ionized gas, illustrated with results from our own work reflionx. We discuss how the reflection spectrum can be used to obtain the geometry of the accretion flow, particularly the inner regions around black holes and neutron stars.

Space instrumentation for gamma-ray astronomy

NASA Astrophysics Data System (ADS)

Teegarden, B. J.

1999-02-01

The decade of the 1990s has witnessed a renaissance in the field of gamma-ray astronomy. The seminal event was the launch of the Compton Gamma-Ray Observatory (CGRO) in April 1991. There have been a flood of major discoveries from CGRO including breakthroughs in gamma-ray bursts, annihilation radiation, and blazars. The Italian SAX satellite was launched in April 1996. Although not primarily a gamma-ray mission, it has added a new dimension to our understanding of gamma-ray bursts. Along with these new discoveries a firm groundwork has been laid for missions and new technology development that should maintain a healthy and vigorous field throughout most of the next decade. These include the ESA INTEGRAL mission (INTErnational Gamma-Ray Astrophysics Laboratory, to be launched in mid-2001) and the NASA GLAST mission (Gamma-Ray Large Area Space Telescope) with a likely launch in the middle of the next decade. These two missions will extend the observational capabilities well beyond those of CGRO. New technologies (to gamma-ray astronomy), such as cooled germanium detectors, silicon strip detectors, and CdTe detectors are planned for these new missions. Additional promising new technologies such as CdZnTe strip detectors, scintillator fibers, and a gamma-ray lens for future gamma-ray astronomy missions are under development in laboratories around the world.

7 years of MAXI: monitoring X-ray transients

NASA Astrophysics Data System (ADS)

Serino, M.; Shidatsu, M.; Iwakiri, W.; Mihara, T.

2017-03-01

This workshop was held to celebrate the successful 7 years of observation with Monitor of All-sky X-ray Image (MAXI), a Japanese astrophysics payload on the International Space Station. Since the launch in 2009, MAXI has been monitoring the variable X-ray sky, and has discovered 17 new X-ray sources. Often with a help of multi-wavelength follow-up observations, one of them has been identified with the nuclear ignition of a massive nova, 6 with black-hole binaries, and 5 with those involving neutron stars. Nevertheless, 4 of them remain unidentified, and are considered to form a potentially new class of short soft transients. MAXI is also leading the time-domain astronomy, with its capability to issue alerts which triggers prompt follow-up observations in the optical and other wavelengths. So far, MAXI has detected about a hundred gamma-ray bursts, and performing unbiased watch for stellar flares. In addition, long-term X-ray variations of about a hundred of sources are continuously tracked with MAXI. This has enabled a variety of new astrophysics that cannot be achieved by snapshot observations. The recent detections of the gravitation wave events have significantly increased the importance of MAXI as a currently operating all-sky monitor, and as a member of multi-messenger astronomy which covers electromagnetic waves, neutrinos, and gravitational waves. In this symposium, the MAXI results obtained during the 7 years are reviewed, with a session assigned to those from Hitomi. The symposium also covers new prospects in the time-domain astronomy, to be developed with future X-ray missions/instruments.

Advanced X-ray Astrophysics Facility (AXAF): An overview

NASA Technical Reports Server (NTRS)

Weisskopf, M. C.; ODell, S. L.; Elsner, R. F.; VanSpeybroeck, L. P.

1995-01-01

The Advanced X-ray Astrophysics Facility (AXAF) is the x-ray component of NASA's Great Observatories. To be launched in late 1998, AXAF will provide unprecedented capabilities for high-resolution imaging, spectrometric imaging, and high-resolution disperse spectroscopy, over the x-ray band from about 0.1 keV to 10 keV. With these capabilities, AXAF observations will address many of the outstanding questions in astronomy, astrophysics, and cosmology.

X-Ray astronomy the 1980's. [conferences

NASA Technical Reports Server (NTRS)

Holt, S. S. (Editor)

1981-01-01

The status of the current understanding of important problems to which X-ray astronomical techniques can be applied is summarized and the prospects for such research in the future is discussed. Relatively near-term X-ray astronomical research objectives are presented. The importance of a continuing program of balloon-borne research as a cost effective means by which studies at energies in excess of 20 keV may be performed is emphasized. The scientific opportunities presented by the Space Transpotation System to develop low cost experiments which are beyond the scope of balloon-borne capabilities are also highlighted.

Characteristics and performance of thin LaBr3(Ce) crystal for hard X-ray astronomy

NASA Astrophysics Data System (ADS)

Manchanda, R. K.

2011-01-01

We have developed a new detector using thin lanthanum bromide crystal (32 × 3 mm) for use in X-ray astronomy. The instrument was launched in high altitude balloon flight on two different occasions, December 21, 2007, which reached a ceiling altitude of 4.3 mbs and April 25, 2008 reaching a ceiling altitude 2.8 mbs. The observed background counting rate at the ceiling altitude of 4 mbs was ˜4 × 10-3 ct cm-2 s-1 keV-1 sr-1. This paper describes the details of the experiment, the detector characteristics, and the background behaviour at the ceiling altitude.

VETA-I x ray test analysis

NASA Technical Reports Server (NTRS)

Brissenden, R. J. V.; Chartas, G.; Freeman, M. D.; Hughes, J. P.; Kellogg, E. M.; Podgorski, W. A.; Schwartz, D. A.; Zhao, P.

1992-01-01

This interim report presents some definitive results from our analysis of the VETA-I x-ray testing data. It also provides a description of the hardware and software used in the conduct of the VETA-I x-ray test program performed at the MSFC x-ray Calibration Facility (XRCF). These test results also serve to supply data and information to include in the TRW final report required by DPD 692, DR XC04. To provide an authoritative compendium of results, we have taken nine papers as published in the SPIE Symposium, 'Grazing Incidence X-ray/EUV Optics for Astronomy and Projection Lithography' and have reproduced them as the content of this report.

Toward Active X-ray Telescopes II

NASA Technical Reports Server (NTRS)

O'Dell, Stephen L.; Aldroft, Thomas L.; Atkins, Carolyn; Button, Timothy W.; Cotroneo, Vincenzo; Davis, William N.; Doel, Peter; Feldman, Charlotte H.; Freeman, Mark D.; Gubarev, Mikhail V.;

Small Pixel Hybrid CMOS X-ray Detectors

NASA Astrophysics Data System (ADS)

Hull, Samuel; Bray, Evan; Burrows, David N.; Chattopadhyay, Tanmoy; Falcone, Abraham; Kern, Matthew; McQuaide, Maria; Wages, Mitchell

2018-01-01

Concepts for future space-based X-ray observatories call for a large effective area and high angular resolution instrument to enable precision X-ray astronomy at high redshift and low luminosity. Hybrid CMOS detectors are well suited for such high throughput instruments, and the Penn State X-ray detector lab, in collaboration with Teledyne Imaging Sensors, has recently developed new small pixel hybrid CMOS X-ray detectors. These prototype 128x128 pixel devices have 12.5 micron pixel pitch, 200 micron fully depleted depth, and include crosstalk eliminating CTIA amplifiers and in-pixel correlated double sampling (CDS) capability. We report on characteristics of these new detectors, including the best read noise ever measured for an X-ray hybrid CMOS detector, 5.67 e- (RMS).

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.

Solar X-ray Astronomy Sounding Rocket Program

NASA Technical Reports Server (NTRS)

Moses, J. Daniel

1989-01-01

Several broad objectives were pursued by the development and flight of the High Resolution Soft X-Ray Imaging Sounding Rocket Payload, followed by the analysis of the resulting data and by comparison with both ground based and space based observations from other investigators. The scientific objectives were: to study the thermal equilibrium of active region loop systems by analyzing the X-ray observations to determine electron temperatures, densities, and pressures; by recording the changes in the large scale coronal structures from the maximum and descending phases of Cycle 21 to the ascending phase of Cycle 22; and to extend the study of small scale coronal structures through the minimum of Cycle 21 with new emphasis on correlative observations.

LoCuSS: The infall of X-ray groups onto massive clusters

NASA Astrophysics Data System (ADS)

Haines, C. P.; Finoguenov, A.; Smith, G. P.; Babul, A.; Egami, E.; Mazzotta, P.; Okabe, N.; Pereira, M. J.; Bianconi, M.; McGee, S. L.; Ziparo, F.; Campusano, L. E.; Loyola, C.

2018-03-01

Galaxy clusters are expected to form hierarchically in a ΛCDM universe, growing primarily through mergers with lower mass clusters and the continual accretion of group-mass halos. Galaxy clusters assemble late, doubling their masses since z ˜ 0.5, and so the outer regions of clusters should be replete with accreting group-mass systems. We present an XMM-Newton survey to search for X-ray groups in the infall regions of 23 massive galaxy clusters ( ˜ 1015 M⊙) at z ˜ 0.2, identifying 39 X-ray groups that have been spectroscopically confirmed to lie at the cluster redshift. These groups have mass estimates in the range 2 × 1013 - 7 × 1014 M⊙, and group-to-cluster mass ratios as low as 0.02. The comoving number density of X-ray groups in the infall regions is ˜25 × higher than that seen for isolated X-ray groups from the XXL survey. The average mass per cluster contained within these X-ray groups is 2.2 × 1014 M⊙, or 19 ± 5% of the mass within the primary cluster itself. We estimate that ˜1015 M⊙ clusters increase their masses by 16 ± 4% between z = 0.223 and the present day due to the accretion of groups with M200 ≥ 1013.2 M⊙. This represents about half of the expected mass growth rate of clusters at these late epochs. The other half is likely to come from smooth accretion of matter not bound within halos. The mass function of the infalling X-ray groups appears significantly top heavy with respect to that of "field" X-ray systems, consistent with expectations from numerical simulations, and the basic consequences of collapsed massive dark matter halos being biased tracers of the underlying large-scale density distribution.

Apollo-Soyuz pamphlet no. 2: X-rays, gamma-rays. [experimental design

NASA Technical Reports Server (NTRS)

Page, L. W.; From, T. P.

1977-01-01

The nature of high energy radiation and its penetration through earth's atmosphere is examined with emphasis on X-rays, gamma rays, and cosmic radiation and the instruments used in their detection. The history of radio astronomy and the capabilities of the Uhuru satellite are summarized. The ASTP soft X-ray experiment (MA-048) designed to study the spectra in the range from 0.1 to 10 keV and survey the background over a large section of the sky is described, as well as the determination of SMC C-1 as an X-ray pulsar. The crystal activation experiment (MA-151) used to measure the radioactive isotopes created by cosmic rays in crystals used for gamma ray detectors is also discussed.

Novel wide-field x-ray optics for space

NASA Astrophysics Data System (ADS)

Hudec, René; Pína, Ladislav; Inneman, Adolf

2017-11-01

We report on the program of design and development of innovative very wide field X-ray optics for space applications. We describe the idea of wide field X-ray optics of the lobster-eye type of both Angel and Schmidt arrangements. This optics was suggested in 70ies but not yet used in space experiment due to severe manufacturing problems. The lobster-eye X-ray optics may achieve up to 180 degrees (diameter) field of view at angular resolution of order of 1 arcmin. We report on various prototypes of lobster-eye X-ray lenses based on alternative technologies (replicated double sided X-ray reflecting flats, float glass, replicated square channels etc.) as well as on their optical and X-ray tests. We also discuss the importance and performance of lobster-eye X-ray telescopes in future X-ray astronomy projects.

The high energy X-ray universe

PubMed Central

Giacconi, Riccardo

2010-01-01

Since its beginning in the early 1960s, the field of X-ray astronomy has exploded, experiencing a ten-billion-fold increase in sensitivity, which brought it on par with the most advanced facilities at all wavelengths. I will briefly describe the revolutionary first discoveries prior to the launch of the Chandra and XMM-Newton X-ray observatories, present some of the current achievements, and offer some thoughts about the future of this field. PMID:20404148

Development of EXITE2: a large-area imaging phoswich detector/telescope for hard x-ray astronomy

NASA Astrophysics Data System (ADS)

Manandhar, Raj P.; Lum, Kenneth S.; Eikenberry, Stephen S.; Krockenberger, Martin; Grindlay, Jonathan E.

1993-11-01

We review design considerations and present preliminary details of the performance of a new imaging system for hard X-ray astronomy in the 20 - 600 keV energy range. The detector is a 40 cm X 40 cm NaI(Tl)/CsI(Na) phoswich module, read out by a 7 X 7 array of square PMTs. The detector comprises the main part of the next generation Energetic X-ray Imaging Telescope Experiment (EXITE2), which had its first flight on 13 June 1993 from Palestine, Texas. Imaging is accomplished via the coded-aperture mask technique. The mask consists of 16 mm square lead/tin/copper pixels arranged in a cyclically repeated 13 X 11 uniformly redundant array pattern at a focal length of 2.5 m, giving 22 arcmin resolution. The field of view, determined by the lead/brass collimator (16 mm pitch) is 4.65 degrees FWHM. We anticipate a 3 sigma sensitivity of 1 X 10(superscript -5) photons cm(superscript -2) s(superscript -1) keV(superscript -1) at 100 keV in a 10(superscript 4) sec balloon observation. The electronics incorporate two on-board computers, providing a future capability to record the full data stream and telemeter compressed data. The design of the current detector and electronics allows an upgrade to EXITE3, which adds a proportional counter front-end to achieve lower background and better spatial and spectral resolution below approximately 100 keV.

X-Ray Optics for the 2020's

NASA Technical Reports Server (NTRS)

Zhang, Will

2010-01-01

X-ray optics is an essential and enabling technology for x-ray astronomy. This slide presentation presents the authors views on the requirements for x-ray optics as progress is made toward building IXO and preparing for the 2020's. The presentation reviews the status of several technologies that are being developed and outlines the steps that we as a community needs to take to move toward x-ray optics meeting the five key requirements: (1) high angular resolution, (2) large effective area, (3) low mass, (4) fast production, and (5) low cost. There is discussion of segmentation vs full shell, size of the mirror segment, mirror segment frabrication, post-slumping figure improvement, and characterization of coating quality.

Spectra of cosmic X-ray sources

NASA Technical Reports Server (NTRS)

Holt, S. S.; Mccray, R.

1982-01-01

X-ray measurements provide the most direct probes of astrophysical environments with temperatures exceeding one million K. Progress in experimental research utilizing dispersive techniques (e.g., Bragg and grating spectroscopy) is considerably slower than that in areas utilizing photometric techniques, because of the relative inefficiency of the former for the weak X-ray signals from celestial sources. As a result, the term "spectroscopy" as applied to X-ray astronomy has traditionally satisfied a much less restrictive definition (in terms of resolving power) than it has in other wavebands. Until quite recently, resolving powers of order unity were perfectly respectable, and still provide (in most cases) the most useful spectroscopic data. In the broadest sense, X-ray photometric measurements are spectroscopic, insofar as they represent samples of the overall electromagnetic continua of celestial objects.

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

Rossi and high-energy astronomy

NASA Astrophysics Data System (ADS)

Clark, George W.

2012-03-01

The contributions of Bruno Rossi to high-energy astronomy began in Italy in the 1930s with investigations concerning the nature of cosmic rays in theory and in hands-on experiments at the universities of Florence and Padua. Recent discoveries had cast doubt on Robert Millikan's idea that the primary cosmic rays are gamma rays created in the production of the elements by fusion of hydrogen atoms in interstellar space. Rossi entered the field with a prediction published in 1930 of a difference between the intensity of cosmic rays from the east and the west that would occur if the primary cosmic rays were charged particles of one sign. In the same year he invented the first practical electronic coincidence circuit, which he used in a series of fundamental particle experiments and in an unsuccessful attempt to detect an east-west effect at Florence. Expecting by theory that the effect would be greater at high altitude near the equator, he took his experiment to Eritrea in 1934 where his measurements demonstrated that the primary cosmic rays are predominantly positive particles. In the report of his expedition he also described his discovery of extensive cosmic-ray air showers. After WWII and his work at Los Alamos, Rossi resumed his cosmic-ray research, now at MIT, in a new style best described in his own words: ``Now I had the responsibility of an entire group, and what mattered was no longer my own work, but the work of the group.'' He suggested the new methods of ``density sampling'' and ``fast timing'' for air shower studies, and promoted their application in numerous experiments on the nature and origins of the highest energy cosmic rays. In 1959 he initiated and participated as a consultant in the work of Riccardo Giacconi that led to the discovery of the first x-ray star, Sco X-1, and the development of the first imaging x-ray telescopes. At MIT, members of the Rossi Cosmic Ray Group took the early steps in gamma-ray astronomy, first with balloon experiments

X-Ray Spectroscopic Laboratory Experiments In Support of the NASA X-Ray Astronomy Flight Program

NASA Technical Reports Server (NTRS)

Kahn, Steven M.; Savin, D. W.; Gu, M. F.; Beiersdorfer, P.; Liedahl, D. A.; Brown, G.; Utter, S.

1998-01-01

During the 1997 performance period, our work focused on the L-shell X-ray emission from highly charged iron ions in the 10-18 A region. Details of our accomplishments in 1997 are presented in the following. We start by describing the laboratory measurements made and their impact on the X-ray flight program and conclude by an overview of new instrumental capabilities developed for uses in the coming year.

Development of Position-Sensitive Magnetic Calorimeters for X-Ray Astronomy

NASA Technical Reports Server (NTRS)

Bandler, SImon; Stevenson, Thomas; Hsieh, Wen-Ting

2011-01-01

Metallic magnetic calorimeters (MMC) are one of the most promising devices to provide very high energy resolution needed for future astronomical x-ray spectroscopy. MMC detectors can be built to large detector arrays having thousands of pixels. Position-sensitive magnetic (PoSM) microcalorimeters consist of multiple absorbers thermally coupled to one magnetic micro calorimeter. Each absorber element has a different thermal coupling to the MMC, resulting in a distribution of different pulse shapes and enabling position discrimination between the absorber elements. PoSMs therefore achieve the large focal plane area with fewer number of readout channels without compromising spatial sampling. Excellent performance of PoSMs was achieved by optimizing the designs of key parameters such as the thermal conductance among the absorbers, magnetic sensor, and heat sink, as well as the absorber heat capacities. Micro fab ri - cation techniques were developed to construct four-absorber PoSMs, in which each absorber consists of a two-layer composite of bismuth and gold. The energy resolution (FWHM full width at half maximum) was measured to be better than 5 eV at 6 keV x-rays for all four absorbers. Position determination was demonstrated with pulse-shape discrimination, as well as with pulse rise time. X-ray microcalorimeters are usually designed to thermalize as quickly as possible to avoid degradation in energy resolution from position dependence to the pulse shapes. Each pixel consists of an absorber and a temperature sensor, both decoupled from the cold bath through a weak thermal link. Each pixel requires a separate readout channel; for instance, with a SQUID (superconducting quantum interference device). For future astronomy missions where thousands to millions of resolution elements are required, having an individual SQUID readout channel for each pixel becomes difficult. One route to attaining these goals is a position-sensitive detector in which a large continuous or

X-rays from the Solar System

NASA Astrophysics Data System (ADS)

Dennerl, K.

2017-10-01

While the beginning of X-ray astronomy was motivated by solar system studies (Sun and Moon), the main research interest soon shifted outwards to much more distant and exotic objects. However, the ROSAT discovery of X-rays from comets in 1996 and the insight that this `new' kind of X-ray emission, charge exchange, was underestimated for a long time, has demonstrated that solar system studies are still important for X-ray astrophysics in general. While comets provide the best case for studying the physics of charge exchange, the X-ray signatures of this process have now also been detected at Venus, Mars, and Jupiter, thanks to Chandra and XMM-Newton. An analysis of the X-ray data of solar system objects, however, is challenging in many respects. This is particularly true for comets, which appear as moving, extended X-ray sources, emitting a line-rich spectrum at low energies. Especially for XMM-Newton, which has the unparalleled capability to observe with five highly sensitive X-ray instruments plus an optical monitor simultaneously, it is a long way towards photometrically and spectroscopically calibrated results, which are consistent between all its instruments. I will show this in my talk, where I will also summarize the current state of solar system X-ray research.

Si(Li) X-ray astronomical spectroscopy

NASA Technical Reports Server (NTRS)

Holt, S. S.

1975-01-01

The general considerations involved in the choice of Si(Li) as a non-dispersive spectrometer for X-ray astronomy are discussed. In particular, its adaptation to HEAO-B is described as an example of the space-borne application of Si(Li) technology.

Toward Large-Area Sub-Arcsecond X-Ray Telescopes

NASA Technical Reports Server (NTRS)

O'Dell, Stephen L.; Aldcroft, Thomas L.; Allured, Ryan; Atkins, Carolyn; Burrows, David N.; Cao, Jian; Chalifoux, Brandon D.; Chan, Kai-Wing; Cotroneo, Vincenzo; Elsner, Ronald F.;

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.

Monolithic CMOS imaging x-ray spectrometers

NASA Astrophysics Data System (ADS)

Kenter, Almus; Kraft, Ralph; Gauron, Thomas; Murray, Stephen S.

2014-07-01

The Smithsonian Astrophysical Observatory (SAO) in collaboration with SRI/Sarnoff is developing monolithic CMOS detectors optimized for x-ray astronomy. The goal of this multi-year program is to produce CMOS x-ray imaging spectrometers that are Fano noise limited over the 0.1-10keV energy band while incorporating the many benefits of CMOS technology. These benefits include: low power consumption, radiation "hardness", high levels of integration, and very high read rates. Small format test devices from a previous wafer fabrication run (2011-2012) have recently been back-thinned and tested for response below 1keV. These devices perform as expected in regards to dark current, read noise, spectral response and Quantum Efficiency (QE). We demonstrate that running these devices at rates ~> 1Mpix/second eliminates the need for cooling as shot noise from any dark current is greatly mitigated. The test devices were fabricated on 15μm, high resistivity custom (~30kΩ-cm) epitaxial silicon and have a 16 by 192 pixel format. They incorporate 16μm pitch, 6 Transistor Pinned Photo Diode (6TPPD) pixels which have ~40μV/electron sensitivity and a highly parallel analog CDS signal chain. Newer, improved, lower noise detectors have just been fabricated (October 2013). These new detectors are fabricated on 9μm epitaxial silicon and have a 1k by 1k format. They incorporate similar 16μm pitch, 6TPPD pixels but have ~ 50% higher sensitivity and much (3×) lower read noise. These new detectors have undergone preliminary testing for functionality in Front Illuminated (FI) form and are presently being prepared for back thinning and packaging. Monolithic CMOS devices such as these, would be ideal candidate detectors for the focal planes of Solar, planetary and other space-borne x-ray astronomy missions. The high through-put, low noise and excellent low energy response, provide high dynamic range and good time resolution; bright, time varying x-ray features could be temporally and

New trends in space x-ray optics

NASA Astrophysics Data System (ADS)

Hudec, R.; Maršíková, V.; Pína, L.; Inneman, A.; Skulinová, M.

2017-11-01

The X-ray optics is a key element of various X-ray telescopes, X-ray microscopes, as well as other X-ray imaging instruments. The grazing incidence X-ray lenses represent the important class of X-ray optics. Most of grazing incidence (reflective) X-ray imaging systems used in astronomy but also in other (laboratory) applications are based on the Wolter 1 (or modified) arrangement. But there are also other designs and configurations proposed, used and considered for future applications both in space and in laboratory. The Kirkpatrick-Baez (K-B) lenses as well as various types of Lobster-Eye optics and MCP/Micropore optics serve as an example. Analogously to Wolter lenses, the X-rays are mostly reflected twice in these systems to create focal images. Various future projects in X-ray astronomy and astrophysics will require large segments with multiple thin shells or foils. The large Kirkpatrick-Baez modules, as well as the large Lobster-Eye X-ray telescope modules in Schmidt arrangement may serve as examples. All these space projects will require high quality and light segmented shells (bent or flat foils) with high X-ray reflectivity and excellent mechanical stability. The Multi Foil Optics (MFO) approach represent a promising alternative for both LE and K-B X-ray optical modules. Several types of reflecting substrates may be considered for these applications, with emphasis on thin float glass sheets and, more recently, high quality silicon wafers. This confirms the importance of non- Wolter X-ray optics designs for the future. Future large space X-ray telescopes (such as IXO) require precise and light-weight X-ray optics based on numerous thin reflecting shells. Novel approaches and advanced technologies are to be exploited and developed. In this contribution, we refer on results of tested X-ray mirror shells produced by glass thermal forming (GTF) and by shaping Si wafers. Both glass foils and Si wafers are commercially available, have excellent surface

LoCuSS: The infall of X-ray groups on to massive clusters

NASA Astrophysics Data System (ADS)

Haines, C. P.; Finoguenov, A.; Smith, G. P.; Babul, A.; Egami, E.; Mazzotta, P.; Okabe, N.; Pereira, M. J.; Bianconi, M.; McGee, S. L.; Ziparo, F.; Campusano, L. E.; Loyola, C.

2018-07-01

Galaxy clusters are expected to form hierarchically in a Λ cold dark matter (ΛCDM) universe, growing primarily through mergers with lower mass clusters and the continual accretion of group-mass haloes. Galaxy clusters assemble late, doubling their masses since z ˜ 0.5, and so the outer regions of clusters should be replete with accreting group-mass systems. We present an XMM-Newton survey to search for X-ray groups in the infall regions of 23 massive galaxy clusters ( ˜ 1015 M⊙) at z ˜ 0.2, identifying 39 X-ray groups that have been spectroscopically confirmed to lie at the cluster redshift. These groups have mass estimates in the range 2 × 1013-7 × 1014 M⊙, and group-to-cluster mass ratios as low as 0.02. The comoving number density of X-ray groups in the infall regions is ˜25× higher than that seen for isolated X-ray groups from the XXL survey. The average mass per cluster contained within these X-ray groups is 2.2 × 1014 M⊙, or 19 ± 5 per cent of the mass within the primary cluster itself. We estimate that ˜1015 M⊙ clusters increase their masses by 16 ± 4 per cent between z = 0.223 and the present day due to the accretion of groups with M200 ≥ 1013.2 M⊙. This represents about half of the expected mass growth rate of clusters at these late epochs. The other half is likely to come from smooth accretion of matter not bound within haloes. The mass function of the infalling X-ray groups appears significantly top heavy with respect to that of `field' X-ray systems, consistent with expectations from numerical simulations, and the basic consequences of collapsed massive dark matter haloes being biased tracers of the underlying large-scale density distribution.

INTRAGROUP AND GALAXY-LINKED DIFFUSE X-RAY EMISSION IN HICKSON COMPACT GROUPS

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

Desjardins, Tyler D.; Gallagher, Sarah C.; Tzanavaris, Panayiotis

2013-02-15

Isolated compact groups (CGs) of galaxies present a range of dynamical states, group velocity dispersions, and galaxy morphologies with which to study galaxy evolution, particularly the properties of gas both within the galaxies and in the intragroup medium. As part of a large, multiwavelength examination of CGs, we present an archival study of diffuse X-ray emission in a subset of nine Hickson compact groups (HCGs) observed with the Chandra X-Ray Observatory. We find that seven of the groups in our sample exhibit detectable diffuse emission. However, unlike large-scale emission in galaxy clusters, the diffuse features in the majority of themore » detected groups are linked to the individual galaxies, in the form of both plumes and halos likely as a result of vigourous star formation or activity in the galaxy nucleus, as well as in emission from tidal features. Unlike previous studies from earlier X-ray missions, HCGs 31, 42, 59, and 92 are found to be consistent with the L{sub X} -T relationship from clusters within the errors, while HCGs 16 and 31 are consistent with the cluster L{sub X} -{sigma} relation, though this is likely coincidental given that the hot gas in these two systems is largely due to star formation. We find that L{sub X} increases with decreasing group H I to dynamical-mass ratio with tentative evidence for a dependence in X-ray luminosity on H I morphology whereby systems with intragroup H I indicative of strong interactions are considerably more X-ray luminous than passively evolving groups. We also find a gap in the L{sub X} of groups as a function of the total group specific star formation rate. Our findings suggest that the hot gas in these groups is not in hydrostatic equilibrium and these systems are not low-mass analogs of rich groups or clusters, with the possible exception of HCG 62.« less

Intragroup and Galaxy-linked Diffuse X-ray Emission In Hickson Compact Groups

NASA Technical Reports Server (NTRS)

Desjardins, Tyler D.; Gallagher, Sarah C.; Tzanavaris, Panayiotis; Mulchaey, John S.; Brandt, William N.; Charlton, Jane C.; Garmire, Gordon P.; Gronwall, Caryl; Cardiff, Ann; Johnson, Kelsey E.;

Hard-X-Ray/Soft-Gamma-Ray Imaging Sensor Assembly for Astronomy

NASA Technical Reports Server (NTRS)

Myers, Richard A.

2008-01-01

An improved sensor assembly has been developed for astronomical imaging at photon energies ranging from 1 to 100 keV. The assembly includes a thallium-doped cesium iodide scintillator divided into pixels and coupled to an array of high-gain avalanche photodiodes (APDs). Optionally, the array of APDs can be operated without the scintillator to detect photons at energies below 15 keV. The array of APDs is connected to compact electronic readout circuitry that includes, among other things, 64 independent channels for detection of photons in various energy ranges, up to a maximum energy of 100 keV, at a count rate up to 3 kHz. The readout signals are digitized and processed by imaging software that performs "on-the-fly" analysis. The sensor assembly has been integrated into an imaging spectrometer, along with a pair of coded apertures (Fresnel zone plates) that are used in conjunction with the pixel layout to implement a shadow-masking technique to obtain relatively high spatial resolution without having to use extremely small pixels. Angular resolutions of about 20 arc-seconds have been measured. Thus, for example, the imaging spectrometer can be used to (1) determine both the energy spectrum of a distant x-ray source and the angular deviation of the source from the nominal line of sight of an x-ray telescope in which the spectrometer is mounted or (2) study the spatial and temporal development of solar flares, repeating - ray bursters, and other phenomena that emit transient radiation in the hard-x-ray/soft- -ray region of the electromagnetic spectrum.

X-ray emission from clusters and groups of galaxies

NASA Technical Reports Server (NTRS)

Mushotzky, R.

1998-01-01

Recent major advances in x-ray imaging and spectroscopy of clusters have allowed the determination of their mass and mass profile out to approximately 1/2 the virial radius. In rich clusters, most of the baryonic mass is in the gas phase, and the ratio of mass in gas/stars varies by a factor of 2-4. The baryonic fractions vary by a factor of approximately 3 from cluster to cluster and almost always exceed 0.09 h50-[3/2] and thus are in fundamental conflict with the assumption of Omega = 1 and the results of big bang nucleosynthesis. The derived Fe abundances are 0.2-0.45 solar, and the abundances of O and Si for low redshift systems are 0.6-1.0 solar. This distribution is consistent with an origin in pure type II supernova. The amount of light and energy produced by these supernovae is very large, indicating their importance in influencing the formation of clusters and galaxies. The lack of evolution of Fe to a redshift of z approximately 0.4 argues for very early enrichment of the cluster gas. Groups show a wide range of abundances, 0.1-0.5 solar. The results of an x-ray survey indicate that the contribution of groups to the mass density of the universe is likely to be larger than 0.1 h50-2. Many of the very poor groups have large x-ray halos and are filled with small galaxies whose velocity dispersion is a good match to the x-ray temperatures.

X-ray emission from clusters and groups of galaxies.

PubMed

Mushotzky, R

1998-01-06

Recent major advances in x-ray imaging and spectroscopy of clusters have allowed the determination of their mass and mass profile out to approximately 1/2 the virial radius. In rich clusters, most of the baryonic mass is in the gas phase, and the ratio of mass in gas/stars varies by a factor of 2-4. The baryonic fractions vary by a factor of approximately 3 from cluster to cluster and almost always exceed 0.09 h50-[3/2] and thus are in fundamental conflict with the assumption of Omega = 1 and the results of big bang nucleosynthesis. The derived Fe abundances are 0.2-0.45 solar, and the abundances of O and Si for low redshift systems are 0.6-1.0 solar. This distribution is consistent with an origin in pure type II supernova. The amount of light and energy produced by these supernovae is very large, indicating their importance in influencing the formation of clusters and galaxies. The lack of evolution of Fe to a redshift of z approximately 0.4 argues for very early enrichment of the cluster gas. Groups show a wide range of abundances, 0.1-0.5 solar. The results of an x-ray survey indicate that the contribution of groups to the mass density of the universe is likely to be larger than 0.1 h50-2. Many of the very poor groups have large x-ray halos and are filled with small galaxies whose velocity dispersion is a good match to the x-ray temperatures.

X-ray optics for WHIMex: the Warm Hot Intergalactic Medium Explorer

NASA Astrophysics Data System (ADS)

Cash, W.; McEntaffer, R.; Zhang, W.; Casement, S.; Lillie, C.; Schattenburg, M.; Bautz, M.; Holland, A.; Tsunemi, H.; O'Dell, S.

2011-09-01

The x-ray astronomy community has never flown a celestial source spectrograph that can resolve natural line widths in absorption the way the ultraviolet community did with OAO-3 Copernicus back in 1972. Yet there is important science to be mined there, and right now, the large flagship missions like the International X-ray Observatory are not progressing toward launch. WHIMEx is an Explorer concept proposed earlier this year to open up that science regime in the next few years. The concept features a modified off-plane grating spectrograph design that will support high resolution (λ/δλ ~ 4000) in the soft x-ray band with a high packing density that will enable a modest cost space mission. We discuss the design and capabilities for the WHIMEx mission. Its prime science goal is detecting high temperature oxygen in the Intergalactic Medium, but it has a broad range of science potential cutting across all of x-ray astronomy and should give us a new window on the Universe.

Soft X-ray study of solar wind charge exchange from the Earth's magnetosphere : Suzaku observations and a future X-ray imaging mission concept

NASA Astrophysics Data System (ADS)

Ezoe, Y.; Ishisaki, Y.; Ohashi, T.; Ishikawa, K.; Miyoshi, Y.; Fujimoto, R.; Terada, N.; Kasahara, S.; Fujimoto, M.; Mitsuda, K.; Nishijo, K.; Noda, A.

