Sample records for plerionic supernova remnants

  1. On the Origin of Hard X-ray Structures in the VELA Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Gvaramadze, V. V.

    1998-12-01

    We propose an alternative explanation for the origin of two hard X-ray structures recently discovered in the central part of the Vela supernova remnant (SNR) by Willmore et al. (1992, MNRAS, 254, 139) and Markwardt & Ogelman (1995, Nature, 375, 40; 1997, ApJ, 480, L13), and interpreted as a plerion and a pulsar jet respectively. We suggest that the first structure is a dense material shed by the supernova progenitor star during the red supergiant stage, and reheated after the supernova exploded, while the "jet" is simply a dense filament in the Vela SNR's general shell, whose origin is connected with the Rayleigh-Taylor instability in the (main-sequence) wind-driven shell reaccelerated by the supernova blast wave.

  2. Studies at high frequencies of the 30 Doradus and RCW 57 regions.

    NASA Astrophysics Data System (ADS)

    Sabalisck, N. S. P.; Abraham, Z.

    1990-11-01

    The authors present maps of the 30 Dor region at 22 GHz and of the RCW 57 region at 43 GHz. The data are compared with maps at lower frequencies and similar resolutions. In the 30 Dor region 3 supernova remnants of plerionic type were detected: N 1578, MC 78 and MC 89.

  3. New selection effect in statistical investigations of supernova remnants

    NASA Astrophysics Data System (ADS)

    Allakhverdiev, A. O.; Guseinov, O. Kh.; Kasumov, F. K.

    1986-01-01

    The influence of H II regions on the parameters of supernova remnants (SNR) is investigated. It has been shown that the projection of such regions on the SNRs leads to: a) local changes of morphological structure of young shell-type SNRs and b) considerable distortions of integral parameters of evolved shell-type SNRs (with D > 10 pc) and plerions, up to their complete undetectability on the background of classical and gigantic H II regions. A new selection effect, in fact, arises from these factors connected with additional limitations made by the real structure of the interstellar medium on the statistical investigations of SNRs. The influence of this effect on the statistical completeness of objects has been estimated.

  4. Background Information: Magnetars, Soft Gamma-Ray Repeaters and the Most Powerful Magnetic Fields in the Universe

    NASA Astrophysics Data System (ADS)

    1998-08-01

    Near the end of its life, a star more massive than our Sun finds itself no longer able to support its own weight from the crush of gravity and so it collapses, producing an expanding shock wave that sweeps through the surrounding gas, creating what is called a supernova remnant. All that remains of the original star is a dense, compact object known as a neutron star. Magnetars are the latest addition to the "zoo" of neutron stars and they are truly exotic beasts with magnetic fields hundreds of millions of times stronger than have ever been seen on Earth. The story which led to the prediction of magnetars and then to their discovery is given elsewhere. Here we will focus on the other part of the story, the supernova remnants born at the same time as magnetars and the diffuse emission produced by the energetic outpourings of the magnetars. All four of the soft gamma-ray repeaters that we currently know are located in or near a supernova remnant. It was this discovery that led astronomers to determine that soft gamma-ray repeaters were in our Galaxy and the nearby galaxy known as the Large Magellanic Cloud. Through the study of these supernova remnants, astronomers were able to infer that soft gamma-ray repeaters were solitary young neutron stars speeding away from their birthplace at 3 million miles per hour. Theories predict that the same process which can produce the fantastic bursts of hard X-ray emission that give soft gamma-ray repeaters their name, can also accelerate particles (electrons, protons, etc) to speeds approaching the speed of light. As the saying goes, "where there's smoke there's fire" and this case is no exception. Most of the energy released by the burst event is carried away by these high energy particles and not the gamma-ray burst itself. As the particles spiral in the surrounding magnetic field, they too emit radiation, creating extended nebulae called "plerions". Provided there is some way to confine the outflow, these plerions act as "wind bags" containing the accumulated history of this bursting activity. The study of these plerionic supernova remnants (detailed below) gives us a new and different perspective on the magnetar phenomena. SGR 0526-66: The Famous March 5 1979 Burst SGR 0526-66 lays claim to having produced the brightest gamma-ray burst ever observed: the famous March 5 1979 burst. Owing to the large number of satellites which saw this burst (10 in total) an accurate position could be determined. This put SGR 0526-66 on the edge of the supernova remnant N49 in the Large Magellanic Cloud 180,000 light years from our Sun. This should have been sufficient to convince everyone that the burst and the supernova remnant were associated. However, in 1979 astronomers were working under the misconception that all gamma-ray bursts came from a local (500 light years) population of neutron stars. This new piece of the puzzle didn't fit. Real progress in this area had to wait until the mid-1980's when soft gamma-ray repeaters were recognized as a distinct class of high energy transient and then in the early 1990's when SGR 1806-20 was tied to its supernova remnant (see below). The significance of two other important clues also went unnoticed in the early 1980's. The first was the large offset in the location of SGR 0526-66 from the center of the supernova remnant (i.e. its birthplace) and the second was a compact X-ray source at this same location. These observations, combined with the known age of the supernova remnant (5000 years), require that the magnetar be moving at a high speed and depositing energy into its surroundings as it goes. SGR 1806-20: A Magnetar Powers a Nebula While SGR 1806-20 was the most prolific burster in the 1980's, its true location wasn't known until it was detected by the Japanese X-ray ASCA satellite in 1993, verifying an earlier claim that it was associated with the supernova remnant G10.0-0.3. SGR 1806-20 lies at the center of this egg-shaped supernova remnant whose radio emission peaks toward the center and falls away at its outer edge. On both large scales and small scales G10.0-0.3 fits the conventional definition of a plerion. Prior to the discovery of the pulsed X-ray emission from this magnetar, this nebula was the best evidence that an unusual neutron star was powering its emission. Closer in to SGR 1806-20 the radio images made at the Very Large Array show evidence of large scale outflow of particles that has persisted for a long time. This out-flowing particle wind is especially evident in the abrupt changes seen from a jet-like feature centered on SGR 1806-20, where the "jet" was seen to rotate on the sky by 50 degrees in 1.4 years. The properties of this source are best understood if it is the result of a sudden injection of electrons accelerated nearly at the speed of light and produced as part of the high energy bursts from magnetars. Comparison of the energy contained in these particles versus the total energy released by the flashes of high energy light, shows that the particles are a significant (if not dominant) part of the total energy in these bursts. Moreover, because the lifetime of the particles is so long, studying the plerions is much like looking at the rings of a tree: the burst history of the magnetar is revealed through the study of the plerion. Figure Caption: Two views toward SGR 1806-20. These radio images, taken with the Very Large Array, were made 1.4 years apart on 1994 March (left) and 1995 August (right). A jet-like feature is seen to rotate on the sky during this time. This behavior is thought to result from the sudden injection of high energy particles from the magnetar. SGR 1900+14: New Evidence of Particle Injection by a Magnetar Until recently you could have been excused for thinking that SGR 1900+14 was the least interesting of the four SGRs. It was somewhat inactive as a gamma-ray source, bursting a few times in 1979 and again in 1993. An approximate position for SGR 1900+14 has been determined via triangulation of burst arrival times from the satellites in the Interplanetary Network (IPN). In the next figure we superimpose this long needle-like region on a radio image of the sky taken in this direction. There is an X-ray source interior to this which is thought to be the quiescent X-ray emission from SGR 1900+14. The X-ray source, which goes by the name of RX J190717+0919.3, lies just outside the galactic supernova remnant G42.8+0.6. This is a fairly ordinary-looking supernova remnant located some 15,000 light years from the Sun, and is less than 10,000 years old. It is likely (but still unproven) that SGR 1900+14 and G42.8+0.6 were born in the same explosive event but SGR 1900+14 caught up with and punched through the expanding supernova shock. In late May and late August of this year SGR 1900+14 awoke from its slumber and began bursting like never before. Numerous bright bursts occurred during these two active periods. On August 27 an intense burst occurred that was reminiscent of the famous March 5 1979 burst from SGR 0526-66, causing the detectors of several satellites to saturate. Click here to see the light curve of the August 27 burst as detected by the Ulysses satellite. Shortly after the August 27 burst we observed the region around the quiescent X-ray emission from SGR 1900+14 using the Very Large Array in Socorro, New Mexico. While prior observations of this region have shown only empty sky, our observations in early September 1998 detected a new radio source coincident (within the position uncertainties) with the X-ray source. As an added bonus the discovery of this nebula gives us a position for SGR 1900+14 with sufficient accuracy to search for an optical counterpart. Perhaps even more interestingly than the detection of the radio source was the fact that it was short-lived, fading below detection in only one week. At the top of this page we show a movie of this fast fading source. In a forthcoming scientific paper we argue that we have detected a radio nebula shining in the light of particles accelerated to nearly the speed of light by the same event that gave rise to the bright gamma-ray bursts. Figure Caption: Two views toward SGR 1900+14. These radio images, taken with the Very Large Array, were made on 1998 June 25 (left) and September 3 (right). The position of the quiescent X-ray source RX J190717+0919.3, thought to indicate the approximate location of SGR 1900+14, is indicated by the circle. The radio source turned on shortly after the bright gamma-ray burst of August 27th and then rapidly faded from view a week later. SGR 1627-41: The Newest SGR SGR 1627-41 is the newest member of the SGR family. See the NASA press release announcing this exciting discovery. While its position is not well-determined yet, there is only one known supernova remnant in the region: G337.0-0.1. It is a compact supernova remnant 35,000 light years from the Sun which lies in the CTB 33 complex (see below), a young region with plenty of active star formation going on.

  5. Observations of TeV Gamma Rays from Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Buckley, James H.

    1994-12-01

    Measurements of the gamma ray flux from a number of supernova remnants (SNRs) at energies above 250 GeV have been made with the Whipple Imaging air \\v Cerenkov detector. Observation of the gamma ray emission of SNRs at energies above 1 GeV should provide a sensitive test of shock acceleration models of particle acceleration in SNRs. Gamma-ray luminosities of supernova remnants are well constrained by the observed supernova rate and the cosmic ray flux if supernovae are indeed the source of cosmic rays. Drury et al. (Astron. Astrophys. 287, 959 (1994)) predict that the luminosity of nearby Sedov-phase SNRs should be observable by the Whipple telescope. In this model, diffusive shock acceleration produces energetic charged particles which interact with the ambient medium forming gamma rays. There is an indication that a number of unidentified EGRET sources may correspond to supernova remnants (G. Kanbach, private communication), although at these energies (>100 MeV) the diffuse background is somewhat uncertain. Measurements of the gamma-ray flux with the Whipple instrument have a similar sensitivity to the EGRET detector for a source spectral index of 2.15, and less sensitivity to diffuse background. A number of observations of SNRs including: Tycho, W66, IC443, and others have been made. Currently for Tycho an upper limit of 9times 10(-12) cm(-2) sec(-1) is obtained. The status of these observations will be presented, and it will be shown that these measurements combined with the EGRET observations are beginning to provide a useful constraint on models of cosmic ray origin. Gamma-ray observations may also be used to constrain models of particle acceleration in SNRs exhibiting pulser-powered synchrotron nebula (plerions). The status of observations of this class of objects, including the Crab nebula, will also be presented. Supported in part by the U.S. Dept. of Energy.

  6. MAGIC: First Observational Results and Perspectives for Future Developments

    NASA Astrophysics Data System (ADS)

    Hengstebeck, T.; Kalekin, O.; Merck, M.; Mirzoyan, R.; Pavel, N.; Schweizer, T.; Shayduk, M.; MAGIC Collaboration

    The MAGIC (Major Atmospheric Gamma Imaging Cherenkov) telescope was designed to close the energy gap (~ 10-250 GeV) between ground based and satellite gamma detectors. It is situated on the Roque de los Muchachos, La Palma, Canary Islands at altitude of 2200 m. The main subjects of the investigations with the telescope are: Gamma Ray Bursts, Supernova Remnants, Plerions, Pulsars, Active Galactic Nuclei (AGNs), unidentied EGRET sources, Dark matter and Quantum gravity. More details about physics with a low threshold gamma ray telescope one can nd in [2]. The telescope hardware installation was nished in October 2003. Since that time the observations of the dierent classes of objects have been carried out but the experiment is still in the commission phase.

  7. VHE gamma-ray Emitting Pulsar Wind Nebulae Discovered by H.E.S.S.

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

    Gallant, Y.A.; /Montpellier U.; Carrigan, S.

    2008-06-05

    Recent advances in very-high-energy (VHE) gamma-ray astronomy have opened a new observational window on the physics of pulsars. The high sensitivity of current imaging atmospheric Cherenkov telescopes, and in particular of the H.E.S.S. array, has already led to the discovery of about a dozen VHE-emitting pulsar wind nebulae (PWNe) and PWN candidates. These include the plerions in the composite supernova remnants MSH 15-52, G21.5-0.9, Kes 75, and Vela, two sources in the Kookaburra, and the nebula of PSR B1823-13. This VHE emission is generally interpreted as inverse Compton emission from the relativistic electrons and positrons accelerated by the pulsar andmore » its wind; as such, it can yield a more direct spatial and spectral view of the accelerated particles than can be inferred from observations of their synchrotron emission. The VHE-emitting PWNe detected by the H.E.S.S. telescopes are reviewed and the implications for pulsar physics discussed.« less

  8. Vela X: A plerion or part of a shell?

    NASA Astrophysics Data System (ADS)

    Gvaramadze, V. V.

    1998-03-01

    An analysis of the radio, optical, and X-ray observations of the supernova remnant (SNR) in Vela has led us to conclude that the radio source Vela X is part of the SNR shell. The high brightness of this radio source is assumed to be a result of the interaction of dome-shaped deformations (bubbles) on the SNR shell, which gives rise to bright radio filaments. The deformations could be produced by Richtmaier-Meshkov's instability, which develops during the impulsive acceleration of a shell of gas (swept up from the interstellar medium by the wind from a presupernova) by a shock wave (generated by a supernova explosion). The brightest radio filament and the X-ray jet extending along it are shown to be located in the region of interaction of two prominent bubbles on the SNR shell. We conclude that the X-ray jet, like Vela X, is part of the shell, and that it has its origin in the Mach reflection of two semispherical shock waves. Our estimate of the plasma temperature behind the front of the Mach wave matches the jet temperature. We also show that the large spread in the estimates of the spectral index for Vela X could be caused by the instrumental effect which arises during observations of extended radio sources with a nonuniform surface-brightness distribution.

  9. Neutron stars in supernova remnants and beyond

    NASA Astrophysics Data System (ADS)

    Gvaramadze, V.

    We propose a new approach for studying the neutron star/supernova remnant associations, based on the idea that the supernova remnants can be products of an off-centered supernova explosion in a preexisting bubble created by the wind of a moving massive star. A cavity supernova explosion of a moving star results in a considerable offset of the neutron star birth-place from the geometrical center of the supernova remnant. Therefore: a) the high transverse velocities inferred for a number of neutron stars through their association with supernova remnants can be reduced; b) the proper motion vector of a neutron star should not necessarily point away from the geometrical center of the associated supernova remnant. Taking into account these two facts allow us to enlarge the circle of possible neutron star/supernova remnant associations, and could significantly affect the results of previous studies of associations. The possibilities of our approach are illustrated with some examples. We also show that the concept of an off-centered cavity supernova explosion could be used to explain the peculiar structures of a number of supernova remnants and for searches for stellar remnants possibly associated with them.

  10. Imagery and spectroscopy of supernova remnants and H-2 regions

    NASA Technical Reports Server (NTRS)

    Dufour, R. J.

    1984-01-01

    Research activities relating to supernova remnants were summarized. The topics reviewed include: progenitor stars of supernova remnants, UV/optical/radio/X-ray imagery of selected regions in the Cygnus Loop, UV/optical spectroscopy of the Cygnus Loop spur, and extragalactic supernova remnant spectra.

  11. Investigating the Origin of the Supernova Remnant W49B

    NASA Astrophysics Data System (ADS)

    Crum, Ryan Matthew; Frank, Kari A.; Dwarkadas, Vikram; Burrows, David N.