2013-12-01

Soft X-ray observations of solar wind charge exchange (SWCX) emission from the Earth's magnetosphere using the Japanese X-ray astronomy satellite Suzaku are shown, together with our X-ray imaging mission concept to characterize the solar wind interaction with the magnetosphere. In recent years, the SWCX emission from the Earth's magnetosphere, originally discovered as unexplained noise during the soft X-ray all sky survey (Snowden et al. 1994), is receiving increased attention on studying geospace. The SWCX is a reaction between neutrals in exosphere and highly charged ions in the magnetosphere originated from solar wind. Robertson et al. (2005) modeled the SWCX emission as seen from an observation point 50 Re from Earth. In the resulting X-ray intensities, the magnetopause, bow shock and cusp were clearly visible. High sensitivity soft X-ray observation with CCDs onboard recent X-ray astronomy satellites enables us to resolve SWCX emission lines and investigate time correlation with solar wind as observed with ACE and WIND more accurately. Suzaku is the 5th Japanese X-ray astronomy satellite launched in 2005. The line of sight direction through cusp is observable, while constraints on Earth limb avoidance angle of other satellites often limits observable regions. Suzaku firstly detected the SWCX emission while pointing in the direction of the north ecliptic pole (Fujimoto et al. 2007). Using the Tsyganenko 1996 magnetic field model, the distance to the nearest SWCX region was estimated as 2-8 Re, implying that the line of sight direction can be through magnetospheric cusp. Ezoe et al. (2010) reported SWCX events toward the sub-solar side of the magnetosheath. These cusp and sub-solar side magnetosheath regions are predicted to show high SWCX fluxes by Robertson et al. (2005). On the other hand, Ishikawa et al. (2013) discovered a similarly strong SWCX event when the line of sight direction did not transverse these two regions. Motivated by these detections

The space shuttle payload planning working groups. Volume 3: High energy astrophysics

NASA Technical Reports Server (NTRS)

1973-01-01

The findings of the High Energy Astrophysics working group of the space shuttle payload planning activity are presented. The objectives to be accomplished during space shuttle missions are defined as: (1) X-ray astronomy, (2) hard X-ray and gamma ray astronomy, and (3) cosmic ray astronomy. The instruments and test equipment required to accomplish the mission are identified. Recommendations for managing the installation of the equipment and conducting the missions are included.

X-ray emission from clusters and groups of galaxies

PubMed Central

Mushotzky, Richard

1998-01-01

Recent major advances in x-ray imaging and spectroscopy of clusters have allowed the determination of their mass and mass profile out to ≈1/2 the virial radius. In rich clusters, most of the baryonic mass is in the gas phase, and the ratio of mass in gas/stars varies by a factor of 2–4. The baryonic fractions vary by a factor of ≈3 from cluster to cluster and almost always exceed 0.09 h50−[3/2] and thus are in fundamental conflict with the assumption of Ω = 1 and the results of big bang nucleosynthesis. The derived Fe abundances are 0.2–0.45 solar, and the abundances of O and Si for low redshift systems are 0.6–1.0 solar. This distribution is consistent with an origin in pure type II supernova. The amount of light and energy produced by these supernovae is very large, indicating their importance in influencing the formation of clusters and galaxies. The lack of evolution of Fe to a redshift of z ≈ 0.4 argues for very early enrichment of the cluster gas. Groups show a wide range of abundances, 0.1–0.5 solar. The results of an x-ray survey indicate that the contribution of groups to the mass density of the universe is likely to be larger than 0.1 h50−2. Many of the very poor groups have large x-ray halos and are filled with small galaxies whose velocity dispersion is a good match to the x-ray temperatures. PMID:9419327

XIPE: the x-ray imaging polarimetry explorer

NASA Astrophysics Data System (ADS)

Soffitta, P.; Bellazzini, R.; Bozzo, E.; Burwitz, V.; Castro-Tirado, A.; Costa, E.; Courvoisier, T.; Feng, H.; Gburek, S.; Goosmann, R.; Karas, V.; Matt, G.; Muleri, F.; Nandra, K.; Pearce, M.; Poutanen, J.; Reglero, V.; Sabau Maria, D.; Santangelo, A.; Tagliaferri, G.; Tenzer, C.; Vink, J.; Weisskopf, M. C.; Zane, S.; Agudo, I.; Antonelli, A.; Attina, P.; Baldini, L.; Bykov, A.; Carpentiero, R.; Cavazzuti, E.; Churazov, E.; Del Monte, E.; De Martino, D.; Donnarumma, I.; Doroshenko, V.; Evangelista, Y.; Ferreira, I.; Gallo, E.; Grosso, N.; Kaaret, P.; Kuulkers, E.; Laranaga, J.; Latronico, L.; Lumb, D. H.; Macian, J.; Malzac, J.; Marin, F.; Massaro, E.; Minuti, M.; Mundell, C.; Ness, J. U.; Oosterbroek, T.; Paltani, S.; Pareschi, G.; Perna, R.; Petrucci, P.-O.; Pinazo, H. B.; Pinchera, M.; Rodriguez, J. P.; Roncadelli, M.; Santovincenzo, A.; Sazonov, S.; Sgro, C.; Spiga, D.; Svoboda, J.; Theobald, C.; Theodorou, T.; Turolla, R.; Wilhelmi de Ona, E.; Winter, B.; Akbar, A. M.; Allan, H.; Aloisio, R.; Altamirano, D.; Amati, L.; Amato, E.; Angelakis, E.; Arezu, J.; Atteia, J.-L.; Axelsson, M.; Bachetti, M.; Ballo, L.; Balman, S.; Bandiera, R.; Barcons, X.; Basso, S.; Baykal, A.; Becker, W.; Behar, E.; Beheshtipour, B.; Belmont, R.; Berger, E.; Bernardini, F.; Bianchi, S.; Bisnovatyi-Kogan, G.; Blasi, P.; Blay, P.; Bodaghee, A.; Boer, M.; Boettcher, M.; Bogdanov, S.; Bombaci, I.; Bonino, R.; Braga, J.; Brandt, W.; Brez, A.; Bucciantini, N.; Burderi, L.; Caiazzo, I.; Campana, R.; Campana, S.; Capitanio, F.; Cappi, M.; Cardillo, M.; Casella, P.; Catmabacak, O.; Cenko, B.; Cerda-Duran, P.; Cerruti, C.; Chaty, S.; Chauvin, M.; Chen, Y.; Chenevez, J.; Chernyakova, M.; Cheung, C. C. Teddy; Christodoulou, D.; Connell, P.; Corbet, R.; Coti Zelati, F.; Covino, S.; Cui, W.; Cusumano, G.; D'Ai, A.; D'Ammando, F.; Dadina, M.; Dai, Z.; De Rosa, A.; de Ruvo, L.; Degenaar, N.; Del Santo, M.; Del Zanna, L.; Dewangan, G.; Di Cosimo, S.; Di Lalla, N.; Di Persio, G.; Di Salvo, T.; Dias, T.; Done, C.; Dovciak, M.; Doyle, G.; Ducci, L.; Elsner, R.; Enoto, T.; Escada, J.; Esposito, P.; Eyles, C.; Fabiani, S.; Falanga, M.; Falocco, S.; Fan, Y.; Fender, R.; Feroci, M.; Ferrigno, C.; Forman, W.; Foschini, L.; Fragile, C.; Fuerst, F.; Fujita, Y.; Gasent-Blesa, J. L.; Gelfand, J.; Gendre, B.; Ghirlanda, G.; Ghisellini, G.; Giroletti, M.; Goetz, D.; Gogus, E.; Gomez, J.-L.; Gonzalez, D.; Gonzalez-Riestra, R.; Gotthelf, E.; Gou, L.; Grandi, P.; Grinberg, V.; Grise, F.; Guidorzi, C.; Gurlebeck, N.; Guver, T.; Haggard, D.; Hardcastle, M.; Hartmann, D.; Haswell, C.; Heger, A.; Hernanz, M.; Heyl, J.; Ho, L.; Hoormann, J.; Horak, J.; Huovelin, J.; Huppenkothen, D.; Iaria, R.; Inam Sitki, C.; Ingram, A.; Israel, G.; Izzo, L.; Burgess, M.; Jackson, M.; Ji, L.; Jiang, J.; Johannsen, T.; Jones, C.; Jorstad, S.; Kajava, J. J. E.; Kalamkar, M.; Kalemci, E.; Kallman, T.; Kamble, A.; Kislat, F.; Kiss, M.; Klochkov, D.; Koerding, E.; Kolehmainen, M.; Koljonen, K.; Komossa, S.; Kong, A.; Korpela, S.; Kowalinski, M.; Krawczynski, H.; Kreykenbohm, I.; Kuss, M.; Lai, D.; Lan, M.; Larsson, J.; Laycock, S.; Lazzati, D.; Leahy, D.; Li, H.; Li, J.; Li, L.-X.; Li, T.; Li, Z.; Linares, M.; Lister, M.; Liu, H.; Lodato, G.; Lohfink, A.; Longo, F.; Luna, G.; Lutovinov, A.; Mahmoodifar, S.; Maia, J.; Mainieri, V.; Maitra, C.; Maitra, D.; Majczyna, A.; Maldera, S.; Malyshev, D.; Manfreda, A.; Manousakis, A.; Manuel, R.; Margutti, R.; Marinucci, A.; Markoff, S.; Marscher, A.; Marshall, H.; Massaro, F.; McLaughlin, M.; Medina-Tanco, G.; Mehdipour, M.; Middleton, M.; Mignani, R.; Mimica, P.; Mineo, T.; Mingo, B.; Miniutti, G.; Mirac, S. M.; Morlino, G.; Motlagh, A. V.; Motta, S.; Mushtukov, A.; Nagataki, S.; Nardini, F.; Nattila, J.; Navarro, G. J.; Negri, B.; Negro, Matteo; Nenonen, S.; Neustroev, V.; Nicastro, F.; Norton, A.; Nucita, A.; O'Brien, P.; O'Dell, S.

2016-07-01

XIPE, the X-ray Imaging Polarimetry Explorer, is a mission dedicated to X-ray Astronomy. At the time of writing XIPE is in a competitive phase A as fourth medium size mission of ESA (M4). It promises to reopen the polarimetry window in high energy Astrophysics after more than 4 decades thanks to a detector that efficiently exploits the photoelectric effect and to X-ray optics with large effective area. XIPE uniqueness is time-spectrally-spatially- resolved X-ray polarimetry as a breakthrough in high energy astrophysics and fundamental physics. Indeed the payload consists of three Gas Pixel Detectors at the focus of three X-ray optics with a total effective area larger than one XMM mirror but with a low weight. The payload is compatible with the fairing of the Vega launcher. XIPE is designed as an observatory for X-ray astronomers with 75 % of the time dedicated to a Guest Observer competitive program and it is organized as a consortium across Europe with main contributions from Italy, Germany, Spain, United Kingdom, Poland, Sweden.

X-ray characterization of curved crystals for hard x-ray astronomy

NASA Astrophysics Data System (ADS)

Buffagni, Elisa; Bonnini, Elisa; Ferrari, Claudio; Virgilli, Enrico; Frontera, Filippo

2015-05-01

Among the methods to focus photons the diffraction in crystals results as one of the most effective for high energy photons. An assembling of properly oriented crystals can form a lens able to focus x-rays at high energy via Laue diffraction in transmission geometry; this is a Laue lens. The x-ray diffraction theory provides that the maximum diffraction efficiency is achieved in ideal mosaic crystals, but real mosaic crystals show diffraction efficiencies several times lower than the ideal case due to technological problems. An alternative and convenient approach is the use of curved crystals. We have recently optimized an efficient method based on the surface damage of crystals to produce self-standing uniformly curved Si, GaAs and Ge tiles of thickness up to 2-3 mm and curvature radii R down to a few meters. We show that, for curved diffracting planes, such crystals have a diffraction efficiency nearly forty times higher than the diffraction efficiency of perfect similar flat crystals, thus very close to that of ideal mosaic crystals. Moreover, in an alternative configuration where the diffracting planes are perpendicular to the curved ones, a focusing effect occurs and will be shown. These results were obtained for several energies between 17 and 120 keV with lab sources or at high energy facilities such as LARIX at Ferrara (Italy), ESRF at Grenoble (France), and ANKA at Karlsruhe (Germany).

Explorer Program: X-ray Timing Explorer

NASA Technical Reports Server (NTRS)

1995-01-01

This booklet describes the X-ray Timing Explorer (XTE), one in a series of Explorer missions administered by the National Aeronautics and Space Administration's (NASA) Office of Space Science and managed by the NASA Goddard Space Flight Center (GSFC). The X-ray astronomy observatory is scheduled for launch into low-Earth orbit by Delta 2 expendable launch vehicle in late summer of 1995. The mission is expected to operate for at least 2 years and will carry out in-depth timing and spectral studies of the X-ray sources in the 2 to 200 kilo-electron Volt (keV) range. XTE is intended to study the temporal and broad-band spectral phenomena associated with stellar and galactic systems containing compact objects, including neutron stars, white dwarfs, and black holes.

Exploring transient X-ray sky with Einstein Probe

NASA Astrophysics Data System (ADS)

Yuan, W.; Zhang, C.; Ling, Z.; Zhao, D.; Chen, Y.; Lu, F.; Zhang, S.

2017-10-01

The Einstein Probe is a small satellite in time-domain astronomy to monitor the soft X-ray sky. It is a small mission in the space science programme of the Chinese Academy of Sciences. It will carry out systematic survey and characterisation of high-energy transients at unprecedented sensitivity, spatial resolution, Grasp and monitoring cadence. Its wide-field imaging capability is achieved by using established technology of micro-pore lobster-eye X-ray focusing optics. Complementary to this is X-ray follow-up capability enabled by a narrow-field X-ray telescope. It is capable of on-board triggering and real time downlink of transient alerts, in order to trigger fast follow-up observations at multi-wavelengths. Its scientific goals are concerned with discovering and characterising diverse types of X-ray transients, including tidal disruption events, supernova shock breakouts, high-redshift GRBs, and of particular interest, X-ray counterparts of gravitational wave events.

From cosmic ray physics to cosmic ray astronomy: Bruno Rossi and the opening of new windows on the universe

NASA Astrophysics Data System (ADS)

Bonolis, Luisa

2014-01-01

Bruno Rossi is considered one of the fathers of modern physics, being also a pioneer in virtually every aspect of what is today called high-energy astrophysics. At the beginning of 1930s he was the pioneer of cosmic ray research in Italy, and, as one of the leading actors in the study of the nature and behavior of the cosmic radiation, he witnessed the birth of particle physics and was one of the main investigators in this fields for many years. While cosmic ray physics moved more and more towards astrophysics, Rossi continued to be one of the inspirers of this line of research. When outer space became a reality, he did not hesitate to leap into this new scientific dimension. Rossi's intuition on the importance of exploiting new technological windows to look at the universe with new eyes, is a fundamental key to understand the profound unity which guided his scientific research path up to its culminating moments at the beginning of 1960s, when his group at MIT performed the first in situ measurements of the density, speed and direction of the solar wind at the boundary of Earth's magnetosphere, and when he promoted the search for extra-solar sources of X rays. A visionary idea which eventually led to the breakthrough experiment which discovered Scorpius X-1 in 1962, and inaugurated X-ray astronomy.

Czechoslovak Replica X-Ray Mirrors for Astronomical Applications

NASA Astrophysics Data System (ADS)

Hudec, R.; Valnicek, B.

Imaging X-ray mirrors has been developed in Czechoslovakia since 1970 by a way of two different replica technologies based on galvanoplastics and reactoplastics as a natural part of Czechoslovak X-ray astronomy program. Until now about 30 mirros with diameters between 1.7 and 24 cm were manufactured. Seven mirrors were flown in space experiments. The new technology used since 1981 allows to produce light-weight X-ray mirrors at relatively very low cost. The technology offers interesting possibilities in construction of (1) large arrays of identical optical systems, (2) very small (microscopic) mirros and (3) lobster-eye type optics. Advantages and drawbacks of replica techology are discussed.

First centenary of Röntgen's discovery of X-rays

NASA Astrophysics Data System (ADS)

Valkovic, V.

1996-04-01

Usually it takes a decade or even several decades, from a discovery to its practical applications. This was not the case with X-rays; they were widely applied in medical and industrial radiography within a year of their discovery in 1895 by W.C. Röntgen. Today, X-ray analysis covers a wide range of techniques and fields of applications: from deduction of atomic arrangements by observation of diffraction phenomena to measurements of trace element concentration levels, distributions and maps by measuring fluorescence, X-ray attenuation or scattering. Although the contribution of analytical applications of X-rays to the present knowledge is difficult to surpass, modern application cover a wide range of activities from three-dimensional microfabrication using synchroton radiation to collecting information from the deep space by X-ray astronomy.

Development of a mercuric iodide solid state spectrometer for X-ray astronomy

NASA Technical Reports Server (NTRS)

Vallerga, J.

1983-01-01

Mercuric iodide detectors, experimental development for astronomical use, X ray observations of the 1980 Cygnus X-1 High State, astronomical had X ray detectors in current use, detector development, balloon flight of large area (1500 sq cm) Phoswich detectors, had X ray telescope design, shielded mercuric iodide background measurement, Monte Carlo analysis, measurements with a shielded mercuric iodide detector are discussed.

ROSAT: X ray survey of compact groups

NASA Technical Reports Server (NTRS)

Vangorkom, Jacqueline

1993-01-01

This is the final technical report on grant NAG5-1954, which was awarded under the NASA ROSAT Guest Investigator Program to Columbia University. This grant was awarded for a number of projects on two rather different topics: (1) an x-ray survey of compact groups of galaxies; and (2) the fate of gas in merging galaxies. Progress made in these projects is presented.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1979-01-01

This is an x-ray image of the Crab Nebula taken with the High Energy Astronomy Observatory (HEAO)-2/Einstein Observatory. The image is demonstrated by a pulsar, which appears as a bright point due to its pulsed x-ray emissions. The strongest region of diffused emissions comes from just northwest of the pulsar, and corresponds closely to the region of brightest visible-light emission. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO-2, designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center, was launched aboard an Atlas/Centaur launch vehicle on November 13, 1978.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1980-01-01

This x-ray photograph of the Supernova remnant Cassiopeia A, taken with the High Energy Astronomy Observatory (HEAO) 2/Einstein Observatory, shows that the regions with fast moving knots of material in the expanding shell are bright and clear. A faint x-ray halo, just outside the bright shell, is interpreted as a shock wave moving ahead of the expanding debris. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO-2, designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center, was launched aboard an Atlas/Centaur launch vehicle on November 13, 1978.

Ultrahigh resolution photographic films for X-ray/EUV/FUV astronomy

NASA Technical Reports Server (NTRS)

Hoover, Richard B.; Walker, Arthur B. C., Jr.; Deforest, Craig E.; Watts, Richard; Tarrio, Charles

1993-01-01

The quest for ultrahigh resolution full-disk images of the sun at soft X-ray/EUV/FUV wavelengths has increased the demand for photographic films with broad spectral sensitivity, high spatial resolution, and wide dynamic range. These requirements were made more stringent by the recent development of multilayer telescopes and coronagraphs capable of operating at normal incidence at soft X-ray/EUV wavelengths. Photographic films are the only detectors now available with the information storage capacity and dynamic range such as is required for recording images of the solar disk and corona simultaneously with sub arc second spatial resolution. During the Stanford/MSFC/LLNL Rocket X-Ray Spectroheliograph and Multi-Spectral Solar Telescope Array (MSSTA) programs, we utilized photographic films to obtain high resolution full-disk images of the sun at selected soft X-ray/EUV/FUV wavelengths. In order to calibrate our instrumentation for quantitative analysis of our solar data and to select the best emulsions and processing conditions for the MSSTA reflight, we recently tested several photographic films. These studies were carried out at the NIST SURF II synchrotron and the Stanford Synchrotron Radiation Laboratory. In this paper, we provide the results of those investigations.

High Energy Astronomy Observatory

NASA Technical Reports Server (NTRS)

1980-01-01

An overview of the High Energy Astronomy Observatory 2 contributions to X-ray astronomy is presented along with a brief description of the satellite and onboard telescope. Observations relating to galaxies and galactic clusters, black holes, supernova remnants, quasars, and cosmology are discussed.

An X-Ray Atlas of Groups of Galaxies

NASA Technical Reports Server (NTRS)

Mulchaey, John S.; Davis, David S.; Mushotzky, Richard F.; Burnstein, David

2003-01-01

A search was conducted for a hot intragroup medium in 10(exp 9) low-redshift galaxy groups observed with the ROSAT PSPC. Evidence for diffuse, extended X-ray emission is found in at least 61 groups. Approximately one-third of these detections have not been previously reported in the literature. Most of the groups are detected out to less than half of the virial radius with ROSAT. Although some spiral-rich groups do contain an intragroup medium, diffuse emission is restricted to groups that contain at least one early-type galaxy.

Fabrication of imaging X-ray optics

NASA Astrophysics Data System (ADS)

Catura, R. C.; Joki, E. G.; Brookover, W. J.

The design, fabrication, and performance of optics for X-ray astronomy and laboratory applications are described and illustrated with diagrams, drawings, graphs, photographs, and sample images. Particular attention is given to the Wolter I telescope developed for spectroscopic observation of 8-30-A cosmic X-ray sources from a rocketborne X-ray Objective Grating Spectrometer; this instrument employs three nested paraboloid-hyperboloid mirrors of 5083 Al alloy, figured by diamond turning and covered with a thin coating of acrylic lacquer prior to deposition of a 40-nm-thick layer of Sn. In calibration tests at NASA Marshall, the FWHM of the line-spread function at 1.33 nm was found to be 240 microns, corresponding to 21 arcsec. Also presented are the results of reflectivity measurements on C and W multilayers sputtered on Si and fusion glass substrates.

ASTRONOMY: Neighborhood Gamma Ray Burst Boosts Theory.

PubMed

Schilling, G

2000-07-07

Titanic explosions that emit powerful flashes of energetic gamma rays are one of astronomy's hottest mysteries. Now an analysis of the nearest gamma ray burst yet detected has added weight to the popular theory that they are expelled during the death throes of supermassive stars.

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.

Globular cluster x-ray sources

PubMed Central

Pooley, David

2010-01-01

Globular clusters and x-ray astronomy have a long and fruitful history. Uhuru and OSO-7 revealed highly luminous (> 1036 ergs-1) x-ray sources in globular clusters, and Einstein and ROSAT revealed a larger population of low-luminosity (< 1033 ergs-1) x-ray sources. It was realized early on that the high-luminosity sources were low-mass x-ray binaries in outburst and that they were orders of magnitude more abundant per unit mass in globular clusters than in the rest of the galaxy. However, the low-luminosity sources proved difficult to classify. Many ideas were put forth—low-mass x-ray binaries in quiescence (qLMXBs), cataclysmic variables (CVs), active main-sequence binaries (ABs), and millisecond pulsars (MSPs)—but secure identifications were scarce. In ROSAT observations of 55 clusters, about 25 low-luminosity sources were found. Chandra has now observed over 80 Galactic globular clusters, and these observations have revealed over 1,500 x-ray sources. The superb angular resolution has allowed for many counterpart identifications, providing clues to the nature of this population. It is a heterogeneous mix of qLMXBs, CVs, ABs, and MSPs, and it has been shown that the qLMXBs and CVs are both, in part, overabundant like the luminous LMXBs. The number of x-ray sources in a cluster correlates very well with its encounter frequency. This points to dynamical formation scenarios for the x-ray sources and shows them to be excellent tracers of the complicated internal dynamics. The relation between the encounter frequency and the number of x-ray sources has been used to suggest that we have misunderstood the dynamical states of globular clusters. PMID:20404204

Astronomy Education. Third Newsletter of the TGEA (Task Group on Education in Astronomy).

ERIC Educational Resources Information Center

Wentzel, Donat G., Comp.

This newsletter, published by the Task Group on Education in Astronomy, focuses on astronomy education both for the public and for schools. Topics in this issue include new publications related to astronomy education; a roster of consultants on astronomy education; a collection of course syllabuses (college level); teaching astronomy in schools,…

Significance of medium energy gamma ray astronomy in the study of cosmic rays

NASA Technical Reports Server (NTRS)

Fichtel, C. E.; Kniffen, D. A.; Thompson, D. J.; Bignami, G. F.; Cheung, C. Y.

1975-01-01

Medium energy (about 10 to 30 MeV) gamma ray astronomy provides information on the product of the galactic electron cosmic ray intensity and the galactic matter to which the electrons are dynamically coupled by the magnetic field. Because high energy (greater than 100 MeV) gamma ray astronomy provides analogous information for the nucleonic cosmic rays and the relevant matter, a comparison between high energy and medium energy gamma ray intensities provides a direct ratio of the cosmic ray electrons and nucleons throughout the galaxy. A calculation of gamma ray production by electron bremsstrahlung shows that: bremsstrahlung energy loss is probably not negligible over the lifetime of the electrons in the galaxy; and the approximate bremsstrahlung calculation often used previously overestimates the gamma ray intensity by about a factor of two. As a specific example, expected medium energy gamma ray intensities are calculated for the speral arm model.

Space astronomy and upper atmospheric sounding

NASA Technical Reports Server (NTRS)

Friedman, H.

1971-01-01

The discoveries and activities of the Space Science Program are reported. Results of studies are presented for the following areas: gamma and x-ray astronomy, optical geophysics and solar wind, infrared astronomy, radio astronomy, and rocket spectroscopy. Lists of publications, talks, and conferences are included.

Coded mask telescopes for X-ray astronomy

NASA Astrophysics Data System (ADS)

Skinner, G. K.; Ponman, T. J.

1987-04-01

The principle of the coded mask techniques are discussed together with the methods of image reconstruction. The coded mask telescopes built at the University of Birmingham, including the SL 1501 coded mask X-ray telescope flown on the Skylark rocket and the Coded Mask Imaging Spectrometer (COMIS) projected for the Soviet space station Mir, are described. A diagram of a coded mask telescope and some designs for coded masks are included.

Design criteria for small coded aperture masks in gamma-ray astronomy

NASA Technical Reports Server (NTRS)

Sembay, S.; Gehrels, Neil

1990-01-01

Most theoretical work on coded aperture masks in X-ray and low-energy gamma-ray astronomy has concentrated on masks with large numbers of elements. For gamma-ray spectrometers in the MeV range, the detector plane usually has only a few discrete elements, so that masks with small numbers of elements are called for. For this case it is feasible to analyze by computer all the possible mask patterns of given dimension to find the ones that best satisfy the desired performance criteria. A particular set of performance criteria for comparing the flux sensitivities, source positioning accuracies and transparencies of different mask patterns is developed. The results of such a computer analysis for masks up to dimension 5 x 5 unit cell are presented and it is concluded that there is a great deal of flexibility in the choice of mask pattern for each dimension.

ESA presents INTEGRAL, its space observatory for Gamma-ray astronomy

NASA Astrophysics Data System (ADS)

1998-09-01

more strange than the energetic radiation coming from the centre of distant galaxies are flashes of extremely powerful radiation that suddenly appear somewhere on the gamma-sky and disappear again after a short time. These gamma-bursts seem to be the biggest observed explosions in the Universe. But nobody knows their source. Integral will help to solve this long-standing mystery. ESA, the pioneer in gamma-ray astronomy The satellite as it can now be seen at ESA's test centre is five meters high and weighs more than four tonnes. Two main instruments observe the gamma-rays. An imager will give the sharpest gamma-ray images. It is provided by a consortium led by an Italian scientist. Gamma-rays ignore lenses and mirror, so INTEGRAL makes its images with so-called coded-masks. A coded-mask telescope is basically a pinhole camera, but with a larger aperture, i.e. many pinholes. A spectrometer will gauge gamma-ray energies extremely precisely. It is developed by a team of scientists under joint French-German leadership and will be a 100 times more sensitive than the previous high spectral resolution space instrument. It is made of a high-purity Germanium detector that has to be cooled down to minus 188 degree Celsius. These two gamma-ray-instruments are supported by two monitor instruments that play a crucial role in the detection and identification of the gamma-ray sources. An X-ray monitor developed in Denmark will observe X-rays, still powerful but less energetic than gamma-rays. An optical telescope provided by Spain will observe the visible light emitted by the energetic objects. Switzerland will host the Integral Science Data Centre which will preprocess and distribute the scientific data. The mission is conceived as an observatory led by ESA with Russia contributing the launcher and NASA providing tracking support with its Deep Space Network. Alenia Aerospazio in Turin, Italy is ESA's prime contractor for building INTEGRAL. Launch by a Russian Proton rocket from

Goddard X-ray astronomy contributions to the IAU/COSPAR (1982)

NASA Technical Reports Server (NTRS)

Holt, S. S.; Petre, R.; Shafer, R. A.; Urry, C. M.; Mushotzky, R. F.

1982-01-01

The relation of X-ray flux to both the continuum flux in the optical and radio bands, and to the line emission properties of these objects were studied. The Einstein Observatory, because of increased sensitivity and improved angular resolution, increased substantially the number of known X-ray emitting active galactic nuclei. The Einstein imaging instruments detected morphology in AGN X-ray emission, in particular from jetlike structures in Cen-A, M87, and 3C273. The improved energy resolution and sensitivity of the spectrometers onboard the Observatory provide information on the geometry and ionization structure of the region responsible for the broad optical emission lines in a few AGN's. This information, combined with theoretical modeling and IUE and optical observations, allows the construction of a moderately detailed picture of the broad line region in these objects.

High Resolution Adjustable Mirror Control for X-ray Astronomy

NASA Astrophysics Data System (ADS)

Trolier-McKinstry, Susan

We propose to build and test thin film transistor control circuitry for a new highresolution adjustable X-ray mirror technology. This control circuitry will greatly simplify the wiring scheme to address individual actuator cells. The result will be a transformative improvement for the X-ray Surveyor mission concept: mathematical models, which fit the experimental data quite well, indicate that 0.5 arcsecond imaging is feasible through this technique utilizing thin slumped glass substrates with uncorrected angular resolution of order 5-10 arcseconds. In order to correct for figures errors in a telescope with several square meters of collecting area, millions of actuator cells must be set and held at specific voltages. It is clearly not feasible to do this via millions of wires, each one connected to an actuator. Instead, we propose to develop and test thin-film technology that operates on the same principle as megapixel computer screens. We will develop the technologies needed to build thin film piezoelectric actuators, controlled by thin film ZnO transistors, on flexible polyimide films, and to connect those films to the back surfaces of X-ray mirrors on thin glass substrates without deforming the surface. These technologies represent a promising avenue of the development of mirrors for the X-Ray Surveyor mission concept. Such a telescope will make possible detailed studies of a wide variety of astrophysical sources. One example is the Warm-Hot Intergalactic Medium (WHIM), which is thought to account for a large fraction of the normal matter in the universe but which has not been detected unambiguously to date. Another is the growth of supermassive black holes in the early universe. This proposal supports NASA's goals of technical advancement of technologies suitable for future missions, and training of graduate students.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1978-01-01

Both of the High Energy Astronomy Observatory (HEAO) 2/Einstein Observatory imaging devices were used to observe the Great Nebula in Andromeda, M31. This image is a wide field x-ray view of the center region of M31 by the HEAO-2's Imaging Proportional Counter. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO-2, designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center, was launched aboard an Atlas/Centaur launch vehicle on November 13, 1978.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1980-01-01

The dramatic change in x-ray emission from the Terzan 2 cluster is shown in this series of 2.5-minute exposures taken with the High Energy Astronomy Observatory (HEAO)-2/Einstein Observatory immediately before, during, and after the burst. Total exposure (20 minutes) of the object, including the outburst, is shown in the fourth photograph. These images represent the first observation of an x-ray burst in progress. The actual burst lasted 50 seconds. Among the rarest, and most bizarre, phenomena observed by x-ray astronomers are the so-called cosmic bursters (x-ray sources that suddenly and dramatically increase in intensity then subside). These sudden bursts of intense x-ray radiation apparently come from compact objects with a diameter smaller than 30 miles (48 kilometers). Yet, despite their minuscule size, a typical x-ray burster can release more x-ray energy in a single brief burst than our Sun does in an entire week. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO was designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center.

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

High Resolution X-ray Imaging

NASA Technical Reports Server (NTRS)

Cash, Webster

2002-01-01

NAG5-5020 covered a period of 7.5 years during which a great deal of progress was made in x-ray optical techniques under this grant. We survived peer review numerous times during the effort to keep the grant going. In 1994, when the grant started we were actively pursuing the application of spherical mirrors to improving x-ray telescopes. We had found that x-ray detectors were becoming rapidly more sophisticated and affordable, but that x-ray telescopes were only being improved through the intense application of money within the AXAF program. Clearly new techniques for the future were needed. We were successful in developing and testing at the HELSTF facility in New Mexico a four reflection coma-corrected telescope made from spheres. We were able to demonstrate 0.3 arcsecond resolution, almost to the diffraction limit of the system. The community as a whole was, at that time, not particularly interested in looking past AXAF (Chandra) and the effort needed to evolve. Since we had reached the diffraction limit using non-Wolter optics we then decided to see if we could build an x-ray interferometer in the laboratory. In the lab the potential for improved resolution was substantial. If synthetic aperture telescopes could be built in space, then orders of magnitude improvement would become feasible. In 1998 NASA, under the direction of Dr Nick White of Goddard, started a study to assess the potential and feasibility of x-ray interferometry in space. My work became of central interest to the committee because it indicated that such was possible. In early 1999 we had the breakthrough that allowed us build a practical interferometer. By using flats and hooking up with the Marshall Space Flight Center facilities we were able to demonstrate fringes at 1.25keV on a one millimeter baseline. This actual laboratory demonstration provided the solid proof of concept that NASA needed. As the year progressed the future of x-ray astronomy jelled around the Maxim program. Maxim is a

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

Lifting the veil on the X-ray universe

NASA Astrophysics Data System (ADS)

1999-11-01

Universe. The mission will study X-rays that originate from "vampire stars" that feed upon their companions, where intense gravitational fields swirl matter from one sphere to the other in strange and terrifying ballets. XMM's high-speed cameras will examine celestial sources whose X-rays pulse rhythmically and mysteriously, and those that flash briefly, pinpointing perhaps gigantic explosions that result from colliding black holes in far off galaxies. XMM will delve into enigmatic black holes, cosmic dustbins that consign matter and light to oblivion, where tired X-rays have lost energy and time itself is slowing down. The golden X-ray eyes of ESA's observatory will try to make sense of a 'bigger picture', ascertaining how galaxies aggregate millions of stars, how these galaxies themselves form clusters and groups scattered across cosmic space. XMM will also attempt to understand the nature of the invisible dark matter that fills interstellar space. A high-flying mission The XMM spacecraft, the largest science satellite ever built in Europe, is due to be launched in December 1999 by an Ariane-5 from the European Spaceport in Kourou. After being released by the launcher, XMM will be placed in a highly eccentric 48-hour orbit, rising to a distance of 114 000 km from the Earth, then returning to within 7 000 km of our planet. This orbit has been chosen for several reasons. It offers an optimal contact between ground tracking stations and the satellite; it will allow the satellite to pass rapidly through the Earth's radiation belts which could harm its delicate science instruments; and above all it will offer astronomers the longest possible observation periods. Note to editors: No X-rays from space can penetrate the Earth's atmosphere so all X-ray astronomy is carried out with instruments on rockets, stratospheric balloons or satellites. X-rays from the Sun were first detected during sounding rocket flights in the 1950s. By 1970, more than forty X-rays sources had been

A Search for Quiet Massive X-ray Binaries

NASA Astrophysics Data System (ADS)

McSwain, M. V.; Boyajian, T. S.; Grundstrom, E.; Gies, D. R.

2005-12-01

Wind accretion models of the X-ray luminosity in massive X-ray binaries (MXRBs) predict a class of "quiet" MXRBs in which the stellar wind is too weak to power a strong X-ray source. The first two candidates systems, HD 14633 and HD 15137, were recently detected. These O star + neutron star systems were ejected from the open cluster NGC 654, but although they both show evidence of a past supernova within the binary system, neither is a known X-ray emitter. These systems provide a new opportunity to examine the ejection mechanisms responsible for the OB runaway stars, and they can also provide key information about the evolution of spun-up, rejuvenated massive stars. We present here preliminary results from a search for other such quiet MXRBs. MVM is supported by an NSF Astronomy and Astrophysics Postdoctoral Fellowship under award AST-0401460.

Image of the Black Hole, Cygnus X-1, Taken by the High Energy Astronomy Observatory (HEAO)-2

NASA Technical Reports Server (NTRS)

1980-01-01

This image of the suspected Black Hole, Cygnus X-1, was the first object seen by the High Energy Astronomy Observatory (HEAO)-2/Einstein Observatory. According to the theories to date, one concept of a black hole is a star, perhaps 10 times more massive than the Sun, that has entered the last stages of stelar evolution. There is an explosion triggered by nuclear reactions after which the star's outer shell of lighter elements and gases is blown away into space and the heavier elements in the stellar core begin to collapse upon themselves. Once this collapse begins, the inexorable force of gravity continues to compact the material until it becomes so dense it is squeezed into a mere point and nothing can escape from its extreme gravitational field, not even light. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1980-01-01

This supernova in the constellation Cassiopeia was observed by Tycho Brahe in 1572. In this x-ray image from the High Energy Astronomy Observatory (HEAO-2/Einstein Observatory produced by nearly a day of exposure time, the center region appears filled with emissions that can be resolved into patches or knots of material. However, no central pulsar or other collapsed object can be seen. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO-2, designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center, was launched aboard an Atlas/Centaur launch vehicle on November 13, 1978.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1979-01-01

This image is an x-ray view of Eta Carinae Nebula showing bright stars taken with the High Energy Astronomy Observatory (HEAO)-2/Einstein Observatory. The Eta Carinae Nebula is a large and complex cloud of gas, crisscrossed with dark lanes of dust, some 6,500 light years from Earth. Buried deep in this cloud are many bright young stars and a very peculiar variable star. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO-2, designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center, was launched aboard an Atlas/Centaur launch vehicle on November 13, 1978.

X-ray stars observed in LAMOST spectral survey

NASA Astrophysics Data System (ADS)

Lu, Hong-peng; Zhang, Li-yun; Han, Xianming L.; Shi, Jianrong

2018-05-01

X-ray stars have been studied since the beginning of X-ray astronomy. Investigating and studying the chromospheric activity from X-ray stellar optical spectra is highly significant in providing insights into stellar magnetic activity. The big data of LAMOST survey provides an opportunity for researching stellar optical spectroscopic properties of X-ray stars. We inferred the physical properties of X-ray stellar sources from the analysis of LAMOST spectra. First, we cross-matched the X-ray stellar catalogue (12254 X-ray stars) from ARXA with LAMOST data release 3 (DR3), and obtained 984 good spectra from 713 X-ray sources. We then visually inspected and assigned spectral type to each spectrum and calculated the equivalent width (EW) of Hα line using the Hammer spectral typing facility. Based on the EW of Hα line, we found 203 spectra of 145 X-ray sources with Hα emission above the continuum. For these spectra we also measured the EWs of Hβ, Hγ, Hδ and Ca ii IRT lines of these spectra. After removing novae, planetary nebulae and OB-type stars, we found there are 127 X-ray late-type stars with Hα line emission. By using our spectra and results from the literature, we found 53 X-ray stars showing Hα variability; these objects are Classical T Tauri stars (CTTs), cataclysmic variables (CVs) or chromospheric activity stars. We also found 18 X-ray stars showing obvious emissions in the Ca ii IRT lines. Of the 18 X-ray stars, 16 are CTTs and 2 are CVs. Finally, we discussed the relationships between the EW of Hα line and X-ray flux.

X-Ray Spectroscopic Laboratory Experiments in Support of the X-Ray Astronomy Program

NASA Technical Reports Server (NTRS)

Kahn, Steven M.

1997-01-01

Our program is to perform a series of laboratory investigations designed to resolved significant atomic physics uncertainties that limit the interpretation of cosmic X-ray spectra. Specific goals include a quantitative characterization of Fe L-shell spectra; the development of new techniques to simulate Maxwellian plasmas using an Electron Beam Ion Trap (EBIT); and the measurement of dielectronic recombination rates for photoionized gas. New atomic calculations have also been carried out in parallel with the laboratory investigations.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1982-01-01

This artist's concept depicts the High Energy Astronomy Observatory (HEAO)-2 in orbit. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO-2, designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center, was launched aboard an Atlas/Centaur launch vehicle on November 13, 1978. The HEAO-2 was originally identified as HEAO-B but the designation was changed once the spacecraft achieved orbit.

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

The Astronomy Spacelab Payloads Study: Executive volume

NASA Technical Reports Server (NTRS)

1975-01-01

The progress of the Astronomy Spacelab Payloads Project at the Goddard Space Flight Center is reported. Astronomical research in space, using the Spacelab in conjunction with the Space Shuttle, is described. The various fields of solar astronomy or solar physics, ultraviolet and optical astronomy, and high energy astrophysics are among the topics discussed. These fields include scientific studies of the sun and its dynamical processes, of the stars in wavelength regions not accessible to ground based observations, and the exciting new fields of X-ray, gamma ray, and particle astronomy.

Explorers of the Southern Sky: A History of Australian Astronomy

NASA Astrophysics Data System (ADS)

Haynes, Raymond; Haynes, Roslynn D.; Malin, David; McGee, Richard

1996-06-01

This well-illustrated volume is the most comprehensive account of Australian astronomy to date. It is both an indispensable reference book on the history of astronomy in Australia, and a highly readable study of a scientific discipline in the context of emerging nationhood. It covers not only the science, but the individuals involved and the social and economic climate in which they worked. Starting from the ancient Aboriginal beliefs about the Sky World - the earliest known astronomy, anywhere in the world - we are led through to the most exciting high-tech current and projected research being carried out at Australia's world-class national astronomy facilities, and by groups in Australian universities. All branches of astronomy are covered - optical, infrared, X-ray, gamma-ray, microwave, gravitational wave and theoretical - including the contribution of amateur astronomers. The non-technical language, many illustrations, and explanatory figures, ensure that this guide will appeal to a wide range of readers - including professional astronomers, historians of science, students, amateur astronomers and general readers.

On the viability of exploiting L-shell fluorescence for X-ray polarimetry

NASA Technical Reports Server (NTRS)

Weisskopf, M. C.; Sutherland, P. G.; Elsner, R. F.; Ramsey, B. D.

1985-01-01

It has been suggested that one may build an X-ray polarimeter by exploiting the polarization dependence of the angular distribution of L-shell fluorescence photons. In this paper the sensitivity of this approach to polarimetry is examined theoretically. The calculations are applied to several detection schemes using imaging proportional counters that would have direct application in X-ray astronomy. It is found, however, that the sensitivity of this method for measuring X-ray polarization is too low to be of use for other than laboratory applications.

Quark Phase Transition in Compact Objects and Multimessenger Astronomy: Neutrino Signals, Supernovae and Gamma-Ray Bursts

NASA Astrophysics Data System (ADS)

Sokolov, V. V.; Vlasyuk, V. V.; Petkov, V. B.

2016-06-01

The International Workshop on Quark Phase Transition in Compact Objects and Multimessenger Astronomy: Neutrino Signals, Supernovae and Gamma-Ray Bursts (October, 7-14, 2015) was dedicated to Quantum ChromoDynamics (QCD) Phase Transitions and observational signals of these transitions related to formation of compact astrophysical objects. The aim of this workshop was to bring together researchers working on the problems of behavior of matter under critical conditions achievable in such astrophysical objects as "strange" or "hybrid" stars and in laboratories at heavy-ion collisions to discuss fundamental issues and recent developments. Topics included both observations (radio, optical and X-ray astronomy, gamma ray bursts, gravitational waves, neutrino detection, heavy-ion collisions, etc.) and theory (supernova simulations, proto-neutron and neutron stars, equation of state of dense matter, neutron star cooling, unstable modes, nucleosynthesis, explosive transitions, quark-gluon plasma).

The cosmic X-ray background-IRAS galaxy correlation and the local X-ray volume emissivity

NASA Technical Reports Server (NTRS)

Miyaji, Takamitsu; Lahav, Ofer; Jahoda, Keith; Boldt, Elihu

1994-01-01

We have cross-correlated the galaxies from the IRAS 2 Jy redshift survey sample and the 0.7 Jy projected sample with the all-sky cosmic X-ray background (CXB) map obtained from the High Energy Astronomy Observatory (HEAO) 1 A-2 experiment. We have detected a significant correlation signal between surface density of IRAS galaxies and the X-ray background intensity, with W(sub xg) = (mean value of ((delta I)(delta N)))/(mean value of I)(mean value of N)) of several times 10(exp -3). While this correlation signal has a significant implication for the contribution of the local universe to the hard (E greater than 2 keV) X-ray background, its interpretation is model-dependent. We have developed a formulation to model the cross-correlation between CXB surface brightness and galaxy counts. This includes the effects of source clustering and the X-ray-far-infrared luminosity correlation. Using an X-ray flux-limited sample of active galactic nuclei (AGNs), which has IRAS 60 micrometer measurements, we have estimated the contribution of the AGN component to the observed CXB-IRAS galaxy count correlations in order to see whether there is an excess component, i.e., contribution from low X-ray luminosity sources. We have applied both the analytical approach and Monte Carlo simulations for the estimations. Our estimate of the local X-ray volume emissivity in the 2-10 keV band is rho(sub x) approximately = (4.3 +/- 1.2) x 10(exp 38) h(sub 50) ergs/s/cu Mpc, consistent with the value expected from the luminosity function of AGNs alone. This sets a limit to the local volume emissivity from lower luminosity sources (e.g., star-forming galaxies, low-ionization nuclear emission-line regions (LINERs)) to rho(sub x) less than or approximately = 2 x 10(exp 38) h(sub 50) ergs/s/cu Mpc.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1980-01-01

Like the Crab Nebula, the Vela Supernova Remnant has a radio pulsar at its center. In this image taken by the High Energy Astronomy Observatory (HEAO)-2/Einstein Observatory, the pulsar appears as a point source surrounded by weak and diffused emissions of x-rays. HEAO-2's computer processing system was able to record and display the total number of x-ray photons (a tiny bundle of radiant energy used as the fundamental unit of electromagnetic radiation) on a scale along the margin of the picture. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO-2, designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center, was launched aboard an Atlas/Centaur launch vehicle on November 13, 1978.

Oscillations During Thermonuclear X-ray Bursts

NASA Technical Reports Server (NTRS)

Strohmayer, Tod E.; White, Nicholas E. (Technical Monitor)

2001-01-01

High amplitude, nearly coherent X-ray brightness oscillations during thermonuclear X-ray bursts were discovered with the Rossi X-ray Timing Explorer (RXTE) in early 1996. Spectral and timing evidence strongly supports the conclusion that these oscillations are caused by rotational modulation of the burst emission and that they reveal the spin frequency of neutron stars in low mass X-ray binaries, a long sought goal of X-ray astronomy. Studies carried out over the past year have led to the discovery of burst oscillations in four new sources, bringing to ten the number with confirmed burst oscillations. I review the status of our knowledge of these oscillations and indicate how they can be used to probe the physics of neutron stars. For a few burst oscillation sources it has been proposed that the strongest and most ubiquitous frequency is actually the first overtone of the spin frequency and hence that two nearly antipodal hot spots are present on the neutron star. This inference has important implications for both the physics of thermonuclear burning as well as the mass - radius relation for neutron stars, so its confirmation is crucial. I discuss recent attempts to confirm this hypothesis for 4U 1636-53, the source for which a signal at the putative fundamental (290Hz) has, been claimed.

Replicated Nickel Optics for the Hard-X-Ray Region

NASA Technical Reports Server (NTRS)

Ramsey, Brian

2005-01-01

Replicated nickel optics has been used extensively in x-ray astronomy, most notable for the XMM/Newton mission. Thc combination of relative ease of fabrication and the inherent stability of full shell optics, make them FIJI attractive approach for medium-resolution, high-throughput applications. MSFC has been developing these optics for use in the hard-x-ray region. Efforts at improving the resolution of these, particularly the very-thin shells required to meet thc weight budget of future missions, will be described together with the prospects for significant improvements down to the 5-arcsec level.

GSFC Contributions to the NATO X-ray Astronomy Institute, Erice, July 1979. [X-ray spectra of supernova remants, galactic X-ray sources, active galactic nuclei, and clusters of galaxies

NASA Technical Reports Server (NTRS)

Holt, S. S.; Mushotzky, R. F.

1979-01-01

An overview of X-ray astronomical spectroscopy in general is presented and results obtained by HEAO 1 and 2 as well as earlier spacecraft are examined. Particular emphasis is given to the spectra of supernova remnants; galactic binary X-ray sources, cataclysmic variables, bulges, pulsars, and stars; the active nuclei of Seyfert 1 galaxy, BL Lac, and quasars; the diffuse X-ray background; and galactic clusters.

The active galactic nucleus population in X-ray-selected galaxy groups at 0.5 < Z < 1.1

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

Oh, Semyeong; Woo, Jong-Hak; Matsuoka, Kenta

2014-07-20

We use Chandra data to study the incidence and properties of active galactic nuclei (AGNs) in 16 intermediate redshift (0.5 < z < 1.1) X-ray-selected galaxy groups in the Chandra Deep Field-South. We measure an AGN fraction of f(L{sub X,H}>10{sup 42};M{sub R}<−20)=8.0{sub −2.3}{sup +3.0}% at z-bar ∼0.74, approximately a factor of two higher than the AGN fraction found for rich clusters at comparable redshift. This extends the trend found at low redshift for groups to have higher AGN fractions than clusters. Our estimate of the AGN fraction is also more than a factor of three higher than that of lowmore » redshift X-ray-selected groups. Using optical spectra from various surveys, we also constrain the properties of emission-line selected AGNs in these groups. In contrast to the large population of X-ray AGNs (N(L{sub X,{sub H}} > 10{sup 41} erg s{sup –1}) = 25), we find only four emission-line AGNs, three of which are also X-ray bright. Furthermore, most of the X-ray AGNs in our groups are optically dull (i.e., lack strong emission-lines), similar to those found in low redshift X-ray groups and clusters of galaxies. This contrasts with the AGN population found in low redshift optically selected groups which are dominated by emission-line AGNs. The differences between the optically and X-ray-selected AGNs populations in groups are consistent with a scenario where most AGNs in the densest environments are currently in a low accretion state.« less

Scatter of X-rays on polished surfaces

NASA Technical Reports Server (NTRS)

Hasinger, G.

1981-01-01

In investigating the dispersion properties of telescope mirrors used in X-ray astronomy, the slight scattering characteristics of X-ray radiation by statistically rough surfaces were examined. The mathematics and geometry of scattering theory are described. The measurement test assembly is described and results of measurements on samples of plane mirrors are given. Measurement results are evaluated. The direct beam, the convolution of the direct beam and the scattering halo, curve fitting by the method of least squares, various autocorrelation functions, results of the fitting procedure for small scattering, and deviations in the kernel of the scattering distribution are presented. A procedure for quality testing of mirror systems through diagnosis of rough surfaces is described.

Conjugate observation of electron microburst groups by Bremsstrahlung X-ray and riometer techniques

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

Siren, J.C.; Rosenberg, T.J.; Detrick, D.

1980-12-01

The first evidence is reported of simultaneous conjugate electron microburst group precipitation. Groups of bremsstrahlung X ray microbursts (E>25 keV) were observed during a substorm recovery phase by a balloon-borne scintillation counter over Roberval, Quebec, Canada. The microburst groups were accompanied one-to-one by time-delayed and broadened pulses of ionospheric absorption measured by a high sensitivity 30-MHz riometer at Siple Station, Antarctica (Lapprox. =4.1). For the interval of highest correlation, the absolute lag between the two data sets was 4 +- 1 s, to the limit of the relative timing accuracy. Approximately 2 s of the observed lag had been introducesmore » by a low-pass filter in the riometer data acquistion unit. The remainder (2 s) was due to the ionospheric recombination process, which evidently had a response time (tauapprox.5 s) during this event much shorter than that ordinarily associated with the D region of the ionosphere. Model calculations of the ionspheric response to time-varying precipitation, derived from the profile of the measurement X ray flux, provide a consistent picture of simultaneous microburst group precipitation at conjugate points, absolute absorption and the electron spectrum derived from X rays, the degree of variation in absorption and X ray fluxes, and the characteristic ionospheric time constant at the altitude of maximum energy deposition.« less

Historic Radio Astronomy Working Group

NASA Astrophysics Data System (ADS)

2007-06-01

This special issue of Astronomische Nachrichten contains the proceedings of a session of the Historic Radio Astronomy Working Group of the International Astronomical Union that took place during the 26th General Assembly of the IAU in Prague on 17th August 2006. In addition to the talks presented in Prague some contributions were solicited to give a more complete overview of `The Early History of European Radio Astronomy'.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1979-01-01

This image is an observation of Quasar 3C 273 by the High Energy Astronomy Observatory (HEAO)-2/Einstein Observatory. It reveals the presence of a new source (upper left) with a red shift that indicates that it is about 10 billion light years away. Quasars are mysterious, bright, star-like objects apparently located at the very edge of the visible universe. Although no bigger than our solar system, they radiate as much visible light as a thousand galaxies. Quasars also emit radio signals and were previously recognized as x-ray sources. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO-2 was designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center.

Temporal X-ray astronomy with a pinhole camera. [cygnus and scorpius constellation

NASA Technical Reports Server (NTRS)

Holt, S. S.

1975-01-01

Preliminary results from the Ariel-5 all-sky X-ray monitor are presented, along with sufficient experiment details to define the experiment sensitivity. Periodic modulation of the X-ray emission was investigated from three sources with which specific periods were associated, with the results that the 4.8 hour variation from Cyg X-3 was confirmed, a long-term average 5.6 day variation from Cyg X-1 was discovered, and no detectable 0.787 day modulation of Sco X-1 was observed. Consistency of the long-term Sco X-1 emission with a shot-noise model is discussed, wherein the source behavior is shown to be interpretable as approximately 100 flares per day, each with a duration of several hours. A sudden increase in the Cyg X-1 intensity by almost a factor of three on 22 April 1975 is reported, after 5 months of relative source constancy. The light curve of a bright nova-like transient source in Triangulum is presented, and compared with previously observed transient sources. Preliminary evidence for the existence of X-ray bursts with duration less than 1 hour is offered.

High Energy Astronomy Observatory (HEAO)-2

NASA Technical Reports Server (NTRS)

1982-01-01

This artist's concept depicts the High Energy Astronomy Observatory (HEAO)-2 in orbit. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO-2, designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center, was launched aboard an Atlas/Centaur launch vehicle on November 13, 1978. The HEAO-2 was originally identified as HEAO-B but the designation was changed once the spacecraft achieved orbit.

X-Ray Calorimeter Arrays for Astrophysics

NASA Technical Reports Server (NTRS)

Kilbourne, Caroline A.

2009-01-01

High-resolution x-ray spectroscopy is a powerful tool for studying the evolving universe. The grating spectrometers on the XMM and Chandra satellites started a new era in x-ray astronomy, but there remains a need for instrumentation that can provide higher spectral resolution with high throughput in the Fe-K band (around 6 keV) and can enable imaging spectroscopy of extended sources, such as supernova remnants and galaxy clusters. The instrumentation needed is a broad-band imaging spectrometer - basically an x-ray camera that can distinguish tens of thousands of x-ray colors. The potential benefits to astrophysics of using a low-temperature calorimeter to determine the energy of an incident x-ray photon via measurement of a small change in temperature was first articulated by S. H. Moseley over two decades ago. In the time since, technological progress has been steady, though full realization in an orbiting x-ray telescope is still awaited. A low-temperature calorimeter can be characterized by the type of thermometer it uses, and three types presently dominate the field. The first two types are temperature-sensitive resistors - semiconductors in the metal-insulator transition and superconductors operated in the superconducting-normal transition. The third type uses a paramagnetic thermometer. These types can be considered the three generations of x-ray calorimeters; by now each has demonstrated a resolving power of 2000 at 6 keV, but only a semiconductor calorimeter system has been developed to spaceflight readiness. The Soft X-ray Spectrometer on Astro-H, expected to launch in 2013, will use an array of silicon thermistors with I-IgTe x-ray absorbers that will operate at 50 mK. Both the semiconductor and superconductor calorimeters have been implemented in small arrays, kilo-pixel arrays of the superconducting calorimeters are just now being produced, and it is anticipated that much larger arrays will require the non-dissipative advantage of magnetic thermometers.

Microwave Kinetic Inductance Detectors: Large Format X-ray Spectral Imagers for the Next Generation of X-ray Telescopes

NASA Astrophysics Data System (ADS)

Eckart, Megan E.; Mazin, B. A.; Bumble, B.; Golwala, S. R.; Zmuidzinas, J.; Day, P. K.; Harrison, F. A.

2006-09-01

Microwave Kinetic Inductance Detectors (MKIDs) have the potential to provide megapixel imagers with few eV spectral resolution for future X-ray missions such as Gen-X. MKIDs offer the advantage over many other cryogenic detector technologies that they can be easily multiplexed, so that arrays with many thousand pixels are readily achievable. In addition, the readout electronics can be operated at room temperature, a significant advantage for space applications. MKIDs exploit the dependence of surface impedance of a superconductorwith the quasiparticle density. Quasiparticles are created by absorption of X-rays, with number proportional to the X-ray energy. The impedance change may be sensitively measured using a thin-film resonant circuit. The practical application of MKIDs for photon detection requires a method of efficiently coupling the photon energy to the MKID. To apply the MKID scheme to X-ray detection we pattern tantalum strips with aluminum MKIDs attached at each end. An incident X-ray is absorbed in the Ta and creates millions of quasiparticle excitations, which diffuse to each end of the strip, finally entering the Al resonators where they are trapped and sensed. Simultaneous monitoring of the signal at both ends of the strip allow position and energy determination for each photon. We have demonstrated working strip detectors in the laboratory, and will present our measurements of the quasiparticle diffusion constant and the quasiparticle lifetime in tantalum, the aluminum quasiparticle lifetime, and the energy resolution of the detector. We will also discuss ideas for future detector designs and suggest ultimate performance goals for X-ray astronomy applications.

Hunting for Intrinsically X-ray Weak Quasars: The Case of PHL 1811 Analogs

NASA Astrophysics Data System (ADS)

Brandt, William

2009-09-01

A central dogma of X-ray astronomy is that luminous X-ray emission is a universal property of efficiently accreting supermassive black holes. One interesting challenge to this idea has come from the quasar PHL 1811 which appears to be intrinsically X-ray weak and also has distinctive emission-line properties. We propose to observe a sample of eight SDSS quasars, selected to have similar UV emission-line properties to that of PHL 1811, to test if they are also X-ray weak. Our analyses of the currently available X-ray data appear to support this hypothesis but do not provide a proper test. Our results will have implications for the nature of accretion-disk coronae, emission-line formation, and AGN selection.

Hard X-ray Optics Technology Development for Astronomy at the Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Gubarev, Mikhail; Ramsey, Brian; Kilaru, Kiranmayee

2009-01-01

Grazing-incidence telescopes based on Wolter 1 geometry have delivered impressive advances in astrophysics at soft-x-ray wavelengths, while the hard xray region remains relatively unexplored at fine angular resolution and high sensitivities. The ability to perform ground-breaking science in the hard-x-ray energy range had been the motivation for technology developments aimed at fabricating low-cost, light-weight, high-quality x-ray mirrors. Grazing-incidence x-ray optics for high-energy astrophysical applications is being developed at MSFC using the electroform-nickel replication process.

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.

Characterization and development of an event-driven hybrid CMOS x-ray detector

NASA Astrophysics Data System (ADS)

Griffith, Christopher

2015-06-01

Hybrid CMOS detectors (HCD) have provided great benefit to the infrared and optical fields of astronomy, and they are poised to do the same for X-ray astronomy. Infrared HCDs have already flown on the Hubble Space Telescope and the Wide-Field Infrared Survey Explorer (WISE) mission and are slated to fly on the James Webb Space Telescope (JWST). Hybrid CMOS X-ray detectors offer low susceptibility to radiation damage, low power consumption, and fast readout time to avoid pile-up. The fast readout time is necessary for future high throughput X-ray missions. The Speedster-EXD X-ray HCD presented in this dissertation offers new in-pixel features and reduces known noise sources seen on previous generation HCDs. The Speedster-EXD detector makes a great step forward in the development of these detectors for future space missions. This dissertation begins with an overview of future X-ray space mission concepts and their detector requirements. The background on the physics of semiconductor devices and an explanation of the detection of X-rays with these devices will be discussed followed by a discussion on CCDs and CMOS detectors. Next, hybrid CMOS X-ray detectors will be explained including their advantages and disadvantages. The Speedster-EXD detector and its new features will be outlined including its ability to only read out pixels which contain X-ray events. Test stand design and construction for the Speedster-EXD detector is outlined and the characterization of each parameter on two Speedster-EXD detectors is detailed including read noise, dark current, interpixel capacitance crosstalk (IPC), and energy resolution. Gain variation is also characterized, and a Monte Carlo simulation of its impact on energy resolution is described. This analysis shows that its effect can be successfully nullified with proper calibration, which would be important for a flight mission. Appendix B contains a study of the extreme tidal disruption event, Swift J1644+57, to search for

Compound semiconductor detectors for X-ray astronomy: Spectroscopic measurements and material characterization

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

Bavdaz, M.; Kraft, S.; Peacock, A.

1998-12-31

The use of some specific compound semiconductors in the fabrication of high energy X-ray detectors shows significant potential for X-ray astrophysics space missions. The authors are currently investigating three high purity crystals--CdZnTe, GaAs and TlBr--as the basis for future hard X-ray detectors (above 10 keV). In this paper the authors present the first results on CdZnTe and GaAs based detectors and evaluate the factors currently still constraining the performance. Energy resolutions (FWHM) of 0.9 keV and 1.1 keV at 14 keV and 60 keV, respectively, have been obtained with an epitaxial GaAs detector, while 0.7 keV and 1.5 keV FWHMmore » were measured at the same energies with a CdZnTe detector. Based on these results it is clear, that the next generation of X-ray astrophysics missions now in the planning phase may well consider extending the photon energy range up to {approximately} 100 keV by use of efficient detectors with reasonable spectroscopic capabilities.« less

Design and Analysis of Modules for Segmented X-Ray Optics

NASA Technical Reports Server (NTRS)

McClelland, Ryan S.; BIskach, Michael P.; Chan, Kai-Wing; Saha, Timo T; Zhang, William W.

2012-01-01

Future X-ray astronomy missions demand thin, light, and closely packed optics which lend themselves to segmentation of the annular mirrors and, in turn, a modular approach to the mirror design. The modular approach to X-ray Flight Mirror Assembly (FMA) design allows excellent scalability of the mirror technology to support a variety of mission sizes and science objectives. This paper describes FMA designs using slumped glass mirror segments for several X-ray astrophysics missions studied by NASA and explores the driving requirements and subsequent verification tests necessary to qualify a slumped glass mirror module for space-flight. A rigorous testing program is outlined allowing Technical Development Modules to reach technical readiness for mission implementation while reducing mission cost and schedule risk.

Performance of ASTRO-H Hard X-Ray Telescope (HXT)

NASA Technical Reports Server (NTRS)

Awaki, Hisamitsu; Kunieda, Hideyo; Ishida, Manabu; Matsumoto, Hironori; Furuzawa, Akihiro; Haba, Yohsito; Hayashi, Takayuki; Iizuka, Ryo; Ishibashi, Kazunori; Itoh, Masayuki;

Symbiotic Stars in X-rays

NASA Technical Reports Server (NTRS)

Luna, G. J. M.; Sokoloski, J. L.; Mukai, K.; Nelson, T.

2014-01-01

Until recently, symbiotic binary systems in which a white dwarf accretes from a red giant were thought to be mainly a soft X-ray population. Here we describe the detection with the X-ray Telescope (XRT) on the Swift satellite of 9 white dwarf symbiotics that were not previously known to be X-ray sources and one that was previously detected as a supersoft X-ray source. The 9 new X-ray detections were the result of a survey of 41 symbiotic stars, and they increase the number of symbiotic stars known to be X-ray sources by approximately 30%. Swift/XRT detected all of the new X-ray sources at energies greater than 2 keV. Their X-ray spectra are consistent with thermal emission and fall naturally into three distinct groups. The first group contains those sources with a single, highly absorbed hard component, which we identify as probably coming from an accretion-disk boundary layer. The second group is composed of those sources with a single, soft X-ray spectral component, which likely arises in a region where low-velocity shocks produce X-ray emission, i.e. a colliding-wind region. The third group consists of those sources with both hard and soft X-ray spectral components. We also find that unlike in the optical, where rapid, stochastic brightness variations from the accretion disk typically are not seen, detectable UV flickering is a common property of symbiotic stars. Supporting our physical interpretation of the two X-ray spectral components, simultaneous Swift UV photometry shows that symbiotic stars with harder X-ray emission tend to have stronger UV flickering, which is usually associated with accretion through a disk. To place these new observations in the context of previous work on X-ray emission from symbiotic stars, we modified and extended the alpha/beta/gamma classification scheme for symbiotic-star X-ray spectra that was introduced by Muerset et al. based upon observations with the ROSAT satellite, to include a new sigma classification for sources with

Soft X-Ray Emissions from Planets and Moons

NASA Technical Reports Server (NTRS)

Bhardwaj, A.; Gladstone, G. R.; Elsner, R. F.; Waite, J. H., Jr.; Grodent, D.; Lewis, W. S.; Crary, F. J.; Weisskopf, M. C.; Howell, R. R.; Johnson, R. E.;

Feasibility of spectro-photometry in X-rays (SPHINX) from the moon

NASA Astrophysics Data System (ADS)

Sarkar, Ritabrata; Chakrabarti, Sandip Kumar

2010-08-01

Doing space Astronomy on lunar surface has several advantages. We present here feasibility of an All Sky Monitoring Payload for Spectro-photometry in X-rays (SPHINX) which can be placed on a lander on the moon or in a space craft orbiting around the moon. The Si-PIN photo-diodes and CdTe crystals are used to detect solar flares, bright gamma bursts, soft gamma-ray repeaters from space and also X-ray fluorescence (XRF) from lunar surface. We present the complete Geant4 simulation to study the feasibility of such an instrument in presence of Cosmic Diffused X-Ray Background (CDXRB). We find that the signal to noise ratio is sufficient for moderate to bright GRBs (above 5 keV), for the quiet sun (up to 100 keV), solar flares, soft gamma-ray repeaters, X-ray Fluorescence (XRF) of lunar surface etc. This is a low-cost system which is capable of performing multiple tasks while stationed at the natural satellite of our planet.

Phonon-mediated superconducting transition-edge sensor X-ray detectors for use in astronomy

NASA Astrophysics Data System (ADS)

Leman, Steven W.; Martinez-Galarce, Dennis S.; Brink, Paul L.; Cabrera, Blas; Castle, Joseph P.; Morse, Kathleen; Stern, Robert A.; Tomada, Astrid

2004-09-01

Superconducting Transition-Edge Sensors (TESs) are generating a great deal of interest in the areas of x-ray astrophysics and space science, particularly to develop them as large-array, imaging x-ray spectrometers. We are developing a novel concept that is based on position-sensitive macro-pixels placing TESs on the backside of a silicon or germanium absorber. Each x-ray absorbed will be position (X/δX and Y/δY ~ 100) and energy (E/δE ~ 1000) resolved via four distributed TES readouts. In the future, combining such macropixels with advances in multiplexing could lead to 30 by 30 arrays of close-packed macro-pixels equivalent to imaging instruments of 10 megapixels or more. We report on our progress to date and discuss its application to a plausible solar satellite mission and plans for future development.

Low-Energy Microfocus X-Ray Source for Enhanced Testing Capability in the Stray Light Facility

NASA Technical Reports Server (NTRS)

Gaskin, Jessica; O'Dell, Stephen; Kolodziejczak, Jeff

2015-01-01

Research toward high-resolution, soft x-ray optics (mirrors and gratings) necessary for the next generation large x-ray observatories requires x-ray testing using a low-energy x-ray source with fine angular size (<1 arcsecond). To accommodate this somewhat demanding requirement, NASA Marshall Space Flight Center (MSFC) has procured a custom, windowless low-energy microfocus (approximately 0.1 mm spot) x-ray source from TruFocus Corporation that mates directly to the Stray Light Facility (SLF). MSFC X-ray Astronomy team members are internationally recognized for their expertise in the development, fabrication, and testing of grazing-incidence optics for x-ray telescopes. One of the key MSFC facilities for testing novel x-ray instrumentation is the SLF. This facility is an approximately 100-m-long beam line equipped with multiple x-ray sources and detectors. This new source adds to the already robust compliment of instrumentation, allowing MSFC to support additional internal and community x-ray testing needs.

Gas Scintillation Proportional Counters for High-Energy X-ray Astronomy

NASA Technical Reports Server (NTRS)

Gubarev, Mikhail; Ramsey, Brian; Apple, Jeffery

2003-01-01

A focal plane array of high-pressure gas scintillation proportional counters (GSPC) for a balloon-borne hard-x-ray telescope is under development at the Marshall Space Flight Center. These detectors have an active area of approx. 20 sq cm, and are filled with a high pressure (10(exp 6) Pa) xenon-helium mixture. Imaging is via crossed-grid position-sensitive phototubes sensitive in the UV region. The performance of the GSPC is well matched to that of the telescopes x-ray optics which have response to 75 keV and a focal spot size of approx. 500 microns. The detector s energy resolution, 4% FWHM at 60 keV, is adequate for resolving the broad spectral lines of astrophysical importance and for accurate continuum measurements. Full details of the instrument and its performance will be provided.

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.

The Complete Local-Volume Groups Sample (CLoGS): Early results from X-ray and radio observations

NASA Astrophysics Data System (ADS)

Vrtilek, Jan M.; O'Sullivan, Ewan; David, Laurence P.; Giacintucci, Simona; Kolokythas, Konstantinos

2017-08-01

Although the group environment is the dominant locus of galaxy evolution (in contrast to rich clusters, which contain only a few percent of galaxies), there has been a lack of reliable, representative group samples in the local Universe. In particular, X-ray selected samples are strongly biased in favor of the X-ray bright, centrally-concentrated cool-core systems. In response, we have designed the Complete Local-Volume Groups Sample (CLoGS), an optically-selected statistically-complete sample of 53 groups within 80 Mpc which is intended to overcome the limitations of X-ray selected samples and serve as a representative survey of groups in the local Universe. We have supplemented X-ray data from Chandra and XMM (70% complete to date, using both archival and new observations, with a 26-group high richness subsample 100% complete) with GMRT radio continuum observations (at 235 and 610 MHz, complete for the entire sample). CLoGS includes groups with a wide variety of properties in terms of galaxy population, hot gas content, and AGN power. We here describe early results from the survey, including the range of AGN activity observed in the dominant galaxies, the relative fraction of cool-core and non-cool-core groups in our sample, and the degree of disturbance observed in the IGM.