    2018-01-01

    W49B is a Galactic supernova remnant whose origin is still debated. Is it the remains of an unusual asymmetric Type 1a supernova or of a jet-driven core collapse supernova? Using the X-ray analysis method, Smoothed Particle Inference (SPI), we dig deeper into understanding the complex properties of SNR W49B. We do this by characterizing the temperatures and abundance ratios throughout the remnant. We will compare the results with a wide variety of supernova nucleosynthesis models in order to constrain the mechanism behind this unusual supernova remnant.

  12. Neutron Stars in Supernova Remnants and Beyond

    NASA Astrophysics Data System (ADS)

    Gvaramadze, V. V.

    We discuss a concept of off-centred cavity supernova explosion as applied to neutron star/supernova remnant associations and show how this concept could be used to preclude the anti-humane decapitating the Duck (G5.4-1.2 + G5.27-0.9) and dismembering the Swan (Cygnus Loop), as well as to search for a stellar remnant associated with the supernova remnant RCW86.

  13. Supernova Remnant Kes 17: An Efficient Cosmic Ray Accelerator inside a Molecular Cloud

    NASA Astrophysics Data System (ADS)

    Gelfand, Joseph; Slane, Patrick; Hughes, John; Temim, Tea; Castro, Daniel; Rakowski, Cara

    Supernova remnant are believed to be the dominant source of cosmic rays protons below the "knee" in the energy spectrum. However, relatively few supernova remnants have been identified as efficient producers of cosmic ray protons. In this talk, I will present evidence that the production of cosmic ray protons is required to explain the broadband non-thermal spectrum of supernova remnant Kes 17 (SNR G304.6+0.1). Evidence for efficient cosmic ray acceleration in Kes 17 supports recent theoretical work concluding that the strong magnetic field, turbulence, and clumpy nature of molecular clouds enhance cosmic ray production in supernova remnants. While additional observations are needed to confirm this interpretation, further study of Kes 17 and similar sources are important for understanding how cosmic rays are accelerated in supernova remnants.

  14. Supernova Explosions Stay In Shape

    NASA Astrophysics Data System (ADS)

    2009-12-01

    At a very early age, children learn how to classify objects according to their shape. Now, new research suggests studying the shape of the aftermath of supernovas may allow astronomers to do the same. A new study of images from NASA's Chandra X-ray Observatory on supernova remnants - the debris from exploded stars - shows that the symmetry of the remnants, or lack thereof, reveals how the star exploded. This is an important discovery because it shows that the remnants retain information about how the star exploded even though hundreds or thousands of years have passed. "It's almost like the supernova remnants have a 'memory' of the original explosion," said Laura Lopez of the University of California at Santa Cruz, who led the study. "This is the first time anyone has systematically compared the shape of these remnants in X-rays in this way." Astronomers sort supernovas into several categories, or "types", based on properties observed days after the explosion and which reflect very different physical mechanisms that cause stars to explode. But, since observed remnants of supernovas are leftover from explosions that occurred long ago, other methods are needed to accurately classify the original supernovas. Lopez and colleagues focused on the relatively young supernova remnants that exhibited strong X-ray emission from silicon ejected by the explosion so as to rule out the effects of interstellar matter surrounding the explosion. Their analysis showed that the X-ray images of the ejecta can be used to identify the way the star exploded. The team studied 17 supernova remnants both in the Milky Way galaxy and a neighboring galaxy, the Large Magellanic Cloud. For each of these remnants there is independent information about the type of supernova involved, based not on the shape of the remnant but, for example, on the elements observed in it. The researchers found that one type of supernova explosion - the so-called Type Ia - left behind relatively symmetric, circular remnants. This type of supernova is thought to be caused by a thermonuclear explosion of a white dwarf, and is often used by astronomers as "standard candles" for measuring cosmic distances. On the other hand, the remnants tied to the "core-collapse" supernova explosions were distinctly more asymmetric. This type of supernova occurs when a very massive, young star collapses onto itself and then explodes. "If we can link supernova remnants with the type of explosion", said co-author Enrico Ramirez-Ruiz, also of University of California, Santa Cruz, "then we can use that information in theoretical models to really help us nail down the details of how the supernovas went off." Models of core-collapse supernovas must include a way to reproduce the asymmetries measured in this work and models of Type Ia supernovas must produce the symmetric, circular remnants that have been observed. Out of the 17 supernova remnants sampled, ten were classified as the core-collapse variety, while the remaining seven of them were classified as Type Ia. One of these, a remnant known as SNR 0548-70.4, was a bit of an "oddball". This one was considered a Type Ia based on its chemical abundances, but Lopez finds it has the asymmetry of a core-collapse remnant. "We do have one mysterious object, but we think that is probably a Type Ia with an unusual orientation to our line of sight," said Lopez. "But we'll definitely be looking at that one again." While the supernova remnants in the Lopez sample were taken from the Milky Way and its close neighbor, it is possible this technique could be extended to remnants at even greater distances. For example, large, bright supernova remnants in the galaxy M33 could be included in future studies to determine the types of supernova that generated them. The paper describing these results appeared in the November 20 issue of The Astrophysical Journal Letters. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass. More information, including images and other multimedia, can be found at: http://chandra.harvard.edu and http://chandra.nasa.gov

  15. Evolution of Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Arbutina, B.

    2017-12-01

    This book, both a monograph and a graduate textbook, is based on my original research and partly on the materials prepared earlier for the 2007 and 2008 IARS Astrophysics Summer School in Istanbul, AstroMundus course 'Supernovae and Their Remnants' that was held for the first time in 2011 at the Department of Astronomy, Faculty of Mathematics, University of Belgrade, and a graduate course 'Evolution of Supernova Remnants' that I teach at the aforementioned university. The first part Supernovae (introduction, thermonuclear supernovae, core-collapse supernovae) provides introductory information and explains the classification and physics of supernova explosions, while the second part Supernova remnants (introduction, shock waves, cosmic rays and particle acceleration, magnetic fields, synchrotron radiation, hydrodynamic and radio evolution of supernova remnants), which is the field I work in, is more detailed in scope i.e. technical/mathematical. Special attention is paid to details of mathematical derivations that often cannot be found in original works or available literature. Therefore, I believe it can be useful to both, graduate students and researchers interested in the field.

  16. X-ray studies of supernova remnants: A different view of supernova explosions

    PubMed Central

    Badenes, Carles

    2010-01-01

    The unprecedented spatial and spectral resolutions of Chandra have revolutionized our view of the X-ray emission from supernova remnants. The excellent datasets accumulated on young, ejecta-dominated objects like Cas A or Tycho present a unique opportunity to study at the same time the chemical and physical structure of the explosion debris and the characteristics of the circumstellar medium sculpted by the progenitor before the explosion. Supernova remnants can thus put strong constraints on fundamental aspects of both supernova explosion physics and stellar evolution scenarios for supernova progenitors. This view of the supernova phenomenon is completely independent of, and complementary to, the study of distant extragalactic supernovae at optical wavelengths. The calibration of these two techniques has recently become possible thanks to the detection and spectroscopic follow-up of supernova light echoes. In this paper, I review the most relevant results on supernova remnants obtained during the first decade of Chandra and the impact that these results have had on open issues in supernova research. PMID:20404206

  17. Kepler Supernova Remnant: A View from Hubble Space Telescope

    NASA Image and Video Library

    2004-10-06

    This image represents a view of NASA Kepler supernova remnant taken in X-rays, visible light, and infrared radiation, indicating that the bubble of gas that makes up the supernova remnant appears different in various types of light. http://photojournal.jpl.nasa.gov/catalog/PIA06909

  18. The Impact of Progenitor Mass Loss on the Dynamical and Spectral Evolution of Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Patnaude, Daniel J.; Lee, Shiu-Hang; Slane, Patrick O.; Badenes, Carles; Nagataki, Shigehiro; Ellison, Donald C.; Milisavljevic, Dan

    2017-11-01

    There is now substantial evidence that the progenitors of some core-collapse supernovae undergo enhanced or extreme mass loss prior to explosion. The imprint of this mass loss is observed in the spectra and dynamics of the expanding blast wave on timescales of days to years after core collapse, and the effects on the spectral and dynamical evolution may linger long after the supernova has evolved into the remnant stage. In this paper, we present, for the first time, largely self-consistent end-to-end simulations for the evolution of a massive star from the pre-main sequence, up to and through core collapse, and into the remnant phase. We present three models and compare and contrast how the progenitor mass-loss history impacts the dynamics and spectral evolution of the supernovae and supernova remnants. We study a model that only includes steady mass loss, a model with enhanced mass loss over a period of ˜5000 yr prior to core collapse, and a model with extreme mass loss over a period of ˜500 yr prior to core collapse. The models are not meant to address any particular supernova or supernova remnant, but rather to highlight the important role that the progenitor evolution plays in the observable qualities of supernovae and supernova remnants. Through comparisons of these three different progenitor evolution scenarios, we find that the mass loss in late stages (during and after core carbon burning) can have a profound impact on the dynamics and spectral evolution of the supernova remnant centuries after core collapse.

  19. How high energy fluxes may affect Rayleigh–Taylor instability growth in young supernova remnants

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

    Kuranz, Carolyn C.; Park, Hye -Sook; Huntington, Channing M.

    Here, energy-transport effects can alter the structure that develops as a supernova evolves into a supernova remnant. The Rayleigh–Taylor instability is thought to produce structure at the interface between the stellar ejecta and the circumstellar matter, based on simple models and hydrodynamic simulations. Here we report experimental results from the National Ignition Facility to explore how large energy fluxes, which are present in supernovae, affect this structure. We observed a reduction in Rayleigh–Taylor growth. In analyzing the comparison with supernova SN1993J, a Type II supernova, we found that the energy fluxes produced by heat conduction appear to be larger thanmore » the radiative energy fluxes, and large enough to have dramatic consequences. No reported astrophysical simulations have included radiation and heat conduction self-consistently in modeling supernova remnants and these dynamics should be noted in the understanding of young supernova remnants.« less

  20. How high energy fluxes may affect Rayleigh–Taylor instability growth in young supernova remnants

    DOE PAGES

    Kuranz, Carolyn C.; Park, Hye -Sook; Huntington, Channing M.; ...

    2018-04-19

    Here, energy-transport effects can alter the structure that develops as a supernova evolves into a supernova remnant. The Rayleigh–Taylor instability is thought to produce structure at the interface between the stellar ejecta and the circumstellar matter, based on simple models and hydrodynamic simulations. Here we report experimental results from the National Ignition Facility to explore how large energy fluxes, which are present in supernovae, affect this structure. We observed a reduction in Rayleigh–Taylor growth. In analyzing the comparison with supernova SN1993J, a Type II supernova, we found that the energy fluxes produced by heat conduction appear to be larger thanmore » the radiative energy fluxes, and large enough to have dramatic consequences. No reported astrophysical simulations have included radiation and heat conduction self-consistently in modeling supernova remnants and these dynamics should be noted in the understanding of young supernova remnants.« less

  1. 30 Dor B - A supernova remnant in a star formation region

    NASA Technical Reports Server (NTRS)

    Chu, You-Hua; Kennicutt, Robert C., Jr.; Schommer, Robert A.; Laff, Joshua

    1992-01-01

    The supernova remnant 30 Dor B is embedded in an H II region around the OB association LH 99, and has been suggested to be a Crab-type remnant. To determine the spatial extent and kinematic properties of this supernova remnant, long-slit echelle observations were obtained in the H-alpha and forbidden N II lines, along with imaging Fabry-Perot observations in the H-alpha line. It is found that 30 Dor B is partially obscured by a dark cloud with which the supernova remnant also interacts. The size of 30 Dor B is much larger than previously thought, making it much older than the Crab Nebula. If the progenitor of the supernova was formed coevally with LH 99, then it would have been more massive than the O3 members of the OB association.

  2. G65.2+5.7: A Thermal Composite Supernova Remnant with a Cool Shell

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

    This paper presents archival ROSAT PSPC observations of the G65.2+5.7 supernova remnant (also known as G65.3+5.7). Little material obscures this remnant and so it was well observed, even at the softest end of ROSATs bandpass (approx. 0.11 to 0.28 keV). These soft X-ray images reveal the remnant s centrally-filled morphology which, in combination with existing radio frequency observations, places G65.2+5.7 in the thermal composite (mixed morphology) class of supernova remnants. Not only might G65.2+5.7 be the oldest known thermal composite supernova remnant, but owing to its optically revealed cool, dense shell, this remnant supports the proposal that thermal composite supernova remnants lack X-ray bright shells because they have evolved beyond the adiabatic phase. These observations also reveal a slightly extended point source centered on RA = l9(sup h) 36(sup m) 46(sup s). dec = 30 deg.40 min.07 sec.and extending 6.5 arc min in radius in the band 67 map. The source of this emission has yet to be discovered, as there is no known pulsar at this location.

  3. Expansion of Kes 73, a shell supernova remnant containing a magnetar

    NASA Astrophysics Data System (ADS)

    Borkowski, Kazimierz

    2014-09-01

    Formation and evolution of highly magnetized neutron stars (magnetars) remain poorly understood. We can learn about magnetars by studying their remnants. Kes 73 is a young supernova remnant containing a magnetar. But basic properties of Kes 73, including its age, remain poorly known. We propose a third-epoch observation of Kes 73 with Chandra. When combined with the 2000 and 2006 observations, this will allow for determination of the remnant's age through expansion rate measurements. We will also search for spatial variations in expansion rate that will help in understanding of the remnant's dynamics. New observations will also be used to determine abundances of heavy-element supernova ejecta, placing further constraints on the supernova that produced Kes 73.

  4. High energy neutrinos from gamma-ray bursts with precursor supernovae.

    PubMed

    Razzaque, Soebur; Mészáros, Peter; Waxman, Eli

    2003-06-20

    The high energy neutrino signature from proton-proton and photo-meson interactions in a supernova remnant shell ejected prior to a gamma-ray burst provides a test for the precursor supernova, or supranova, model of gamma-ray bursts. Protons in the supernova remnant shell and photons entrapped from a supernova explosion or a pulsar wind from a fast-rotating neutron star remnant provide ample targets for protons escaping the internal shocks of the gamma-ray burst to interact and produce high energy neutrinos. We calculate the expected neutrino fluxes, which can be detected by current and future experiments.

  5. Einstein Observations of Galactic supernova remnants

    NASA Technical Reports Server (NTRS)

    Seward, Frederick D.

    1990-01-01

    This paper summarizes the observations of Galactic supernova remnants with the imaging detectors of the Einstein Observatory. X-ray surface brightness contours of 47 remnants are shown together with gray-scale pictures. Count rates for these remnants have been derived and are listed for the HRI, IPC, and MPC detectors.

  6. G29.7-0.3: another supernova remnant with an identity crisis

    NASA Technical Reports Server (NTRS)

    Becker, R. H.; Helfand, D. J.; Szymkowiak, A. E.

    1983-01-01

    New radio and X-ray observations of the galactic supernova remnant G29.7-0.3 show that it is composed of two spectrally distinct components: a steep-spectrum, incomplete shell 3 arcmin in extent enclosing a flat-spectrum, X-ray emitting region 30 arcsec across. Thus, G29.7-0.3 joins the ranks of supernova remnants which exhibit a combination of Crab-like and shell remnant attributes. The Crab-like core has the highest ratio of X-ray radio luminosity of all the Crab-like remnants observed to date, suggesting that it is an extremely young object.

  7. Hot interstellar tunnels. 1: Simulation of interacting supernova remnants

    NASA Technical Reports Server (NTRS)

    Smith, B. W.

    1976-01-01

    The theory required to build a numerical simulation of interacting supernova remnants is developed. The hot cavities within a population of remnants will become connected, with varying ease and speed, for a variety of assumed conditions in the outer shells of old remnants. Apparently neither radiative cooling nor thermal conduction in a large-scale galactic magnetic field can destroy hot cavity regions, if they grow, faster than they are reheated by supernova shock waves, but interstellar mass motions disrupt the contiguity of extensive cavities necessary for the dispersal of these shocks over a wide volume. Monte Carlo simulations show that a quasi-equilibrium is reached in the test space within 10 million yrs of the first supernova and is characterized by an average cavity filling fraction of the interstellar volume. Aspects of this equilibrium are discussed for a range of supernova rates. Two predictions are not confirmed within this range: critical growth of hot regions to encompass the entire medium, and the efficient quenching of a remnant's expansion by interaction with other cavities.