Carbon-based Fresnel optics for hard x-ray astronomy.

PubMed

Braig, Christoph; Zizak, Ivo

2018-03-10

We investigate the potential of large-scale diffractive-refractive normal-incidence transmission lenses for the development of space-based hard x-ray telescopes with an angular resolution in the range of (10 -6 -10 -3 )  arcsec over a field of view that is restricted by the available detector size. Coherently stepped achromatic lenses with diameters up to 5 m for compact apertures and 13 m in the case of segmentation provide an access to spectrally resolved imaging within keV-wide bands around the design energy between 10 and 30 keV. Within an integration time of 10 6   s, a photon-limited 5σ sensitivity down to (10 -9 -10 -7 )  s -1  cm -2  keV -1 can be achieved depending on the specific design. An appropriate fabrication strategy, feasible nowadays with micro-optical technologies, is considered and relies on the availability of high-purity carbon or polymer membranes. X-ray fluorescence measurements of various commercially available carbon-based materials prove for most of them the existence of a virtually negligible contamination by critical trace elements such as transition metals on the ppm level.

Small astronomy satellite-A, Uhuru data analysis

NASA Technical Reports Server (NTRS)

Koch, D.

1974-01-01

Objectives were to conduct observations with the first satellite entirely devoted to X-ray astronomy and to analyze the results obtained. A catalog of X-ray sources was generated, and results of discoveries and further detailed observations of sources were presented in scientific journals and meetings. A list of how objectives were met, a brief description of the instrument, significant results, the X-ray catalog, and a complete bibliography of results are included.

IAU Astronomy for Equity and Inclusion Working Group

NASA Astrophysics Data System (ADS)

Ortiz-Gil, A.; García, B.; WG3 of Commission C1 Division C of the IAU

2017-03-01

In this talk we present the aims, goals and activities that have been started by the working group on Astronomy for Equity and Inclusion. This working group is part of Commission 1 ''Astronomy Education and Development'' of Division C ''Education, Outreach and Heritage'' of the International Astronomical Union (IAU). The working group was born with the aim of developing new strategies and resources to promote the access to Astronomy, both at the profesional and outreach levels, for persons with special needs or for those who could be excluded because of race or sexual orientation (among other reasons). It is composed of astronomers affiliated with the IAU and other volunteers who work in astronomy, education and special needs, as well as partner organizations like the IAU Office of Astronomy for Development (OAD), Astronomers without Borders (AWB), the Galileo Teacher Training Program (GTTP) or Universe Awareness (UNAWE). To reach those goals we have started different initiatives which are outlined at the working group’s website, like a repository of resources or the creation of a document about good practices, and the establishment of a tight collaboration with the Working Group about Accessibility of the American Astronomical Society, which was formed recently too.

High-redshift Extremely Red Quasars in X-Rays

NASA Astrophysics Data System (ADS)

Goulding, Andy D.; Zakamska, Nadia L.; Alexandroff, Rachael M.; Assef, Roberto J.; Banerji, Manda; Hamann, Fred; Wylezalek, Dominika; Brandt, William N.; Greene, Jenny E.; Lansbury, George B.; Pâris, Isabelle; Richards, Gordon; Stern, Daniel; Strauss, Michael A.

2018-03-01

Quasars may have played a key role in limiting the stellar mass of massive galaxies. Identifying those quasars in the process of removing star formation fuel from their hosts is an exciting ongoing challenge in extragalactic astronomy. In this paper, we present X-ray observations of 11 extremely red quasars (ERQs) with L bol ∼ 1047 erg s‑1 at z = 1.5–3.2 with evidence for high-velocity (v ≥slant 1000 km s‑1) [O III] λ5007 outflows. X-rays allow us to directly probe circumnuclear obscuration and to measure the instantaneous accretion luminosity. We detect 10 out of 11 ERQs available in targeted and archival data. Using a combination of X-ray spectral fitting and hardness ratios, we find that all of the ERQs show signs of absorption in the X-rays with inferred column densities of N H ≈ 1023 cm‑2, including four Compton-thick candidates (N H ≥slant 1024 cm‑2). We stack the X-ray emission of the seven weakly detected sources, measuring an average column density of N H ∼ 8 × 1023 cm‑2. The absorption-corrected (intrinsic) 2–10 keV X-ray luminosity of the stack is 2.7 × 1045 erg s‑1, consistent with X-ray luminosities of type 1 quasars of the same infrared luminosity. Thus, we find that ERQs are a highly obscured, borderline Compton-thick population, and based on optical and infrared data we suggest that these objects are partially hidden by their own equatorial outflows. However, unlike some quasars with known outflows, ERQs do not appear to be intrinsically underluminous in X-rays for their bolometric luminosity. Our observations indicate that low X-rays are not necessary to enable some types of radiatively driven winds.

X-rays and photocarcinogenesis in hairless mice.

PubMed

Lerche, Catharina M; Philipsen, Peter A; Wulf, Hans Christian

2013-08-01

It is well known that excessive X-ray radiation can cause non-melanoma skin cancers. With the increased incidence of sun-related skin cancer there is a need to investigate the combination of sunlight and X-rays. Immunocompetent C3.Cg/TifBomTac mice (n = 298) were divided into 12 groups. Mice were irradiated with 12, 29 or 50 kV X-rays. The mice received a total dose of 45 Gy. They were irradiated with 3 SED simulated solar radiation (SSR) either before or after irradiation with X-rays. The groups irradiated with X-rays alone, 0, 3, 9 and 10 mice (0, 12, 29 and 50 kV, respectively) developed squamous cell carcinoma. In the groups irradiated with SSR after X-rays the development of tumours was significantly faster in the 50 kV group than in the corresponding control group (175 vs. 194 days, p < 0.001). In the groups irradiated with SSR prior to the X-ray radiation the development of tumours was significantly faster in the 29 and the 50 kV groups than in the corresponding control group (175 vs. 202 days, p < 0.001 and 158 vs. 202 days, p < 0.001, respectively). In conclusion, X-ray radiation alone is a weak carcinogen in hairless mice. There is an added carcinogenic effect if X-ray radiation is given on prior sun-exposed skin or if the skin is sun-exposed after X-rays. We still believe that X-ray radiation is a safe and effective therapy for various dermatological diseases but caution should be observed if a patient has severely sun-damaged skin or has a high-risk sun behaviour.

The Complete Local Volume Groups Sample - I. Sample selection and X-ray properties of the high-richness subsample

NASA Astrophysics Data System (ADS)

O'Sullivan, Ewan; Ponman, Trevor J.; Kolokythas, Konstantinos; Raychaudhury, Somak; Babul, Arif; Vrtilek, Jan M.; David, Laurence P.; Giacintucci, Simona; Gitti, Myriam; Haines, Chris P.

2017-12-01

We present the Complete Local-Volume Groups Sample (CLoGS), a statistically complete optically selected sample of 53 groups within 80 Mpc. Our goal is to combine X-ray, radio and optical data to investigate the relationship between member galaxies, their active nuclei and the hot intra-group medium (IGM). We describe sample selection, define a 26-group high-richness subsample of groups containing at least four optically bright (log LB ≥ 10.2 LB⊙) galaxies, and report the results of XMM-Newton and Chandra observations of these systems. We find that 14 of the 26 groups are X-ray bright, possessing a group-scale IGM extending at least 65 kpc and with luminosity >1041 erg s-1, while a further three groups host smaller galaxy-scale gas haloes. The X-ray bright groups have masses in the range M500 ≃ 0.5-5 × 1013 M⊙, based on system temperatures of 0.4-1.4 keV, and X-ray luminosities in the range 2-200 × 1041 erg s-1. We find that ∼53-65 per cent of the X-ray bright groups have cool cores, a somewhat lower fraction than found by previous archival surveys. Approximately 30 per cent of the X-ray bright groups show evidence of recent dynamical interactions (mergers or sloshing), and ∼35 per cent of their dominant early-type galaxies host active galactic nuclei with radio jets. We find no groups with unusually high central entropies, as predicted by some simulations, and confirm that CLoGS is in principle capable of detecting such systems. We identify three previously unrecognized groups, and find that they are either faint (LX, R500 < 1042 erg s-1) with no concentrated cool core, or highly disturbed. This leads us to suggest that ∼20 per cent of X-ray bright groups in the local universe may still be unidentified.

Background in X-ray astronomy proportional counters

NASA Technical Reports Server (NTRS)

Bower, C. R.; Dietz, K. L.; Ramsey, B. D.; Weisskopf, M. C.

1991-01-01

The authors report the results of an investigation into the nature of background events in proportional counters sensitive to X-ray photons having energy of less than 150 keV. Even with the use of thick shields composed of high-atomic-number material, a significant flux background in the detector's energy region can result from multiple Compton scattering in the mass surrounding the active region of the detector. The importance of the selection of detector components in the reduction of the background by more than an order of magnitude is emphasized. Experimental results are shown to agree qualitatively with Monte Carlo simulations. It is concluded that escape gating is a powerful means of determining the nature of background in flight detectors: the single/pair ratios reveal whether the detected events are charged particles or photons.

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

NASA Names Premier X-Ray Observatory and Schedules Launch

NASA Astrophysics Data System (ADS)

1998-12-01

Chicago until his death in 1995. The Chandra X-ray Observatory 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-radiation is an invisible form of light produced by multimillion degree gas. Chandra will provide X-ray images that are fifty times more detailed than previous missions. At more than 45 feet in length and weighing more than five tons, it will be one of the largest objects ever placed in Earth orbit by the Space Shuttle. Tyrel Johnson, a student at Priest River Lamanna High School in Priest River, Idaho, and Jatila van der Veen, a physics and astronomy teacher at Adolfo Camarillo High School in Camarillo, California, who submitted the winning name and essays, will receive a trip to the Kennedy Space Center in Florida to view the launch of the Chandra X-ray Observatory, a prize donated by TRW. Members of the contest's selection committee were Timothy Hannemann, executive vice president and general manager, TRW Space & Electronics Group; the late CNN correspondent John Holliman; former Secretary of the Air Force Sheila Widnall, professor of aeronautics at MIT; Charles Petit, senior writer for U.S. News & World Report; Sidney Wolff, Director, National Optical Astronomy Observatories; Martin Weisskopf, Advanced X-ray Astrophysics Facility project scientist, Marshall Space Flight Center, Huntsville, AL.; and Harvey Tananbaum, director of the Advanced X-ray Astrophysics Facility Science Center, Smithsonian Astrophysical Observatory, Cambridge, MA. The Chandra X-ray Observatory program is managed by the Marshall Center for the Office of Space Science, NASA Headquarters, Washington, DC. TRW Space and Electronics Group, Redondo Beach, CA, is NASA's prime contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations of the observatory for NASA

Focal plane transport assembly for the HEAO-B X-ray telescope

NASA Technical Reports Server (NTRS)

Brissette, R.; Allard, P. D.; Keller, F.; Strizhak, E.; Wester, E.

1979-01-01

The High Energy Astronomy Observatory - Mission B (HEAO-B), an earth orbiting X-ray telescope facility capable of locating and imaging celestial X-ray sources within one second of arc in the celestial sphere, is considered. The Focal Plane Transport Assembly (FPTA) is one of the basic structural elements of the three thousand pound HEAO-B experiment payload. The FPTA is a multifunctional assembly which supports seven imaging X-ray detectors circumferentially about a central shaft and accurately positions any particular one into the focus of a high resolution mirror assembly. A drive system, position sensor, rotary coupler, and detent alignment system, all an integral part of the rotatable portion which in turn is supported by main bearings to the stationary focal plane housing are described.

Toward Large-Area Sub-Arcsecond X-Ray Telescopes

NASA Technical Reports Server (NTRS)

ODell, Stephen L.; Aldcroft, Thomas L.; Allured, Ryan; Atkins, Carolyn; Burrows, David N.; Cao, Jian; Chalifoux, Brandon D.; Chan, Kai-Wing; Cotroneo, Vincenzo; Elsner, Ronald F.;

X-Ray Emission from the Soft X-Ray Transient Aquila X-1

NASA Technical Reports Server (NTRS)

Tavani, Marco

1998-01-01

Aquila X-1 is the most prolific of soft X-ray transients. It is believed to contain a rapidly spinning neutron star sporadically accreting near the Eddington limit from a low-mass companion star. The interest in studying the repeated X-ray outbursts from Aquila X-1 is twofold: (1) studying the relation between optical, soft and hard X-ray emission during the outburst onset, development and decay; (2) relating the spectral component to thermal and non-thermal processes occurring near the magnetosphere and in the boundary layer of a time-variable accretion disk. Our investigation is based on the BATSE monitoring of Aquila X-1 performed by our group. We observed Aquila X-1 in 1997 and re-analyzed archival information obtained in April 1994 during a period of extraordinary outbursting activity of the source in the hard X-ray range. Our results allow, for the first time for this important source, to obtain simultaneous spectral information from 2 keV to 200 keV. A black body (T = 0.8 keV) plus a broken power-law spectrum describe accurately the 1994 spectrum. Substantial hard X-ray emission is evident in the data, confirming that the accretion phase during sub-Eddington limit episodes is capable of producing energetic hard emission near 5 x 10(exp 35) ergs(exp -1). A preliminary paper summarizes our results, and a more comprehensive account is being written. We performed a theoretical analysis of possible emission mechanisms, and confirmed that a non-thermal emission mechanism triggered in a highly sheared magnetosphere at the accretion disk inner boundary can explain the hard X-ray emission. An anticorrelation between soft and hard X-ray emission is indeed prominently observed as predicted by this model.

Lightweight and High-Resolution Single Crystal Silicon Optics for X-ray Astronomy

NASA Technical Reports Server (NTRS)

Zhang, William W.; Biskach, Michael P.; Chan, Kai-Wing; Mazzarella, James R.; McClelland, Ryan S.; Riveros, Raul E.; Saha, Timo T.; Solly, Peter M.

2016-01-01

We describe an approach to building mirror assemblies for next generation X-ray telescopes. It incorporates knowledge and lessons learned from building existing telescopes, including Chandra, XMM-Newton, Suzaku, and NuSTAR, as well as from our direct experience of the last 15 years developing mirror technology for the Constellation-X and International X-ray Observatory mission concepts. This approach combines single crystal silicon and precision polishing, thus has the potential of achieving the highest possible angular resolution with the least possible mass. Moreover, it is simple, consisting of several technical elements that can be developed independently in parallel. Lastly, it is highly amenable to mass production, therefore enabling the making of telescopes of very large photon collecting areas.

SUZAKU OBSERVATIONS OF THE X-RAY BRIGHTEST FOSSIL GROUP ESO 3060170

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

Su, Yuanyuan; White, Raymond E. III; Miller, Eric D., E-mail: ysu@crimson.ua.edu

2013-10-01

'Fossil' galaxy groups, each dominated by a relatively isolated giant elliptical galaxy, have many properties intermediate between groups and clusters of galaxies. We used the Suzaku X-ray observatory to observe the X-ray brightest fossil group, ESO 3060170, out to R{sub 200}, in order to better elucidate the relation between fossil groups, normal groups, and clusters. We determined the intragroup gas temperature, density, and metal abundance distributions and derived the entropy, pressure, and mass profiles for this group. The entropy and pressure profiles in the outer regions are flatter than in simulated clusters, similar to what is seen in observations ofmore » massive clusters. This may indicate that the gas is clumpy and/or the gas has been redistributed. Assuming hydrostatic equilibrium, the total mass is estimated to be ∼1.7 × 10{sup 14} M{sub ☉} within a radius R{sub 200} of ∼1.15 Mpc, with an enclosed baryon mass fraction of 0.13. The integrated iron mass-to-light ratio of this fossil group is larger than in most groups and comparable to those of clusters, indicating that this fossil group has retained the bulk of its metals. A galaxy luminosity density map on a scale of 25 Mpc shows that this fossil group resides in a relatively isolated environment, unlike the filamentary structures in which typical groups and clusters are embedded.« less

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.

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.

A Study of the X-Ray Emission from Three Radio Pulsars

NASA Technical Reports Server (NTRS)

Slane, Patrick O. (Principal Investigator)

1996-01-01

The subject grant is for work on a study of x-ray emission from isolated pulsars. The purpose of the study was to: determine whether the pulsars were x-ray sources; and, if so, search for evidence of pulsations at the known radio period; and study the nature of the x-ray emission. Observation of the pulsar PSR 0355+54 were obtained, and the analysis of these data is complete. These results were reported at the 183rd AAS Meeting, and in a paper entitled 'X-Ray Emission from PSR 0355+54' which as published in the The Astrophysical Journal. Also obtained an approx. 3 ks PSPC observations of PSR 1642-03. A summary of the results from these data were reported in a Conference Proceedings for the 'New Horizon of X-ray Astronomy' symposium. In addition, as part of a study with a student from the SAO Summer Intern Program, I incorporated ROSAT archival data in an extended study of pulsar emission. These results were reported at the 185th AAS Meeting, and in a paper entitled 'Soft X-ray Emission from Selected Isolated Pulsars' which was published in The Astrophysical Journal (Letters).

Recent results from the Japanese X-ray astronomy satellites

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

Tanaka, Y.

1986-01-01

Observations of neutron stars and their environments, and the emission and absorption of iron, obtained with the Hakucho and Tenma satellites, are examined. The characteristics of X-ray bursts, neutron stars, and accretion disks, in particular spectra, color and effective temperatures, blackbody temperature and radius, the emissivity factor, and the Eddington limit luminosity, are discussed. Consideration is given to the rapid burster discovered by Lewin et al. (1976) and potential blackhole sources. 43 references.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1980-01-01

This image of the suspected Black Hole, Cygnus X-1, was the first object seen by the High Energy Astronomy Observatory (HEAO)-2/Einstein Observatory. According to the theories to date, one concept of a black hole is a star, perhaps 10 times more massive than the Sun, that has entered the last stages of stelar evolution. There is an explosion triggered by nuclear reactions after which the star's outer shell of lighter elements and gases is blown away into space and the heavier elements in the stellar core begin to collapse upon themselves. Once this collapse begins, the inexorable force of gravity continues to compact the material until it becomes so dense it is squeezed into a mere point and nothing can escape from its extreme gravitational field, not even light. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy.

Atelier d'astronomie X

NASA Astrophysics Data System (ADS)

Ballet, J.; Barret, D.

2001-01-01

L'astronomie X connait aujourd'hui une de ses périodes les plus actives et les plus fastes, après le lancement de Chandra et XMM-Newton, et alors que Beppo SAX et Rossi XTE sont toujours en orbite. L'extraordinaire complémentarité de ces satellites est telle que leur domaine d'utilisation est extrêmement vaste, couvrant des étoiles jeunes aux toujours énigmatiques sursauts γ, en passant bien entendu par les trous noirs accrétants dans les binaires X ou dans les noyaux actifs de galaxies. L'atelier fut organisé selon quatre thèmes les étoiles, les phénomènes explosifs, les binaires X et les noyaux actifs de galaxies. Les résultats qui y furent présentés, pour chacun de ces thèmes témoignent de la superbe qualité des données obtenues. En particulier l'accès à la haute résolution spectrale (réseaux) en rayons X marque un pas important. Les présentations plus théoriques ont montré que parallèlement des progrès significatifs sont réalisés dans la physique de l'accrétion autour des objets compacts. Les actes de l'atelier donnent un panorama représentatif des progrès réalisés récemment par l'astronomie X, aussi bien du point de vue observationnel que théorique. Ces actes de colloque sont aussi l'occasion de rappeler l'historique et ce que furent les activités scientifiques de notre GdR au moment ou il doit s'intègrer au GdR PCHE et au PNPS. Enfin, pour toutes informations complémentaires concernant l'atelier: http://www.cesr.fr/~barret/adj/vg.html Ce site donne accès en particulier à la plupart des présentations (transparents).

Development Roadmap for an Adjustable X-Ray Optics Observatory

NASA Technical Reports Server (NTRS)

Schwartz, Dan; Brissenden, R.; Bookbinder, J.; Davis, W.; Forman, W.; Freeman, M.; O'Dell, S.; Ramsey, B.; Reid, P.; Romaine, S.;

Hard X-ray (greater than 10 keV) telescope for space astronomy from the Moon

NASA Astrophysics Data System (ADS)

Frontera, F.; de Chiara, P.; Pasqualini, G.

1994-06-01

The use of the Moon as site for deep observations of astrophysical sources in hard X-rays (greater than 10 keV) is very exciting, in spite of several technological problems to be solved. A strong limitation to the sensitivity of hard X-ray experiments is imposed by the use of direct-viewing (with or without masks) detectors. We propose a lunar hard X-ray observatory, (LHEXO), that makes use of a hard X-ray concentrator which is based on the use of confocal paraboloidal mirrors made of mosaic crystals of graphite (002). In this paper we describe telescope concept and its expected performances.

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

From Uhuru at CfA to SAS-3 at MIT: Looking for X-Ray Binaries in all the Right Places

NASA Astrophysics Data System (ADS)

Cominsky, Lynn R.

2013-01-01

My career in X-ray astronomy started almost accidentally, when in 1975 I was hired fresh out of college as a “data aide” for the Uhuru satellite, in Riccardo Giacconi’s group at the Harvard-Smithsonian Center for Astrophysics. Working first for Mel Ulmer, and later for Bill Forman and Christine Jones, I learned the fundamentals of data analysis, and helped produce the Fourth Uhuru catalog of X-ray sources (Forman et al. 1978), as well as studying transient X-ray sources (Cominsky et al. 1978). Christine was the first woman scientist I had ever met, and with her encouragement, I applied to graduate school to continue on in X-ray astronomy. Lured down the street to MIT by the chance to work on SAS-3, I eagerly learned how to operate the satellite from a control room in the Center for Space Research. The SAS-3 group was led by Prof. George Clark, and it was my good luck that he was around during the holiday break in January 1978 when everyone else in the group was at an AAS meeting in Hawaii. A source I recognized from my Uhuru work, 4U0115+63, had reappeared, and I knew that it was likely to be a pulsar. With the help of George and Project Scientist Bill Mayer, I managed to send the commands to stop SAS-3 and point at the source. The 3.6 second pulsations were so strong that they could be seen in the raw data! This discovery made the New York Times, as 4U0115+63 was the first transient x-ray source shown to be in a binary system (Cominsky et al. 1978, Rappaport et al. 1978). Another personal SAS-3 highlight included working on Prof. Walter Lewin’s “World-wide Burst Watch” - coordinated multi-wavelength observations of x-ray burst sources which led to the discoveries of slightly delayed but coincident optical bursts (Grindlay et al. 1978, McClintock et al. 1979). Although live operations of SAS-3 ended when it re-entered on April 9, 1979, many years of additional data analysis remained. And later, as a continuation of work I began in my Ph.D. Thesis on X-ray

A laboratory demonstration of high-resolution hard X-ray and gamma-ray imaging using Fourier-transform techniques

NASA Technical Reports Server (NTRS)

Palmer, David; Prince, Thomas A.

1987-01-01

A laboratory imaging system has been developed to study the use of Fourier-transform techniques in high-resolution hard X-ray and gamma-ray imaging, with particular emphasis on possible applications to high-energy astronomy. Considerations for the design of a Fourier-transform imager and the instrumentation used in the laboratory studies is described. Several analysis methods for image reconstruction are discussed including the CLEAN algorithm and maximum entropy methods. Images obtained using these methods are presented.

Toward Large-Area Sub-Arcsecond X-Ray Telescopes II

NASA Technical Reports Server (NTRS)

O'Dell, Stephen L.; Allured, Ryan; Ames, Andrew O.; Biskach, Michael P.; Broadway David M.; Bruni, Ricardo J.; Burrows, David; Cao, Jian; Chalifoux, Brandon D.; Chan, Kai-Wing;

Aligning, Bonding, and Testing Mirrors for Lightweight X-ray Telescopes

NASA Technical Reports Server (NTRS)

Chan, Kai-Wing; Zhang, William W.; Saha, Timo T.; McClelland, Ryan S.; Biskach, Michael P.; Niemeyer, Jason; Schofield, Mark J.; Mazzarella, James R.; Kolos, Linette D.; Hong, Melinda M.;

X-Ray Diffraction Studies on Metal Deposition in Group D Streptococci

PubMed Central

Tucker, Fayne L.; Thomas, John W.; Appleman, Milo D.; Goodman, Stewart H.; Donohue, Jerry

1966-01-01

Tucker, Fayne L. (University of Southern California, Los Angeles), John W. Thomas, Milo D. Appleman, Stewart H. Goodman, and Jerry Donohue. X-ray diffraction studies on metal deposition in group D streptococci. J. Bacteriol. 92:1311–1314. 1966.—Streptococcus faecalis N83 and S. faecium K6A reduced several compounds of Group VI elements to the elemental form, but reduced none of several compounds tested containing elements of other groups. The elemental tellurium deposited by S. faecium K6A was in general of a larger particle size than that deposited by S. faecalis N83 as judged from X-ray diffraction analysis. The particle size of the deposited tellurium was correlated with the blackness of the precipitate produced by cells growing in the presence of tellurite. A black and gray variation was observed in S. faecium K6A which was considered to be due to particle size, the amount of tellurium present, and the location of the deposited tellurium. The gray color of S. faecium K6A was not due to the presence of any oxidized tellurium products. PMID:4958879

Electro-Formed Mirrors for Both X-Ray and Visible Astronomy

NASA Technical Reports Server (NTRS)

Ritter, J.; Smith, W. Scott; Rose, M. Frank (Technical Monitor)

2000-01-01

The Space Optics Manufacturing Technology Center of NASA's Marshall Space Flight Center is involved in the development of nickel and nickel alloy electroformed mirrors for rapid production of space-based optical systems. The current state of the process is discussed- for both cylindrical x-ray mirrors and normal incidence mirrors for visible and infrared applications.

Multilayer and grazing incidence X-ray/EUV optics; Proceedings of the Meeting, San Diego, CA, July 22-24, 1991

NASA Technical Reports Server (NTRS)

Hoover, Richard B. (Editor)

1992-01-01

The present conference discusses the Advanced X-ray Astrophysics Facility (AXAF) calibration by means of synchrotron radiation and its X-ray reflectivity, X-ray scattering measurements from thin-foil X-ray mirrors, lobster-eye X-ray optics using microchannel plates, space-based interferometry at EUV and soft X-ray wavelengths, a water-window imaging X-ray telescope, a graded d-spacing multilayer telescope for high energy X-ray astronomy, photographic films for the multispectral solar telescope array, a soft X-ray ion chamber, and the development of hard X-ray optics. Also discussed are X-ray spectroscopy with multilayered optics, a slit aperture for monitoring X-ray experiments, an objective double-crystal spectrometer, a Ly-alpha coronagraph/polarimeter, tungsten/boron nitride multilayers for XUV optical applications, the evaluation of reflectors for soft X-ray optics, the manufacture of elastically bent crystals and multilayer mirrors, and selective photodevices for the VUV.

ISS-Lobster: A Proposed Wide-Field X-Ray Telescope on the International Space Station

NASA Technical Reports Server (NTRS)

Camp, Jordan

2012-01-01

The Lobster wide-field imaging telescope combines simultaneous high FOV, high sensitivity and good position resolution. These characteristics can open the field of X-Ray time domain astronomy, which will study many interesting transient sources, including tidal disruptions of stars, supernova shock breakouts, and high redshift gamma-ray bursts. Also important will be its use for the X-ray follow-up of gravitational wave detections. I will describe our present effort to propose the Lobster concept for deployment on the International Space Station through a NASA Mission of Opportunity this fall.

Thin plastic foil X-ray optics with spiral geometry

NASA Astrophysics Data System (ADS)

Barbera, Marco; Mineo, Teresa; Perinati, Emanuele; Schnopper, Herbert W.; Taibi, Angelo

2007-09-01

Winding a plastic foil ribbon into spiral cylinder or spiral cones we can design and build single or multiple reflection X-ray grazing incidence focusing optics with potential applications in Astronomy as well as experimental physics. The use of thin plastic foils from common industrial applications and of a mounting technique which does not require the construction of mandrels make these optics very cost effective. A spiral geometry focusing optic produces an annular image of a point source with the angular size of the annulus depending mainly on the pitch of the winding and the focal length. We use a ray-tracing code to evaluate the performances of cylindrical, and double conical spiral geometry as a function of the design parameters e.g. focal length, diameter, optic length. Some preliminary results are presented on X-ray imaging tests performed on spiral cylindrical optics.

End of the Golden Age for X-ray Astronomy: Technical and Fiscal Challenges

NASA Astrophysics Data System (ADS)

Elvis, Martin

2012-09-01

Golden Ages don't last much more than 50 years (viz. Athens 4th century BCE, Renaissance Italy, Dutch Golden Age) - that's why they're golden. X-ray astronomy is now 50 years old. Should we expect it to continue to flourish? Or is this the end of our Golden Age? Technologically there is tremendous promise. New optics and detectors are set to deliver great improvements along all axes: collecting area, angular and spectral resolution, field of view, polarimetry. To be optimal along a given axis, missions should not try to combine all these improvements in a single mission. Hence specialized missions of modest size (similar to NASA's Explorer class) should be pursued world-wide. Multiple missions also support a wide, varied, and creative community, not only of observers but also of instrument builders, operations staff and data/archive developers. All are necessary for a healthy field. We should encourage our agencies to adopt vigorous modest-mission programs, and to encourage open access to promote intellectual creativity. But some axes are almost certainly out of reach for Explorer-class missions. Most likely equaling or bettering Chandra angular resolution with larger area will require an Observatory-class, flagship, mission. While the technology is promising, the world-wide prospects for such a mission are grim. This is not merely the result of current economic woes, although they have brought the crisis to a head. Each generation of mission has to be an order of magnitude better than its predecessor in order to win funding. But to achieve this costs go up by a factor of a few each time. The progression: rockets - UHURU - Einstein - Chandra illustrates this clearly. The same exponentiation is evident in UV/visible astronomy and, perhaps, in Mars exploration. We have now hit the "funding wall" where each flagship mission costs so much that they pop into politicians notice. JWST is now a budget line item in the US, a precarious position previously held by the

Absorber Materials for Transition-Edge Sensor X-ray Microcalorimeters

NASA Technical Reports Server (NTRS)

Brown, Ari-David; Bandler, Simon; Brekosky, Regis; Chervenak, James; Figueroa-Feliciano, Enectali; Finkbeiner, Fred; Sadleir, Jack; Iyomoto, Naoko; Kelley, Richard; Kilbourne, Caroline;

Ray tracing method for the evaluation of grazing incidence x-ray telescopes described by spatially sampled surfaces.

PubMed

Yu, Jun; Shen, Zhengxiang; Sheng, Pengfeng; Wang, Xiaoqiang; Hailey, Charles J; Wang, Zhanshan

2018-03-01

The nested grazing incidence telescope can achieve a large collecting area in x-ray astronomy, with a large number of closely packed, thin conical mirrors. Exploiting the surface metrological data, the ray tracing method used to reconstruct the shell surface topography and evaluate the imaging performance is a powerful tool to assist iterative improvement in the fabrication process. However, current two-dimensional (2D) ray tracing codes, especially when utilized with densely sampled surface shape data, may not provide sufficient accuracy of reconstruction and are computationally cumbersome. In particular, 2D ray tracing currently employed considers coplanar rays and thus simulates only these rays along the meridional plane. This captures axial figure errors but leaves other important errors, such as roundness errors, unaccounted for. We introduce a semianalytic, three-dimensional (3D) ray tracing approach for x-ray optics that overcomes these shortcomings. And the present method is both computationally fast and accurate. We first introduce the principles and the computational details of this 3D ray tracing method. Then the computer simulations of this approach compared to 2D ray tracing are demonstrated, using an ideal conic Wolter-I telescope for benchmarking. Finally, the present 3D ray tracing is used to evaluate the performance of a prototype x-ray telescope fabricated for the enhanced x-ray timing and polarization mission.

Crystals and collimators for X-ray spectrometry. [Bragg reflection properties and design for astronomical applications

NASA Technical Reports Server (NTRS)

Mckenzie, D. L.; Landecker, P. B.; Underwood, J. H.

1976-01-01

Results of the measurement of Bragg reflection properties of crystals suitable for use in X-ray astronomy are presented. Measurements with a double crystal spectrometer were performed on rubidium acid phthalate and thallium acid phthalate to yield values of the integrated reflectivity and diffraction width in the range 8-18 A, and measurements of integrated reflectivity were also performed on ammonium dihydrogen phosphate. The theory and design of an arc-minute range multigrid collimator to be flown on a rocket for solar X-ray studies are also described, along with a method for determining the collimator's X-ray axis.

Next Generation Astronomical X-ray Optics: High Angular Resolution, Light Weight, and Low Production Cost

NASA Technical Reports Server (NTRS)

Zhang. W. W.; Biskach, M. P.; Blake, P. N.; Chan, K. W.; Gaskin, J. A.; Hong, M. L.; Jones, W. D.; Kolos, L. D.; Mazzarella, J. R.; McClelland, R. S.;

Columbia University OSO-8 instrument for stellar and solar X-ray spectroscopy and polarimetry

NASA Technical Reports Server (NTRS)

Wolff, R. S.

1976-01-01

A spectrometer and a polarimeter consisting of large-area panels of mosaic crystals have been constructed and prepared for use in the OSO-8 satellite. The instrumentation is planned for study of stellar and solar X-ray spectra between 1.8-8 keV and stellar X-ray polarization at 2.6 keV. Aspects of the design which enable the instrument to make measurements of the diverse range of stellar and solar phenomena are described. Some of the unique features, such as high sensitivity, high temporal resolution, and spectral range, are discussed. The applicability of the spectrometer and polarimeter to various current problems in X-ray astronomy is considered.

Open high-level data formats and software for gamma-ray astronomy

NASA Astrophysics Data System (ADS)

Deil, Christoph; Boisson, Catherine; Kosack, Karl; Perkins, Jeremy; King, Johannes; Eger, Peter; Mayer, Michael; Wood, Matthew; Zabalza, Victor; Knödlseder, Jürgen; Hassan, Tarek; Mohrmann, Lars; Ziegler, Alexander; Khelifi, Bruno; Dorner, Daniela; Maier, Gernot; Pedaletti, Giovanna; Rosado, Jaime; Contreras, José Luis; Lefaucheur, Julien; Brügge, Kai; Servillat, Mathieu; Terrier, Régis; Walter, Roland; Lombardi, Saverio

2017-01-01

In gamma-ray astronomy, a variety of data formats and proprietary software have been traditionally used, often developed for one specific mission or experiment. Especially for ground-based imaging atmospheric Cherenkov telescopes (IACTs), data and software are mostly private to the collaborations operating the telescopes. However, there is a general movement in science towards the use of open data and software. In addition, the next-generation IACT instrument, the Cherenkov Telescope Array (CTA), will be operated as an open observatory. We have created a Github organisation at https://github.com/open-gamma-ray-astro where we are developing high-level data format specifications. A public mailing list was set up at https://lists.nasa.gov/mailman/listinfo/open-gamma-ray-astro and a first face-to-face meeting on the IACT high-level data model and formats took place in April 2016 in Meudon (France). This open multi-mission effort will help to accelerate the development of open data formats and open-source software for gamma-ray astronomy, leading to synergies in the development of analysis codes and eventually better scientific results (reproducible, multi-mission). This write-up presents this effort for the first time, explaining the motivation and context, the available resources and process we use, as well as the status and planned next steps for the data format specifications. We hope that it will stimulate feedback and future contributions from the gamma-ray astronomy community.