  8. A Model of the Vela Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Gvaramadze, Vasilii

    2000-10-01

    A model of the Vela supernova remnant (SNR) based on a cavity explosion of a supernova (SN) star is proposed. It is suggested that the general structure of the remnant is determined by the interaction of the SN blast wave with a massive shell created by the SN progenitor (15-20 M_solar) star. A possible origin of the nebula of hard X-ray emission detected around the Vela pulsar is discussed.

  9. NASA Scientists Witness a Supernova Cosmic Rite of Passage

    NASA Astrophysics Data System (ADS)

    2005-11-01

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

  10. A solar-type star polluted by calcium-rich supernova ejecta inside the supernova remnant RCW 86

    NASA Astrophysics Data System (ADS)

    Gvaramadze, Vasilii V.; Langer, Norbert; Fossati, Luca; Bock, Douglas C.-J.; Castro, Norberto; Georgiev, Iskren Y.; Greiner, Jochen; Johnston, Simon; Rau, Arne; Tauris, Thomas M.

    2017-06-01

    When a massive star in a binary system explodes as a supernova, its companion star may be polluted with heavy elements from the supernova ejecta. Such pollution has been detected in a handful of post-supernova binaries 1 , but none of them is associated with a supernova remnant. We report the discovery of a binary G star strongly polluted with calcium and other elements at the position of the candidate neutron star [GV2003] N within the young galactic supernova remnant RCW 86. Our discovery suggests that the progenitor of the supernova that produced RCW 86 could have been a moving star, which exploded near the edge of its wind bubble and lost most of its initial mass because of common-envelope evolution shortly before core collapse, and that the supernova explosion might belong to the class of calcium-rich supernovae — faint and fast transients 2,3 , the origin of which is strongly debated 4-6 .

  11. Supernova remnant S 147 and its associated neutron star(s)

    NASA Astrophysics Data System (ADS)

    Gvaramadze, V. V.

    2006-07-01

    The supernova remnant S 147 harbors the pulsar PSR J 0538+2817 whose characteristic age is more than an order of magnitude greater than the kinematic age of the system (inferred from the angular offset of the pulsar from the geometric center of the supernova remnant and the pulsar proper motion). To reconcile this discrepancy we propose that PSR J 0538+2817 could be the stellar remnant of the first supernova explosion in a massive binary system and therefore could be as old as its characteristic age. Our proposal implies that S 147 is the diffuse remnant of the second supernova explosion (that disrupted the binary system) and that a much younger second neutron star (not necessarily manifesting itself as a radio pulsar) should be associated with S 147. We use the existing observational data on the system to suggest that the progenitor of the supernova that formed S 147 was a Wolf-Rayet star (so that the supernova explosion occurred within a wind bubble surrounded by a massive shell) and to constrain the parameters of the binary system. We also restrict the magnitude and direction of the kick velocity received by the young neutron star at birth and find that the kick vector should not strongly deviate from the orbital plane of the binary system.

  12. Recent Progress on Supernova Remnants - Progenitors, Evolution, Cosmic-ray Acceleration

    NASA Astrophysics Data System (ADS)

    Bamba, A.

    2017-10-01

    Supernova remnants supplies heavy elements, kinetic and thermal energies, and cosmic rays, into the universe, and are the key sources to make the diversity of the universe. On the other hand, we do not know the fundamental issues of supernova remnants, such as (1) what their main progenitors are, (2) how they evolve into the realistic (non-uniform) interstellar space, and (3) which type of supernova remnants can accelerate cosmic rays to the knee energy. Recent X-ray studies with XMM-Newton, Chandra, Suzaku, NuSTAR, and Hitomi, progressed understandings of these issues, and found that each issue connect others tightly. In this paper, we will overview these progresses with focusing the above three topics, and discuss what we should do next.

  13. G25.5 + 0.2 - A very young galactic supernova remnant

    NASA Technical Reports Server (NTRS)

    Cowan, John J.; Ekers, R. D.; Goss, W. M.; Sramek, R. A.; Roberts, Douglas A.

    1989-01-01

    Radio emission has been detected from a compact source which satisfies the criteria for a very young galactic supernova remnant. The source, G25.5 + 0.2 has a partially-filled shell structure, a total integrated flux density at 20 cm of 315 mJy, and a flat spectrum between 2 and 20 cm. Observations at 843 and 327 MHz indicate thermal absorption at low frequencies with a turnover in the spectrum near 1 GHz. It is suggested that the lower limit for the age of the supernova remnant is 25 yr, while the upper limit is about 100 yr. It is concluded that G25.5 + 0.2 could be the youngest known supernova remnant in the Galaxy.

  14. Supernova Remnant Kes 17: An Efficient Cosmic Ray Accelerator inside a Molecular Cloud

    NASA Astrophysics Data System (ADS)

    Gelfand, Joseph D.; Castro, Daniel; Slane, Patrick O.; Temim, Tea; Hughes, John P.; Rakowski, Cara

    2013-11-01

    The supernova remnant Kes 17 (SNR G304.6+0.1) is one of a few but growing number of remnants detected across the electromagnetic spectrum. In this paper, we analyze recent radio, X-ray, and γ-ray observations of this object, determining that efficient cosmic ray acceleration is required to explain its broadband non-thermal spectrum. These observations also suggest that Kes 17 is expanding inside a molecular cloud, though our determination of its age depends on whether thermal conduction or clump evaporation is primarily responsible for its center-filled thermal X-ray morphology. Evidence for efficient cosmic ray acceleration in Kes 17 supports recent theoretical work concluding that the strong magnetic field, turbulence, and clumpy nature of molecular clouds enhance cosmic ray production in supernova remnants. While additional observations are needed to confirm this interpretation, further study of Kes 17 is important for understanding how cosmic rays are accelerated in supernova remnants.

  15. The nature of the Vela X-ray ``jet". The Rayleigh-Taylor instability and the origin of filamentary structures in the Vela supernova remnant

    NASA Astrophysics Data System (ADS)

    Gvaramadze, Vasilii

    1999-12-01

    The nature of the Vela X-ray ``jet", recently discovered by Markwardt & Ögelman (1995), is examined. It is suggested that the ``jet" arises along the interface of domelike deformations of the Rayleigh-Taylor unstable shell of the Vela supernova remnant; thereby the ``jet" is interpreted as a part of the general shell of the remnant. The origin of deformations as well as the general structure of the remnant are discussed in the framework of a model based on a cavity explosion of a supernova star. It is suggested that the shell deformations viewed at various angles appear as filamentary structures visible throughout the Vela supernova remnant at radio, optical, and X-ray wavelengths. A possible origin of the nebula of hard X-ray emission detected by Willmore et al. (1992) around the Vela pulsar is proposed.

  16. Predicted TeV Gamma-ray Spectra and Images of Shell Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Reynolds, S. P.

    1999-04-01

    One supernova remnant, SN 1006, is now known to produce synchrotron X-rays (Koyama et al., 1995, Nature, 378, 255), requiring 100 TeV electrons. SN 1006 has also been seen in TeV gamma rays (Tanimori et al., 1998, ApJ, 497, L25), almost certainly due to cosmic-microwave-background photons being upscattered by those same electrons. Other young supernova remnants should also produce high-energy electrons, even if their X-ray synchrotron emission is swamped by conventional thermal X-ray emission. Upper limits to the maximum energy of shock-accelerated electrons can be found for those remnants by requiring that their synchrotron spectrum steepen enough to fall below observed thermal X-rays (Reynolds and Keohane 1999, ApJ, submitted). For those upper-limit spectra, I present predicted TeV inverse-Compton spectra and images for assumed values of the mean remnant magnetic field. Ground-based TeV gamma-ray observations of remnants may be able to put even more severe limits on the presence of highly energetic electrons in remnants, raising problems for conventional theories of galactic cosmic-ray production in supernova remnants. Detections will immediately confirm that SN 1006 is not alone, and will give mean remnant magnetic field strengths.

  17. Timing of 29 Pulsars Discovered in the PALFA Survey

    NASA Astrophysics Data System (ADS)

    Lyne, A. G.; Stappers, B. W.; Bogdanov, S.; Ferdman, R. D.; Freire, P. C. C.; Kaspi, V. M.; Knispel, B.; Lynch, R.; Allen, B.; Brazier, A.; Camilo, F.; Cardoso, F.; Chatterjee, S.; Cordes, J. M.; Crawford, F.; Deneva, J. S.; Hessels, J. W. T.; Jenet, F. A.; Lazarus, P.; van Leeuwen, J.; Lorimer, D. R.; Madsen, E.; McKee, J.; McLaughlin, M. A.; Parent, E.; Patel, C.; Ransom, S. M.; Scholz, P.; Seymour, A.; Siemens, X.; Spitler, L. G.; Stairs, I. H.; Stovall, K.; Swiggum, J.; Wharton, R. S.; Zhu, W. W.; Aulbert, C.; Bock, O.; Eggenstein, H.-B.; Fehrmann, H.; Machenschalk, B.

    2017-01-01

    We report on the discovery and timing observations of 29 distant long-period pulsars found in the ongoing Arecibo L-band Feed Array pulsar survey. Following discovery with the Arecibo Telescope, confirmation and timing observations of these pulsars over several years at Jodrell Bank Observatory have yielded high-precision positions and measurements of rotation and radiation properties. We have used multi-frequency data to measure the interstellar scattering properties of some of these pulsars. Most of the pulsars have properties that mirror those of the previously known pulsar population, although four show some notable characteristics. PSRs J1907+0631 and J1925+1720 are young and are associated with supernova remnants or plerionic nebulae: J1907+0631 lies close to the center of SNR G40.5-0.5, while J1925+1720 is coincident with a high-energy Fermi γ-ray source. One pulsar, J1932+1500, is in a surprisingly eccentric, 199 day binary orbit with a companion having a minimum mass of 0.33 M⊙. Several of the sources exhibit timing noise, and two, PSRs J0611+1436 and J1907+0631, have both suffered large glitches, but with very different post-glitch rotation properties. In particular, the rotational period of PSR J0611+1436 will not recover to its pre-glitch value for about 12 years, a far greater recovery timescale than seen following any other large glitches.

  18. Very-high energy observations of the galactic center region by VERITAS in 2010-2012

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

    Archer, A.; Beilicke, M.; Buckley, J. H.

    2014-08-01

    The Galactic center is an interesting region for high-energy (0.1-100 GeV) and very-high-energy (E > 100 GeV) γ-ray observations. Potential sources of GeV/TeV γ-ray emission have been suggested, e.g., the accretion of matter onto the supermassive black hole, cosmic rays from a nearby supernova remnant (e.g., Sgr A East), particle acceleration in a plerion, or the annihilation of dark matter particles. The Galactic center has been detected by EGRET and by Fermi/LAT in the MeV/GeV energy band. At TeV energies, the Galactic center was detected with moderate significance by the CANGAROO and Whipple 10 m telescopes and with high significancemore » by H.E.S.S., MAGIC, and VERITAS. We present the results from three years of VERITAS observations conducted at large zenith angles resulting in a detection of the Galactic center on the level of 18 standard deviations at energies above ∼2.5 TeV. The energy spectrum is derived and is found to be compatible with hadronic, leptonic, and hybrid emission models discussed in the literature. Future, more detailed measurements of the high-energy cutoff and better constraints on the high-energy flux variability will help to refine and/or disentangle the individual models.« less

  19. 44Ti Nucleosynthesis Lines and Hard X-ray Continuum in Young SNRs: from INTEGRAL to Simbol-X

    NASA Astrophysics Data System (ADS)

    Renaud, M.; Terrier, R.; Trap, G.; Lebrun, F.; Decourchelle, A.; Vink, J.

    2009-05-01

    Supemovae and their remnants are the main Galactic nucleosynthesis sites and the privileged sources of Galactic cosmic rays. The youngest of such remnants can be studied through two distinct observational features: 44Ti γ-ray lines and the hard X-ray nonthermal continuum emission. The former gives unique information on the nucleosynthesis conditions occuring during the first stages of the explosion, while the latter provides clues on acceleration processes at supernova remnant shocks. In this contribution, we present new INTEGRAL results on Tycho, the remnant of a historical supernova, and on G1.9+0.3, which has been recently unveiled as the youngest Galactic supernova remnant. Expectations with Simbol-X are also addressed.

  20. Chandra Reveals Rich Oxygen Supply

    NASA Technical Reports Server (NTRS)

    2003-01-01

    This striking Chandra X-Ray Observatory image of supernova remnant SNR0103-72.6 reveals a nearly perfect ring about 150 light years in diameter surrounding a cloud of gas enriched in oxygen and shock-heated to millions of degrees Celsius. The ring marks the outer limits of a shock wave produced as material ejected in the supernova explosion collides with the interstellar gas. The size of the ring indicates that we see the supernova remnant as it was about 10,000 years after its progenitor star exploded. Located in the Small Magenellanic Cloud (SMC), SNR 0103-72.6 is about 190,000 light years from Earth. The x-rays take about 190,000 years to reach us from the SMC, so the supernova explosion occurred about 200,000 years ago, as measured on Earth. Scientists have know for years that oxygen and many other elements necessary for life are created in massive stars and dispersed in supernova explosions, but few remnants rich in these elements have been observed. This supernova remnant will hence become an important laboratory for studying how stars forge the elements necessary for life.

  1. A HIRES analysis of the FIR emission of supernova remnants

    NASA Technical Reports Server (NTRS)

    Wang, Zhong

    1994-01-01

    The high resolution (HiRes) algorithm has been used to analyze the far infrared emission of shocked gas and dust in supernova remnants. In the case of supernova remnant IC 443, we find a very good match between the resolved features in the deconvolved images and the emissions of shocked gas mapped in other wavelengths (lines of H2, CO, HCO+, and HI). Dust emission is also found to be surrounding hot bubbles of supernova remnants which are seen in soft X-ray maps. Optical spectroscopy on the emission of the shocked gas suggests a close correlation between the FIR color and local shock speed, which is a strong function of the ambient (preshock) gas density. These provide a potentially effective way to identify regions of strong shock interaction, and thus facilitate studies of kinematics and energetics in the interstellar medium.

  2. On the search for Galactic supernova remnant PeVatrons with current TeV instruments

    NASA Astrophysics Data System (ADS)

    Cristofari, P.; Gabici, S.; Terrier, R.; Humensky, T. B.

    2018-06-01

    The supernova remnant hypothesis for the origin of Galactic cosmic rays has passed several tests, but the firm identification of a supernova remnant pevatron, considered to be a decisive step to prove the hypothesis, is still missing. While a lot of hope has been placed in next-generation instruments operating in the multi-TeV range, it is possible that current gamma-ray instruments, operating in the TeV range, could pinpoint these objects or, most likely, identify a number of promising targets for instruments of next generation. Starting from the assumption that supernova remnants are indeed the sources of Galactic cosmic rays, and therefore must be pevatrons for some fraction of their lifetime, we investigate the ability of current instruments to detect such objects, or to identify the most promising candidates.

  3. A kinematic study of 0509-67.5, the second youngest supernova remnant in the Large Magellanic Cloud, and its astrophysical implications

    NASA Astrophysics Data System (ADS)

    Hovey, Luke

    2016-05-01

    Supernova remnants are the lasting interactions of shock waves that develop in the wake of supernovae. These remnants, especially those in our galaxy and our companion galaxies, allow us to study supernovae for thousands of years after the initial stellar explosions. Remnants that are formed from Ia supernovae, which are the explosions and complete annihilation of white dwarf stars, are of particular interest due to the explosions' value as standard candles in cosmological studies. The shock waves in these young supernova remnants offer an unparalleled look into the physical processes that take place there, especially since these shocks are often simpler to study than shocks with strong radiative components that are present in remnants that are formed from the core-collapse supernovae of massive stars. I will detail the work of my kinematic study of the second youngest remnant in the Large Magellanic Cloud, 0509--67.5, which has been confirmed to be the result of a Ia supernova. Chapter 2 details the proper motion measurements made on the forward shock of this remnant, which has led to many key results. I was able to use the results of ii the global shock speed in the remnant to measure the density of neutral hydrogen in the ambient medium into which these shocks expand. In addition, I use the measurements of the shock speed for select portions of the forward shock to search for signatures of efficient cosmic-ray acceleration. Hydrodynamic simulations are then employed to constrain the age and ambient medium density of 0509--67.5, as well as to place limits on the compression factor at the immediate location of the blast wave. Chapter 3 uses the proper motion results from chapter 2 to determine possible asymmetries in the expansion of the remnant for the eastern and western limbs. These measurements are then used as constraints in hydrodynamic simulations to assess the possible dynamical offset of the explosion site compared to the geometric center of 0509?67.5 that we observe today. I find a continuum of possible offsets, which are sensitive to assumptions that are made about the evolutionary history of the remnant, and use the uncertainties in these calculations to determine the area in which to search for a leftover progenitor companion star in the event that the explosion resulted from a single-degenerate system. The stars within this search area are explored with a multi-band photometric study, wherein we determine the mass ranges for these candidates. Chapter four concludes this thesis, recapping the main results from chapters 2 and 3, and highlights the future projects I will carry out that are motivated by my findings in this comprehensive study of the supernova remnant 0509--67.5.

  4. Optical Emission Associated with the Galactic Supernova Remnant G179.0+2.6

    NASA Astrophysics Data System (ADS)

    How, Thomas G.; Fesen, Robert A.; Neustadt, Jack M. M.; Black, Christine S.; Outters, Nicolas

    2018-04-01

    Narrow passband optical images of the large Galactic supernova remnant G179.0+2.6 reveal a faint but nearly complete emission shell dominated by strong [O 3] 4959,5007 Å line emission. The remnant's optical emission, which consists of both diffuse and filamentary features, is brightest along its southern and northeastern limbs. Deep Hα images detect little coincidence emission indicating an unusually high [O 3]/Hα emission ratio for such a large and apparently old remnant. Low-dispersion optical spectra of several regions confirm large [O 3]/Hα line ratios with typical values around 10. The dominance of [O 3] emission for the majority of the remnant's optical filaments suggests shock velocities above 100 km s-1 are present throughout most of the remnant, likely reflecting a relatively low density ambient ISM. The remnant's unusually strong [O 3] emission adds to the remnant's interesting set of properties which include a thick radio emission shell, radial polarization of its radio emission like that typically seen in young supernova remnants, and an unusually slow-rotating gamma-ray pulsar with a characteristic spin-down age ≃ 50 kyr.

  5. OT2_jhewitt_2: Understanding Shock Oxygen Chemistry in Interacting Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Hewitt, J.

    2011-09-01

    Supernova remnants interacting with dense moelcular clouds provide astrochemical laboratories to study heating and cooling of the dense ISM, shock chemistry, destruction and sputtering of dust, and the reformation of molecules. Water is expected to be a major coolant for shocks into dense gas, yet the number of remnants in which IR lines of hydroxyl and water are detected is very limited. We propose Herschel PACS, SPIRE and HIFI observations of three remnants with particularly high shocked gas densities, high dust and IR line luinosities, and extreme ionization environments. The scientific objectives of this proposal are: (1) to determine the abundance and excitation of oxygen-bearing molecules, and (2) to study the effects of variable ionization sources on oxygen chemistry in dense molecular gas shocked by powerful supernova remnant blast waves.

  6. Are supernova remnants quasi-parallel or quasi-perpendicular accelerators

    NASA Technical Reports Server (NTRS)

    Spangler, S. R.; Leckband, J. A.; Cairns, I. H.

    1989-01-01

    Observations of shock waves in the solar system which show a pronounced difference in the plasma wave and particle environment depending on whether the shock is propagating along or perpendicular to the interplanetary magnetic field are discussed. Theories for particle acceleration developed for quasi-parallel and quasi-perpendicular shocks, when extended to the interstellar medium suggest that the relativistic electrons in radio supernova remnants are accelerated by either the Q parallel or Q perpendicular mechanisms. A model for the galactic magnetic field and published maps of supernova remnants were used to search for a dependence of structure on the angle Phi. Results show no tendency for the remnants as a whole to favor the relationship expected for either mechanism, although individual sources resemble model remnants of one or the other acceleration process.

  7. Surprisingly high-pressure shocks in the supernova remnant IC 443

    NASA Technical Reports Server (NTRS)

    Moorhouse, A.; Brand, P. W. J. L.; Geballe, T. R.; Burton, M. G.

    1991-01-01

    The intensities of several lines of molecular hydrogen have been measured from two regions of the supernova-remnant/molecular-cloud shock in IC 443. The lines measured have upper-state energies ranging from 7000 K to 23,000 K. Their relative intensities differ in the two regions, but are consistent with those predicted from the post-shock regions of simple jump-type shocks of different pressure. The pressures so derived are far higher than the pressure in the supernova remnant itself, and a possible reason for this discrepancy is discussed.

  8. Long term variability of the cosmic ray intensity

    NASA Technical Reports Server (NTRS)

    Bhat, C. L.; Houston, B. P.; Mayer, C. J.; Wolfendale, A. W.

    1985-01-01

    In a previous paper Bhat, et al., assess the evidence for the continuing acceleration of cosmic rays in the Loop I supernova remnant. The enhanced gamma-ray emission is found consistent with the Blandford and Cowie model for particle acceleration at the remnant shock wave. The contributions of other supernovae remnants to the galactic cosmic ray energy density are now considered, paying anisotropy of cosmic rays accelerated by local supernovae ( 100 pc). The results are compared with geophysical data on the fluctuations in the cosmic ray intensity over the previous one billion years.

  9. A Low-Frequency Survey of the Galactic Plane Near l = 11 degs: Discovery of Three New Supernova Remnants

    DTIC Science & Technology

    2004-01-01

    A LOW-FREQUENCY SURVEY OF THE GALACTIC PLANE NEAR l = 11: DISCOVERY OF THREE NEW SUPERNOVA REMNANTS C. L. Brogan,1,2 K. E. Devine,3,4 T. J. Lazio,5...230; Green 2002). This paucity is likely due in part to selection effects acting against the discovery of the more mature, faint, extended remnants...00-00-2004 to 00-00-2004 4. TITLE AND SUBTITLE A Low-Frequency Survey of the Galactic Plane Near l=11degrees: Discovery of Three New Supernova

  10. Chandra Associates Pulsar and Historic Supernova

    NASA Astrophysics Data System (ADS)

    2001-01-01

    SAN DIEGO -- Scientists using NASA’s Chandra X-ray Observatory have found new evidence that a pulsar in the constellation of Sagittarius was created when a massive star exploded, witnessed by Chinese astronomers in the year 386 AD. If confirmed, this will be only the second pulsar to be clearly associated with a historic event. These results were presented today by Victoria Kaspi and Mallory Roberts of McGill University at the American Astronomical Society meeting. Also participating in the research were Gautum Vasisht from the Jet Propulsion Laboratory, Eric Gotthelf from Columbia University, Michael Pivovaroff from Therma-Wave, Inc., and Nobuyuki Kawai from the Institute of Physical and Chemical Research, Japan. The scientists used Chandra to locate the pulsar exactly at the geometric center of the supernova remnant known as G11.2-0.3. This location provides very strong evidence that the pulsar, a neutron star that is rotating 14 times a second, was formed in the supernova of 386 AD, and therefore has an age of 1615 years. "Determining the true ages of astronomical objects is notoriously difficult, and for this reason, historical records of supernovas are of great importance,"said Kaspi."In roughly the past 2,000 years, fewer than 10 reports of probable supernovae have been archived mostly by Asian astronomers. Of those handful, the remnant of 1054 AD, the Crab Nebula, was until now the only pulsar whose birth could be associated with a historic event - and, hence, the only neutron star that has a firm age." Between mid-April and mid-May in the year 386 AD, a young "guest star", presumably a supernova, was recorded by Chinese observers in the direction of the sky now known as the constellation of Sagittarius. In the 1970s, radio astronomers discovered an expanding nebula of gas and high-energy particles, called G11.2-0.3, that is believed to be the remnant of that explosion. In 1997, a team of X-ray astronomers used Japan’s ASCA satellite to discover a pulsar in the same area of the sky. Past attempts to identify the pulsar with G11.2-0.3, and hence the ancient Chinese observations, have been controversial. The location of the pulsar at the center of the remnant provides new evidence that it is associated with the remnant. Since pulsars are known to move rapidly away from where they are formed, a pulsar near the center of the remnant implies the system must be very young, since not enough time has elapsed for the pulsar to travel far from its birthplace. "We believe that the pulsar and the supernova remnant G11.2-0.3 are both likely to be left over from the explosion seen by the Chinese observers over 1600 years ago," said Roberts. "While this is exciting by itself, it also raises new questions about what we know about pulsars especially during their infancies." These questions follow from a discrepancy that arose when the ASCA team applied the present spin rate to current models to determine the pulsar’s estimated lifetime and compare it to the age of G11.2-0.3. The result was an age of roughly 24,000 years - far predating the birth year of 386 AD. To explain this contradiction, the Chandra team argues that this pulsar may have had approximately the same spin rate today as it did at its birth, as had been suggested by the ASCA data. If this is true, then it could have important implications for the conventional wisdom regarding pulsars, which, may be born spinning more slowly than has been thought. "We now have strong evidence that the standard age estimate for this pulsar is probably wrong, and it is much younger than previously believed," said Kaspi. "This, in turn, suggests that other standard pulsar age estimates may be wrong as well, and this has important implications for the population as a whole." In addition to these results, the Chandra observations of G11.2-0.3 have, for the first time, revealed the bizarre appearance of the pulsar wind nebula (also known as "plerions") at the center of the supernova remnant. Its rough cigar-like shape is in contrast to the graceful arcs observed around the Crab and Vela pulsars. However, together with those pulsars, G11.2-0.3 demonstrates that such complicated structures are ubiquitous around young pulsars. This has left astronomers confounded. Chandra observed G11.2-0.3 with the Advanced CCD Imaging Spectrometer at two epochs: August 6, 2000, and October 15, 2000, for approximately 20,000 and 15,000 seconds respectively. The ACIS X-ray camera was developed for NASA by Pennsylvania State University and MIT. NASA's Marshall Space Flight Center in Huntsville, AL, manages the Chandra program. TRW, Inc., Redondo Beach, California, is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, MA. In addition to their appointments at McGill, Dr. Kaspi is also affiliated with the Massachusetts Institute of Technology and Dr. Roberts is a Quebec Merit Postdoctoral Fellow. Funding for this work was provided by NASA, NSF, and NSERC (Canada). During the AAS meeting, the scientists involved in this release can be reached at the AAS Press Room at the Town & Country Resort in San Diego, CA. The phone numbers for the Press Room are (619) 908-5057, (619) 908-5040, and (619) 908-5041 from January 8-11. Images associated with this release are available on the World Wide Web at: http://chandra.harvard.edu AND http://chandra.nasa.gov

  11. Supernova Remnant in 3-D

    NASA Image and Video Library

    2009-01-06

    For the first time, a multiwavelength three-dimensional reconstruction of a supernova remnant has been created. This visualization of Cassiopeia A, or Cas A, the result of an explosion approximately 330 years ago, uses data from several NASA telescopes.

  12. Fermi Large Area Telescope Detection of Supernova Remnant RCW 86

    NASA Astrophysics Data System (ADS)

    Yuan, Qiang; Huang, Xiaoyuan; Liu, Siming; Zhang, Bing

    2014-04-01

    Using 5.4 yr Fermi Large Area Telescope data, we report the detection of GeV γ-ray emission from the shell-type supernova remnant RCW 86 (G315.4-2.3) with a significance of ~5.1σ. The data slightly favors an extended emission of this supernova remnant. The spectral index of RCW 86 is found to be very hard, Γ ~ 1.4, in the 0.4-300 GeV range. A one-zone leptonic model can well fit the multi-wavelength data from radio to very high energy γ-rays. The very hard GeV γ-ray spectrum and the inferred low gas density seem to disfavor a hadronic origin for the γ-rays. The γ-ray behavior of RCW 86 is very similar to several other TeV shell-type supernova remnants, e.g., RX J1713.7-3946, RX J0852.0-4622, SN 1006, and HESS J1731-347.

  13. Parameterizing the Supernova Engine and Its Effect on Remnants and Basic Yields

    NASA Astrophysics Data System (ADS)

    Fryer, Chris L.; Andrews, Sydney; Even, Wesley; Heger, Alex; Safi-Harb, Samar

    2018-03-01

    Core-collapse supernova science is now entering an era in which engine models are beginning to make both qualitative and, in some cases, quantitative predictions. Although the evidence in support of the convective engine for core-collapse supernova continues to grow, it is difficult to place quantitative constraints on this engine. Some studies have made specific predictions for the remnant distribution from the convective engine, but the results differ between different groups. Here we use a broad parameterization for the supernova engine to understand the differences between distinct studies. With this broader set of models, we place error bars on the remnant mass and basic yields from the uncertainties in the explosive engine. We find that, even with only three progenitors and a narrow range of explosion energies, we can produce a wide range of remnant masses and nucleosynthetic yields.

  14. Nonthermal X-Ray Emission from the Shell-Type Supernova Remnant G347.3-0.5

    NASA Technical Reports Server (NTRS)

    Slane, Patrick O.; Gaensler, Bryan M.; Dame, T. M.; Hughes, John P.; Plucinsky, Paul P.; Green, Anne

    2002-01-01

    Recent Advanced Spacecraft for Cosmology Astrophysics (ASCA) observations of G347.3-0.5, a supernova remnant (SNR) discovered in the ROSAT All-Sky Survey, reveal nonthermal emission from a region along the northwestern shell. Here we report on new pointed ASCA observations of G347.3-0.5 that confirm this result for all the bright shell regions and also reveal similar emission, although with slightly different spectral properties, from the remainder of the SNR. Curiously, no thermal X-ray emission is detected anywhere in the remnant. We derive limits on the amount of thermal emitting material present in G347.3-0.5 and present new radio continuum, CO, and infrared results that indicate that the remnant is distant and of moderate age. We show that our observations are broadly consistent with a scenario that has most of the supernova remnant shock wave still within the stellar wind bubble of its progenitor star, while part of it appears to be interacting with denser material. A point source at the center of the remnant has spectral properties similar to those expected for a neutron star and may represent the compact relic of the supernova progenitor.

  15. A high-resolution radio image of a young supernova

    NASA Technical Reports Server (NTRS)

    Bartel, N.; Rupen, M. P.; Shapiro, I. I.; Preston, R. A.; Rius, A.

    1991-01-01

    A VLBI radio images of the bright supernova 1986J, which occurred in the galaxy NGC891 at a distance of about 12 Mpc, is presented. No detailed image of any supernova or remnant has been obtained before so soon after the explosion. The image shows a shell of emission with jetlike protrusions. Analysis of the images should advance understanding of the dynamics of the expanding debris, the dissipation of energy into the surrounding circumstellar medium, and the evolution of the supernova into the remnant.