Monitoring X-Ray Emission from X-Ray Bursters

NASA Technical Reports Server (NTRS)

Halpern, Jules P.; Kaaret, Philip

1999-01-01

The scientific goal of this project was to monitor a selected sample of x-ray bursters using data from the All-Sky Monitor (ASM) on the Rossi X-Ray Timing Explorer together with data from the Burst and Transient Source Experiment (BATSE) on the Compton Gamma-Ray Observatory to study the long-term temporal evolution of these sources in the x-ray and hard x-ray bands. The project was closely related to "Long-Term Hard X-Ray Monitoring of X-Ray Bursters", NASA project NAG5-3891, and and "Hard x-ray emission of x-ray bursters", NASA project NAG5-4633, and shares publications in common with both of these. The project involved preparation of software for use in monitoring and then the actual monitoring itself. These efforts have lead to results directly from the ASM data and also from Target of Opportunity Observations (TOO) made with the Rossi X-Ray Timing Explorer based on detection of transient hard x-ray outbursts with the ASM and BATSE.

Geant4 simulations of a wide-angle x-ray focusing telescope

NASA Astrophysics Data System (ADS)

Zhao, Donghua; Zhang, Chen; Yuan, Weimin; Zhang, Shuangnan; Willingale, Richard; Ling, Zhixing

2017-06-01

The rapid development of X-ray astronomy has been made possible by widely deploying X-ray focusing telescopes on board many X-ray satellites. Geant4 is a very powerful toolkit for Monte Carlo simulations and has remarkable abilities to model complex geometrical configurations. However, the library of physical processes available in Geant4 lacks a description of the reflection of X-ray photons at a grazing incident angle which is the core physical process in the simulation of X-ray focusing telescopes. The scattering of low-energy charged particles from the mirror surfaces is another noteworthy process which is not yet incorporated into Geant4. Here we describe a Monte Carlo model of a simplified wide-angle X-ray focusing telescope adopting lobster-eye optics and a silicon detector using the Geant4 toolkit. With this model, we simulate the X-ray tracing, proton scattering and background detection. We find that: (1) the effective area obtained using Geant4 is in agreement with that obtained using Q software with an average difference of less than 3%; (2) X-rays are the dominant background source below 10 keV; (3) the sensitivity of the telescope is better by at least one order of magnitude than that of a coded mask telescope with the same physical dimensions; (4) the number of protons passing through the optics and reaching the detector by Firsov scattering is about 2.5 times that of multiple scattering for the lobster-eye telescope.

Characteristics and performance of thin LaBr3(Ce) crystal for X-ray astronomy

NASA Astrophysics Data System (ADS)

Manchanda, R. K.

Lanthanum Bromide crystal is the latest among the family of the scintillation counters and has an advantage over conventional room temperature detectors. It has a high atomic number, high light yield, and fast decay time compared to NaI(Tl) crystal and therefore, the energy resolution, of LaBr3 detector is superior and it has higher detection efficiency. In recent past, laboratory studies have been generally made using thick crystal geometry (1.5×1.5-inch and 2×2-inch). Similarly, simulation studies are also in progress for the use of LaBr3 detectors in the ground based high energy physics experiments. The detector background counting rate of LaBr3 crystal is affected by the internal radioactivity and is due to naturally occurring radioisotopes 138La and 227Ac, similar to the sodium Iodide detector which is affected by the iodine isotopes. We have developed a new detector using thin lanthanum bromide crystal (3×30-mm) for use in X-ray astronomy. The instrument was launched in high altitude balloon flight on Dec. 21, 2007, which reached a ceiling altitude of 4.3 mbs. A background counting rate of 1.6 ×10-2 ct cm-2 s-1 keV-1 sr-1 was observed at the ceiling altitude. This paper describes the details of the electronics hardware, energy resolution and the background characteristics of the detector at ceiling altitude

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1978-01-01

Managed by the Marshall Space Flight Center and built by TRW, the second High Energy Astronomy Observatory was launched November 13, 1978. The observatory carried the largest X-ray telescope ever built and was renamed the Einstein Observatory after achieving orbit.

Some Like it Hot: Linking Diffuse X-Ray Luminosity, Baryonic Mass, and Star Formation Rate in Compact Groups of Galaxies

NASA Technical Reports Server (NTRS)

Desjardins, Tyler D.; Gallagher, Sarah C.; Hornschemeier, Ann E.; Mulchaey, John S.; Walker, Lisa May; Brandt, Willian N.; Charlton, Jane C.; Johnson, Kelsey E.; Tzanavaris, Panayiotis

2014-01-01

We present an analysis of the diffuse X-ray emission in 19 compact groups (CGs) of galaxies observed with Chandra. The hottest, most X-ray luminous CGs agree well with the galaxy cluster X-ray scaling relations in L(x-T) and (L(x-sigma), even in CGs where the hot gas is associated with only the brightest galaxy. Using Spitzer photometry, we compute stellar masses and classify Hickson CGs 19, 22, 40, and 42, and RSCGs 32, 44, and 86 as fossil groups using a new definition for fossil systems that includes a broader range of masses. We find that CGs with total stellar and Hi masses are great than or equal to 10(sup (11.3) solar mass are often X-ray luminous, while lower-mass CGs only sometimes exhibit faint, localized X-ray emission. Additionally, we compare the diffuse X-ray luminosity against both the total UV and 24 micron star formation rates of each CG and optical colors of the most massive galaxy in each of the CGs. The most X-ray luminous CGs have the lowest star formation rates, likely because there is no cold gas available for star formation, either because the majority of the baryons in these CGs are in stars or the X-ray halo, or due togas stripping from the galaxies in CGs with hot halos. Finally, the optical colors that trace recent star formation histories of the most massive group galaxies do not correlate with the X-ray luminosities of the CGs, indicating that perhaps the current state of the X-ray halos is independent of the recent history of stellar mass assembly in the most massive galaxies.

X-ray evaluation of crystals for stellar spectrometers

NASA Technical Reports Server (NTRS)

Alexandropolos, N. G. (Editor)

1974-01-01

The report consists of three parts. The first part is an analysis of the principles involved in X-ray crystal evaluation and how they are applied to a number of crystals. The principles of crystal evaluation analysis as they apply to the special problems of X-ray astronomy are presented. A number of crystals were evaluated, and the energy dependence of the diffraction properties of (002) PET, (111) Ge, (101) ADP, (001) KAP, and (001) RAP are reported. The second part is a compilation of the diffraction properties of a number of crystals as reported by other authors. In the third part some technical details of a triple crystal spectrometer built by the author at Polytechnic Institute of Brooklyn are given. This spectrometer seems to be a most appropriate instrument for evaluation of crystal properties. (Modified author abstract)

Topics in gamma ray astronomy

NASA Technical Reports Server (NTRS)

Ramaty, R.; Lingenfelter, R. E.

1986-01-01

Observations of gamma rays from solar flares, gamma ray bursts, the Galactic center, galactic nucleosynthesis, SS433, and Cygnus X-3, and their effects on astrophysical problems are discussed. It is observed that gamma ray spectra from solar flares are applicable to the study of particle acceleration and confinement and the determination of chemical abundances in the solar atmosphere. The gamma ray lines from the compact galactic object SS433 are utilized to examine the acceleration of jets, and analysis of the gamma ray lines of Cygnus X-3 reveal that particles can be accelerated in compact sources to ultrahigh energies.

AtomDB: Expanding an Accessible and Accurate Atomic Database for X-ray Astronomy

NASA Astrophysics Data System (ADS)

Smith, Randall

Since its inception in 2001, the AtomDB has become the standard repository of accurate and accessible atomic data for the X-ray astrophysics community, including laboratory astrophysicists, observers, and modelers. Modern calculations of collisional excitation rates now exist - and are in AtomDB - for all abundant ions in a hot plasma. AtomDB has expanded beyond providing just a collisional model, and now also contains photoionization data from XSTAR as well as a charge exchange model, amongst others. However, building and maintaining an accurate and complete database that can fully exploit the diagnostic potential of high-resolution X-ray spectra requires further work. The Hitomi results, sadly limited as they were, demonstrated the urgent need for the best possible wavelength and rate data, not merely for the strongest lines but for the diagnostic features that may have 1% or less of the flux of the strong lines. In particular, incorporation of weak but powerfully diagnostic satellite lines will be crucial to understanding the spectra expected from upcoming deep observations with Chandra and XMM-Newton, as well as the XARM and Athena satellites. Beyond incorporating this new data, a number of groups, both experimental and theoretical, have begun to produce data with errors and/or sensitivity estimates. We plan to use this to create statistically meaningful spectral errors on collisional plasmas, providing practical uncertainties together with model spectra. We propose to continue to (1) engage the X-ray astrophysics community regarding their issues and needs, notably by a critical comparison with other related databases and tools, (2) enhance AtomDB to incorporate a large number of satellite lines as well as updated wavelengths with error estimates, (3) continue to update the AtomDB with the latest calculations and laboratory measurements, in particular velocity-dependent charge exchange rates, and (4) enhance existing tools, and create new ones as needed to

Finite element analyses of thin film active grazing incidence x-ray optics

NASA Astrophysics Data System (ADS)

Davis, William N.; Reid, Paul B.; Schwartz, Daniel A.

2010-09-01

The Chandra X-ray Observatory, with its sub-arc second resolution, has revolutionized X-ray astronomy by revealing an extremely complex X-ray sky and demonstrating the power of the X-ray window in exploring fundamental astrophysical problems. Larger area telescopes of still higher angular resolution promise further advances. We are engaged in the development of a mission concept, Generation-X, a 0.1 arc second resolution x-ray telescope with tens of square meters of collecting area, 500 times that of Chandra. To achieve these two requirements of imaging and area, we are developing a grazing incidence telescope comprised of many mirror segments. Each segment is an adjustable mirror that is a section of a paraboloid or hyperboloid, aligned and figure corrected in situ on-orbit. To that end, finite element analyses of thin glass mirrors are performed to determine influence functions for each actuator on the mirrors, in order to develop algorithms for correction of mirror deformations. The effects of several mirror mounting schemes are also studied. The finite element analysis results, combined with measurements made on prototype mirrors, will be used to further refine the correction algorithms.

High Angular Resolution and Lightweight X-Ray Optics for Astronomical Missions

NASA Technical Reports Server (NTRS)

Zhang, W. W.; Biskach, M. P.; Blake, P. N.; Chan, K. W.; Evans, T. C.; Hong, M.; Jones, W. D.; Jones, W. D.; Kolos, L. D.; Mazzarella, J. M.;

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1978-01-01

This photograph was taken during the assembly of the High Energy Astronomy Observatory (HEAO)-2 at TRW, Inc., the prime contractor for the HEAOs. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. TRW, Inc. designed and developed the HEAO, under the project management of the Marshall Space Flight Center. The HEAO-2 was originally identified as HEAO-B but the designation was changed once the spacecraft achieved orbit.

X-ray filter for x-ray powder diffraction

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

Sinsheimer, John Jay; Conley, Raymond P.; Bouet, Nathalie C. D.

Technologies are described for apparatus, methods and systems effective for filtering. The filters may comprise a first plate. The first plate may include an x-ray absorbing material and walls defining first slits. The first slits may include arc shaped openings through the first plate. The walls of the first plate may be configured to absorb at least some of first x-rays when the first x-rays are incident on the x-ray absorbing material, and to output second x-rays. The filters may comprise a second plate spaced from the first plate. The second plate may include the x-ray absorbing material and wallsmore » defining second slits. The second slits may include arc shaped openings through the second plate. The walls of the second plate may be configured to absorb at least some of second x-rays and to output third x-rays.« less

Radio Videos of Orion Protostars (with X-ray Colors!)

NASA Astrophysics Data System (ADS)

Forbrich, Jan; Wolk, Scott; Menten, Karl; Reid, Mark; Osten, Rachel

2013-07-01

High-energy processes in Young Stellar Objects (YSOs) can be observed both in X-rays and in the centimetric radio wavelength range. While the past decade has brought a lot of progress in the field of X-ray observations of YSOs, (proto)stellar centimetric radio astronomy has only recently begun to catch up with the advent of the newly expanded Karl G. Jansky Very Large Array (JVLA). The enhanced sensitivity is fundamentally improving our understanding of YSO radio properties by providing unprecedented sensitivity and thus spectral as well as temporal resolution. As a result, it is becoming easier to disentangle coronal-type nonthermal radio emission emanating from the immediate vicinity of YSOs from thermal emission on larger spatial scales, for example ionized material at the base of outflows. Of particular interest is the correlation of the by now relatively well-characterized X-ray flaring variability with the nonthermal radio variability. We present first results of multi-epoch simultaneous observations using Chandra and the JVLA, targeting the Orion Nebula Cluster and highlighting the capabilities of the JVLA for radio continuum observations of YSOs.

The Virtual World Presence of the International Year of Astronomy 2009

NASA Astrophysics Data System (ADS)

Gauthier, Adrienne J.; Huber, D.; Gay, P. L.; New Media Task Group IYA2009

2010-01-01

From January 2009 to January 2010, the virtual celebration of the International Year of Astronomy 2009 has come full circle side-by-side with the real world celebrations. Throughout the year, the 'Astronomy 2009' island promoted the IYA2009 within the virtual world of Second Life(R) with the goal to engage and inspire the general public in astronomy. This island is situated in the group area called SciLands, a science and technology focused mini-continent of over 60 islands. We are host to immersive exhibits for the real life projects: From Earth to the Universe, The World at Night, Dark Skies Awareness, Let There Be Night, IAAA The Artists' Universe, 365 Days of Astronomy podcast, Spitzer's MIPSGAL/GLIMPSE walkable image, and Adler Planetarium's Far Out Fridays lecture series. Spitzer Space Telescope, Chandra X-ray Observatory, and the Hubble Heritage project provided over 300 free textures in a gift pack to visitors. Other exhibits include a replica of the Lord Rosse Leviathan telescope, an astrophotography grotto featuring Adam Block, David Malin, and John Gleason's work, a functional planetarium donated by Rob Knop, and live star party events from Chico Observatory. We'll review the exhibits and live events presented throughout the past year and speak towards the plans for the future. Formative evaluation strategies and first impressions of the summative evaluation of the first year of the project will be presented. Special thanks to our sponsors: Interstellar Studios/400 Years of the Telescope, Department of Astronomy University of Arizona, Spitzer Space Telescope, Chandra X-Ray Observatory, and Helio Huet.

Much NICER Monitoring of the X-ray Spectrum of Eta Carinae

NASA Astrophysics Data System (ADS)

Corcoran, Michael Francis; Hamaguchi, Kenji; Drake, Stephen; Pasham, Dheeraj; Gendreau, Keith C.; Arzoumanian, Zaven

2018-01-01

Eta Carinae is the most massive and luminous stellar system within 3 kpc. It is a known binary system with an orbital period of 5.52 years in which bright, thermal, X-ray emission is produced by a strong shock driven by the collisions of the wind of the visible primary star with the thin, fast wind of an otherwise unseen companion. Variations of the X-ray spectrum are produced by intrinsic changes in the density of the hot shocked gas and by intervening changes in wind absorption as the two stars revolve in a long-period, highly eccentric orbit. Previous X-ray monitoring studies since 1996 have detailed these variations, but have been either restricted to the E>3 keV band or have been affected by optical loading which limited measurement of X-ray absorption changes which can be used to determine the overlying density profile of the primary's wind around the orbit. The Neutron Star Interior Composition Explorer (NICER) is an excellent general-purpose observatory for X-ray astronomy, and in particular, its soft response and large effective area facilitate monitoring of X-ray spectral variations for bright sources like Eta Car without any bias due to photon pileup. We present the first observations of the X-ray spectrum of Eta Car obtained by NICER, and discuss limits on changes in column density, emission measure and temperature we derive from the NICER spectra.

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.

NASA Unveils First Images From Chandra X-Ray Observatory

NASA Astrophysics Data System (ADS)

1999-08-01

to precisely measure these X-rays tells how much of each element is present. With this information, astronomers can investigate how the elements necessary for life are created and spread throughout the galaxy by exploding stars. "Chandra will help to confirm one of the most fascinating theories of modern science -- that we came from the stars," said Professor Robert Kirshner of Harvard University. "Its ability to make X-ray images of comparable quality to optical images will have an impact on virtually every area of astronomy." Chandra also imaged a distant and very luminous quasar -- a single star-like object -- sporting a powerful X-ray jet blasting into space. The quasar radiates with the power of 10 trillion suns, energy which scientists believe comes from a supermassive black hole at its center. Chandra's image, combined with radio telescope observations, should provide insight into the process by which supermassive black holes can produce such cosmic jets. "Chandra has allowed NASA to seize the opportunity to put the U.S. back in the lead of observational X-ray astronomy," said Dr. Edward Weiler, Associate Administrator of Space Science, NASA Headquarters, Washington, DC. "History teaches us that whenever you develop a telescope 10 times better than what came before, you will revolutionize astronomy. Chandra is poised to do just that." The Chandra X-ray observatory 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's Chandra X-ray Center controls science and flight operations from Cambridge, MA. Press: Fact Sheet The first Chandra images will be posted to the Internet at: http://chandra.nasa.gov and http://chandra.harvard.edu NASA press releases and other information are available automatically by sending an Internet electronic mail message to domo@hq.nasa.gov. In the body of the

High energy gamma-ray astronomy; Proceedings of the International Conference, ANN Arbor, MI, Oct. 2-5, 1990

NASA Astrophysics Data System (ADS)

Matthews, James

The present volume on high energy gamma-ray astronomy discusses the composition and properties of heavy cosmic rays greater than 10 exp 12 eV, implications of the IRAS Survey for galactic gamma-ray astronomy, gamma-ray emission from young neutron stars, and high-energy diffuse gamma rays. Attention is given to observations of TeV photons at the Whipple Observatory, TeV gamma rays from millisecond pulsars, recent data from the CYGNUS experiment, and recent results from the Woomera Telescope. Topics addressed include bounds on a possible He/VHE gamma-ray line signal of Galactic dark matter, albedo gamma rays from cosmic ray interactions on the solar surface, source studies, and the CANGAROO project. Also discussed are neural nets and other methods for maximizing the sensitivity of a low-threshold VHE gamma-ray telescope, a prototype water-Cerenkov air-shower detector, detection of point sources with spark chamber gamma-ray telescopes, and real-time image parameterization in high energy gamma-ray astronomy using transputers. (For individual items see A93-25002 to A93-25039)

Next generation of pnCCDs for X-ray spectroscopy and imaging

NASA Astrophysics Data System (ADS)

Meidinger, Norbert; Andritschke, Robert; Hälker, Olaf; Hartmann, Robert; Herrmann, Sven; Holl, Peter; Lutz, Gerhard; Kimmel, Nils; Schaller, Gerhard; Schnecke, Martina; Schopper, Florian; Soltau, Heike; Strüder, Lothar

2006-11-01

A special type of charge-coupled device, the pnCCD, has been developed in the nineties as focal-plane detector for the X-ray astronomy mission XMM-Newton of the European Space Agency. The pnCCD detector has been in operation since the satellite launch in 1999. It is performing up to date spectroscopy of X-rays in combination with imaging and high time resolution. The excellent performance of the flight camera is still maintained; in particular, the energy resolution has been nearly constant since launch. In order to satisfy the requirements of future X-ray astronomy missions as well as those of ground-based experiments, a new type of pnCCD has been developed. The ‘frame store pnCCD’ shows various optimizations in device design and fabrication process. Devices with up to 256×512 pixels have been fabricated in 2004 and recently tested. Simultaneously, a programmable analog signal processor for the readout of the CCD signals, the DUO CAMEX, has been developed. The readout noise of the new detector has a value of 2 electrons ENC which is less than half of the figure of the XMM-Newton pnCCD. We measured an energy resolution that is close to the theoretical limit given by the Fano noise. In particular the low-energy response of the new devices was substantially improved. The quantum efficiency for X-rays is at least 90% in the entire energy band from 0.3 keV up to 11 keV. This is due to the ultra-thin photon entrance window as well as the full depletion of the 450 μm thick back-illuminated pnCCD. The position resolution is better than the pixel sizes of 75 μm×75 μm or 51 μm×51 μm because the signal charge is spread over up to four pixels which allows a more accurate event position determination. ‘Out of time’ events are substantially reduced to the order of 0.1% by operating the pnCCD in frame store mode. Higher operating temperatures, e.g. -20 °C, are possible due to the smaller thermally generated dark-current level of the new devices and the operation

X-Ray Astronomy--A New View of the Sky From Space

ERIC Educational Resources Information Center

Gursky, Herbert

1973-01-01

Objects and energy sources are detected whose existence was only hinted at a few years ago. The X-Ray sky has a large number of sources along the Milky Way, most of which lie within 30 degrees of the galactic center, plus a number of faint sources associated with external galaxies. (DF)

The Stellar Mass-Halo Mass Relation for Low-mass X-Ray Groups At 0.5< z< 1 in the CDFS With CSI

NASA Astrophysics Data System (ADS)

Patel, Shannon G.; Kelson, Daniel D.; Williams, Rik J.; Mulchaey, John S.; Dressler, Alan; McCarthy, Patrick J.; Shectman, Stephen A.

2015-02-01

Since z˜ 1, the stellar mass density locked in low-mass groups and clusters has grown by a factor of ˜8. Here, we make the first statistical measurements of the stellar mass content of low-mass X-ray groups at 0.5\\lt z\\lt 1, enabling the calibration of stellar-to-halo mass scales for wide-field optical and infrared surveys. Groups are selected from combined Chandra and XMM-Newton X-ray observations in the Chandra Deep Field South. These ultra-deep observations allow us to identify bona fide low-mass groups at high redshift and enable measurements of their total halo masses. We compute aggregate stellar masses for these halos using galaxies from the Carnegie-Spitzer-IMACS (CSI) spectroscopic redshift survey. Stars comprise ˜3%-4% of the total mass of group halos with masses {{10}12.8}\\lt {{M}200}/{{M}⊙ }\\lt {{10}13.5} (about the mass of Fornax and one-fiftieth the mass of Virgo). Complementing our sample with higher mass halos at these redshifts, we find that the stellar-to-halo mass ratio decreases toward higher halo masses, consistent with other work in the local and high redshift universe. The observed scatter about the stellar-halo mass relation is σ ˜ 0.25 dex, which is relatively small and suggests that total group stellar mass can serve as a rough proxy for halo mass. We find no evidence for any significant evolution in the stellar-halo mass relation since z≲ 1. Quantifying the stellar content in groups since this epoch is critical given that hierarchical assembly leads to such halos growing in number density and hosting increasing shares of quiescent galaxies. This Letter includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile. This research is based on observations made with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS 5-26555.

X-ray astronomy in the Uhuru epoch and beyond /Newton Lacy Pierce Prize Lecture/

NASA Technical Reports Server (NTRS)

Kellogg, E. M.

1975-01-01

A review of results from the Uhuru satellite is presented. An intensive treatment of two subjects is given, rather than a broad review. First, Cyg X-1, a stellar X-ray source and a candidate for a black hole, is discussed; second, the X-ray source in the Perseus cluster of galaxies, which may be a cloud of hot intergalactic gas, is treated. In both cases, the train of logic used in establishing the nature of these objects is presented and evaluated. For both, while alternative explanations cannot be completely eliminated, they become more difficult to sustain when examined in detail, suggesting that the candidate explanations are more likely correct.

Skylab experiments. Volume 1: Physical science, solar astronomy

NASA Technical Reports Server (NTRS)

1973-01-01

The basic subject of this volume is the solar astronomy program conducted on Skylab. In addition to descriptions of the individual experiments and the principles involved in their performance, a brief description is included of the sun and the energy characteristics associated with each zone. Wherever possible, related classroom activities have been identified and discussed in some detail. It will be apparent that the relationships rest not only in the field of solar astronomy, but also in the following subjects: (1) physics - optics, electromagnetic spectrum, atomic structure, etc.; (2) chemistry - emission spectra, kinetic theory, X-ray absorption, etc.; (3) biology - radiation and dependence on the sun; (4) electronics - cathode ray tubes, detectors, photomultipliers, etc.; (5) photography; (6) astronomy; and (7) industrial arts.

Spectral studies of cosmic X-ray sources

NASA Astrophysics Data System (ADS)

Blissett, R. J.

1980-01-01

The conventional "indirect" method of reduction and data analysis of spectral data from non-dispersive X-ray detectors, by the fitting of assumed spectral models, is examined. The limitations of this procedure are presented, and alternative schemes are considered in which the derived spectra are not biased to an astrophysical source model. A new method is developed in detail to directly restore incident photon spectra from the detected count histograms. This Spectral Restoration Technique allows an increase in resolution, to a degree dependent on the statistical precision of the data. This is illustrated by numerical simulations. Proportional counter data from Ariel 5 are analysed using this technique. The results obtained for the sources Cas A and the Crab Nebula are consistent with previous analyses and show that increases in resolution of up to a factor three are possible in practice. The source Cyg X-3 is closely examined. Complex spectral variability is found, with the continuum and iron-line emission modulated with the 4.8 hour period of the source. The data suggest multi-component emission in the source. Comparing separate Ariel 5 observations and published data from other experiments, a correlation between the spectral shape and source intensity is evident. The source behaviour is discussed with reference to proposed source models. Data acquired by the low-energy detectors on-board HEAO-1 are analysed using the Spectral Restoration Technique. This treatment explicitly demonstrates the existence of oxygen K-absorption edges in the soft X-ray spectra of the Crab Nebula and Sco X-1. These results are considered with reference to current theories of the interstellar medium. The thesis commences with a review of cosmic X-ray sources and the mechanisms responsible for their spectral signatures, and continues with a discussion of the instruments appropriate for spectral studies in X-ray astronomy.

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.

Image of the Crab Nebula Taken by the High Energy Astronomy Observatory (HEAO)-2

NASA Technical Reports Server (NTRS)

1979-01-01

This is an x-ray image of the Crab Nebula taken with the High Energy Astronomy Observatory (HEAO)-2/Einstein Observatory. The image is demonstrated by a pulsar, which appears as a bright point due to its pulsed x-ray emissions. The strongest region of diffused emissions comes from just northwest of the pulsar, and corresponds closely to the region of brightest visible-light emission. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO-2, designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center, was launched aboard an Atlas/Centaur launch vehicle on November 13, 1978.

Mac OS X for Astronomy

NASA Astrophysics Data System (ADS)

Pierfederici, F.; Pirzkal, N.; Hook, R. N.

Mac OS X is the new Unix based version of the Macintosh operating system. It combines a high performance DisplayPDF user interface with a standard BSD UNIX subsystem and provides users with simultaneous access to a broad range of applications which were not previously available on a single system such as Microsoft Office and Adobe Photoshop, as well as legacy X11-based scientific tools and packages like IRAF, SuperMongo, MIDAS, etc. The combination of a modern GUI layered on top of a familiar UNIX environment paves the way for new, more flexible and powerful astronomical tools to be developed while assuring compatibility with already existing, older programs. In this paper, we outline the strengths of the Mac OS X platform in a scientific environment, astronomy in particular, and point to the numerous astronomical software packages available for this platform; most notably the Scisoft collection which we have compiled.

A 3D CZT high resolution detector for x- and gamma-ray astronomy

NASA Astrophysics Data System (ADS)

Kuvvetli, I.; Budtz-Jørgensen, C.; Zappettini, A.; Zambelli, N.; Benassi, G.; Kalemci, E.; Caroli, E.; Stephen, J. B.; Auricchio, N.

2014-07-01

At DTU Space we have developed a high resolution three dimensional (3D) position sensitive CZT detector for high energy astronomy. The design of the 3D CZT detector is based on the CZT Drift Strip detector principle. The position determination perpendicular to the anode strips is performed using a novel interpolating technique based on the drift strip signals. The position determination in the detector depth direction, is made using the DOI technique based the detector cathode and anode signals. The position determination along the anode strips is made with the help of 10 cathode strips orthogonal to the anode strips. The position resolutions are at low energies dominated by the electronic noise and improve therefore with increased signal to noise ratio as the energy increases. The achievable position resolution at higher energies will however be dominated by the extended spatial distribution of the photon produced ionization charge. The main sources of noise contribution of the drift signals are the leakage current between the strips and the strip capacitance. For the leakage current, we used a metallization process that reduces the leakage current by means of a high resistive thin layer between the drift strip electrodes and CZT detector material. This method was applied to all the proto type detectors and was a very effective method to reduce the surface leakage current between the strips. The proto type detector was recently investigated at the European Synchrotron Radiation Facility, Grenoble which provided a fine 50 × 50 μm2 collimated X-ray beam covering an energy band up to 600 keV. The Beam positions are resolved very well with a ~ 0.2 mm position resolution (FWHM ) at 400 keV in all directions.

The First Non-Dispersive High-Resolution Spectroscopy of an X-ray-bright Galaxy Cluster

NASA Astrophysics Data System (ADS)

Yamaguchi, Hiroya; Hitomi Collaboration

2018-06-01

The Hitomi X-ray Observatory was equipped with the Soft X-ray Spectrometer (SXS), an X-ray microcalorimeter that achieved an energy resolution of 5 eV (@0.5-10 keV) for extended objects. This offered an unprecedented benchmark of atomic modeling and database for hot collisional plasmas, revealing both successes and challenges in the current atomic codes that are widely used by the X-ray astronomy community. I will review the Hitomi observations of the brightest part of the Perseus Cluster, whose X-ray spectrum is dominated by thermal emission from the intra-cluster medium (ICM). The SXS successfully measured the turbulent velocities and metal abundances of the ICM, which radically altered our understanding of the dynamics and chemical enrichment in this object. At the same time, the high-resolution X-ray data led to significant improvement in the atomic models, such as AtomDB and SPEX -- I will briefly overview how this improvement was made. Nevertheless, there are still significant discrepancies among the public atomic models, causing systematic uncertainties in measurements of the temperature, abundance, and degree of the resonance scattering. Requirements for future improvements will be summarized in this context.

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

The Terzan 2 Cluster Taken by the High Energy Astronomy Observatory (HEAO)-2

NASA Technical Reports Server (NTRS)

1980-01-01

The dramatic change in x-ray emission from the Terzan 2 cluster is shown in this series of 2.5-minute exposures taken with the High Energy Astronomy Observatory (HEAO)-2/Einstein Observatory immediately before, during, and after the burst. Total exposure (20 minutes) of the object, including the outburst, is shown in the fourth photograph. These images represent the first observation of an x-ray burst in progress. The actual burst lasted 50 seconds. Among the rarest, and most bizarre, phenomena observed by x-ray astronomers are the so-called cosmic bursters (x-ray sources that suddenly and dramatically increase in intensity then subside). These sudden bursts of intense x-ray radiation apparently come from compact objects with a diameter smaller than 30 miles (48 kilometers). Yet, despite their minuscule size, a typical x-ray burster can release more x-ray energy in a single brief burst than our Sun does in an entire week. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO was designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center.

High efficiency spectrographs for the EUV and soft X-rays

NASA Technical Reports Server (NTRS)

Cash, W.

1983-01-01

The use of grazing incidence optics and reflection grating designs is shown to be a method that improves the performance of spectrographs at wavelengths shorter than 1200 A. Emphasis is laid on spectroscopic designs for X ray and EUV astronomy, with sample designs for an objective reflection grating spectrograph (ORGS) and an echelle spectrograph for wavelengths longer than 100 A. Conical diffraction allows operations at grazing incidence in the echelle spectrograph. In ORGS, the extreme distance of X ray objects aids in collimating the source radiation, which encounters conical diffraction within the instrument, proceeds parallel to the optical axis, and arrives at the detector. A series of gratings is used to achieve the effect. A grazing echelle is employed for EUV observations, and offers a resolution of 20,000 over a 300 A bandpass.

Mathematical Design Optimization of Wide-Field X-ray Telescopes: Mirror Nodal Positions and Detector Tilts

NASA Technical Reports Server (NTRS)

Elsner, R. F.; O'Dell, S. L.; Ramsey, B. D.; Weisskopf, M. C.

2011-01-01

We describe a mathematical formalism for determining the mirror shell nodal positions and detector tilts that optimize the spatial resolution averaged over a field-of-view for a nested x-ray telescope, assuming known mirror segment surface prescriptions and known detector focal surface. The results are expressed in terms of ensemble averages over variable combinations of the ray positions and wave vectors in the flat focal plane intersecting the optical axis at the nominal on-axis focus, which can be determined by Monte-Carlo ray traces of the individual mirror shells. This work is part of our continuing efforts to provide analytical tools to aid in the design process for wide-field survey x-ray astronomy missions.

Mathematical Design Optimization of Wide-Field X-ray Telescopes: Mirror Nodal Positions and Detector Tilts

NASA Technical Reports Server (NTRS)

Elsner, Ronald; O'Dell, Stephen; Ramsey, Brian; Weisskopf, Martin

2011-01-01

We describe a mathematical formalism for determining the mirror shell nodal positions and detector tilts that optimize the spatial resolution averaged over a field-of-view for a nested x-ray telescope, assuming known mirror segment surface prescriptions and known detector focal surface. The results are expressed in terms of ensemble averages over variable combinations of the ray positions and wavevectors in the flat focal plane intersecting the optical axis at the nominal on-axis focus, which can be determined by Monte-Carlo ray traces of the individual mirror shells. This work is part of our continuing efforts to provide analytical tools to aid in the design process for wide-field survey x-ray astronomy missions.

Gamma ray astrophysics to the year 2000. Report of the NASA Gamma Ray Program Working Group

NASA Technical Reports Server (NTRS)

1988-01-01

Important developments in gamma-ray astrophysics up to energies of 100 GeV during the last decade are reviewed. Also, the report seeks to define the major current scientific goals of the field and proposes a vigorous program to pursue them, extending to the year 2000. The goals of gamma-ray astronomy include the study of gamma rays which provide the most direct means of studying many important problems in high energy astrophysics including explosive nucleosynthesis, accelerated particle interactions and sources, and high-energy processes around compact objects. The current research program in gamma-ray astronomy in the U.S. including the space program, balloon program and foreign programs in gamma-ray astronomy is described. The high priority recommendations for future study include an Explorer-class high resolution gamma-ray spectroscopy mission and a Get Away Special cannister (GAS-can) or Scout class multiwavelength experiment for the study of gamma-ray bursts. Continuing programs include an extended Gamma Ray Observatory mission, continuation of the vigorous program of balloon observations of the nearby Supernova 1987A, augmentation of the balloon program to provide for new instruments and rapid scientific results, and continuation of support for theoretical research. Long term recommendations include new space missions using advanced detectors to better study gamma-ray sources, the development of these detectors, continued study for the assembly of large detectors in space, collaboration with the gamma-ray astronomy missions initiated by other countries, and consideration of the Space Station attached payloads for gamma-ray experiments.