  16. The Fermi Gamma-Ray Space Telescope discovers the pulsar in the young galactic supernova remnant CTA 1.

    PubMed

    Abdo, A A; Ackermann, M; Atwood, W B; Baldini, L; Ballet, J; Barbiellini, G; Baring, M G; Bastieri, D; Baughman, B M; Bechtol, K; Bellazzini, R; Berenji, B; Blandford, R D; Bloom, E D; Bogaert, G; Bonamente, E; Borgland, A W; Bregeon, J; Brez, A; Brigida, M; Bruel, P; Burnett, T H; Caliandro, G A; Cameron, R A; Caraveo, P A; Carlson, P; Casandjian, J M; Cecchi, C; Charles, E; Chekhtman, A; Cheung, C C; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; Cominsky, L R; Conrad, J; Cutini, S; Davis, D S; Dermer, C D; de Angelis, A; de Palma, F; Digel, S W; Dormody, M; do Couto E Silva, E; Drell, P S; Dubois, R; Dumora, D; Edmonds, Y; Farnier, C; Focke, W B; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Gehrels, N; Germani, S; Giebels, B; Giglietto, N; Giordano, F; Glanzman, T; Godfrey, G; Grenier, I A; Grondin, M-H; Grove, J E; Guillemot, L; Guiriec, S; Harding, A K; Hartman, R C; Hays, E; Hughes, R E; Jóhannesson, G; Johnson, A S; Johnson, R P; Johnson, T J; Johnson, W N; Kamae, T; Kanai, Y; Kanbach, G; Katagiri, H; Kawai, N; Kerr, M; Kishishita, T; Kiziltan, B; Knödlseder, J; Kocian, M L; Komin, N; Kuehn, F; Kuss, M; Latronico, L; Lemoine-Goumard, M; Longo, F; Lonjou, V; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Makeev, A; Marelli, M; Mazziotta, M N; McEnery, J E; McGlynn, S; Meurer, C; Michelson, P F; Mineo, T; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nakamori, T; Nolan, P L; Nuss, E; Ohno, M; Ohsugi, T; Okumura, A; Omodei, N; Orlando, E; Ormes, J F; Ozaki, M; Paneque, D; Panetta, J H; Parent, D; Pelassa, V; Pepe, M; Pesce-Rollins, M; Piano, G; Pieri, L; Piron, F; Porter, T A; Rainò, S; Rando, R; Ray, P S; Razzano, M; Reimer, A; Reimer, O; Reposeur, T; Ritz, S; Rochester, L S; Rodriguez, A Y; Romani, R W; Roth, M; Ryde, F; Sadrozinski, H F-W; Sanchez, D; Sander, A; Parkinson, P M Saz; Schalk, T L; Sellerholm, A; Sgrò, C; Siskind, E J; Smith, D A; Smith, P D; Spandre, G; Spinelli, P; Starck, J-L; Strickman, M S; Suson, D J; Tajima, H; Takahashi, H; Takahashi, T; Tanaka, T; Thayer, J B; Thayer, J G; Thompson, D J; Thorsett, S E; Tibaldo, L; Torres, D F; Tosti, G; Tramacere, A; Usher, T L; Van Etten, A; Vilchez, N; Vitale, V; Wang, P; Watters, K; Winer, B L; Wood, K S; Yasuda, H; Ylinen, T; Ziegler, M

    2008-11-21

    Energetic young pulsars and expanding blast waves [supernova remnants (SNRs)] are the most visible remains after massive stars, ending their lives, explode in core-collapse supernovae. The Fermi Gamma-Ray Space Telescope has unveiled a radio quiet pulsar located near the center of the compact synchrotron nebula inside the supernova remnant CTA 1. The pulsar, discovered through its gamma-ray pulsations, has a period of 316.86 milliseconds and a period derivative of 3.614 x 10(-13) seconds per second. Its characteristic age of 10(4) years is comparable to that estimated for the SNR. We speculate that most unidentified Galactic gamma-ray sources associated with star-forming regions and SNRs are such young pulsars.

  17. An explanation of the formation of the peculiar periphery of Tycho's supernova remnant

    NASA Astrophysics Data System (ADS)

    Fang, Jun; Yu, Huan; Zhang, Li

    2018-02-01

    Tycho's supernova remnant (SNR) has a periphery that clearly deviates from a spherical shape, based on X-ray and radio observations. The forward shock from the south-east to the north of the remnant has a deformed outline with a depression in the east, although in the west it is generally round and smooth. Moreover, at some locations in the shell, the supernova ejecta is located close to the forward shock, resulting in protrusions. Using 3D hydrodynamical simulations, we studied the dynamical evolution of the supernova ejecta in an inhomogeneous medium and the formation process of the profile of the forward shock. In order to reproduce the peculiar periphery of the remnant, we propose a model in which the supernova ejecta has evolved in a cavity blown by a latitude-dependent outflow. The results indicate that the depression to the east and the protrusion to the south-east on the observed periphery of the remnant can be generally reproduced if we assume a wind bubble driven by an anisotropic wind with a mass-loss rate of ˜10-7 M⊙ yr-1, a pole velocity of ˜100 km s-1, a duration of ˜105 yr prior to the supernova explosion, and a spatial velocity of ˜30 km s-1 of the progenitor with respect to the circumstellar medium. In conclusion, an explanation of the peculiar shape of the periphery of Tycho's SNR is that the supernova ejecta evolved in the cavity driven by a latitude-dependent wind.

  18. The Cygnus Loop: An Older Supernova Remnant.

    ERIC Educational Resources Information Center

    Straka, William

    1987-01-01

    Describes the Cygnus Loop, one of brightest and most easily studied of the older "remnant nebulae" of supernova outbursts. Discusses some of the historical events surrounding the discovery and measurement of the Cygnus Loop and makes some projections on its future. (TW)

  19. X-ray spectra of supernova remnants

    NASA Technical Reports Server (NTRS)

    Szymkowiak, A. E.

    1985-01-01

    X-ray spectra were obtained from fields in three supernova remnants with the solid state spectrometer of the HEAO 2 satellite. These spectra, which contain lines from K-shell transitions of several abundant elements with atomic numbers between 10 and 22, were compared with various models, including some of spectra that would be produced by adiabatic phase remnants when the time-dependence of the ionization is considered.

  20. Identification of the central compact object in the young supernova remnant 1E 0102.2-7219

    NASA Astrophysics Data System (ADS)

    Vogt, Frédéric P. A.; Bartlett, Elizabeth S.; Seitenzahl, Ivo R.; Dopita, Michael A.; Ghavamian, Parviz; Ruiter, Ashley J.; Terry, Jason P.

    2018-04-01

    Oxygen-rich young supernova remnants1 are valuable objects for probing the outcome of nucleosynthetic processes in massive stars, as well as the physics of supernova explosions. Observed within a few thousand years after the supernova explosion2, these systems contain fast-moving oxygen-rich and hydrogen-poor filaments visible at optical wavelengths: fragments of the progenitor's interior expelled at a few thousand kilometres per second during the supernova explosion. Here we report the identification of the compact object in the supernova remnant 1E 0102.2-7219 in reprocessed Chandra X-ray Observatory data, enabled by the discovery of a ring-shaped structure visible primarily in optical recombination lines of Ne i and O i. The optical ring has a radius of (2.10 ± 0.35)″ ≡ (0.63 ± 0.11) pc, and is expanding at a velocity of 90 .5-30+40 km s-1. It surrounds an X-ray point source with an intrinsic X-ray luminosity Li (1.2-2.0 keV) = (1.4 ± 0.2) × 1033 erg s-1. The energy distribution of the source indicates that this object is an isolated neutron star: a central compact object akin to those present in the Cas A3-5 and Pup A6 supernova remnants, and the first of its kind to be identified outside of our Galaxy.

  1. Identification of the central compact object in the young supernova remnant 1E 0102.2-7219

    NASA Astrophysics Data System (ADS)

    Vogt, Frédéric P. A.; Bartlett, Elizabeth S.; Seitenzahl, Ivo R.; Dopita, Michael A.; Ghavamian, Parviz; Ruiter, Ashley J.; Terry, Jason P.

    2018-06-01

    Oxygen-rich young supernova remnants1 are valuable objects for probing the outcome of nucleosynthetic processes in massive stars, as well as the physics of supernova explosions. Observed within a few thousand years after the supernova explosion2, these systems contain fast-moving oxygen-rich and hydrogen-poor filaments visible at optical wavelengths: fragments of the progenitor's interior expelled at a few thousand kilometres per second during the supernova explosion. Here we report the identification of the compact object in the supernova remnant 1E 0102.2-7219 in reprocessed Chandra X-ray Observatory data, enabled by the discovery of a ring-shaped structure visible primarily in optical recombination lines of Ne i and O i. The optical ring has a radius of (2.10 ± 0.35)″ ≡ (0.63 ± 0.11) pc, and is expanding at a velocity of 90 .5-30+40 km s-1. It surrounds an X-ray point source with an intrinsic X-ray luminosity Li (1.2-2.0 keV) = (1.4 ± 0.2) × 1033 erg s-1. The energy distribution of the source indicates that this object is an isolated neutron star: a central compact object akin to those present in the Cas A3-5 and Pup A6 supernova remnants, and the first of its kind to be identified outside of our Galaxy.

  2. Dust in Supernovae and Supernova Remnants II: Processing and Survival

    NASA Astrophysics Data System (ADS)

    Micelotta, E. R.; Matsuura, M.; Sarangi, A.

    2018-03-01

    Observations have recently shown that supernovae are efficient dust factories, as predicted for a long time by theoretical models. The rapid evolution of their stellar progenitors combined with their efficiency in precipitating refractory elements from the gas phase into dust grains make supernovae the major potential suppliers of dust in the early Universe, where more conventional sources like Asymptotic Giant Branch (AGB) stars did not have time to evolve. However, dust yields inferred from observations of young supernovae or derived from models do not reflect the net amount of supernova-condensed dust able to be expelled from the remnants and reach the interstellar medium. The cavity where the dust is formed and initially resides is crossed by the high velocity reverse shock which is generated by the pressure of the circumstellar material shocked by the expanding supernova blast wave. Depending on grain composition and initial size, processing by the reverse shock may lead to substantial dust erosion and even complete destruction. The goal of this review is to present the state of the art about processing and survival of dust inside supernova remnants, in terms of theoretical modelling and comparison to observations.

  3. The Fermi Gamma-Ray Space Telescope Discovers the Pulsar in the Young Galactic Supernova Remnant CTA 1

    DOE PAGES

    Abdo, A. A.; Ackermann, M.; Atwood, W. B.; ...

    2008-11-21

    Energetic young pulsars and expanding blast waves (supernova remnants, SNRs) are the most visible remains after massive stars, ending their lives, explode in core-collapse supernovae. The Fermi Gamma-Ray Space Telescope has unveiled a radio quiet pulsar located near the center of the compact synchrotron nebula inside the supernova remnant CTA 1. The pulsar, discovered through its gamma-ray pulsations, has a period of 316.86 ms, a period derivative of 3.614 x 10 -13 s s -1 . Its characteristic age of 10 4 years is comparable to that estimated for the SNR. It is conjectured that most unidentified Galactic gamma raymore » sources associated with star-forming regions and SNRs are such young pulsars.« less

  4. The Fermi Gamma Ray Space Telescope discovers the Pulsar in the Young Galactic Supernova-Remnant CTA 1

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

    Abdo, Aous A.; Ackermann, M.; Atwood, W.B.

    Energetic young pulsars and expanding blast waves (supernova remnants, SNRs) are the most visible remains after massive stars, ending their lives, explode in core-collapse supernovae. The Fermi Gamma-Ray Space Telescope has unveiled a radio quiet pulsar located near the center of the compact synchrotron nebula inside the supernova remnant CTA 1. The pulsar, discovered through its gamma-ray pulsations, has a period of 316.86 ms, a period derivative of 3.614 x 10{sup -13} s s{sup -1}. Its characteristic age of 10{sup 4} years is comparable to that estimated for the SNR. It is conjectured that most unidentified Galactic gamma ray sourcesmore » associated with star-forming regions and SNRs are such young pulsars.« less

  5. Bridging the gap between supernovae and their remnants through multi-dimensional hydrodynamic modeling

    NASA Astrophysics Data System (ADS)

    Orlando, S.; Miceli, M.; Petruk, O.

    2017-02-01

    Supernova remnants (SNRs) are diffuse extended sources characterized by a complex morphology and a non-uniform distribution of ejecta. Such a morphology reflects pristine structures and features of the progenitor supernova (SN) and the early interaction of the SN blast wave with the inhomogeneous circumstellar medium (CSM). Deciphering the observations of SNRs might open the possibility to investigate the physical properties of both the interacting ejecta and the shocked CSM. This requires accurate numerical models which describe the evolution from the SN explosion to the remnant development and which connect the emission properties of the remnants to the progenitor SNe. Here we show how multi-dimensional SN-SNR hydrodynamic models have been very effective in deciphering observations of SNR Cassiopeia A and SN 1987A, thus unveiling the structure of ejecta in the immediate aftermath of the SN explosion and constraining the 3D pre-supernova structure and geometry of the environment surrounding the progenitor SN.

  6. A Study of Supernova Remnants with Center-Filled X-Ray Morphology

    NASA Technical Reports Server (NTRS)

    Slane, Patrick O.

    1997-01-01

    CTA 1 is a center-filled supernova remnant (SNR) whose morphology and spectrum indicate the presence of a central pulsar, a synchrotron nebula, and a thermal component associated with the expansion of the blast wave into the interstellar medium. The centrally bright emission surrounds the position of a faint point source of x-rays observed with the ROSAT PSPC. Here we report on ASCA observations that confirm the nonthermal nature of the diffuse emission from the central regions of the remnant. We also present evidence for weak thermal emission that appears to increase in strength toward the outer boundary of the SNR. Thus, CTA 1 appears to be an x-ray composite remnant. Both the aftermath of the explosive supernova event and the energetic compact core are observable.

  7. The XMM-Newton view of the non-thermal supernova remnant HESS J1731-347

    NASA Astrophysics Data System (ADS)

    Puehlhofer, G.; Doroshenko, V.; Acero, F.; Bamba, A.; Klochkov, D.; Tian, W.

    2017-10-01

    HESS J1731-347 belongs to a small group of supernova remnants that are characterized by a spatially-resolved shell-type TeV morphology and strong synchrotron X-ray emission. We report on XMM-Newton observations of the source that provide for the first time a complete X-ray view of the remnant. The data show an emissivity gradient across the source, which is not observed in the TeV gamma-ray and radio bands. While the broadband spectral analysis is compatible with a pure leptonic emission scenario up to TeV energies, the morphological analysis could be indicative of a blend of hadronic and leptonic TeV emission. We discuss the possibility of an interaction of the supernova remnant with nearby molecular clouds.

  8. Probing r-Process Production of Nuclei Beyond 209Bi with Gamma Rays

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

    Qian, Y.-Z.; Vogel, P.; Wasserburg, G. J.

    We estimate gamma-ray fluxes due to the decay of nuclei beyond 209Bi from a supernova or a supernova remnant assuming that the r-process occurs in supernovae. We find that a detector with a sensitivity of {approx}10-7 {gamma} cm-2 s-1 at energies from {approx}40 keV to {approx}3 MeV may detect fluxes due to the decay of 226Ra, 229Th, 241Am, 243Am, 249Cf, and 251Cf in the newly discovered supernova remnant near Vela. In addition, such a detector may detect fluxes due to the decay of 227Ac and 228Ra produced in a future supernova at a distance of {approx}1 kpc. Because nuclei withmore » mass numbers A>209 are produced solely by the r-process, such detections are the best proof for a supernova r-process site. Further, they provide the most direct information on yields of progenitor nuclei with A>209 at r-process freeze-out. Finally, detection of fluxes due to the decay of r-process nuclei over a range of masses from a supernova or a supernova remnant provides the opportunity to compare yields in a single supernova event with the solar r-process abundance pattern. (c) (c) 1999. The American Astronomical Society.« less

  9. TIMING OF 29 PULSARS DISCOVERED IN THE PALFA SURVEY

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

    Lyne, A. G.; Stappers, B. W.; Bogdanov, S.

    2017-01-10

    We report on the discovery and timing observations of 29 distant long-period pulsars found in the ongoing Arecibo L-band Feed Array pulsar survey. Following discovery with the Arecibo Telescope, confirmation and timing observations of these pulsars over several years at Jodrell Bank Observatory have yielded high-precision positions and measurements of rotation and radiation properties. We have used multi-frequency data to measure the interstellar scattering properties of some of these pulsars. Most of the pulsars have properties that mirror those of the previously known pulsar population, although four show some notable characteristics. PSRs J1907+0631 and J1925+1720 are young and are associatedmore » with supernova remnants or plerionic nebulae: J1907+0631 lies close to the center of SNR G40.5−0.5, while J1925+1720 is coincident with a high-energy Fermi γ -ray source. One pulsar, J1932+1500, is in a surprisingly eccentric, 199 day binary orbit with a companion having a minimum mass of 0.33 M {sub ⊙}. Several of the sources exhibit timing noise, and two, PSRs J0611+1436 and J1907+0631, have both suffered large glitches, but with very different post-glitch rotation properties. In particular, the rotational period of PSR J0611+1436 will not recover to its pre-glitch value for about 12 years, a far greater recovery timescale than seen following any other large glitches.« less

  10. The Supernova - A Stellar Spectacle.

    ERIC Educational Resources Information Center

    Straka, W. C.

    This booklet is part of an American Astronomical Society curriculum project designed to provide teaching materials to teachers of secondary school chemistry, physics, and earth science. The following topics concerning supernovae are included: the outburst as observed and according to theory, the stellar remnant, the nebular remnant, and a summary…

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

    NASA Image and Video Library

    2004-10-06

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

  12. Modelling Hard Gamma-Ray Emission from Supernova Remnants

    NASA Technical Reports Server (NTRS)

    Baring, Matthew

    2000-01-01

    The observation by the CANGAROO experiment of TeV emission from SN 1006, in conjunction with several instances of non-thermal X-ray emission from supernova remnants, has led to inferences of super-TeV electrons in these extended sources. While this is sufficient to propel the theoretical community in their modelling of particle acceleration and associated radiation, the anticipated emergence in the next decade of a number of new experiments probing the TeV and sub-TeV bands provides further substantial motivation for modellers. In particular, the quest for obtaining unambiguous gamma-ray signatures of cosmic ray ion acceleration defines a "Holy Grail" for observers and theorists alike. This review summarizes theoretical developments in the prediction of MeV-TeV gamma-rays from supernova remnants over the last five years, focusing on how global properties of models can impact, and be impacted by, hard gamma-ray observational programs, thereby probing the supernova remnant environment. Properties of central consideration include the maximum energy of accelerated particles, the density of the unshocked interstellar medium, the ambient magnetic field, and the relativistic electron-to-proton ratio. Criteria for determining good candidate remnants for observability in the TeV band are identified.

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

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

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

  14. High resolution observations of Cassiopeia A at meter wavelengths. [pulsar source in supernova remnant

    NASA Technical Reports Server (NTRS)

    Hutton, L. K.; Clark, T. A.; Erickson, W. C.; Resch, G. M.; Vandenberg, N. R.; Knowles, S. H.; Youmans, A. B.

    1974-01-01

    Very long baseline interferometric (VLBI) observations of the supernova remnant Cassiopeia A, at 74 MHz with a 12,000-wavelength baseline and at 111 MHz with a 18,500-wavelength baseline, are reported. The fringe amplitudes are strongly varying on a time scale of about 15 to 30 minutes. The location of the extra source must lie outside the supernova remnant shell possibly associated with a concentration of emission north of the shell, or lying outside the gap in the northeastern side of the shell. The flux and spectral index deduced for the compact source depend on the assumed size, with a range of 100 Jy to 500 Jy at 74 MHz. If the source is associated with the supernova explosion, it must have been traveling at least 5000 km s/2.

  15. Optical emission from a fast shock wave - The remnants of Tycho's supernova and SN 1006

    NASA Technical Reports Server (NTRS)

    Chevalier, R. A.; Raymond, J. C.

    1978-01-01

    The faint optical filaments in Tycho's supernova remnant appear to be emission from a shock front moving at 5600 km/s. The intensity of the hydrogen lines, the absence of forbidden lines of heavy elements in the spectrum, and the width of the filaments are explained by a model in which a collisionless shock wave is moving into partially neutral gas. The presence of the neutral gas can be used to set an upper limit of approximately 5 x 10 to the 47th power ergs to the energy in ionizing radiation emitted by a Type I supernova. The patchy neutral gas is probably part of the warm neutral component of the interstellar medium. The existing information on the remnant of SN 1006 indicates that its emission is similar in nature to that from Tycho's remnant.

  16. A Newly Discovered Supernova Remnant and MSH 11-62 and 3C58

    NASA Technical Reports Server (NTRS)

    Slane, Patrick O.

    2000-01-01

    CTA 1 is a center-filled supernova remnant (SNR) whose morphology and spectrum indicate the presence of a central pulsar, a synchrotron nebula, and a thermal component associated with the expansion of the blast wave into the interstellar medium. The centrally bright emission surrounds the position of a faint point source of X-rays observed with the ROSAT Position Sensitive Proportional Counter (PSPC). Here we report on Advanced Spacecraft for Cosmology Astrophysics (ASCA) observations that confirm the nonthermal nature of the diffuse emission from the central regions of the remnant. We also present evidence for weak thermal emission that appears to increase in strength toward the outer boundary of the SNR. Thus, CTA 1 appears to be an X-ray composite remnant. Both the aftermath of the explosive supernova event and the energetic compact core are observable.

  17. Dust Production and Particle Acceleration in Supernova 1987A Revealed with ALMA

    NASA Technical Reports Server (NTRS)

    Indebetouw, R.; Matsuura, M.; Dwek, E.; Zanardo, G.; Barlow, M. J.; Baes, M.; Bouchet, P.; Burrows, D. N.; Chevalier, R.; Clayton, G. C.; hide

    2014-01-01

    Supernova (SN) explosions are crucial engines driving the evolution of galaxies by shock heating gas, increasing the metallicity, creating dust, and accelerating energetic particles. In 2012 we used the Atacama Large Millimeter/ Submillimeter Array to observe SN1987A, one of the best-observed supernovae since the invention of the telescope. We present spatially resolved images at 450 µm, 870 µm, 1.4 mm, and 2.8 mm, an important transition wavelength range. Longer wavelength emission is dominated by synchrotron radiation from shock-accelerated particles, shorter wavelengths by emission from the largest mass of dust measured in a supernova remnant (>0.2 Solar Mass). For the first time we show unambiguously that this dust has formed in the inner ejecta (the cold remnants of the exploded star's core). The dust emission is concentrated at the center of the remnant, so the dust has not yet been affected by the shocks. If a significant fraction survives, and if SN 1987A is typical, supernovae are important cosmological dust producers.

  18. Exploring the X-ray Morphology of the Supernova Remnant Kes 27 using Numerical Simulations

    NASA Astrophysics Data System (ADS)

    Dwarkadas, Vikram; Dewey, D.

    2013-04-01

    Kesteven 27 is a member of the class of thermal composite or mixed-morphology remnants, which can show thermal X-ray emission extending all the way in towards the center. The Chandra image shows two incomplete shell-like features in the north-eastern half, with brightness fading towards the southwest. The X-ray and radio structure led Chen et al. (2008) to suggest that the morphology represents a supernova remnant expanding in a windblown bubble. The two X-ray rings represent the outer shock of the supernova remnant, and a reflected shock arising from collision with a dense shell. Using numerical simulations followed by a computation of the X-ray emission, we explore this possibility. Our initial modeling suggests that the scenario discussed by Chen et al. (2008) may not work. We suggest and discuss modifications to this scenario that may be able to reproduce the observed morphology, and the implications for thermal composite remnants.

  19. ASCA observations of the Large Magellanic Cloud supernova remnant sample: Typing supernovae from their remnants

    NASA Technical Reports Server (NTRS)

    Hughes, John P.; Hayashi, Ichizo; Helfand, David; Hwang, Una; Itoh, Masayuki; Kirshner, Robert; Koyama, Katsuji; Markert, Thomas; Tsunemi, Hiroshi; Woo, Jonathan

    1995-01-01

    We present our first results from a study of the supernova remnants (SNRs) in the Large Magellanic Cloud (LMC) using data from ASCA. The three remnants we have analyzed to date, 0509-67.5, 0519-69.0, and N103B, are among the smallest, and presumably also the youngest, in the Cloud. The X-ray spectra of these SNRs show strong K alpha emission lines of silicon, sulfur, argon, and calcium with no evidence for corresponding lines of oxygen, neon, or magnesium. The dominant feature in the spectra is a broad blend of emission lines around 1 keV which we attribute to L-shell emission lines of iron. Model calculations (Nomoto, Thielemann, & Yokoi 1984) show that the major products of nucleosynthesis in Type Ia supernovae (SNs) are the elements from silicon to iron, as observed here. The calculated nucleosynthetic yields from Type Ib and II SNs are shown to be qualitatively inconsistent with the data. We conclude that the SNs which produced these remnants were of Type Ia. This finding also confirms earlier suggestions that the class of Balmer-dominated remnants arise from Type Ia SN explosions. Based on these early results from the LMC SNR sample, we find that roughly one-half of the SNRs produced in the LMC within the last approximately 1500 yr came from Type Ia SNs.

  20. GBT Observations of Radio Recombination Line Emission Associated with Supernova Remnants W28 and W44

    NASA Astrophysics Data System (ADS)

    Hewitt, John W.; Yusef-Zadeh, F.

    2006-06-01

    Since the 1970's weak radio recombination line(RRL) emission has been observed toward several supernova remnants. It has remained unclear if this emission is in fact associated with these remnants or due to intervening sources such as extended HII envelopes along the line of sight. To explore the origin of this emitting gas we have recently undertaken Green Bank Telescope (GBT) observations of prominent supernova remnants W28 and W44 which are well-known to be interacting with molecular clouds. Eight alpha and beta RRL transitions were mapped at C-Band (4-6 GHz) with 2.5' resolution. Maps cover 0.5 and 0.25 square degrees of W28 and W44, respectively, permitting comparison with the distribution of X-rays, Radio, and H-alpha emission. Both remnants are observed to have a mixed-morphology: a radio-continuum shell centrally-filled by thermal X-rays. We find the observed velocity of RRL emission is near the systemic velocity of both remnants as traced by OH(1720 MHz) masers. Preliminary results are presented exploring the association of the RRL-emitting gas with these interacting supernova remants and implications for the origins of the hot thermal X-ray plasma that fills their centers. Support for this work was provided by the NSF through The GBT Student Support Program from the NRAO.

  1. Newly Formed Dust in the Core-Collapse Supernova Remnant E0102

    NASA Astrophysics Data System (ADS)

    Ludwig, Bethany; Sandstrom, Karin; Bolatto, Alberto

    2018-01-01

    The mechanism of interstellar dust formation is a matter of continuing debate. In the very early universe, some high redshift galaxies are observed to have a substantial amount of dust. This has led to the suggestion that core collapse supernovae must be the producers of much of the dust in the universe. However, most observed supernova remnants (SNRs) in the local universe have measured dust yields far below the necessary levels. Cassiopeia A and SN 1987A are exceptions--in these young remnants, Herschel Space Observatory observations found large quantities of newly-formed dust. In these two cases, the SNR is young enough that the reverse shock has not yet interacted with most of the newly formed dust. To study supernova dust production, we observe SNR 1E0102.2-7219, which is approximately 1000 years old with a reverse shock that has only reached into a small part of its ejecta making it an excellent candidate to search for newly formed dust that has not yet been destroyed by those shocks. Using Herschel data, we carefully model the background around the remnant to remove emission that is unrelated to the SNR. We then measure the mass, temperature, and chemical composition of the dust by fitting the spectral energy distribution. Our findings reveal a substantial amount of previously undetected cold dust in the remnant, suggesting that indeed core collapse supernovae may host substantial amounts of newly formed dust, at least prior to the passage of the reverse shock.

  2. Very high-resolution observations of compact radio sources in the directions of supernova remnants

    NASA Technical Reports Server (NTRS)

    Geldzahler, B. J.; Shaffer, D. B.

    1981-01-01

    Compact radio sources whose positions lie within the outlines of supernova remnants may be the stellar remnants of supernova explosions and, if they are related to the supernova remnants, may be used to explore the nature of any morphological connection between the Galactic and extragalactic radio sources. Three such compact sources, G 127.11+0.54, CL 4, and 2051+433, have been observed at 10.65 GHz with an array of very long baseline interferometers having elements in the USA and West Germany. The radio source 2051+433 was also observed briefly at 5.01 GHz. The measured size of CL 4 at 10.65 GHz is about 0.0005 arcsec and seems to be dominated by the effects of interstellar scattering. No fringes were seen in 2051+433, and results indicate there is no compact component of 2051+433 smaller than 0.001 arcsec radiating at 10.65 GHz above a level of about 50 mJy. The possibility is presented that G 127.11+0.54 is a Galactic object. It is found to consist of two components separated by about 0.002 arcsec and oriented perpendicular to both the radio bridge of the supernova remnant G 127.1+0.5 and the underlying optical image. G 127.11+0.54, if Galactic, lies at the extreme low-luminosity end of an apparent continuum of Galactic and extragalactic compact radio source luminosities.

  3. Search for gamma ray lines from supernovae and supernova remnants

    NASA Technical Reports Server (NTRS)

    Chupp, E. L.; Forrest, D. J.; Suri, A. N.; Adams, R.; Tsai, C.

    1974-01-01

    A gamma ray monitor with a NaI crystal shielded with a cup-shaped CsI cover was contained in the rotating wheel compartment of the OSO-7 spacecraft for measuring the gamma ray spectra from 0.3 to 10 MeV in search for gamma ray lines from a possible remnant in the Gum Nebula and the apparent Type I supernovae in NGC5253. A brief analysis of data yielded no positive indications for X-rays, gamma ray lines, or continuum from these sources.

  4. Shocked Clouds in the Vela Supernova Remnant

    NASA Technical Reports Server (NTRS)

    Nichols, Joy S.; Slavin, Jonathan D.

    2004-01-01

    Unusually strong high-excitation C I has been detected in eleven lines of sight through the Vela supernova remnant by means of UV absorption-line studies of IUE data. Most of these lines of sight lie near the western edge of the X-ray bright region of the supernova remnant in a spatially distinct band approximately 1deg by 4deg oriented approximately north/south. The high-excitation C I (denoted C I*) is interpreted as evidence of a complex of shocked dense clouds inside the supernova remnant, due to the high pressures indicated in this region. To further analyze the properties of this region of C I*, we present new HIRES-processed IRAS data of the entire Vela SNR. A temperature map calculated from the HIRES IRAS data, based on a two-component dust model, reveals the signature of hot dust at several locations in the SNR. The hot dust is anti-correlated spatially with X-ray emission as revealed by ROSAT, as would be expected for a dusty medium interacting with a shock wave. The regions of hot dust are strongly correlated with optical filaments, supporting a scenario of dense clouds interior to the SNR that have been shocked and are now cooling behind the supernova blast wave. With few exceptions, the lines of sight to the strong C I* pass through regions of hot dust and optical filaments. Possible mechanisms for the production of the anomalously large columns of C I and C I* are discussed. Dense clouds on the back western hemisphere of the remnant may explain the relatively low X-ray emission in the western portion of the Vela supernova remnant due to the slower forward shock velocity in regions where the shock has encountered the dense clouds. An alternate explanation for the presence of neutral, excited state, and ionized species along the same line of sight may be a magnetic precusor that heats and compresses the gas ahead of the shock.

  5. The supernova - supernova remnant connection through multi-dimensional magnetohydrodynamic modeling

    NASA Astrophysics Data System (ADS)

    Orlando, S.; Miceli, M.; Petruk, O.; Ono, M.

    2017-10-01

    Supernova remnants (SNRs) are diffuse extended sources often characterized by a rather complex morphology and a highly non-uniform distribution of ejecta. General consensus is that such a morphology reflects, on one hand, pristine structures and features of the progenitor supernova (SN) explosion and, on the other hand, the early interaction of the SN blast wave with the inhomogeneous circumstellar medium (CSM) formed in the latest stages of the progenitor star's evolution. Deciphering X-ray observations of SNRs, therefore, might open the possibility to reconstruct the ejecta structure as it was soon after the SN explosion and the structure and geometry of the medium immediately surrounding the progenitor star. This requires accurate and detailed models which describe the evolution from the on-set of the SN to the full remnant development and which connect the X-ray emission properties of the remnants to the progenitor SNe. Here we show how multi-dimensional SN-SNR magnetohydrodynamic models have been very effective in deciphering X-ray observations of SNR Cassiopeia A and SN 1987A. This has allowed us to unveil the average structure of ejecta in the immediate aftermath of the SN explosion and to constrain the 3D pre-supernova structure and geometry of the environment surrounding the progenitor SN.