Tunka Advanced Instrument for cosmic rays and Gamma Astronomy (TAIGA): Status, results and perspectives

NASA Astrophysics Data System (ADS)

Kuzmichev, L.; Astapov, I.; Bezyazeekov, P.; Boreyko, V.; Borodin, A.; Brückner, M.; Budnev, N.; Chiavassa, A.; Gress, O.; Gress, T.; Grishin, O.; Dyachok, A.; Epimakhov, S.; Fedorov, O.; Gafarov, A.; Grebenyuk, V.; Grinyuk, A.; Haungs, A.; Horns, D.; Huege, T.; Ivanova, A.; Jurov, D.; Kalmykov, N.; Kazarina, Y.; Kindin, V.; Kiryuhin, V.; Kokoulin, R.; Kompaniets, K.; Korosteleva, E.; Kostunin, D.; Kozhin, V.; Kravchenko, E.; Kunnas, M.; Lenok, V.; Lubsandorzhiev, B.; Lubsandorzhiev, N.; Mirgazov, R.; Mirzoyan, R.; Monkhoev, R.; Nachtigal, R.; Osipova, E.; Pakharukov, A.; Panasyuk, M.; Pankov, L.; Petrukhin, A.; Poleschuk, V.; Popesku, M.; Popova, E.; Porelli, A.; Postnikov, E.; Prosin, V.; Ptuskin, V.; Pushnin, A.; Rubtsov, G.; Ryabov, E.; Sagan, Y.; Samoliga, V.; Schröder, F. G.; Semeney, Yu.; Silaev, A.; Silaev, A.; Sidorenko, A.; Skurikhin, A.; Slunecka, V.; Sokolov, A.; Spiering, C.; Sveshnikova, L.; Sulakov, V.; Tabolenko, V.; Tarashansky, B.; Tkachenko, A.; Tkachev, L.; Tluczykont, M.; Wischnewski, R.; Zagorodnikov, A.; Zurbanov, V.; Yashin, I.

2017-06-01

We present the current status of high-energy cosmic-ray physics and gamma-ray astronomy at the Tunka Astrophysical Center (AC). This complex is located in the Tunka Valley, about 50 km from Lake Baikal. Present efforts are focused on the construction of the first stage of the gamma-ray observatory TAIGA - the TAIGA prototype. TAIGA (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy) is designed for the study of gamma rays and charged cosmic rays in the energy range 1013 eV-1018 eV. The array includes a network of wide angle timing Cherenkov stations (TAIGA-HiSCORE), each with a FOV = 0.6 sr, plus up to 16 IACTs (FOV - 10∘× 10∘). This part covers an area of 5 km2. Additional muon detectors (TAIGA-Muon), with a total coverage of 2000 m2, are distributed over an area of 1 km2.

Synchrotron-induced X-ray fluorescence from rat bone and lumber vertebra of different age groups

NASA Astrophysics Data System (ADS)

Rao, Donepudi V.; Swapna, Medasani; Cesareo, Roberto; Brunetti, Antonio; Akatsuka, Tako; Yuasa, Tetsuya; Takeda, Tohoru; Tromba, Giuliana; Gigante, Giovanni E.

2009-02-01

The fluorescence spectra from rat bones of different age groups (8, 56 and 78 weeks) and lumber vertebra were measured with 8, 10 and 12 keV synchrotron X-rays. We have utilized the new hard X-ray micro-spectroscopy beamline facility, X27A, available at NSLS with a primary beam spot size of the order of ˜10 μm. With this spatial resolution and high flux throughput, X-ray fluorescent intensities for Ca and other trace elements were measured using a liquid-nitrogen-cooled 13-element energy-dispersive high-purity germanium detector. Regarding the lumber vertebra, we acquired the fluorescence spectra from the left, right and middle portions and calcium accumulation was evaluated and compared with the other samples. We have identified the major trace elements of Ca, Ni, Fe and Zn and minor trace elements of Ti, Cr and Mn in the sample. The percentage of scattered radiation and trace element contributions from these samples were highlighted at different energies.

X-ray scattering study

NASA Technical Reports Server (NTRS)

Wriston, R. S.; Froechtenigt, J. F.

1972-01-01

A soft X-ray glancing incidence telescope mirror and a group of twelve optical flat samples were used to study the scattering of X-rays. The mirror was made of Kanigen coated beryllium and the images produced were severely limited by scattering of X-rays. The best resolution attained was about fifteen arc seconds. The telescope efficiency was found to be 0.0006. The X-ray beam reflected from the twelve optical flat samples was analyzed by means of a long vacuum system of special design for these tests. The scattering then decreased with increasing angle of incidence until a critical angle was passed. At larger angles the scattering increased again. The samples all scattered more at 44 A than at 8 A. Metal samples were found to have about the same scattering at 44 A but greater scattering at 8 A than glass samples.

Classification of fracture and non-fracture groups by analysis of coherent X-ray scatter

PubMed Central

Dicken, A. J.; Evans, J. P. O.; Rogers, K. D.; Stone, N.; Greenwood, C.; Godber, S. X.; Clement, J. G.; Lyburn, I. D.; Martin, R. M.; Zioupos, P.

2016-01-01

Osteoporotic fractures present a significant social and economic burden, which is set to rise commensurately with the aging population. Greater understanding of the physicochemical differences between osteoporotic and normal conditions will facilitate the development of diagnostic technologies with increased performance and treatments with increased efficacy. Using coherent X-ray scattering we have evaluated a population of 108 ex vivo human bone samples comprised of non-fracture and fracture groups. Principal component fed linear discriminant analysis was used to develop a classification model to discern each condition resulting in a sensitivity and specificity of 93% and 91%, respectively. Evaluating the coherent X-ray scatter differences from each condition supports the hypothesis that a causal physicochemical change has occurred in the fracture group. This work is a critical step along the path towards developing an in vivo diagnostic tool for fracture risk prediction. PMID:27363947

Diffuse X-ray emission from the NGC 2300 group of galaxies - Implications for dark matter and galaxy evolution in small groups

NASA Technical Reports Server (NTRS)

Mulchaey, John S.; Davis, David S.; Mushotzky, Richard F.; Burstein, David

1993-01-01

The discovery of diffuse X-ray emission from the NGC 2300 group of galaxies using the ROSAT Position Sensitive Proportional Counter is reported. The gas distributions is roughly symmetric and extends to a radius of at least 0.2/h(50) Mpc. A Raymond-Smith hot plasma model provides an excellent fit the X-ray spectrum with a best-fit value temperature of 0.9 + -/15 or - 0.14 keV and abundance 0.06 + 0/.12 or - 0.05 solar. The assumption of gravitational confinement leads to a total mass of the group of 3.0 + 0.4 or - 0.5 x 10 exp 13 solar. Baryons can reasonably account for 4 percent of this mass, and errors could push this number not higher than 10-15 percent. This is one of the strongest pieces of evidence that dark matter dominates small groups such as this one. The intragroup medium in this system has the lowest metal abundance yet found in diffuse gas in a group or cluster.

Research of advanced techniques for X-ray detectors and telescopes with applications to rockets and the LAMAR facility

NASA Technical Reports Server (NTRS)

Gorenstein, P.

1985-01-01

A program for the development of high throughput instrumentation for X-ray astronomy based upon focusing optics is being carried out by the Smithsonian Astrophysical Observatory. The instrumentation is applicable to investigations requiring large area focusing optics for direct imaging or dispersive spectroscopy. The long range goals of this program are the development of telescopes and gratings for future major X-ray astronomy facilities, including additions to the LAMAR OSS-2/SHEAL experiment after the initial flights. Tests of the devices and their more immediate utilization in scientific investigations can be carried out with SPARTAN payloads deployed and retrieved by the Space Shuttle. However, the present backlog of approved SPARTAN missions is longer than the three-year duration of the program described in this program. Laboratory studies and breadboarding of instrumentation are discussed.

Pushing the Boundaries of Suborbital Soft X-ray Spectroscopy

NASA Astrophysics Data System (ADS)

McEntaffer, Randall

optics are planned for every future large X-ray mission and flight-proving the design is extremely important. The gratings will be radially grooved and blazed to reduce grating aberrations and to focus the spectrum to one side of zero-order. Gratings of this type have been well developed by the IXO Off- Plane X-ray Grating Spectrometer concept study, but have not been flight proven. The spectrum will be focused onto high spatial resolution CCD detectors. OGRE will draw heavily from the heritage gained from OGRESS. OGRE will observe Capella. Due to its high flux and spectral line density, Capella is an ideal target for showcasing the resolution capabilities of our instrument. As an important calibration target, our improved resolution measurements will be extremely helpful for many future X-ray observations. OGRESS has already provided three thesis projects for past graduate students. The upgrades and flights proposed here will produce at least two more PhD theses. This program in hands-on training of young scientists in the techniques of instrumental X-ray astronomy has proven very successful over nearly three decades, leading to high rates of launch, publication, graduation, and flight qualification of instrumental PI's. It will also provide full experiment cycle experience - design, fabrication, tolerancing, assembly, flight-qualification, calibration, integration, launch, and data analysis - with reflection gratings, GEM and CCD detectors, and other technologies suitable for adaptation to NASA's major missions. The University of Iowa and University of Colorado programs in suborbital X-ray astronomy represent an exciting mix of compelling science, cutting- edge technology development, and training of young scientists.

Monte-Carlo background simulations of present and future detectors in x-ray astronomy

NASA Astrophysics Data System (ADS)

Tenzer, C.; Kendziorra, E.; Santangelo, A.

2008-07-01

Reaching a low-level and well understood internal instrumental background is crucial for the scientific performance of an X-ray detector and, therefore, a main objective of the instrument designers. Monte-Carlo simulations of the physics processes and interactions taking place in a space-based X-ray detector as a result of its orbital environment can be applied to explain the measured background of existing missions. They are thus an excellent tool to predict and optimize the background of future observatories. Weak points of a design and the main sources of the background can be identified and methods to reduce them can be implemented and studied within the simulations. Using the Geant4 Monte-Carlo toolkit, we have created a simulation environment for space-based detectors and we present results of such background simulations for XMM-Newton's EPIC pn-CCD camera. The environment is also currently used to estimate and optimize the background of the future instruments Simbol-X and eRosita.

Development study of the X-ray scattering properties of a group of optically polished flat samples

NASA Technical Reports Server (NTRS)

Froechtenigt, J. F.

1973-01-01

A group of twelve optically polished flat samples were used to study the scattering of X-rays. The X-ray beam reflected from the twelve optical flat samples was analyzed by means of a long vacuum system of special design for these tests. The scattering measurements were made at 8.34A and 0.92 deg angle of incidence. The results for ten of the samples are comparable, the two exceptions being the fire polished samples.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1977-01-01

Managed by the Marshall Space Flight Center and designed by TRW, the first High Energy Astronomy Observatory was launched August 12, 1977 aboard an Atlas Centaur rocket. HEAO-1, devoted to the study of X-rays in space, carried four instruments all used primarily in a scarning mode. The mission lasted seventeen months.

The X-Ray Surveyor Mission Concept Study: Forging the Path to NASA Astrophysics 2020 Decadal Survey Prioritization

NASA Technical Reports Server (NTRS)

Gaskin, Jessica; Ozel, Feryal; Vikhlinin, Alexey

2016-01-01

The X-Ray Surveyor mission concept is unique among those being studied for prioritization in the NASA Astrophysics 2020 Decadal Survey. The X-Ray Surveyor mission will explore the high-energy Universe; providing essential and complimentary observations to the Astronomy Community. The NASA Astrophysics Roadmap (Enduring Quests, Daring Visions) describes the need for an X-Ray Observatory that is capable of addressing topics such as the origin and growth of the first supermassive black holes, galaxy evolution and growth of the cosmic structure, and the origin and evolution of the stars that make up our Universe. To address these scientifically compelling topics and more, an Observatory that exhibits leaps in capability over that of previous X-Ray Observatories in needed. This paper describes the current status of the X-Ray Surveyor Mission Concept Study and the path forward, which includes scientific investigations, technology development, and community participation.

The X-Ray Surveyor mission concept study: forging the path to NASA astrophysics 2020 decadal survey prioritization

NASA Astrophysics Data System (ADS)

Gaskin, Jessica; Özel, Feryal; Vikhlinin, Alexey

2016-07-01

The X-Ray Surveyor mission concept is unique among those being studied for prioritization in the NASA Astrophysics 2020 Decadal Survey. The X-Ray Surveyor mission will explore the high-energy Universe; providing essential and complimentary observations to the Astronomy Community. The NASA Astrophysics Roadmap (Enduring Quests, Daring Visions) describes the need for an X-Ray Observatory that is capable of addressing topics such as the origin and growth of the first supermassive black holes, galaxy evolution and growth of the cosmic structure, and the origin and evolution of the stars that make up our Universe. To address these scientifically compelling topics and more, an Observatory that exhibits leaps in capability over that of previous X-Ray Observatories in needed. This paper describes the current status of the X-Ray Surveyor Mission Concept Study and the path forward, which includes scientific investigations, technology development, and community participation.

Comparing Data from Telescopic X-Ray Instruments: Can We Trust All Satellites?

NASA Astrophysics Data System (ADS)

Joyce, Quianah T.; Fortenberry, Alexander; Gendre, Bruce

2017-01-01

In astronomy and astrophysics, X-ray emissions from cosmic entities aid in revealing what type of sources they emanate from. Swift, NASA’s latest X-ray satellite, has not been operating at its intended configurations. The satellite is experiencing difficulties maintaining a stable temperature in its charge capture device. This research intends to determine if this complication causes discrepancies in Swift’s collected data by using gamma-ray burst data. Gamma-ray bursts are excellent comparison candidates due to their brightness and fluctuations. We compared archived data of GRB 130427A and GRB 090423A from Swift and the European Space Agency’s XMM-Newton observatory. Next, we reduced the data and produced the respective spectra. We then analyzed and compared the spectra to one another to find any discrepancies. We have determined, based on data analysis of the spectra, that Swift is working properly despite the cooling malfunction.

The mercedes-benz approach to γ-ray astronomy

NASA Astrophysics Data System (ADS)

Akerlof, Carl W.

1988-02-01

The sensitivity requirements for ground-based γ-ray astronomy are reviewed in the light of the most reliable estimates of stellar fluxes above 100 GeV. Current data strongly favor the construction of detectors with the lowest energy thresholds. Since improvements in angular resolution are limited by shower fluctuations, better methods of rejecting hadronic showers must be found to reliably observe the known astrophysical sources. Several possible methods for reducing this hadronic background are discussed.

X-Rays

MedlinePlus

X-rays are a type of radiation called electromagnetic waves. X-ray imaging creates pictures of the inside of ... different amounts of radiation. Calcium in bones absorbs x-rays the most, so bones look white. Fat ...

High resolution studies of the solar X-ray corona from Aerobee rockets

NASA Technical Reports Server (NTRS)

Davis, J. M.; Haggerty, R.; Krieger, A. S.; Manko, H.; Sherman, G.; Ting, J. W. S.; Vaiana, G. S.

1973-01-01

The research in high resolution solar X-ray astronomy is reported. The payload for the Aerobee 150 launch vehicle, which included a 23 cm diameter mirror whose polished surface was a nickel-phosphorus alloy is discussed along with the high resolution measurements, by Flight 13.028 CS, of the temperature and density structure of the lower corona. Flight 13.029 CS is also discussed.

Reflective Coating for Lightweight X-Ray Optics

NASA Technical Reports Server (NTRS)

Chan, Kai-Wing; Zhang, William W.; Windt, David; Hong, Mao-Ling; Saha, Timo; McClelland, Ryan; Sharpe, Marton; Dwivedi, Vivek H.

2012-01-01

X-ray reflective coating for next generation's lightweight, high resolution, optics for astronomy requires thin-film deposition that is precisely fine-tuned so that it will not distort the thin sub-mm substrates. Film of very low stress is required. Alternatively, mirror distortion can be cancelled by precisely balancing the deformation from multiple films. We will present results on metallic film deposition for the lightweight optics under development. These efforts include: low-stress deposition by magnetron sputtering and atomic layer deposition of the metals, balancing of gross deformation with two-layer depositions of opposite stresses and with depositions on both sides of the thin mirrors.

From X-Ray Telescopes to Neutron Focusing

NASA Technical Reports Server (NTRS)

Gubarev, M. V.; Khaykovich, B.; Ramsey, B.; Moncton, D. E.

2011-01-01

In the case of neutrons the refractive index is slightly less than unity for most elements and their isotopes. Consequently, thermal and cold neutrons can be reflected from smooth surfaces at grazing-incidence angles. Hence, the optical technologies developed for x-ray astronomy can be applied for neutron focusing. The focusing capabilities of grazing incidence neutron imaging optics have been successfully demonstrated using nickel mirrors. The mirrors were fabricated using an electroformed nickel replication process at Marshall Space Flight Center. Results of the neutron optics experiments will be presented. Challenges of the neutron imaging optics as well as possible applications of the optics will be discussed.

Slumped glass foils as substrate for adjustable x-ray optics

NASA Astrophysics Data System (ADS)

Salmaso, Bianca; Basso, Stefano; Civitani, Marta; Ghigo, Mauro; Hołyszko, Joanna; Pelliciari, Carlo; Spiga, Daniele; Vecchi, Gabriele; Pareschi, Giovanni

2016-09-01

Thin glass modular mirrors are a viable solution to build future X-ray telescopes with high angular resolution and large collecting area. In our laboratories, we shape thin glass foils by hot slumping and we apply pressure to assist the replication of a cylindrical mould figure; this technology is coupled with an integration process able to damp low frequency errors and produces optics in the Wolter I configuration, typical for the X-ray telescopes. From the point of view of the hot slumping process, the efforts were focused in reducing low-, mid- and high- frequency errors of the formed Eagle glass foils. Some of our slumped glass foils were used for the development of active X-ray optics, where piezoelectric actuators are used to correct the slumped glass foil deviations from the ideal shape. In particular, they were used for the Adjustable X-raY optics for astrOnoMy project (AXYOM) developed in Italy, and the X-ray Surveyor mission, as developed at the Smithsonian Astrophysical Observatory / Center for Astrophysics (SAO/CfA) in USA. In this paper we describe the optimisation of the hot slumping process, comparing the results with the requirements of the considered active optics projects. Finally, since the present configuration of the Pennsylvania State University (PSU) coating equipment is limited to 100 x 100 mm2, the slumped glass foils used for the SAO project were cut from 200 x 200 mm2 to 100 x 100 mm2, and a low-frequency change was observed. A characterisation of the profile change upon cutting is presented.

Study of the Jupiter X-ray imaging spectrometer on JMO

NASA Astrophysics Data System (ADS)

Kimura, T.; Ezoe, Y.; Kasahara, S.; Miyoshi, Y.; Yamazaki, A.; Fujimoto, M.; JMO X-ray Experiment Team

2011-12-01

In 2000's, the new generation X-ray observatories (Chandra, XMM-Newton and Suzaku) have revealed various new X-ray phenomena in the Jupiter system. The detected objects include Jupiter's aurorae, disk (middle and low-latitude emission), Io, Europa, the Io Plasma Torus, and radiation belts. For example, Jupiter's aurorae emit time variable X-rays via bremsstrahlung by keV electrons and charge exchange by MeV ions (Gladstone et al. 2002 Nature). A diffuse X-ray emission associated with the Jupiter's radiation belts suggests an inverse Compton scattering of tens MeV electrons (Ezoe et al. 2010 ApJ). Hence, the X-ray emission can be a unique diagnostic tool to investigate key fundamental problems on the Jupiter system such as the relativistic particle acceleration and the Jupiter-satellite reaction. However, since these observations have been done with the X-ray astronomy satellites orbiting the Earth, the photon statistics of X-ray spectra and light curves, and the angular resolution of X-ray images were severely limited. In this context, we have started to study design of an X-ray imaging spectrometer for JMO (Jupiter Magnetospheric Orbiter) which is expected to collaborate with international Jupiter exploration mission JUICE (JUpiter ICy moon Explorer). JUICE is originally EJSM (Europa Jupiter System Mission) but recently renamed JUICE as ESA-lead mission, which is proposed to be launched in 2020's. It consists of one main flight element developed by ESA to explore icy moons of Jupiter, and JMO by JAXA is expected to perform high-latitude (10-30 deg inclination) measurements of the Jupiter system and overview the magnetospheric activities. The in-situ measurements by EJSM JMO provide us with an unprecedented opportunity to observe Jupiter with extremely high photon statistics, high time and angular resolution. To realize the in-situ X-ray instrument for EJSM JMO, stringent mass and power limitations must be fulfilled. Furthermore, the radiation and the contamination

A Test Stand to Characterize and Contribute to the Development of DEPFET X-ray Detectors

NASA Astrophysics Data System (ADS)

Falcone, Abe

The field of X-ray astronomy is currently looking forward to several new missions (e.g Athena, BeppiColumbo, and IXPE which is a new SMEX polarimeter), and there is the possibility of a flag-ship mission (e.g. the Lynx X-ray Surveyor) and/or other SMEX through probe class missions in the long-term future with many mission concepts being developed (e.g. ARCUS). The X-ray detec-tors for these future missions must be developed to suitable maturity to be proposed for flight, and expertise operating the newest versions of the detectors must be acquired by potential mis-sion designers and proposers. There are several silicon X-ray imaging active pixel sensor (APS) detectors being developed at this time (hybrid CMOS, monolithic CMOS, and DEPFETs), and each of these have their own advantages and levels of maturity, while they all provide enhanced radia-tion hardness, lower power operation, and versatile readout modes. Of the new APS X-ray detec-tors being developed, the DEPleted p-channel Field Effect Transistors (DEPFETs) have exhibited the best noise performance to-date. While they do require larger pixel structures than their com-petitors, the low noise performance of these detectors makes them an excellent choice for many mission applications (e.g. they will be launched on 2 ESA missions, Athena & BepiColumbo), and their further development could benefit other missions, particularly future missions that might be led by NASA and US scientists. Up until now, the development of these detectors has been lim-ited to only two groups located in Germany; one group is at Max Planck Institute and the other is PNSensors which is comprised of engineers and scientists that previously led the DEPFET design work at Max Planck. We propose to engage one of these groups in order to: (a) acquire newly de-signed test DEPFET detectors built by PNSensor, through a very-low-cost arrangement, (b) build a test stand that can operate these detectors and gain valuable experience running them in

Image of the Supernova Remnant Cassiopeia A Taken by the High Energy Astronomy Observatory (HEAO)-2

NASA Technical Reports Server (NTRS)

1980-01-01

This x-ray photograph of the Supernova remnant Cassiopeia A, taken with the High Energy Astronomy Observatory (HEAO) 2/Einstein Observatory, shows that the regions with fast moving knots of material in the expanding shell are bright and clear. A faint x-ray halo, just outside the bright shell, is interpreted as a shock wave moving ahead of the expanding debris. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO-2, designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center, was launched aboard an Atlas/Centaur launch vehicle on November 13, 1978.

The X-Ray Weakness of GPS Radio Galaxies: A Volume-Limited Complete Sample

NASA Technical Reports Server (NTRS)

Mushotzky, Richard F. (Technical Monitor); Siemiginowska, Aneta (Principal Investigator)

2004-01-01

The XMM observations of Mkn 668 have been analyzed. We found soft X-ray signatures of a hot plasma (kT approximately 10^7 approximately K) and a hard X-ray emission from the nucleus. The X-ray spectrum above 2.5 approximately keV is characterized by a very flat (observed photon index, Gamma approximately 0.5) power-law continuum, alongside with a strong Fe-K-alpha neutral iron fluorescent line (EW approximately 600 approximately eV). The best explanation for the origin of this high energy X-ray emission is in terms of the Compton-reflection of the nuclear emission. The primary X-ray emission is obscured by a Compton-thick (N_H approximately 10^24 approximately cm-2) matter which becomes transparent at higher energies. The observed above 2.5-keV X-rays are mostly due to reflection which is indicated by a strong Fe-K-alpha line. This represents the second hard X-ray detection of the GPS galaxy ever (the first one being 1345+125; O Dea et al. 2000). Interestingly, the both such trend is confirmed by our on going XMM-Newton observations of a larger GPS sample, it would lead us to looking into the question on how the dense nuclear environment impacts the nature and evolution of a GPS source, and more generally, on the history of radio power in the universe. The paper summarizing the results has been submitted to Astronomy and Astrophysics in December 2003.

X-ray and optical observations of four polars

NASA Astrophysics Data System (ADS)

Worpel, H.; Schwope, A. D.; Granzer, T.; Reinsch, K.; Schwarz, R.; Traulsen, I.

2016-08-01

Aims: We investigate the temporal and spectral behaviour of four polar cataclysmic variables from the infrared to X-ray regimes, refine our knowledge of the physical parameters of these systems at different accretion rates, and search for a possible excess of soft X-ray photons. Methods: We obtained and analysed four XMM-Newton X-ray observations of three of the sources, two of them discovered with the SDSS and one in the RASS. The X-ray data were complemented by optical photometric and spectroscopic observations and, for two sources, archival Swift observations. Results: SDSSJ032855.00+052254.2 was X-ray bright in two XMM-Newton and two Swift observations, and shows transitions from high and low accretion states on a timescale of a few months. The source shows no significant soft excess. We measured the magnetic field strength at the main accreting pole to be 39 MG and the inclination to be 45° ≤ I ≤ 77°, and we refined the long-term ephemeris. SDSSJ133309.20+143706.9 was X-ray faint. We measured a faint phase X-ray flux and plasma temperature for this source, which seems to spend almost all of its time accreting at a low level. Its inclination is less than about 76°. 1RXSJ173006.4+033813 was X-ray bright in the XMM-Newton observation. Its spectrum contained a modest soft blackbody component, not luminous enough to be considered a significant soft excess. We inferred a magnetic field strength at the main accreting pole of 20 to 25 MG, and that the inclination is less than 77° and probably less than 63°. V808 Aur, also known as CSS081231:J071126+440405, was X-ray faint in the Swift observation, but there is nonetheless strong evidence for bright and faint phases in X-rays and perhaps in UV. Residual X-ray flux from the faint phase is difficult to explain by thermal emission from the white dwarf surface, or by accretion onto the second pole. We present a revised distance estimate of 250 pc. Conclusions: The three systems we were able to study in detail

High-Mass X-ray Binaries in hard X- rays

NASA Astrophysics Data System (ADS)

Lutovinov, Alexander

We present a review of the latest results of the all-sky survey, performed with the INTEGRAL observatory. The deep exposure spent by INTEGRAL in the Galactic plane region, as well as for nearby galaxies allowed us to obtain a flux limited sample for High Mass X-ray Binaries in the Local Galactic Group and measure their physical properties, like a luminosity function, spatial density distribution, etc. Particularly, it was determined the most accurate up to date spatial density distribution of HMXBs in the Galaxy and its correlation with the star formation rate distribution. Based on the measured value of the vertical distribution of HMXBs (a scale-height h~85 pc) we also estimated a kinematical age of HMXBs. Properties of the population of HMXBs are explained in the framework of the population synthesis model. Based on this model we argue that a flaring activity of so-called supergiant fast X-ray transients (SFXTs), the recently recognized sub-sample of HMXBs, is likely related with the magnetic arrest of their accretion. The resulted global characteristics of the HMXB population are used for predictions of sources number counts in sky surveys of future X-ray missions.

Non-Quiescent X-ray Emission from Neutron Stars and Black Holes

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

Tournear, Derek M

X-ray astronomy began with the detection of the persistent source Scorpius X-1. Shortly afterwards, sources were detected that were variable. Centaurus X-2, was determined to be an X-ray transient, having a quiescent state, and a state that was much brighter. As X-ray astronomy progressed, classifications of transient sources developed. One class of sources, believed to be neutron stars, undergo extreme luminosity transitions lasting a few seconds. These outbursts are believed to be thermonuclear explosions occurring on the surface of neutron stars (type I X-ray bursts). Other sources undergo luminosity changes that cannot be explained by thermonuclear burning and last formore » days to months. These sources are soft X-ray transients (SXTs) and are believed to be the result of instabilities in the accretion of matter onto either a neutron star or black hole. Type I X-ray bursts provide a tool for probing the surfaces of neutron stars. Requiring a surface for the burning has led authors to use the presence of X-ray bursts to rule out the existence of a black hole (where an event horizon exists not a surface) for systems which exhibit type I X-ray bursts. Distinguishing between neutron stars and black holes has been a problem for decades. Narayan and Heyl have developed a theoretical framework to convert suitable upper limits on type I X-ray bursts from accreting black hole candidates (BHCs) into evidence for an event horizon. We survey 2101.2 ks of data from the USA X-ray timing experiment and 5142 ks of data from the Rossi X-ray Timing Explorer (RXTE) experiment to obtain the first formal constraint of this type. 1122 ks of neutron star data yield a population averaged mean burst rate of 1.7 {+-} 0.4 x 10{sup -5} bursts s{sup -1}, while 6081 ks of BHC data yield a 95% confidence level upper limit of 4.9 x 10{sup -7} bursts s{sup -1}. Applying the framework of Narayan and Heyl we calculate regions of luminosity where the neutron stars are expected to burst and the

Image of the Supernova Cassiopeia Taken by the High Energy Astronomy Observatory (HEAO)-2

NASA Technical Reports Server (NTRS)

1980-01-01

This supernova in the constellation Cassiopeia was observed by Tycho Brahe in 1572. In this x-ray image from the High Energy Astronomy Observatory (HEAO-2/Einstein Observatory produced by nearly a day of exposure time, the center region appears filled with emissions that can be resolved into patches or knots of material. However, no central pulsar or other collapsed object can be seen. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO-2, designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center, was launched aboard an Atlas/Centaur launch vehicle on November 13, 1978.

X-ray/EUV optics for astronomy, microscopy, polarimetry, and projection lithography; Proceedings of the Meeting, San Diego, CA, July 9-13, 1990

NASA Technical Reports Server (NTRS)

Hoover, Richard B. (Editor); Walker, Arthur B. C., Jr. (Editor)

1991-01-01

Topics discussed in this issue include the fabrication of multilayer X-ray/EUV coatings; the design, characterization, and test of multilayer X-ray/EUV coatings; multilayer X-ray/EUV monochromators and imaging microscopes; X-ray/EUV telescopes; the test and calibration performance of X-ray/EUV instruments; XUV/soft X-ray projection lithography; X-ray/EUV space observatories and missions; X-ray/EUV telescopes for solar research; X-ray/EUV polarimetry; X-ray/EUV spectrographs; and X-ray/EUV filters and gratings. Papers are presented on the deposition-controlled uniformity of multilayer mirrors, interfaces in Mo/Si multilayers, the design and analysis of an aspherical multilayer imaging X-ray microscope, recent developments in the production of thin X-ray reflecting foils, and the ultraprecise scanning technology. Consideration is also given to an active sun telescope array, the fabrication and performance at 1.33 nm of a 0.24-micron-period multilayer grating, a cylindrical proportional counter for X-ray polarimetry, and the design and analysis of the reflection grating arrays for the X-Ray Multi-Mirror Mission.

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.

The origin of the X-ray, radio and H I structures in the NGC 5903 galaxy group

NASA Astrophysics Data System (ADS)

O'Sullivan, Ewan; Kolokythas, Konstantinos; Kantharia, Nimisha G.; Raychaudhury, Somak; David, Laurence P.; Vrtilek, Jan M.

2018-02-01

The NGC 5903 galaxy group is a nearby (∼30 Mpc) system of ∼30 members, dominated by the giant ellipticals NGC 5903 and NGC 5898. The group contains two unusual structures: a ∼110 kpc long H I filament crossing NGC 5903 and a ∼75 kpc wide diffuse, steep-spectrum radio source of unknown origin that overlaps NGC 5903 and appears to be partly enclosed by the H I filament. Using a combination of Chandra, XMM-Newton, Giant Meterwave Radio Telescope (GMRT) and Very Large Array (VLA) observations, we detect a previously unknown ∼0.65 keV intra-group medium filling the volume within 145 kpc of NGC 5903 and find a loop of enhanced X-ray emission extending ∼35 kpc south-west from the galaxy, enclosing the brightest part of the radio source. The northern and eastern parts of this X-ray structure are also strongly correlated with the southern parts of the H I filament. We determine the spectral index of the bright radio emission to be α _{150}^{612} = 1.03 ± 0.08, indicating a radiative age >360 Myr. We discuss the origin of the correlated radio, X-ray and H I structures, either through an interaction-triggered active galactic nucleus (AGN) outburst with enthalpy 1.8 × 1057 erg, or via a high-velocity collision between a galaxy and the H I filament. While neither scenario provides a complete explanation, we find that an AGN outburst is the most likely source of the principal X-ray and radio structures. However, it is clear that galaxy interactions continue to play an important role in the development of this relatively highly evolved galaxy group. We also resolve the question of whether the group member galaxy ESO 514-3 hosts a double-lobed radio source, confirming that the source is a superposed background AGN.

X-ray Fluorescence Spectroscopy: the Potential of Astrophysics-developed Techniques

NASA Astrophysics Data System (ADS)

Elvis, M.; Allen, B.; Hong, J.; Grindlay, J.; Kraft, R.; Binzel, R. P.; Masterton, R.

2012-12-01

X-ray fluorescence from the surface of airless bodies has been studied since the Apollo X-ray fluorescence experiment mapped parts of the lunar surface in 1971-1972. That experiment used a collimated proportional counter with a resolving power of ~1 and a beam size of ~1degree. Filters separated only Mg, Al and SI lines. We review progress in X-ray detectors and imaging for astrophysics and show how these advances enable much more powerful use of X-ray fluorescence for the study of airless bodies. Astrophysics X-ray instrumentation has developed enormously since 1972. Low noise, high quantum efficiency, X-ray CCDs have flown on ASCA, XMM-Newton, the Chandra X-ray Observatory, Swift and Suzaku, and are the workhorses of X-ray astronomy. They normally span 0.5 to ~8 keV with an energy resolution of ~100 eV. New developments in silicon based detectors, especially individual pixel addressable devices, such as CMOS detectors, can withstand many orders of magnitude more radiation than conventional CCDs before degradation. The capability of high read rates provides dynamic range and temporal resolution. Additionally, the rapid read rates minimize shot noise from thermal dark current and optical light. CMOS detectors can therefore run at warmer temperatures and with ultra-thin optical blocking filters. Thin OBFs mean near unity quantum efficiency below 1 keV, thus maximizing response at the C and O lines.such as CMOS detectors, promise advances. X-ray imaging has advanced similarly far. Two types of imager are now available: specular reflection and coded apertures. X-ray mirrors have been flown on the Einstein Observatory, XMM-Newton, Chandra and others. However, as X-ray reflection only occurs at small (~1degree) incidence angles, which then requires long focal lengths (meters), mirrors are not usually practical for planetary missions. Moreover the field of view of X-ray mirrors is comparable to the incident angle, so can only image relatively small regions. More useful

Performance of Magnetic Penetration Thermometers for X-Ray Astronomy

NASA Technical Reports Server (NTRS)

Nagler, P. C.; Adams, J. S.; Balvin, M. A.; Bandler, S. R.; Denis, K. L.; Hsieh, W. T.; Kelly, D. P.; Porst, J. P.; Sadleir, J. E.; Seidel, G. M.;

Reflectivity Around the Gold M-Edges of X-ray Reflector of the Soft X-Ray Telescope Onboard ASTRO-H

NASA Technical Reports Server (NTRS)

Kurashimaa, Sho; Furuzawa, Akihiro; Sato, Toshiki; Kikuchia, Naomichi; Nakaniwaa, Nozomi; Maeda, Yoshitomo; Ishida, Manabu; Izuka, Ryo; Okajima, Takashi; Mori, Hideyuki;

X-ray beamsplitter

DOEpatents

Ceglio, Natale M.; Stearns, Daniel S.; Hawryluk, Andrew M.; Barbee, Jr., Troy W.