  6. Kepler Supernova Remnant: A View from Spitzer Space Telescope

    NASA Image and Video Library

    2004-10-06

    This Spitzer false-color image is a composite of data from the 24 micron channel of Spitzer's multiband imaging photometer (red), and three channels of its infrared array camera: 8 micron (yellow), 5.6 micron (blue), and 4.8 micron (green). Stars are most prominent in the two shorter wavelengths, causing them to show up as turquoise. The supernova remnant is most prominent at 24 microns, arising from dust that has been heated by the supernova shock wave, and re-radiated in the infrared. The 8 micron data shows infrared emission from regions closely associated with the optically emitting regions. These are the densest regions being encountered by the shock wave, and probably arose from condensations in the surrounding material that was lost by the supernova star before it exploded. The composite above (PIA06908, PIA06909, and PIA06910) represent views of Kepler's supernova remnant taken in X-rays, visible light, and infrared radiation. Each top panel in the composite above shows the entire remnant. Each color in the composite represents a different region of the electromagnetic spectrum, from X-rays to infrared light. The X-ray and infrared data cannot be seen with the human eye. Astronomers have color-coded those data so they can be seen in these images. http://photojournal.jpl.nasa.gov/catalog/PIA06910

  7. Modelling Hard Gamma-Ray Emission from Supernova Remnants

    NASA Technical Reports Server (NTRS)

    Baring, Matthew G.

    1999-01-01

    The observation by the CANGAROO (Collaboration of Australia and Nippon Gamma Ray Observatory at Outback) experiment of TeV emission from SN 1006, in conjunction with several instances of non-thermal X-ray emission from supernova remnants, has led to inferences of super-TeV electrons in these extended sources. While this is sufficient to propel the theoretical community in their modelling of particle acceleration and associated radiation, the anticipated emergence in the next decade of a number of new experiments probing the TeV and sub-TeV bands provides further substantial motivation for modellers. In particular, the quest for obtaining unambiguous gamma-ray signatures of cosmic ray ion acceleration defines a "Holy Grail" for observers and theorists alike. This review summarizes theoretical developments in the prediction of MeV-TeV gamma-rays from supernova remnants over the last five years, focusing on how global properties of models can impact, and be impacted by, hard gamma-ray observational programs, thereby probing the supernova remnant environment. Properties of central consideration include the maximum energy of accelerated particles, the density of the unshocked interstellar medium, the ambient magnetic field, and the relativistic electron-to-proton ratio. Criteria for determining good candidate remnants for observability in the TeV band are identified.

  8. Left Behind: A Bound Remnant from a White Dwarf Supernova?

    NASA Astrophysics Data System (ADS)

    Jha, Saurabh

    2017-08-01

    Type Ia supernovae (SN Ia) have enormous importance to cosmology and astrophysics, but their progenitors and explosion mechanisms are not understood in detail. Recently, observations and theoretical models have suggested that not all thermonuclear white-dwarf supernova explosions are normal SN Ia. In particular, type Iax supernovae (peculiar cousins to SN Ia), are thought to be exploding white dwarfs that are not completely disrupted, leaving behind a bound remnant. In deep and serendipitous HST pre-explosion data, we have discovered a luminous, blue progenitor system for the type Iax SN 2012Z in NGC 1309, which we interpret as a helium-star donor to the exploding white dwarf. HST observations of SN 2012Z in 2016, when the supernova light was expected to have faded away, still show a source at the location, as expected in our model where the pre-explosion flux was coming from the companion. However, the 2016 data also show a surprise: an excess flux compared to the progenitor system. Our proposed observations here will help unravel the mystery of that excess flux: is it from the bound ex-white dwarf remnant? Or is it from the shocked companion star that has been bombarded by supernova ejecta? Either of these possibilities would provide key new evidence as to the nature of these white dwarf supernovae.

  9. Hardy Star Survives Supernova Blast

    NASA Image and Video Library

    2014-03-20

    This composite image contains data from Chandra (purple) that provides evidence for the survival of a companion star from the blast of a supernova explosion. Chandra's X-rays reveal a point-like source in the supernova remnant at the location of a massive star. The data suggest that mass is being pulled away from the massive star towards a neutron star or a black hole companion. If confirmed, this would be only the third binary system containing both a massive star and a neutron star or black hole ever found in the aftermath of a supernova. This supernova remnant is found embedded in clouds of ionized hydrogen, which are shown in optical light (yellow and cyan) from the MCELS survey, along with additional optical data from the DSS (white).

  10. ROSAT PSPC Observations of CL0016+16

    NASA Technical Reports Server (NTRS)

    Hughes, John P.

    1996-01-01

    This report is an update of progress on NASA grant NAG5-2156. The following papers which were published or submitted since April 1966 were supported by this grant. Preprints of each are attached: HST Observations of Oxygen-rich Supernova Remnants in the Magellanic Clouds, and SuperNova Remnants Associated with Molecular Clouds in the Large Magellanic Cloud.

  11. X-ray emission from reverse-shocked ejecta in supernova remnants

    NASA Technical Reports Server (NTRS)

    Cioffi, Denis F.; Mckee, Christopher F.

    1990-01-01

    A simple physical model of the dynamics of a young supernova remnant is used to derive a straightforward kinematical description of the reverse shock. With suitable approximations, formulae can then be developed to give the X-ray emission of the reverse-shocked ejecta. The results are found to agree favorably with observations of SN1006.

  12. On The Origin Of Two-Shell Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Gvaramadze, Vasilii

    2007-07-01

    The proper motion of massive stars could cause them to explode far from the geometric centers of their wind-driven bubbles and thereby could affect the symmetry of the resulting diffuse supernova remnants (SNRs). We use this fact to explain the origin of SNRs consisting of two partially overlapping shells (e.g. Cygnus Loop, 3C 400.2, etc.).

  13. Recombining plasma in the remnant of a core-collapsed supernova, Kes 17

    NASA Astrophysics Data System (ADS)

    Washino, Ryosaku; Uchida, Hiroyuki; Nobukawa, Masayoshi; Tsuru, Takeshi Go; Tanaka, Takaaki; Kawabata Nobukawa, Kumiko; Koyama, Katsuji

    2016-06-01

    We report on Suzaku results concerning Kes 17, a Galactic mixed-morphology supernova remnant. The X-ray spectrum of the whole Kes 17 is well explained by a pure thermal plasma, in which we found Lyα of Al XIII and Heα of Al XII, Ar XVII, and Ca XIX lines for the first time. The abundance pattern and the plasma mass suggest that Kes 17 is a remnant of a core-collapsed supernova of a 25-30 M⊙ progenitor star. The X-ray spectrum of the north region is expressed by a recombining plasma. The origin would be due to the cooling of electrons by thermal conduction to molecular clouds located near the north region.

  14. Onion-shell model of cosmic ray acceleration in supernova remnants

    NASA Technical Reports Server (NTRS)

    Bogdan, T. J.; Volk, H. J.

    1983-01-01

    A method is devised to approximate the spatially averaged momentum distribution function for the accelerated particles at the end of the active lifetime of a supernova remnant. The analysis is confined to the test particle approximation and adiabatic losses are oversimplified, but unsteady shock motion, evolving shock strength, and non-uniform gas flow effects on the accelerated particle spectrum are included. Monoenergetic protons are injected at the shock front. It is found that the dominant effect on the resultant accelerated particle spectrum is a changing spectral index with shock strength. High energy particles are produced in early phases, and the resultant distribution function is a slowly varying power law over several orders of magnitude, independent of the specific details of the supernova remnant.

  15. Is the Eagle Nebula powered by a hidden supernova remnant ?

    NASA Astrophysics Data System (ADS)

    Boulanger, Francois

    2008-10-01

    Spitzer observations of the Eagle nebula (M16) reveal the presence of a large (8 pc diameter) shell of dust heated to anomalously high temperatures. Modeling of dust excitation shows that the shell emission cannot be powered by the cluster UV radiation but that it can be accounted for by collisionally heated dust in a young (a few 1000 yrs) supernova remnant. We have re-analyzed deep Chandra observations that show diffuse emission consistent with this hypothesis, but also with galactic ridge emission. We propose a 50 ksec XMM observation to probe the spatial extent of the diffuse X-ray emission beyond the Spitzer shell. Absence of emission outside of this shell will strongly support the supernova remnant interpretation

  16. Fermi Large Area Telescope detection of a break in the gamma-ray spectrum of the supernova remnant Cassiopeia A [ Fermi-LAT detection of a break in the gamma-ray spectrum of the supernova remnant Cassiopeia A

    DOE PAGES

    Yuan, Yajie; Funk, Stefan; Jóhannesson, Gülauger; ...

    2013-12-02

    Here, we report on observations of the supernova remnant Cassiopeia A in the energy range from 100 MeV to 100 GeV using 44 months of observations from the Large Area Telescope on board the Fermi Gamma-Ray Space Telescope. We perform a detailed spectral analysis of this source and report on a low-energy break in the spectrum atmore » $$1.72^{+1.35}_{-0.89}$$ GeV. By comparing the results with models for the gamma-ray emission, we find that hadronic emission is preferred for the GeV energy range.« less

  17. DEM L241, A SUPERNOVA REMNANT CONTAINING A HIGH-MASS X-RAY BINARY

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

    Seward, F. D.; Charles, P. A.; Foster, D. L.

    2012-11-10

    A Chandra observation of the Large Magellanic Cloud supernova remnant DEM L241 reveals an interior unresolved source which is probably an accretion-powered binary. The optical counterpart is an O5III(f) star making this a high-mass X-ray binary with an orbital period likely to be of the order of tens of days. Emission from the remnant interior is thermal and spectral information is used to derive density and mass of the hot material. Elongation of the remnant is unusual and possible causes of this are discussed. The precursor star probably had mass >25 M {sub Sun}.

  18. The many sides of RCW 86: a Type Ia supernova remnant evolving in its progenitor's wind bubble

    NASA Astrophysics Data System (ADS)

    Broersen, Sjors; Chiotellis, Alexandros; Vink, Jacco; Bamba, Aya

    2014-07-01

    We present the results of a detailed investigation of the Galactic supernova remnant RCW 86 using the XMM-Newton X-ray telescope. RCW 86 is the probable remnant of SN 185 A.D., a supernova that likely exploded inside a wind-blown cavity. We use the XMM-Newton Reflection Grating Spectrometer to derive precise temperatures and ionization ages of the plasma, which are an indication of the interaction history of the remnant with the presumed cavity. We find that the spectra are well fitted by two non-equilibrium ionization models, which enables us to constrain the properties of the ejecta and interstellar matter plasma. Furthermore, we performed a principal component analysis on EPIC MOS and pn data to find regions with particular spectral properties. We present evidence that the shocked ejecta, emitting Fe K and Si line emission, are confined to a shell of approximately 2 pc width with an oblate spheroidal morphology. Using detailed hydrodynamical simulations, we show that general dynamical and emission properties at different portions of the remnant can be well reproduced by a Type Ia supernova that exploded in a non-spherically symmetric wind-blown cavity. We also show that this cavity can be created using general wind properties for a single degenerate system. Our data and simulations provide further evidence that RCW 86 is indeed the remnant of SN 185, and is the likely result of a Type Ia explosion of single degenerate origin.

  19. On the origin of cosmic rays. [gamma rays and supernova remnants

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1975-01-01

    Using Recent surveys of molecular clouds and gamma rays in the galaxy, it is possible to determine the distribution of 1 to 10 GeV cosmic-ray nucleons in the galaxy. This distribution appears to be identical to the supernova remnant distribution to within experimental error and provides strong support for the hypothesis that supernovae produce most of the observed cosmic rays. This distribution resembles that of OB associations of average age approximately 30 million years suggesting that cosmic rays are produced by population objects about 30 million years after their birth.

  20. Evidence for the Stochastic Acceleration of Secondary Antiprotons by Supernova Remnants

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

    Cholis, Ilias; Hooper, Dan; Linden, Tim

    2017-01-16

    The antiproton-to-proton ratio in the cosmic-ray spectrum is a sensitive probe of new physics. Using recent measurements of the cosmic-ray antiproton and proton fluxes in the energy range of 1-1000 GeV, we study the contribution to themore » $$\\bar{p}/p$$ ratio from secondary antiprotons that are produced and subsequently accelerated within individual supernova remnants. We consider several well-motivated models for cosmic-ray propagation in the interstellar medium and marginalize our results over the uncertainties related to the antiproton production cross section and the time-, charge-, and energy-dependent effects of solar modulation. We find that the increase in the $$\\bar{p}/p$$ ratio observed at rigidities above $$\\sim$$ 100 GV cannot be accounted for within the context of conventional cosmic-ray propagation models, but is consistent with scenarios in which cosmic-ray antiprotons are produced and subsequently accelerated by shocks within a given supernova remnant. In light of this, the acceleration of secondary cosmic rays in supernova remnants is predicted to substantially contribute to the cosmic-ray positron spectrum, accounting for a significant fraction of the observed positron excess.« less

  1. Supernovae-generated high-velocity compact clouds

    NASA Astrophysics Data System (ADS)

    Yalinewich, A.; Beniamini, P.

    2018-05-01

    Context. A previous study claimed the discovery of an intermediate-mass black hole (IMBH). This hypothetical black hole was invoked in order to explain the high-velocity dispersion in one of several dense molecular clouds near the Galactic center. The same study considered the possibility that this cloud was due to a supernova explosion, but disqualified this scenario because no X-rays were detected. Aims: We here check whether a supernova explosion could have produced that cloud, and whether this explanation is more likely than an IMBH. More specifically, we wish to determine whether a supernova inside a dense molecular cloud would emit in the X-rays. Methods: We have approached this problem from two different directions. First, we performed an analytic calculation to determine the cooling rate by thermal bremsstrahlung and compared this time to the lifetime of the cloud. Second, we estimated the creation rate of these dense clouds in the central molecular zone (CMZ) region near the Galactic center, where they were observed. Based on this rate, we can place lower bounds on the total mass of IMBHs and clouds and compare this to the masses of the components of the CMZ. Results: We find that the cooling time of the supernova remnant inside a molecular cloud is shorter than its dynamical time. This means that the temperature in such a remnant would be much lower than that of a typical supernova remnant. At such a low temperature, the remnant is not expected to emit in the X-rays. We also find that to explain the rate at which such dense clouds are created requires fine-tuning the number of IMBHs. Conclusions: We find the supernova model to be a more likely explanation for the formation of high-velocity compact clouds than an IMBH.

  2. X-ray spectroscopic observations and modeling of supernova remnants

    NASA Technical Reports Server (NTRS)

    Shull, J. M.

    1981-01-01

    The X-ray observations of young remnants and their theoretical interpretation are described. A number of questions concerning the nature of the blast wave interaction with the interstellar gas and grains and of atomic processes in these hot plasmas are considered. It is concluded that future X-ray spectrometers with high collecting area, moderate spectral resolution and good spatial resolution can make important contributions to the understanding of supernova remnants in the Milky Way and neighboring galaxies and of their role in the global chemical and dynamical evolution of the interstellar medium.