1989-01-01

An x-ray beamsplitter which splits an x-ray beam into two coherent parts by reflecting and transmitting some fraction of an incident beam has applications for x-ray interferometry, x-ray holography, x-ray beam manipulation, and x-ray laser cavity output couplers. The beamsplitter is formed of a wavelength selective multilayer thin film supported by a very thin x-ray transparent membrane. The beamsplitter resonantly transmits and reflects x-rays through thin film interference effects. A thin film is formed of 5-50 pairs of alternate Mo/Si layers with a period of 20-250 A. The support membrane is 10-200 nm of silicon nitride or boron nitride. The multilayer/support membrane structure is formed across a window in a substrate by first forming the structure on a solid substrate and then forming a window in the substrate to leave a free-standing structure over the window.

Search for Hard X-Ray Emission from the Soft X-Ray Transient Aquila X-1

NASA Astrophysics Data System (ADS)

Harmon, B. A.; Zhang, S. N.; Paciesas, W. S.; Tavani, M.; Kaaret, P.; Ford, E.

1994-12-01

We are investigating the possibility of hard x-ray emission from the recurrent soft x-ray transient and x-ray burst source Aquila X-1 (Aql X-1). Outbursts of this source are relatively frequent with a spacing of ~ 4-10 months (Kitamoto, S. et al. 1993, ApJ, 403, 315). The recent detections of hard tails (\\(>\\)20 keV) in low luminosity x-ray bursters (Barret, D. & Vedrenne, G. 1994, ApJ Supp. S. 92, 505) suggest that neutron star transient systems such as Aql X-1 can produce hard x-ray emission which is detectable by BATSE. We are correlating reported optical and soft x-ray observations since 1991 of Aql X-1 with BATSE observations in order to search for hard x-ray emission episodes, and to study their temporal and spectral evolution. We will present preliminary results of this search in the 20-1000 keV band using the Earth occultation technique applied to the large area detectors. If this work is successful, we hope to alert the astronomical community for the next Aql X-1 outburst expected in 1995. Simultaneous x-ray/hard x-ray and optical observations of Aql X-1 during outburst would be of great importance for the modeling of soft x-ray transients and related systems.

A year after lift-off, XMM-Newton is impressing the X-ray astronomy community

NASA Astrophysics Data System (ADS)

2000-11-01

XMM-Newton was launched from Kourou on 10 December 1999 on the first Ariane-5 commercial flight. After in-orbit commissioning of the spacecraft, and calibration and performance verification of its science instruments, the observatory entered its routine operations phase on 1 July. At the press conference, ESA's Director of Science Prof. Roger-Maurice Bonnet and XMM-Newton Project Scientist Fred Jansen will present some of the many scientific results from the first eight months of the mission. Also present will be two of Europe's foremost X-ray astronomers, Prof. Johan Bleeker of the Space Research Organisation of the Netherlands, and Prof. Guenther Hasinger of the Astrophysikalisches Institut Potsdam, Germany. Amongst the topics to be illustrated with some remarkably vivid "colour" images of the X-ray Universe, will be XMM-Newton's first examination of a cataclysmic binary star, its first insights into some enigmatic black hole systems, analysis of the morphology of a few supernovae remnants, and evidence it has collected to end the long-standing mystery over X-ray cosmic background emission... The press conference will also recap on the spacecraft's operations, the performance of its science instruments, the issue of radiation constraints and future aspects of the mission. Media representatives wishing to attend the press event are kindly invited to complete the attached reply form and fax it back to ESA Media Relations Office +33(0)1.53.69.7690. Note to editors XMM-Newton is ESA's second Cornerstone Mission of the Horizon 2000 programme. The spacecraft was built by a European consortium of companies led by Astrium (formerly Dornier Satellitensysteme), Friedrichshafen, Germany. Its X-ray imaging and spectrographic instruments (EPIC and RGS) and its optical telescope (OM) were provided by large consortia, whose principal investigators are from, respectively, the University of Leicester, UK, SRON University of Utrecht Netherlands, and the Mullard Space Science

X-Ray Spectrometer For ROSAT II (SPECTROSAT)

NASA Astrophysics Data System (ADS)

Predehl, Peter; Brauninger, Heinrich

1986-01-01

The objective transmission grating was one of the earliest inventions in the field of X-ray astronomy and has been incorporated into Skylab, HERO-P, and EXOTAT. In recent years there have been advances in grating technology and spectrometer design. A high precision mechanical ruling and replication process for manufacturing large self-supporting transmission gratings has been developed by an industrial manufacturer in cooperation with the Max-Planck-Institute (MPI). Theoretical analyses have determined the optimum configuration of the grating facets and the grating surface in order to correct third order aberations and obtain maximum resolving power. We have verified experimentally that the predicted efficiencies may be achieved. In addition, an experimental study of large grating assemblies for space telescopes was made in industry with scientific guidance by MPI. Main objectives of this study were the determination of mechanical loads during launch, as well as the design, construction and fabrication of a representative model of a ROSAT grating ring. Performancy studies including instrument pro-perties as well as the simulated radiation from hot plasmas have shown the ability of SPECTROSAT to perform high efficiency, high resolution line-spectroscopy on a wide variety of cosmic X-ray sources.

Advancing the technology of monolithic CMOS detectors for use as x-ray imaging spectrometers

NASA Astrophysics Data System (ADS)

Kenter, Almus; Kraft, Ralph; Gauron, Thomas; Amato, Stephen

2017-08-01

The Smithsonian Astrophysical Observatory (SAO) in collaboration with SRI/Sarnoff has been engaged in a multi year effort to advance the technology of monolithic back-thinned CMOS detectors for use as X-ray imaging spectrometers. The long term goal of this campaign is to produce X-ray Active Pixel Sensor (APS) detectors with Fano limited performance over the 0.1-10keV band while incorporating the many benefits of CMOS technology. These benefits include: low power consumption, radiation "hardness", high levels of integration, and very high read rates. Such devices would be ideal for candidate post 2020 decadal missions such as LYNX and for smaller more immediate applications such as CubeX. Devices from a recent fabrication have been back-thinned, packaged and tested for soft X-ray response. These devices have 16μm pitch, 6 Transistor Pinned Photo Diode (6TPPD) pixels with ˜135μV/electron sensitivity and a highly parallel signal chain. These new detectors are fabricated on 10μm epitaxial silicon and have a 1k by 1k format. We present details of our camera design and device performance with particular emphasis on those aspects of interest to single photon counting X-ray astronomy. These features include read noise, X-ray spectral response and quantum efficiency.

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

Functional group quantification of polymer nanomembranes with soft x-rays

NASA Astrophysics Data System (ADS)

Sunday, Daniel F.; Chan, Edwin P.; Orski, Sara V.; Nieuwendaal, Ryan C.; Stafford, Christopher M.

2018-03-01

Polyamide nanomembranes are at the heart of water desalination, a process which plays a critical role in clean water production. Improving their efficiency requires a better understanding of the relationship between chemistry, network structure, and performance but few techniques afford compositional information in ultrathin films (<100 nm). Here, we leverage resonant soft x-ray reflectivity, a measurement that is sensitive to the specific chemical bonds in organic materials, to quantify the functional group concentration in these polyamides. We first employ reference materials to establish quantitative relationships between changes in the optical constants and functional group density, and then use the results to evaluate the functional group concentrations of polyamide nanomembranes. We demonstrate that the difference in the amide carbonyl and carboxylic acid group concentrations can be used to calculate the crosslink density, which is shown to vary significantly across three different polyamide chemistries. A clear relationship is established between the functional group density and the permselectivity (α ), indicating that more densely crosslinked materials result in a higher α of the nanomembranes. Finally, measurements on a polyamide/poly(acrylic acid) bilayer demonstrate the ability of this approach to quantify depth-dependent functional group concentrations in thin films.

The X-Ray Background and the AGN Luminosity Function

NASA Astrophysics Data System (ADS)

Hasinger, G.

The deepest X-ray surveys performed with ROSAT were able to resolve as much as 70-80% of the 1-2 keV X-ray background into resolved sources. Optical follow-up observations were able to identify the majority of faint X-ray sources as active galactic nuclei (AGN) out to redshifts of 4.5 as well as a sizeable fraction as groups of galaxies out to redshifts of 0.7. A new population of X-ray luminous, optically innocent narrow emission line galaxies (NELGs) at the faintest X-ray fluxes is still a matter of debate, most likely many of them are also connected to AGN. First deep surveys with the Japanese ASCA satellite give us a glimpse of the harder X-ray background where the bulk of the energy density resides. Future X-ray observatories (XMM and AXAF) will be able to resolve the harder X-ray background. For the first time we are now in a position to study the cosmological evolution of the X-ray luminosity function of AGN, groups of galaxies and galaxies and simultaneously constrain their total luminosity output over cosmic time.

X-ray beamsplitter

DOEpatents

Ceglio, N.M.; Stearns, D.G.; Hawryluk, A.M.; Barbee, T.W. Jr.

1987-08-07

An x-ray beamsplitter which splits an x-ray beam into two coherent parts by reflecting and transmitting some fraction of an incident beam has applications for x-ray interferometry, x-ray holography, x-ray beam manipulation, and x-ray laser cavity output couplers. The beamsplitter is formed of a wavelength selective multilayer thin film supported by a very thin x-ray transparent membrane. The beamsplitter resonantly transmits and reflects x-rays through thin film interference effects. A thin film is formed of 5--50 pairs of alternate Mo/Si layers with a period of 20--250 A. The support membrane is 10--200 nm of silicon nitride or boron nitride. The multilayer/support membrane structure is formed across a window in a substrate by first forming the structure on a solid substrate and then forming a window in the substrate to leave a free-standing structure over the window. 6 figs.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1975-07-01

This illustration is a schematic of the High Energy Astronomy Observatory (HEAO)-2 and its experiments. It shows the focal plane instruments (at the right) plus the associated electronics for operating the telescope as it transmitted its observations to the ground. A fifth instrument, the Monitor Proportional Counter, is located near the front of the telescope. Four separate astronomical instruments are located at the focus of this telescope and they could be interchanged for different types of observations as the observatory pointed at interesting areas of the Sky. Two of these instruments produced images; a High Resolution Imaging Detector and an Imaging Proportional Counter. The other two instruments, the Solid State Spectrometer and the Crystal Spectrometer, measured the spectra of x-ray objects. A fifth instrument, the Monitor Proportional Counter, continuously viewed space independently to study a wider band of x-ray wavelengths and to examine the rapid time variations in the sources. The HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO-2, designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center, was launched aboard an Atlas/Centaur launch vehicle on November 13, 1978. The HEAO-2 was originally identified as HEAO-B but the designation was changed once the spacecraft achieved orbit.

Nontechnical Astronomy Books of 1989.

ERIC Educational Resources Information Center

Mercury, 1990

1990-01-01

Presented are 126 reviews. Categories include amateur astronomy, children's books, computers and astronomy, cosmic rays, cosmology, education in astronomy, galaxies, general astronomy, history of astronomy, life in the universe, physics and astronomy, pseudoscience, quasars and active galaxies, reference, solar system, space exploration, stars and…

X-ray Weak Broad-line Qquasars: Absorption or Intrinsic X-ray Weakness

NASA Technical Reports Server (NTRS)

Mushotzky, Richard (Technical Monitor); Risaliti, Guida

2005-01-01

XMM observations of X-ray weak quasars have been performed during 2003 and 2004. The data for all the observations have become available in 2004 (there has been a delay of several months on the initial schedule, due to high background flares which contaminated the observations: as a consequence, most of them had to be rescheduled). We have reduced and analyzed all the data, and obtained interesting scientific results. Out of the eight sources, 4 are confirmed to be extremely X-ray weak, in agreement with the results of previous Chandra observations. 3 sources are confined to be highly variable both in flux (by factor 20-50) and in spectral properties (dramatic changes in spectral index). For both these groups of objects we are completing a publication: 1) For the X-ray weak sources, a paper is submitted with a complete analysis of the X-ray spectra both from Chandra and XMM-Newton, and a comparison with optical and near-IR photometry obtained from all-sky surveys. Possible models for the unusual spectral energy distribution of these sources are also presented. 2) For the variable sources, a paper is being finalized where the X-ray spectra obtained with XMM-Newton are compared with previous X-ray observations and with observations at other wavelengths. It is shown that these sources are high luminosity and extreme cases of the highly variable class of narrow-line Seyfert Is. In order to further understand the nature of these X-ray weak quasars, we submitted proposals for spectroscopy at optical and infrared telescopes. We obtained time at the TNG 4 meter telescope for near-IR observations and at the Hobby-Eberly Telescope for optical high-resolution spectroscopy. These observations have been performed in early 2004. They will complement the XMM data and will lead to understanding of whether the X-ray weakness of these sources is an intrinsic property or is due to absorption by circum-nuclear material. The infrared spectra of the variable sources have been already

The Presence of Thermally Unstable X-Ray Filaments and the Production of Cold Gas in the NGC 5044 Group

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

David, Laurence P.; Vrtilek, Jan; O’Sullivan, Ewan

We present the results of a deep Chandra observation of the X-ray bright moderate-cooling flow group NGC 5044 along with the observed correlations between the ionized, atomic, and molecular gas in this system. The Chandra observation shows that the central AGN has undergone two outbursts in the past 10{sup 8} years, based on the presence of two pairs of nearly bipolar X-ray cavities. The molecular gas and dust within the central 2 kpc is aligned with the orientation of the inner pair of bipolar X-ray cavities, suggesting that the most recent AGN outburst had a dynamical impact on the molecularmore » gas. NGC 5044 also hosts many X-ray filaments within the central 8 kpc, but there are no obvious connections between the X-ray and H α filaments and the more extended X-ray cavities that were inflated during the prior AGN outburst. Using the line width of the blended Fe-L line complex as a diagnostic for multiphase gas, we find that the majority of the multiphase thermally unstable gas in NGC 5044 is confined within the X-ray filaments. While the cooling time and entropy of the gas within the X-ray filaments are very similar, not all filaments show evidence of gas cooling or an association with H α emission. We suggest that the various observed properties of the X-ray filaments are suggestive of an evolutionary sequence where thermally unstable gas begins to cool, becomes multiphased, develops H α emitting plasma, and finally produces cold gas.« less

A fast scintillator Compton telescope for medium-energy gamma-ray astronomy

NASA Astrophysics Data System (ADS)

Bloser, Peter F.; Ryan, James M.; Legere, Jason S.; Julien, Manuel; Bancroft, Christopher M.; McConnell, Mark L.; Wallace, Mark; Kippen, R. Marc; Tornga, Shawn

2010-07-01

The field of medium-energy gamma-ray astronomy urgently needs a new mission to build on the success of the COMPTEL instrument on the Compton Gamma Ray Observatory. This mission must achieve sensitivity significantly greater than that of COMPTEL in order to advance the science of relativistic particle accelerators, nuclear astrophysics, and diffuse backgrounds, and bridge the gap between current and future hard X-ray missions and the high-energy Fermi mission. Such an increase in sensitivity can only come about via a dramatic decrease in the instrumental background. We are currently developing a concept for a low-background Compton telescope that employs modern scintillator technology to achieve this increase in sensitivity. Specifically, by employing LaBr3 scintillators for the calorimeter, one can take advantage of the unique speed and resolving power of this material to improve the instrument sensitivity while simultaneously enhancing its spectroscopic and imaging performance. Also, using deuterated organic scintillator in the scattering detector will reduce internal background from neutron capture. We present calibration results from a laboratory prototype of such an instrument, including time-of-flight, energy, and angular resolution, and compare them to simulation results using a detailed Monte Carlo model. We also describe the balloon payload we have built for a test flight of the instrument in the fall of 2010.

Image of the Eta Carinae Nebula Taken by the High Energy Astronomy Observatory (HEAO)-2

NASA Technical Reports Server (NTRS)

1979-01-01

This image is an x-ray view of Eta Carinae Nebula showing bright stars taken with the High Energy Astronomy Observatory (HEAO)-2/Einstein Observatory. The Eta Carinae Nebula is a large and complex cloud of gas, crisscrossed with dark lanes of dust, some 6,500 light years from Earth. Buried deep in this cloud are many bright young stars and a very peculiar variable star. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO-2, designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center, was launched aboard an Atlas/Centaur launch vehicle on November 13, 1978.

Teaching Astronomy in Extracurricular Study Groups of Armenia

NASA Astrophysics Data System (ADS)

Khachatryan, Mher; Grigoryan, Avetik

2016-12-01

The report presents the history of activity of Extracurricular Study Groups of Ar¬menia teaching astronomy and related subjects. It mainly refers to the Aerospace Club founded in 1988, which has long been acting as an officially unre¬gis¬tered, but efficiently performing non-governmental organization - Armenian Youth Ae¬ro¬space Society. The Club teaches, provides a truly scientific view of the world, advocates astronomy and other scientific and technical areas, provides interesting lectures and ar¬ticles to schools and mass media, arranges seminars and meetings with renowned experts, publishes scientific ar¬ticles, manuals, books, puts forward important scientific and techno-logical problems and offer students to work together on them, seek for solutions and develop possible appli¬ca¬tions. All this is aimed at maintaining and further development of leading positions of Armenia's scientific potential, particularly in astronomy.

Be/X-ray Binary Science for Future X-ray Timing Missions

NASA Technical Reports Server (NTRS)

Wilson-Hodge, Colleen A.

2011-01-01

For future missions, the Be/X-ray binary community needs to clearly define our science priorities for the future to advocate for their inclusion in future missions. In this talk, I will describe current designs for two potential future missions and Be X-ray binary science enabled by these designs. The Large Observatory For X-ray Timing (LOFT) is an X-ray timing mission selected in February 2011 for the assessment phase from the 2010 ESA M3 call for proposals. The Advanced X-ray Timing ARray (AXTAR) is a NASA explorer concept X-ray timing mission. This talk is intended to initiate discussions of our science priorities for the future.

Abdomen X-Ray (Radiography)

MedlinePlus

... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Abdomen Abdominal x-ray uses a ... of an abdominal x-ray? What is abdominal x-ray? An x-ray (radiograph) is a noninvasive ...

Photodynamic synchrotron x-ray therapy in Glioma cell using superparamagnetic iron nanoparticle

NASA Astrophysics Data System (ADS)

Kim, Hong-Tae; Kim, Ki-Hong; Choi, Gi-Hwan; Jheon, Sanghoon; Park, Sung-Hwan; Kim, Bong-Il; Hyodo, Kazuyuki; Ando, Masami; Kim, Jong-Ki

2009-06-01

In order to evaluate cytotoxic effects of secondary Auger electron emission(Photon Activation Therapy:PAT) from alginate-coated iron nanoparticles(Alg-SNP), Alg-SNP-uptaken C6 glioma cell lines were irradiated with 6.89/7.2 Kev synchrotron X-ray. 0-125 Gy were irradiated on three experimental groups including No-SNP group incubating without SNP as control group, 6hr-SNP group incubating with SNP for 6hr and ON-SNP group incubating with SNP overnight. Irradiated cells were stained with Acridine Orange(AO) and Edithium Bromide(EB) to count their viability with fluorescent microscopy in comparison with control groups. AO stained in damaged DNA, giving FL color change in X-ray plus SNP group. EB did not or less enter inside the cell nucleus of control group. In contrast, EB entered inside the cell nucleus of Alg-SNP group which means more damage compared with Control groups. The results of MTT assay demonstrated a X-ray dose-dependent reduction generally in cell viability in the experimental groups. 3 or 9 times increase in cell survival loss rate was observed at 6hr-SNP and ON-SNP groups, respectively compared to No-SNP control group in first experiment that was done to test cell survival rate at relatively lower dose, from 0 to 50 Gy. In second experiment X-ray dose was increased to 125 Gy. Survival loss was sharply decreased in a relatively lower dose from 5 to 25 Gy, and then demonstrated an exponentially decreasing behavior with a convergence until 125 Gy for each group. This observation suggests PAT effects on the cell directly by X-ray in the presence of Alg-SNP occurs within lower X-ray dose, and conventional X-ray radiation effect becomes dominant in higher X-ray dose. The cell viability loss of ON-SNP group was three times higher compared with that of 6hr-SNP group. In conclusion, it is possible to design photodynamic X-ray therapy study using a monochromatic x-ray energy and metal nanoparticle as x-ray sensitizer, which may enable new X-ray PDT to

IXPE the Imaging X-ray Polarimetry Explorer

NASA Astrophysics Data System (ADS)

Soffitta, Paolo

2017-08-01

IXPE, the Imaging X-ray Polarimetry Explorer, has been selected as a NASA SMEX mission to be flown in 2021. It will perform polarimetry resolved in energy, in time and in angle as a break-through in High Energy Astrophysics. IXPE promises to 're-open', after 40 years, a window in X-ray astronomy adding two more observables to the usual ones. It will directly measure the geometrical parameters of many different classes of sources eventually breaking possible degeneracies. The probed angular scales (30") are capable of producing the first X-ray polarization maps of extended objects with scientifically relevant sensitivity. This will permit mapping the magnetic fields in Pulsar Wind Nebulae and Super-Nova Remnants at the acceleration sites of 10-100 TeV electrons. Additionally, it will probe vacuum birefringence effects in systems with magnetic fields far larger than those reachable with experiments on Earth. The payload of IXPE consists of three identical telescopes with mirrors provided by MSFC/NASA. The focal plane is provided by ASI with IAPS/INAF responsible for the overall instrument that includes detector units that are provided by INFN. ASI also provides, in kind, the Malindi Ground Station. LASP is responsible for the Mission Operation Center while the Science Operation Center is at MSFC. The operations phase lasts at least two years. All the data including those related to polarization will be made available quickly to the general user. In this paper we present the mission, its payload and we discuss a few examples of astrophysical targets.

Proceedings of the Space Shuttle Sortie Workshop. Volume 2: Working group reports

NASA Technical Reports Server (NTRS)

1972-01-01

Details are presented on the mission planning progress in each of the working paper reports. The general topics covered are the following: space technology; materials processing and space manufacturing; communications and navigation; earth and ocean physics; oceanography; earth resources and surface environmental quality; meteorology and atmospheric environmental quality; life sciences; atmospheric and space physics; solar physics; high energy cosmic rays; X-ray and gamma ray astronomy; ultraviolet-optical astronomy; planetary astronomy; and infrared astronomy.

A search for X-ray polarization in cosmic X-ray sources. [binary X-ray sources and supernovae remnants

NASA Technical Reports Server (NTRS)

Hughes, J. P.; Long, K. S.; Novick, R.

1983-01-01

Fifteen strong X-ray sources were observed by the X-ray polarimeters on board the OSO-8 satellite from 1975 to 1978. The final results of this search for X-ray polarization in cosmic sources are presented in the form of upper limits for the ten sources which are discussed elsewhere. These limits in all cases are consistent with a thermal origin for the X-ray emission.

Differential Deposition to Correct Surface Figure Deviations in Astronomical Grazing-Incidence X-Ray Optics

NASA Technical Reports Server (NTRS)

Kilaru, Kiranmayee; Ramsey, Brian D.; Gubarev, Mikhail V.

2011-01-01

A coating technique is being developed to correct the surface figure deviations in reflective-grazing-incidence X-ray optics. These optics are typically designed to have precise conic profiles, and any deviation in this profile, as a result of fabrication, results in a degradation of the imaging performance. To correct the mirror profiles, physical vapor deposition has been utilized to selectively deposit a filler material inside the mirror shell. The technique, termed differential deposition, has been implemented as a proof of concept on miniature X-ray optics developed at MSFC for medical-imaging applications. The technique is now being transferred to larger grazing-incidence optics suitable for astronomy and progress to date is reported.

"X-Ray Transients in Star-Forming Regions" and "Hard X-Ray Emission from X-Ray Bursters"

NASA Technical Reports Server (NTRS)

Halpern, Jules P.; Kaaret, Philip

1999-01-01

This grant funded work on the analysis of data obtained with the Burst and Transient Experiment (BATSE) on the Compton Gamma-Ray Observatory. The goal of the work was to search for hard x-ray transients in star forming regions using the all-sky hard x-ray monitoring capability of BATSE. Our initial work lead to the discovery of a hard x-ray transient, GRO J1849-03. Follow-up observations of this source made with the Wide Field Camera on BeppoSAX showed that the source should be identified with the previously known x-ray pulsar GS 1843-02 which itself is identified with the x-ray source X1845-024 originally discovered with the SAS-3 satellite. Our identification of the source and measurement of the outburst recurrence time, lead to the identification of the source as a Be/X-ray binary with a spin period of 94.8 s and an orbital period of 241 days. The funding was used primarily for partial salary and travel support for John Tomsick, then a graduate student at Columbia University. John Tomsick, now Dr. Tomsick, received his Ph.D. from Columbia University in July 1999, based partially on results obtained under this investigation. He is now a postdoctoral research scientist at the University of California, San Diego.

X-ray crystal structure and small-angle X-ray scattering of sheep liver sorbitol dehydrogenase

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

Yennawar, Hemant; Møller, Magda; University of Copenhagen, DK-2100 Copenhagen

The X-ray crystal structure and a small-angle X-ray scattering solution structure of sheep liver sorbitol dehydrogenase have been determined. The details of the interactions that enable the tetramer scaffold to be the functional biological unit have been analyzed. The X-ray crystal structure of sheep liver sorbitol dehydrogenase (slSDH) has been determined using the crystal structure of human sorbitol dehydrogenase (hSDH) as a molecular-replacement model. slSDH crystallized in space group I222 with one monomer in the asymmetric unit. A conserved tetramer that superposes well with that seen in hSDH (despite belonging to a different space group) and obeying the 222 crystalmore » symmetry is seen in slSDH. An acetate molecule is bound in the active site, coordinating to the active-site zinc through a water molecule. Glycerol, a substrate of slSDH, also occupies the substrate-binding pocket together with the acetate designed by nature to fit large polyol substrates. The substrate-binding pocket is seen to be in close proximity to the tetramer interface, which explains the need for the structural integrity of the tetramer for enzyme activity. Small-angle X-ray scattering was also used to identify the quaternary structure of the tetramer of slSDH in solution.« less

Mounting and Alignment of Full-Shell Replicated X-Ray Optics

NASA Technical Reports Server (NTRS)

Gubarev, Mikhail; Arnold, William; Kester, Thomas; Ramsey, Brian; Smithers, Martin

2007-01-01

We are developing grazing-incidence x-ray optics for astronomy. The optics are full-cylinder mirror shells fabricated using electroformed-nickel replication off super-polished mandrels. For space-based applications where weight is at a premium, very-thin-walled, light-weight mirrors are required. Such shells have been fabricated at MSFC with greater than 15 arcsec resolution. The challenge, however, is to preserve this resolution during mounting and assembly. We present here a status report on a mounting and alignment system currently under development at Marshall Space Flight Center to meet this challenge.

Lumbosacral spine x-ray

MedlinePlus

X-ray - lumbosacral spine; X-ray - lower spine ... The test is done in a hospital x-ray department or your health care provider's office by an x-ray technician. You will be asked to lie on the x-ray ...

X-ray ptychography

NASA Astrophysics Data System (ADS)

Pfeiffer, Franz

2018-01-01

X-ray ptychographic microscopy combines the advantages of raster scanning X-ray microscopy with the more recently developed techniques of coherent diffraction imaging. It is limited neither by the fabricational challenges associated with X-ray optics nor by the requirements of isolated specimen preparation, and offers in principle wavelength-limited resolution, as well as stable access and solution to the phase problem. In this Review, we discuss the basic principles of X-ray ptychography and summarize the main milestones in the evolution of X-ray ptychographic microscopy and tomography over the past ten years, since its first demonstration with X-rays. We also highlight the potential for applications in the life and materials sciences, and discuss the latest advanced concepts and probable future developments.

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.

A sealed titanium window proportional counter for the detection of .5-keV X rays.

NASA Technical Reports Server (NTRS)

Mcclintock, J. E.; Levine, A.; Rappaport, S.

1972-01-01

A sealed Ti window proportional counter sensitive to X radiation in the energy range 0.35-0.45 keV and above 1.5 keV is described. Measurements of the Ti mass absorption coefficients and a graphical summary of the literature values are presented. For a proportional counter with a 930 microgram/sq cm (2.1-micron) Ti window, the peak efficiency at 0.45 keV is found to lie between 4.6% and 7.1%. An application in X-ray astronomy involving a rocket observation of Sco X-1 is discussed.

Autonomous Modelling of X-ray Spectra Using Robust Global Optimization Methods

NASA Astrophysics Data System (ADS)

Rogers, Adam; Safi-Harb, Samar; Fiege, Jason

2015-08-01

The standard approach to model fitting in X-ray astronomy is by means of local optimization methods. However, these local optimizers suffer from a number of problems, such as a tendency for the fit parameters to become trapped in local minima, and can require an involved process of detailed user intervention to guide them through the optimization process. In this work we introduce a general GUI-driven global optimization method for fitting models to X-ray data, written in MATLAB, which searches for optimal models with minimal user interaction. We directly interface with the commonly used XSPEC libraries to access the full complement of pre-existing spectral models that describe a wide range of physics appropriate for modelling astrophysical sources, including supernova remnants and compact objects. Our algorithm is powered by the Ferret genetic algorithm and Locust particle swarm optimizer from the Qubist Global Optimization Toolbox, which are robust at finding families of solutions and identifying degeneracies. This technique will be particularly instrumental for multi-parameter models and high-fidelity data. In this presentation, we provide details of the code and use our techniques to analyze X-ray data obtained from a variety of astrophysical sources.

Gamma-ray astronomy: From Fermi up to the HAWC high-energy {gamma}-ray observatory in Sierra Negra

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

Carraminana, Alberto; Collaboration: HAWC Collaboration

Gamma-rays represent the most energetic electromagnetic window for the study of the Universe. They are studied both from space at MeV and GeV energies, with instruments like the Fermi{gamma}-ray Space Telescope, and at TeV energies with ground based instruments profiting of particle cascades in the atmosphere and of the Cerenkov radiation of charged particles in the air or in water. The Milagro gamma-ray observatory represented the first instrument to successfully implement the water Cerenkov technique for {gamma}-ray astronomy, opening the ground for the more sensitive HAWC {gamma}-ray observatory, currently under development in the Sierra Negra site and already providing earlymore » science results.« less

X-ray studies of neutron stars and their magnetic fields

PubMed Central

MAKISHIMA, Kazuo

2016-01-01

Utilizing results obtained over the past quarter century mainly with Japanese X-ray astronomy satellites, a review is given to some aspects of neutron stars (NSs), with a particular emphasis on the magnetic fields (MFs) of mass-accreting NSs and magnetars. Measurements of electron cyclotron resonance features in binary X-ray pulsars, using the Ginga and Suzaku observatories, clarified that their surface MFs are concentrated in a narrow range of (1–7) × 108 T. Extensive studies of magnetars with Suzaku reinforced their nature as neutron stars with truly strong MFs, and revealed several important clues to their formation, evolution, and physical states. Taking all these results into account, a discussion is made on the origin and evolution of these strong MFs. One possible scenario is that the MF of NSs is a manifestation of some fundamental physics, e.g., neutron spin alignment or chirality violation, and the MF makes transitions from strong to weak states. PMID:27169348

Design and fabrication of a CCD camera for use with relay optics in solar X-ray astronomy

NASA Technical Reports Server (NTRS)

1984-01-01

Configured as a subsystem of a sounding rocket experiment, a camera system was designed to record and transmit an X-ray image focused on a charge coupled device. The camera consists of a X-ray sensitive detector and the electronics for processing and transmitting image data. The design and operation of the camera are described. Schematics are included.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1978-11-13

The launch of an Atlas/Centaur launch vehicle is shown in this photograph. The Atlas/Centaur, launched on November 13, 1978, carried the High Energy Astronomy Observatory (HEAO)-2 into the required orbit. The second observatory, the HEAO-2 (nicknamed the Einstein Observatory in honor of the centernial of the birth of Albert Einstein) carried the first telescope capable of producing actual photographs of x-ray objects.

The x ray morphology of the relaxed cluster of galaxies A2256. 2: Sources around the extended cluster emission

NASA Technical Reports Server (NTRS)

Henry, J. Patrick; Briel, U. G.

1991-01-01

X-ray emission from cluster galaxies as well as from 'dark objects' (i.e. not visible on the Palomar Observatory Sky Survey (POSS)) seen in the x-ray observation of A2256 with the imaging proportional counter on board ROSAT (x-ray astronomy satellite), is reported. This observation revealed significantly more sources in the field around the extended cluster emission than one would expect by chance. In a preliminary investigation, 14 sources were discovered at the limiting flux for this exposure, whereas about 7 sources would have been expected by chance. At least two of those sources are coincident with cluster member galaxies, having x-ray luminosities of approximately 10(exp +42) erg/s in the ROSAT energy band from 0.1 to 2.4 keV, but at least four more are from 'dark' objects. The similarity of these objects to those in A1367 suggests the existence of a new class of x-ray sources in clusters.

Development of X-ray spectroscopic polarimetry with bent Si crystals and CFRP substrate

NASA Astrophysics Data System (ADS)

Iizuka, Ryo; Izumiya, Takanori; Tsuboi, Yohko

2016-07-01

The light from celestial objects includes four important quantities; images, time variation, energy spectrum, and polarization. In the field of X-ray astronomy, the capabilities of the former three have remarkably developed. On the other hand, the progress for the polarimetry is considerably delayed because of technical difficulties. In order to make a breakthrough in the field of X-ray polarimetry, we have developed a new type of optics for X-ray polarimetry. The system is collecting Bragg crystal with large area and very high sensitivity for the polarization dedicated to Fe-K lines. We adopt the 400 re ection of Si(100) crystals with high sensitivity for the polarization around Fe-K lines (6 7 keV), and bent the crystals with the wide X-ray band and high S/N ratio. Furthermore, to install small area of CCD to non-focal plane, it also has the spectroscopic capability with the better resolution than that of general X-ray CCD. Our previous development was to bent Si crystals to the cylindrical shape of circle and parabola with the DLC deposition. However, for the better optics for the X-ray polarimetry, the shape should be the paraboloid of revolution to collect X-rays with high S/N ratio. We searched for the method to bent the Si crystals to the shape of the paraboloid of revolution. We devised the method to mold the crystal and the CFRP substrate simultaneously pushed to the sophisticated foundation with the paraboloid of revolution. We developed the prototype of about 8 inch in radius of one-quater size. The crystals was also bent in the circumferential direction. Therefore, the image capability examined with optical parallel beam is 0.6 degree. In this thesis, we discussed the new design for X-ray spectroscopic polarimetry, the evaluation of image capability.

Thoracic spine x-ray

MedlinePlus

Vertebral radiography; X-ray - spine; Thoracic x-ray; Spine x-ray; Thoracic spine films; Back films ... The test is done in a hospital radiology department or in the health care provider's office. You will lie on the x-ray table in different positions. If the x-ray ...

Chandra observations of Jupiter's X-ray Aurora during Juno upstream and apojove intervals

NASA Astrophysics Data System (ADS)

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

2017-12-01

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. These campaigns were planned following the Juno orbit correction to capitalise on the opportunity to image the X-ray emission while Juno was orbiting close to the expected position of the magnetopause. Previous work has suggested that the auroral X-ray emissions map close to the magnetopause boundary [e.g. Vogt et al., 2015; Kimura et al., 2016; Dunn et al., 2016] and thus in situ spacecraft coverage in this region combined with remote observation of the X-rays afford the chance to constrain the drivers of these energetic emissions and determine if they originate on open or closed field lines. We aim to examine possible drivers of X-ray emission including reconnection and the Kelvin-Helmholtz instability and to explore the role of the solar wind in controlling the emissions. 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 ks 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.

X-ray binaries

NASA Technical Reports Server (NTRS)

1976-01-01

Satellite X-ray experiments and ground-based programs aimed at observation of X-ray binaries are discussed. Experiments aboard OAO-3, OSO-8, Ariel 5, Uhuru, and Skylab are included along with rocket and ground-based observations. Major topics covered are: Her X-1, Cyg X-3, Cen X-3, Cyg X-1, the transient source A0620-00, other possible X-ray binaries, and plans and prospects for future observational programs.

Image of the Vela Supernova Remnant Taken by the High Energy Astronomy Observatory (HEAO)-2

NASA Technical Reports Server (NTRS)

1980-01-01

Like the Crab Nebula, the Vela Supernova Remnant has a radio pulsar at its center. In this image taken by the High Energy Astronomy Observatory (HEAO)-2/Einstein Observatory, the pulsar appears as a point source surrounded by weak and diffused emissions of x-rays. HEAO-2's computer processing system was able to record and display the total number of x-ray photons (a tiny bundle of radiant energy used as the fundamental unit of electromagnetic radiation) on a scale along the margin of the picture. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO-2, designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center, was launched aboard an Atlas/Centaur launch vehicle on November 13, 1978.

Affordable and Lightweight High-Resolution X-ray Optics for Astronomical Missions

NASA Technical Reports Server (NTRS)

Zhang, W. W.; Biskach, M. P.; Bly, V. T.; Carter, J. M.; Chan, K. W.; Gaskin, J. A.; Hong, M.; Hohl, B. R.; Jones, W. D.; Kolodziejczak, J. J.

2014-01-01

Future x-ray astronomical missions require x-ray mirror assemblies that provide both high angular resolution and large photon collecting area. In addition, as x-ray astronomy undertakes more sensitive sky surveys, a large field of view is becoming increasingly important as well. Since implementation of these requirements must be carried out in broad political and economical contexts, any technology that meets these performance requirements must also be financially affordable and can be implemented on a reasonable schedule. In this paper we report on progress of an x-ray optics development program that has been designed to address all of these requirements. The program adopts the segmented optical design, thereby is capable of making both small and large mirror assemblies for missions of any size. This program has five technical elements: (1) fabrication of mirror substrates, (2) coating, (3) alignment, (4) bonding, and (5) mirror module systems engineering and testing. In the past year we have made progress in each of these five areas, advancing the angular resolution of mirror modules from 10.8 arc-seconds half-power diameter reported (HPD) a year ago to 8.3 arc-seconds now. These mirror modules have been subjected to and passed all environmental tests, including vibration, acoustic, and thermal vacuum. As such this technology is ready for implementing a mission that requires a 10-arc-second mirror assembly. Further development in the next two years would make it ready for a mission requiring a 5-arc-second mirror assembly. We expect that, by the end of this decade, this technology would enable the x-ray astrophysical community to compete effectively for a major x-ray mission in the 2020s that would require one or more 1-arc-second mirror assemblies for imaging, spectroscopic, timing, and survey studies.

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

NASA Technical Reports Server (NTRS)

Broadway, David; Ramsey, Brian; Gubarev, Mikhail

2014-01-01

The proposal objective is to establish the capability to deposit multilayer structures for x-ray, neutron, and 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 the 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 is 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 (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 vacum 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.

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.

Skull x-ray

MedlinePlus

X-ray - head; X-ray - skull; Skull radiography; Head x-ray ... Chernecky CC, Berger BJ. Radiography of skull, chest, and cervical spine - diagnostic. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures . 6th ed. ...

Full-field transmission x-ray imaging with confocal polycapillary x-ray optics

PubMed Central

Sun, Tianxi; MacDonald, C. A.

2013-01-01

A transmission x-ray imaging setup based on a confocal combination of a polycapillary focusing x-ray optic followed by a polycapillary collimating x-ray optic was designed and demonstrated to have good resolution, better than the unmagnified pixel size and unlimited by the x-ray tube spot size. This imaging setup has potential application in x-ray imaging for small samples, for example, for histology specimens. PMID:23460760

X-ray generator

DOEpatents

Dawson, John M.

1976-01-01

Apparatus and method for producing coherent secondary x-rays that are controlled as to direction by illuminating a mixture of high z and low z gases with an intense burst of primary x-rays. The primary x-rays are produced with a laser activated plasma, and these x-rays strip off the electrons of the high z atoms in the lasing medium, while the low z atoms retain their electrons. The neutral atoms transfer electrons to highly excited states of the highly striped high z ions giving an inverted population which produces the desired coherent x-rays. In one embodiment, a laser, light beam provides a laser spark that produces the intense burst of coherent x-rays that illuminates the mixture of high z and low z gases, whereby the high z atoms are stripped while the low z ones are not, giving the desired mixture of highly ionized and neutral atoms. To this end, the laser spark is produced by injecting a laser light beam, or a plurality of beams, into a first gas in a cylindrical container having an adjacent second gas layer co-axial therewith, the laser producing a plasma and the intense primary x-rays in the first gas, and the second gas containing the high and low atomic number elements for receiving the primary x-rays, whereupon the secondary x-rays are produced therein by stripping desired ions in a neutral gas and transfer of electrons to highly excited states of the stripped ions from the unionized atoms. Means for magnetically confining and stabilizing the plasma are disclosed for controlling the direction of the x-rays.

Development of an alternating magnetic-field-assisted finishing process for microelectromechanical systems micropore x-ray optics.

PubMed

Riveros, Raul E; Yamaguchi, Hitomi; Mitsuishi, Ikuyuki; Takagi, Utako; Ezoe, Yuichiro; Kato, Fumiki; Sugiyama, Susumu; Yamasaki, Noriko; Mitsuda, Kazuhisa

2010-06-20

X-ray astronomy research is often limited by the size, weight, complexity, and cost of functioning x-ray optics. Micropore optics promises an economical alternative to traditional (e.g., glass or foil) x-ray optics; however, many manufacturing difficulties prevent micropore optics from being a viable solution. Ezoe et al. introduced microelectromechanical systems (MEMS) micropore optics having curvilinear micropores in 2008. Made by either deep reactive ion etching or x-ray lithography, electroforming, and molding (LIGA), MEMS micropore optics suffer from high micropore sidewall roughness (10-30nmrms) which, by current standards, cannot be improved. In this research, a new alternating magnetic-field-assisted finishing process was developed using a mixture of ferrofluid and microscale abrasive slurry. A machine was built, and a set of working process parameters including alternating frequency, abrasive size, and polishing time was selected. A polishing experiment on a LIGA-fabricated MEMS micropore optic was performed, and a change in micropore sidewall roughness of 9.3+/-2.5nmrms to 5.7+/-0.7nmrms was measured. An improvement in x-ray reflectance was also seen. This research shows the feasibility and confirms the effects of this new polishing process on MEMS micropore optics.

The iron complex in high mass X-ray binaries

NASA Astrophysics Data System (ADS)

Giménez-García, A.; Torrejón, J. M.; Martínez-Núñez, S.; Rodes-Rocas, J. J.; Bernabéu, G.

2013-05-01

An X-ray binary system consists of a compact object (a white dwarf, a neutron star or a black hole) accreting material from an optical companion star. The spectral type of the optical component strongly affects the mass transfer to the compact object. This is the reason why X-ray binary systems are usually divided in High Mass X-ray Binaries (companion O or B type, denoted HMXB) and Low Mass X-ray Binaries (companion type A or later). The HMXB are divided depending on the partner's luminosity class in two main groups: the Supergiant X-ray Binaries (SGXB) and Be X-ray Binaries (BeXB). We introduce the spectral characterization of a sample of 9 High Mass X-ray Binaries in the iron complex (˜ 6-7 keV). This spectral range is a fundamental tool in the study of the surrounding material of these systems. The sources have been divided into three main groups according to their current standard classification: SGXB, BeXB and γ Cassiopeae-like. The purpose of this work is to look for qualitative patterns in the iron complex, around 6-7 keV, in order to discern between current different classes that make up the group of HMXB. We find significant spectral patterns for each of the sets, reflecting differences in accretion physics thereof.

X-ray lithography masking

NASA Technical Reports Server (NTRS)

Smith, Henry I. (Inventor); Lim, Michael (Inventor); Carter, James (Inventor); Schattenburg, Mark (Inventor)

1998-01-01

X-ray masking apparatus includes a frame having a supporting rim surrounding an x-ray transparent region, a thin membrane of hard inorganic x-ray transparent material attached at its periphery to the supporting rim covering the x-ray transparent region and a layer of x-ray opaque material on the thin membrane inside the x-ray transparent region arranged in a pattern to selectively transmit x-ray energy entering the x-ray transparent region through the membrane to a predetermined image plane separated from the layer by the thin membrane. A method of making the masking apparatus includes depositing back and front layers of hard inorganic x-ray transparent material on front and back surfaces of a substrate, depositing back and front layers of reinforcing material on the back and front layers, respectively, of the hard inorganic x-ray transparent material, removing the material including at least a portion of the substrate and the back layers of an inside region adjacent to the front layer of hard inorganic x-ray transparent material, removing a portion of the front layer of reinforcing material opposite the inside region to expose the surface of the front layer of hard inorganic x-ray transparent material separated from the inside region by the latter front layer, and depositing a layer of x-ray opaque material on the surface of the latter front layer adjacent to the inside region.

Sinus x-ray

MedlinePlus

Paranasal sinus radiography; X-ray - sinuses ... sinus x-ray is taken in a hospital radiology department. Or the x-ray may be taken ... Brown J, Rout J. ENT, neck, and dental radiology. In: Adam A, Dixon AK, Gillard JH, Schaefer- ...

X-Ray Data Booklet

Science.gov Websites

X-RAY DATA BOOKLET Center for X-ray Optics and Advanced Light Source Lawrence Berkeley National Laboratory Introduction X-Ray Properties of Elements Electron Binding Energies X-Ray Energy Emission Energies Table of X-Ray Properties Synchrotron Radiation Characteristics of Synchrotron Radiation History of X

High Energy Astronomy Observatory (HEAO)-2

NASA Technical Reports Server (NTRS)

1975-01-01

This illustration is a schematic of the High Energy Astronomy Observatory (HEAO)-2 and its experiments. It shows the focal plane instruments (at the right) plus the associated electronics for operating the telescope as it transmitted its observations to the ground. A fifth instrument, the Monitor Proportional Counter, is located near the front of the telescope. Four separate astronomical instruments are located at the focus of this telescope and they could be interchanged for different types of observations as the observatory pointed at interesting areas of the Sky. Two of these instruments produced images; a High Resolution Imaging Detector and an Imaging Proportional Counter. The other two instruments, the Solid State Spectrometer and the Crystal Spectrometer, measured the spectra of x-ray objects. A fifth instrument, the Monitor Proportional Counter, continuously viewed space independently to study a wider band of x-ray wavelengths and to examine the rapid time variations in the sources. The HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO-2, designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center, was launched aboard an Atlas/Centaur launch vehicle on November 13, 1978. The HEAO-2 was originally identified as HEAO-B but the designation was changed once the spacecraft achieved orbit.

Image of the Great Nebula in Andromeda, M31 Taken by the High Energy Astronomy Observatory (HEAO)-2

NASA Technical Reports Server (NTRS)

1978-01-01

Both of the High Energy Astronomy Observatory (HEAO) 2/Einstein Observatory imaging devices were used to observe the Great Nebula in Andromeda, M31. This image is a wide field x-ray view of the center region of M31 by the HEAO-2's Imaging Proportional Counter. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO-2, designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center, was launched aboard an Atlas/Centaur launch vehicle on November 13, 1978.

X-ray telescope mirrors made of slumped glass sheets

NASA Astrophysics Data System (ADS)

Winter, A.; Breunig, E.; Friedrich, P.; Proserpio, L.

2017-11-01

For several decades, the field of X-ray astronomy has been playing a major role in understanding the processes in our universe. From binary stars and black holes up to galaxy clusters and dark matter, high energetic events have been observed and analysed using powerful X-ray telescopes like e.g. Rosat, Chandra, and XMM-Newton [1,2,3], giving us detailed and unprecedented views of the high-energy universe. In November 2013, the theme of "The Hot and Energetic Universe" was rated as of highest importance for future exploration and in June 2014 the ATHENA Advanced Telescope for High Energy Astrophysics was selected by ESA for the second large science mission (L2) in the ESA Cosmic Vision program, with launch foreseen in 2028 [4]. By combining a large X-ray telescope with state-of-the-art scientific instruments, ATHENA will address key questions in astrophysics, including: How and why does ordinary matter assemble into the galaxies and galactic clusters that we see today? How do black holes grow and influence their surroundings? In order to answer these questions, ATHENA needs a powerful mirror system which exceed the capabilities of current missions, especially in terms of collecting area. However, current technologies have reached the mass limits of the launching rocket, creating the need for more light-weight mirror systems in order to enhance the effective area without increasing the telescope mass. Hence new mirror technologies are being developed which aim for low-weight systems with large collecting areas. Light material like glass can be used, which are shaped to form an X-ray reflecting system via the method of thermal glass slumping.

Recent X-ray Variability of Eta Car Approaching The X-ray Eclipse

NASA Technical Reports Server (NTRS)

Corcoran, M.; Swank, J. H.; Ishibashi, K.; Gull, T.; Humphreys, R.; Damineli, A.; Walborn, N.; Hillier, D. J.; Davidson, K.; White, S. M.

2002-01-01

We discuss recent X-ray spectral variability of the supermassive star Eta Car in the interval since the last X-ray eclipse in 1998. We concentrate on the interval just prior to the next X-ray eclipse which is expected to occur in June 2003. We compare the X-ray behavior during the 2001-2003 cycle with the previous cycle (1996-1998) and note similarities and differences in the temporal X-ray behavior. We also compare a recent X-ray observation of Eta Car obtained with the Chandra high energy transmission grating in October 2002 with an earlier observation from Nov 2002, and interpret these results in terms of the proposed colliding wind binary model for the star. In addition we discuss planned observations for the upcoming X-ray eclipse.

An optical and X-ray survey of s-type Markarian galaxies

NASA Technical Reports Server (NTRS)

Hutter, D. J.; Mufson, S. L.

1981-01-01

The results of a study of 23 compact, lineless Markarian galaxies using broadband optical photometry and X-ray satellite observations are reported. The photometry shows that the sample can be broken into four groups. In one group (Mrk 180, 421, and 501) are composite objects in which a BL Lacertae object is embedded in an elliptical galaxy. For this group, the results of multiepoch X-ray observations using the HEAO-1 and -2 satellites are presented. In addition, photometry is used to decompose the optical emission into nonthermal and galactic components. In the second group are objects showing a small ultraviolet excess relative to normal galaxies. The X-ray survey indicates that the X-ray luminosity of objects in group 2 is much lower than those in group 1. This suggests that there is an intrinsic difference between objects in groups 1 and 2. The third and fourth groups are objects whose colors are indistinguishable from those of normal field galaxies and those of galactic stars, respectively. No X-ray emission was detected from objects in either of these groups.

X-Ray Weak Broad-Line Quasars: Absorption or Intrinsic X-Ray Weakness

NASA Technical Reports Server (NTRS)

Risaliti, Guido; Mushotzky, Richard F. (Technical Monitor)

2004-01-01

XMM observations of X-ray weak quasars have been performed during 2003. The data for all but the last observation are now available (there has been a delay of several months on the initial schedule, due to high background flares which contaminated the observations: as a consequence, most of them had to be rescheduled). We have reduced and analyzed these data, and obtained interesting preliminary scientific results. Out of the eight sources, 4 are confirmed to be extrimely X-ray weak, in agreement with the results of previous Chandra observations. 3 sources are confirmed to be highly variable both in flux (by factors 20-50) and in spectral properties (dramatic changes in spectral index). For both these groups of objects, an article is in preparation. Preliminary results have been presented at an international workshop on AGN surveys in December 2003, in Cozumel (Mexico). In order to further understand the nature of these X-ray weak quasars, we submitted proposals for spectroscopy at optical and infrared telescopes. We obtained time at the TNG 4 meter telescope for near-IR observations, and at the Hobby-Eberly Telescope for optical high-resolution spectroscopy. These observations will be performed in early 2004, and will complement the XMM data, in order to understand whether the X-ray weakness of these sources is an intrinsic property or is due to absorption by circumnuclear material.

Large area soft x-ray collimator to facilitate x-ray optics testing

NASA Technical Reports Server (NTRS)

Espy, Samuel L.

1994-01-01

The first objective of this program is to design a nested conical foil x-ray optic which will collimate x-rays diverging from a point source. The collimator could then be employed in a small, inexpensive x-ray test stand which would be used to test various x-ray optics and detector systems. The second objective is to demonstrate the fabrication of the x-ray reflectors for this optic using lacquer-smoothing and zero-stress electroforming techniques.

Proto Supermassive Binary Black Hole Detected in X-rays

NASA Astrophysics Data System (ADS)

2006-04-01

An international team of astrophysicists, led by D. Hudson from the University of Bonn and including the U.S. Naval Research Laboratory and the University of Virginia, presents their X-ray detection of a proto supermassive binary black hole. Their results will be published in an upcoming issue of Astronomy & Astrophysics. The image of this proto binary black hole was obtained with NASA's Chandra X-ray Observatory. The two black holes have already been seen in radio images. The new X-ray images provide unique evidence that these two black holes are in the process of forming a binary system; that is, they are gravitationally bound and orbit each other. Chandra X-ray Image of 3C 75 Chandra X-ray Image of 3C 75 The two black holes are located in the nearby galaxy cluster Abell 400. With high-resolution Chandra data, the team was able to spatially resolve the two supermassive black holes (separated by 15") at the centre of the cluster. Each black hole is located at the centre of its respective host galaxy and the host galaxies appear to be merging. It is not, however, just the two host galaxies that are colliding - the whole cluster in which they live is merging into another neighbouring galaxy cluster. Using these new data, the team show that the two black holes are moving through the intracluster medium at the supersonic speed of about 1200 km/s. The wind from such a motion would cause the radio plasma emitted from these two black holes to bend backwards. Although this bending had been observed previously, the cause of it was still being debated. Since the bending of the jets due to this motion is in the same direction, it suggests that the two black holes are travelling along the same path within the cluster and are therefore gravitationally bound. Black Hole Merger Animation Black Hole Merger Animation These two black holes became gravitationally bound when their host galaxies collided. In several million years, the two black holes will probably coalesce causing a

Development of x-ray laminography under an x-ray microscopic condition

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

Hoshino, Masato; Uesugi, Kentaro; Takeuchi, Akihisa

2011-07-15

An x-ray laminography system under an x-ray microscopic condition was developed to obtain a three-dimensional structure of laterally-extended planar objects which were difficult to observe by x-ray tomography. An x-ray laminography technique was introduced to an x-ray transmission microscope with zone plate optics. Three prototype sample holders were evaluated for x-ray imaging laminography. Layered copper grid sheets were imaged as a laminated sample. Diatomite powder on a silicon nitride membrane was measured to confirm the applicability of this method to non-planar micro-specimens placed on the membrane. The three-dimensional information of diatom shells on the membrane was obtained at a spatialmore » resolution of sub-micron. Images of biological cells on the membrane were also obtained by using a Zernike phase contrast technique.« less

High Resolution X-Ray Absorption Spectroscopy: Distribution of Matter in and around Galaxies

NASA Astrophysics Data System (ADS)

Schulz, Norbert; MIT/CAT Team

2015-10-01

The chemical evolution of the Universe embraces aspects that reachdeep into modern astrophysics and cosmology. We want to know how present and past matter is affected by various levels and types of nucleo-synthesis and stellar evolution. Three major categories were be identified: 1. The study of pre-mordial star formation including periods of super-massive black hole formation, 2. The embedded evolution of the intergalactic medium IGM, 3. The status and evolution of stars and the interstellar medium ISM in galaxies. Today a fourth category relates to our understanding of dark matter in relationwith these three categories. The X-ray band is particularly sensitive to K- and L-shell absorption and scattering from high abundant elements like C, N, O, Ne, Mg, Si, S,Ar, Ca, Fe, and Ni. Like the Lyman alpha forest in the optical band, absorbers in the IGM produce an X-ray line forest along the line of sight in the X-rayspectrum of a background quasar. Similary bright X-ray sources within galaxies and the Milky Way produce a continuum, which is being absorbed by elements invarious phases of the ISM. High resolution X-ray absorption surveys are possible with technologies ready for flight within decade. == high efficiency X-ray optics with optical performance 3== high resolution X-ray gratings with R 3000 for E 1.5 keV== X-ray micro-calorimeters with R 2000 for E 1.5 keV. The vision for the next decade needs to lead to means and strategies which allows us to perform such absorption surveys as effectively as surveys are now or in very near future quite common in astronomy pursued in other wave length bands such as optical, IR, and sub-mm.

Laser plasma x-ray source for ultrafast time-resolved x-ray absorption spectroscopy

DOE PAGES

Miaja-Avila, L.; O'Neil, G. C.; Uhlig, J.; ...

2015-03-02

We describe a laser-driven x-ray plasma source designed for ultrafast x-ray absorption spectroscopy. The source is comprised of a 1 kHz, 20 W, femtosecond pulsed infrared laser and a water target. We present the x-ray spectra as a function of laser energy and pulse duration. Additionally, we investigate the plasma temperature and photon flux as we vary the laser energy. We obtain a 75 μm FWHM x-ray spot size, containing ~10 6 photons/s, by focusing the produced x-rays with a polycapillary optic. Since the acquisition of x-ray absorption spectra requires the averaging of measurements from >10 7 laser pulses, wemore » also present data on the source stability, including single pulse measurements of the x-ray yield and the x-ray spectral shape. In single pulse measurements, the x-ray flux has a measured standard deviation of 8%, where the laser pointing is the main cause of variability. Further, we show that the variability in x-ray spectral shape from single pulses is low, thus justifying the combining of x-rays obtained from different laser pulses into a single spectrum. Finally, we show a static x-ray absorption spectrum of a ferrioxalate solution as detected by a microcalorimeter array. Altogether, our results demonstrate that this water-jet based plasma source is a suitable candidate for laboratory-based time-resolved x-ray absorption spectroscopy experiments.« less

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

Characterization of multilayer coated replicated Wolter optics for imaging x-ray emission from pulsed power

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

Ames, Andrew; Ampleford, David; Bourdon, Chris

Here, we have developed a process for indirectly coating small diameter electroformed nickel replicated optics with multilayers to increase their response at high energy (i.e. >10 keV). The ability to fabricate small diameter multilayer-coated full-shell Wolter X-ray optics with narrow bandpass opens the door to several applications within astronomy and also provides a path for cross-fertilization to other fields. We report on the characterization and evaluation of the first two prototype X-ray Wolter optics to be delivered to the Z Pulsed Power Facility at Sandia National Laboratories. The intent is to develop and field several optics as part of anmore » imaging system with targeted spectral ranges.« less

Characterization of multilayer coated replicated Wolter optics for imaging x-ray emission from pulsed power

DOE PAGES

Ames, Andrew; Ampleford, David; Bourdon, Chris; ...

2017-08-29

Here, we have developed a process for indirectly coating small diameter electroformed nickel replicated optics with multilayers to increase their response at high energy (i.e. >10 keV). The ability to fabricate small diameter multilayer-coated full-shell Wolter X-ray optics with narrow bandpass opens the door to several applications within astronomy and also provides a path for cross-fertilization to other fields. We report on the characterization and evaluation of the first two prototype X-ray Wolter optics to be delivered to the Z Pulsed Power Facility at Sandia National Laboratories. The intent is to develop and field several optics as part of anmore » imaging system with targeted spectral ranges.« less

Characterization of multilayer coated replicated Wolter optics for imaging x-ray emission from pulsed power

NASA Astrophysics Data System (ADS)

Ames, A.; Ampleford, D.; Bourdon, C.; Bruni, R.; Kilaru, K.; Kozioziemski, B.; Pivovaroff, M.; Ramsey, B.; Romaine, S.; Vogel, J.; Walton, C.; Wu, M.

2017-08-01

We have developed a process for indirectly coating arbitrarily small diameter electroformed nickel replicated optics with multilayers to increase their response at high energy (i.e. >10 keV). The ability to fabricate small diameter multilayer coated full shell Wolter X-ray optics with narrow bandpass opens the door to several applications within astronomy and also provides a path for cross-fertilization to other fields. We report on the characterization and evaluation of the first two prototype X-ray Wolter optics to be delivered to the Z Pulsed Power Facility at Sandia National Laboratories. The intent is to develop and field several optics as part of an imaging system with targeted spectral ranges.

A high resolution gas scintillation proportional counter for studying low energy cosmic X-ray sources

NASA Technical Reports Server (NTRS)

Hamilton, T. T.; Hailey, C. J.; Ku, W. H.-M.; Novick, R.

1980-01-01

In recent years much effort has been devoted to the development of large area gas scintillation proportional counters (GSPCs) suitable for use in X-ray astronomy. The paper deals with a low-energy GSPC for use in detecting sub-keV X-rays from cosmic sources. This instrument has a measured energy resolution of 85 eV (FWHM) at 149 eV over a sensitive area of 5 sq cm. The development of imaging capability for this instrument is discussed. Tests are performed on the feasibility of using an arrangement of several phototubes placed adjacent to one another to determine event locations in a large flat counter. A simple prototype has been constructed and successfully operated.

AN OPTICAL AND X-RAY STUDY OF THE FOSSIL GROUP RX J1340.6+4018

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

Mendes de Oliveira, Claudia L.; Cypriano, Eduardo S.; Sodre, Laerte

2009-08-15

Fossil groups are systems with one single central elliptical galaxy and an unusual lack of luminous galaxies in the inner regions. The standard explanation for the formation of these systems suggests that the lack of bright galaxies is due to galactic cannibalism. In this study, we show the results of an optical and X-ray analysis of RX J1340.6+4018, the prototype fossil group. The data indicate that RX J1340.6+4018 is similar to clusters in almost every sense (dynamical mass, X-ray luminosity, M/L, and luminosity function) except for the lack of L* galaxies. There are claims in the literature that fossil systemsmore » have a lack of small mass halos, compared to predictions based on the lambda cold dark matter scenario. The observational data gathered on this and other fossil groups so far offer no support for this idea. Analysis of the SN Ia/SN II ejecta ratio in the inner and outer regions shows a marginally significant central dominance of SN Ia material. This suggests that either the merger which originated in the central galaxy was dry or the group has been formed at early epochs, although better data are needed to confirm this result.« less

Observational Aspects of Hard X-ray Polarimetry

NASA Astrophysics Data System (ADS)

Chattopadhyay, Tanmoy

2016-04-01

Sensitive polarization measurements in X-ray may address a wealth of astrophysical phenomena, which so far remain beyond our understanding through available X-ray spectroscopic, imaging, and timing studies. Though scientific potential of X-ray polarimetry was realized long ago, there has not been any significant advancement in this field for the last four decades since the birth of X-ray astronomy. The only successful polarization measurement in X-rays dates back to 1976, when a Bragg polarimeter onboard OSO-8 measured polarization of Crab nebula. Primary reason behind the lack in progress is its extreme photon hungry nature, which results in poor sensitivity of the polarimeters. Recently, in the last decade or so, with the advancement in detection technology, X-ray polarimetry may see a significant progress in near future, especially in soft X-rays with the invention of photoelectron tracking polarimeters. Though photoelectric polarimeters are expected to provide sensitive polarization measurements of celestial X-ray sources, they are sensitive only in soft X-rays, where the radiation from the sources is dominated by thermal radiation and therefore expected to be less polarized. On the other hand, in hard X-rays, sources are ex-pected to be highly polarized due to the dominance of nonthermal emission over its thermal counterpart. Moreover, polarization measurements in hard X-rays promises to address few interesting scientific issues regarding geometry of corona for black hole sources, emission mechanism responsible for the higher energy peak in the blazars, accretion geometry close to the magnetic poles in accreting neutron star systems and acceleration mechanism in solar flares. Compton polarimeters provide better sensitivity than photoelectric polarimeters in hard X-rays with a broad energy band of operation. Recently, with the development of hard X-ray focusing optics e.g. NuSTAR, Astro-H, it is now possible to conceive Compton polarimeters at the focal plane

Panoramic Dental X-Ray

MedlinePlus

... Physician Resources Professions Site Index A-Z Panoramic Dental X-ray Panoramic dental x-ray uses a very small dose of ... x-ray , is a two-dimensional (2-D) dental x-ray examination that captures the entire mouth ...

On X-Ray Variability in Seyfert Galaxies

NASA Technical Reports Server (NTRS)

Turner, T. J.; George, I. M.; Nandra, K.; Turcan, D.

1999-01-01

This paper presents a quantification of the X-ray variability amplitude for 79 ASCA observations of 36 Seyfert 1 galaxies. We find that consideration of sources with the narrowest permitted lines in the optical band introduces scatter into the established correlation between X-ray variability and nuclear luminosity. Consideration of the X-ray spectral index and variability properties together shows distinct groupings in parameter space for broad and narrow-line Seyfert 1 galaxies, confirming previous studies. A strong correlation is found between hard X-ray variability and FWHM Hbeta. A range of nuclear mass and accretion rate across the Seyfert population can explain the differences observed in X-ray and optical properties. An attractive alternative model, which does not depend on any systematic difference in central mass, is that the circumnuclear gas of NLSy1s is different to BLSy1s in temperature, optical depth, density or geometry.

Australian rocket results. [X ray astronomy

NASA Technical Reports Server (NTRS)

Garmire, G.

1975-01-01

Cen X-3 was observed twice. A pulse profile and spectrum was obtained in the 2- to 10-keV band, but no soft flux was detected. Vela X-1 was observed to have a rapid flickering characteristic on time scales down to 0.25 sec and a hard spectrum. The source 3U 0614+09 was observed and found to have a softer spectrum (kT of about 4 keV) and an intensity comparable to that of earlier observations. The source eta Car was not detected at a level of 0.03 ph/sq cm/sec in the band from 0.2 to 1.5 keV, and the Large Magellanic Cloud was observed in the band from 0.5 to 1.5 keV at a level of about 0.1 ph/sq cm/sec. Two soft extended regions were observed in Gem-Mon and Eridanus.

A Technology Development Roadmap for a Near-Term Probe-Class X-ray Astrophysics Mission

NASA Technical Reports Server (NTRS)

Daelemans, Gerard J.; Petre, Robert; Bookbinder, Jay; Ptak, Andrew; Smith, Randall

2013-01-01

This document presents a roadmap, including proposed budget and schedule, for maturing the instrumentation needed for an X-ray astrophysics Probe-class mission. The Physics of the Cosmos (PCOS) Program Office was directed to create this roadmap following the December 2012 NASA Astrophysics Implementation Plan (AIP). Definition of this mission is called for in the AIP, with the possibility of selection in 2015 for a start in 2017. The overall mission capabilities and instrument performance requirements were defined in the 2010 Astronomy and Astrophysics Decadal Survey report, New Worlds, New Horizons in Astronomy and Astrophysics (NWNH), in connection with the highly ranked International X-ray Observatory (IXO). In NWNH, recommendations were provided regarding the size of, and instrumentation needed by, the next large X-ray observatory. Specifically, the key instrumental capability would be an X-ray calorimeter spectrometer at the focus of a large mirror with angular resolution of 10 arc seconds (arcsec) or better. If possible, a grating spectrometer should also be incorporated into the instrument complement. In response to these recommendations, four instrumentation technologies are included in this roadmap. Three of these are critical for an X-ray mission designed to address NWNH questions: segmented X-ray mirrors, transition edge sensor calorimeters, and gratings. Two approaches are described for gratings, which represent the least mature technology and thus most in need of a parallel path for risk reduction. Also, while current CCD detectors would likely meet the mission needs for grating spectrum readout, specific improvements are included as an additional approach for achieving the grating system effective area requirement. The technical steps needed for these technologies to attain technology readiness levels (TRL) of 5 and 6 are described, as well as desirable modest risk reduction steps beyond TRL-6. All of the technology development efforts are currently

XMM-Newton X-ray Observatory Guest Observer program (AO-1) at CASA

NASA Technical Reports Server (NTRS)

Skinner, Stephen L.

2003-01-01

In this research program, we obtained and analyzed X-ray observations of the Wolf-Rayet (WR) star WR 110 (HD 165688) using the XMM-Newton space-based observatory. Radio observations were also obtained using the Very Large Array (VLA) radio telescope located in New Mexico and operated by the Natl. Radio Astronomy Observatory (NRAO). This star was targeted for observations primarily because it is believed to be a single WR star without a companion. Single WR stars are thought to emit X-rays from cool plasma in shocks distributed throughout their powerful stellar winds. However, there has been little observational work done to test this idea since single WR stars are relatively weak X-ray sources and have been difficult to detect with previous generation telescopes. The launch of XMM-Newton provides a new telescope that is much more sensitive than its predecessors, allowing single WR stars to be studied in detail for the first time. X-ray emission was clearly detected from WR 110. Analysis of its spectrum yields a surprising result. Its X-ray emitting plasma is distributed over a range of temperatures and is dominated by relatively cool plasma with a characteristic temperature T is approximately 6 million K. Such plasma can be explained by existing theoretical wind shock models. However, the spectrum also shows hotter plasma whose temperature is uncertain but is thought to be in excess of T approximately 30 million K. The origin of this hotter plasma is yet unknown, but possible mechanisms are identified

X-ray Spectral Formation In High-mass X-ray Binaries: The Case Of Vela X-1