  3. Signs of Asymmetry in Exploding Stars

    NASA Astrophysics Data System (ADS)

    Hensley, Kerry

    2018-03-01

    Supernova explosions enrich the interstellar medium and can even briefly outshine their host galaxies. However, the mechanism behind these massive explosions still isnt fully understood. Could probing the asymmetry of supernova remnants help us better understand what drives these explosions?Hubble image of the remnant of supernova 1987A, one of the first remnants discovered to be asymmetrical. [ESA/Hubble, NASA]Stellar Send-OffsHigh-mass stars end their lives spectacularly. Each supernova explosion churns the interstellar medium and unleashes high-energy radiation and swarms of neutrinos. Supernovae also suffuse the surrounding interstellar medium with heavy elements that are incorporated into later generations of stars and the planets that form around them.The bubbles of expanding gas these explosions leave behind often appear roughly spherical, but mounting evidence suggests that many supernova remnants are asymmetrical. While asymmetry in supernova remnants can arise when the expanding material plows into the non-uniform interstellar medium, it can also be an intrinsic feature of the explosion itself.Simulation results clockwise from top left: Mass density, calcium mass fraction, oxygen mass fraction, nickel-56 mass fraction. Click to enlarge. [Adapted from Wollaeger et al. 2017]Coding ExplosionsThe presence or absence of asymmetry in a supernova remnant can hold clues as to what drove the explosion. But how can we best observe asymmetry in a supernova remnant? Modeling lets us explore different observational approaches.A team of scientists led by Ryan T. Wollaeger (Los Alamos National Laboratory) used radiative transfer and radiative hydrodynamics simulations to model the explosion of a core-collapse supernova. Wollaeger and collaborators introduced asymmetry into the explosion by creating a single-lobed, fast-moving outflow along one axis.Their simulations showed that while some chemical elements lingered near the origin of the explosion or were distributed evenly throughout the remnant, calcium was isolated to the asymmetrical region, hinting that spectral lines of calcium may be good tracersof asymmetry.Bolometric (top) and gamma-ray (bottom) synthetic light curves for the authors model for a range of simulated viewing angles. [Adapted from Wollaeger et al. 2017]Synthesizing SpectraWollaeger and collaborators then generated synthetic light curves and spectra from their models to determine which spectral features or characteristics indicated the presence of the asymmetric outflow lobe. They found that when an asymmetric outflow lobe is present, the peak luminosity of the explosion depends on the angle at which you view it; the highest luminosity occurs when the lobe is viewed from the side, while the lowest luminosity nearly40%dimmer is seen when the explosion is viewed down the barrel of the lobe. The dense outflow shades the central radioactive source from view, lowering the luminosity.This effect also plays out in the gamma-ray light curves; when viewed down the barrel, the shading of the central source by ahigh-density lobe slows the rise of the gamma-ray luminosity and changes the shape of the light curve compared to views from other vantage points.Another promising avenue for exploring asymmetry is a near-infrared band encompassing an emission line of singly-ionized calcium near 815 nm. Since calcium is confined within the outflow lobe in the simulation, its emission lines are blueshifted when the lobe points toward the observer.The authors point out that there is much more to be done in their models, such as including the effects of shock heating of circumstellar material, which can contribute strongly to the light curve, but these simulations bring us a step closer to understanding the nature of asymmetrical supernova remnants and the explosions that create them.CitationRyan T. Wollaeger et al 2017ApJ845168. doi:10.3847/1538-4357/aa82bd

  4. Discovery of Most Recent Supernova in Our Galaxy

    NASA Astrophysics Data System (ADS)

    2008-05-01

    The most recent supernova in our Galaxy has been discovered by tracking the rapid expansion of its remains. This result, using NASA's Chandra X-ray Observatory and NRAO's Very Large Array (VLA), has implications for understanding how often supernovas explode in the Milky Way galaxy. The supernova explosion occurred about 140 years ago, making it the most recent supernova in the Milky Way as measured in Earth's time frame. Previously, the last known galactic supernova occurred around 1680, based on studying the expansion of its remnant Cassiopeia A. X-ray Image Radio and X-ray Images The recent supernova explosion was not seen in optical light about 140 years ago because it occurred close to the center of the Galaxy, and is embedded in a dense field of gas and dust. This made it about a trillion times fainter, in optical light, than an unobscured supernova. However, the supernova remnant it caused, G1.9+0.3, is now seen in X-ray and radio images. "We can see some supernova explosions with optical telescopes across half of the Universe, but when they're in this murk we can miss them in our own cosmic backyard," said Stephen Reynolds of North Carolina State University, who led the Chandra study. "Fortunately, the expanding gas cloud from the explosion shines brightly in radio waves and X-rays for thousands of years. X-ray and radio telescopes can see through all that obscuration and show us what we've been missing." Astronomers regularly observe supernovas in other galaxies like ours, and based on those rates, estimate that about three should explode every century in our Milky Way, although these estimates have large margins of error. People Who Read This Also Read... Milky Way's Super-efficient Particle Accelerators Caught in The Act Oldest Known Objects Are Surprisingly Immature Action Replay of Powerful Stellar Explosion Milky Way’s Giant Black Hole Awoke from Slumber 300 Years Ago "If the supernova rate estimates are correct, there should be the remnants of about 10 supernova explosions that are younger than Cassiopeia A," said David Green of the University of Cambridge in the United Kingdom, who led the VLA study. "It's great to finally track one of them down." The tracking of this source began in 1985 when astronomers, led by Green, used the VLA to identify G1.9+0.3 as the remnant of a supernova explosion near the center of our Galaxy. Based on its small size, it was thought to have resulted from a supernova that exploded about 400 to 1000 years ago. Twenty two years later, Chandra observations of this object revealed that the remnant had expanded by a surprisingly large amount, about 16% since 1985. This indicates that the supernova remnant is much younger than previously thought. The young age was confirmed when new radio observations from the VLA were made just within the past several weeks. This "apples to apples" comparison nails the age of the remnant to be about 140 years (less if it has been slowing down), making it the youngest on record in the Milky Way. Finding such a recent, obscured supernova is a vital first step in making a better estimate of the supernova rate in our Galaxy. Knowing this rate is important because supernovas heat and redistribute large amounts of gas, pump large amounts of heavy elements out into their surroundings, and can trigger the formation of new stars, closing the cycle of stellar death and rebirth. The explosion may also leave behind, in addition to the expanding remnant, a central neutron star or black hole. In addition to being a record holder for youth, G1.9+0.3 is of considerable interest for other reasons. The high expansion velocities and the extreme particle energies that have been generated are unprecedented and should stimulate deeper studies of this object with Chandra and the VLA. "No other object in the Galaxy has properties like this," said Reynolds. "Finding G1.9+0.3 is extremely important for learning more about how some stars explode and what happens in the aftermath. Scientists can also use it to probe the environment into which it exploded. At perhaps only a few thousand light years from the center of the Galaxy, it appears to be embedded in the dense environment near the Milky Way's supermassive black hole. These results will appear in The Astrophysical Journal Letters. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass.

  5. Time evolution of gamma rays from supernova remnants

    NASA Astrophysics Data System (ADS)

    Gaggero, Daniele; Zandanel, Fabio; Cristofari, Pierre; Gabici, Stefano

    2018-04-01

    We present a systematic phenomenological study focused on the time evolution of the non-thermal radiation - from radio waves to gamma rays - emitted by typical supernova remnants via hadronic and leptonic mechanisms, for two classes of progenitors: thermonuclear and core-collapse. To this aim, we develop a numerical tool designed to model the evolution of the cosmic ray spectrum inside a supernova remnant, and compute the associated multi-wavelength emission. We demonstrate the potential of this tool in the context of future population studies based on large collection of high-energy gamma-ray data. We discuss and explore the relevant parameter space involved in the problem, and focus in particular on their impact on the maximum energy of accelerated particles, in order to study the effectiveness and duration of the PeVatron phase. We outline the crucial role of the ambient medium through which the shock propagates during the remnant evolution. In particular, we point out the role of dense clumps in creating a significant hardening in the hadronic gamma-ray spectrum.

  6. Walter Baade, Fritz Zwicky, and Rudolph Minkowski's Early Supernova Research, 1927 - 1973

    NASA Astrophysics Data System (ADS)

    Osterbrock, D. E.

    1999-12-01

    Long before he ``discovered" the two stellar populations, Walter Baade was a pioneer in research on supernovae and their remnants. In 1927, while still in Germany, Baade emphasized what he called ``Hauptnovae" (chief novae) as highly luminous, potential distance indicators. He joined the Mount Wilson staff in 1931, bringing the ``secret" of the Schmidt camera with him, and encouraged Fritz Zwicky to carry out a supernova search with one at Palomar. Baade and Zwicky used the term ``supernova" in their 1933 joint paper. Zwicky began a systematic search in 1936, and Baade followed up with the 100-in reflector to derive light curves. He confirmed that Tycho's ``nova" of 1572 and the Crab nebula had been supernovae in our Galaxy. Baade advised N. U. Mayall, at Lick, on his spectroscopic study of the Crab nebula. In 1933, after Hitler came to power, Rudolph Minkowski had to leave Germany. Baade managed to get him a Mount Wilson staff position. Minkowski then did the spectroscopic observations of supernovae, beginning in 1937. Within a few years he and Baade were able to distinguish type I and II supernovae. Baade's further work on supernovae included historical research in Latin, Italian, and German, as well as filter photography. He searched hard for a remnant of SN 1885 in M 31, but never succeeded in finding it. After World War II the Crab nebula was found to be a strong radio source, and Baade and Minkowski used the 200-in to identify other supernova remnants, beginning with Cas A. Baade collaborated closely with Jan Oort and his student, Lo Woltjer, in their studies of the Crab nebula. After Baade retired in 1958, Minkowski continued supernova research for more than a decade; one of his favorite objects was the expanding Cygnus Loop.

  7. Supernova 1987A: The Supernova of a Lifetime

    NASA Astrophysics Data System (ADS)

    Kirshner, Robert

    2017-01-01

    Supernova 1987A, the brightest supernova since Kepler's in 1604, was detected 30 years ago at a distance of 160 000 light years in the Large Magellanic Cloud, a satellite galaxy of the Milky Way. Visible with the naked eye and detected with the full range of technology constructed since Kepler's time, SN 1987A has continued to be a rich source of empirical information to help understand supernova explosions and their evolution into supernova remnants. While the light output has faded by a factor of 10 000 000 over those 30 years, instrumentation, like the Hubble Space Telescope, the Chandra X-ray Observatory, and the Atacama Large Millimeter Array has continued to improve so that this supernova continues to be visible in X-rays, ultraviolet light, visible light, infrared light and in radio emission. In this review, I will sketch what has been learned from these observations about the pre-supernova star and its final stages of evolution, the explosion physics, the energy sources for emission, and the shock physics as the expanding debris encounters the circumstellar ring that was created about 20 000 years before the explosion. Today, SN 1987A is making the transition to a supernova remnant- the energetics are no longer dominated by the radioactive elements produced in the explosion, but by the interaction of the expanding debris with the surrounding gas. While we are confident that the supernova explosion had its origin in gravitational collapse, careful searches for a compact object at the center of the remnant place upper limits of a few solar luminosities on that relic. Support for HST GO programs 13401 and 13405 was provided by NASA through grants from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

  8. A Year in the Life of an Infrared Echo

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Figure 1: Supernova Remnant Cassiopeia A One Year Apart

    These Spitzer Space Telescope images, taken one year apart, show the supernova remnant Cassiopeia A (yellow ball) and surrounding clouds of dust (reddish orange). The pictures illustrate that a blast of light from Cassiopeia A is waltzing outward through the dusty skies. This dance, called an 'infrared echo,' began when the remnant erupted about 50 years ago.

    Cassiopeia A is the remnant of a once massive star that died in a violent supernova explosion 325 years ago. It consists of a dead star, called a neutron star, and a surrounding shell of material that was blasted off as the star died. This remnant is located 10,000 light-years away in the northern constellation Cassiopeia.

    Infrared echoes are created when a star explodes or erupts, flashing light into surrounding clumps of dust. As the light zips through the dust clumps, it heats them up, causing them to glow successively in infrared, like a chain of Christmas bulbs lighting up one by one. The result is an optical illusion, in which the dust appears to be flying outward at the speed of light. Echoes are distinct from supernova shockwaves, which are made up material that is swept up and hurled outward by exploding stars.

    This infrared echo is the largest ever seen, stretching more than 50 light-years away from Cassiopeia A. If viewed from Earth, the entire movie frame would take up the same amount of space as two full moons.

    Hints of an older infrared echo from Cassiopeia A's supernova explosion hundreds of years ago can also be seen.

    The top Spitzer image was taken on November 30, 2003, and the bottom, on December 2, 2004.

  9. Multi-dimensional simulations of the expanding supernova remnant of SN 1987A

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

    Potter, T. M.; Staveley-Smith, L.; Reville, B.

    The expanding remnant from SN 1987A is an excellent laboratory for investigating the physics of supernovae explosions. There is still a large number of outstanding questions, such as the reason for the asymmetric radio morphology, the structure of the pre-supernova environment, and the efficiency of particle acceleration at the supernova shock. We explore these questions using three-dimensional simulations of the expanding remnant between days 820 and 10,000 after the supernova. We combine a hydrodynamical simulation with semi-analytic treatments of diffusive shock acceleration and magnetic field amplification to derive radio emission as part of an inverse problem. Simulations show that anmore » asymmetric explosion, combined with magnetic field amplification at the expanding shock, is able to replicate the persistent one-sided radio morphology of the remnant. We use an asymmetric Truelove and McKee progenitor with an envelope mass of 10 M {sub ☉} and an energy of 1.5 × 10{sup 44} J. A termination shock in the progenitor's stellar wind at a distance of 0.''43-0.''51 provides a good fit to the turn on of radio emission around day 1200. For the H II region, a minimum distance of 0.''63 ± 0.''01 and maximum particle number density of (7.11 ± 1.78) × 10{sup 7} m{sup –3} produces a good fit to the evolving average radius and velocity of the expanding shocks from day 2000 to day 7000 after explosion. The model predicts a noticeable reduction, and possibly a temporary reversal, in the asymmetric radio morphology of the remnant after day 7000, when the forward shock left the eastern lobe of the equatorial ring.« less

  10. Runaway companions of supernova remnants with Gaia

    NASA Astrophysics Data System (ADS)

    Boubert, Douglas; Fraser, Morgan; Evans, N. Wyn

    2018-04-01

    It is expected that most massive stars have companions and thus that some core-collapse supernovae should have a runaway companion. The precise astrometry and photometry provided by Gaia allows for the systematic discovery of these runaway companions. We combine a prior on the properties of runaway stars from binary evolution with data from TGAS and APASS to search for runaway stars within ten nearby supernova remnants. We strongly confirm the existing candidate HD 37424 in S147, propose the Be star BD+50 3188 to be associated with HB 21, and suggest tentative candidates for the Cygnus and Monoceros Loops.

  11. Measuring the Symmetry of Supernova Remnants in the Radio

    NASA Astrophysics Data System (ADS)

    Stafford, Jennifer; Lopez, Laura A.

    2017-01-01

    Nearly 300 supernova remnants (SNRs) are known in the MIlky Way galaxy, and they offer an important means to study the explosions and interactions of supernovae at sub-pc scales. In this poster, we present analysis of the morphology of Galactic SNRs at radio wavelengths. Specifically, we measure the symmetry of several tens of SNRs in 6- and 20-cm Very Large Array images using a multipole expansion technique, the power-ratio method. We explore how the SNRs' morphology changes as a function of their size and estimated dynamical ages, with the aim of probing how SNR shapes evolve with time.

  12. Fermi Large Area Telescope Detection Of The Young Supernova Remnant Tycho

    DOE PAGES

    Giordano, F.; Naumann-Godo, M.; Ballet, J.; ...

    2011-12-07

    After almost three years of data taking in sky survey mode, the Fermi -LAT has detected γ-ray emission toward the Tycho’s Supernova Remnant (SNR). The Tycho SNR is among the youngest remnants in the Galaxy, originating from a Type Ia Supernova in AD 1572. The γ-ray integral flux from 400 MeV up to 100 GeV has been measured to be (3.5±1.1stat±0.7syst)×10 -9 cm -2s -1 with a photon index of 2.3±0.2stat±0.1syst. A simple model consistent with TeV, X-ray and radio data is sufficient to explain the observed emission as originating from π 0-decays as a result of cosmicray acceleration andmore » interaction with the ambient medium.« less

  13. Limits on coronal material in normal galaxies

    NASA Technical Reports Server (NTRS)

    Mccammon, D.

    1986-01-01

    Measurements of the X-ray surface brightness of a face on disk galaxy M101, have previously been used to place upper limits on the power radiated by a hot corona. Such analysis contrains the effective density of the disk; either it must be so low that the remnants drive a fast hot wind (low radiated power) or so high that the remnant temperature at overlap is low (low X-ray power). These X-ray measurements are here used to constrain the properties of the population of supernova remnants evolving in the disk. This adds a further constraint since young remnants evolving in higher density radiate more of their energy in X-rays, whether or not they eventually overlap to generate a hot corona. The strength of this second limit depends strongly on the density history of the remnants and on the assumed supernova rate. For evaporative evolution the analysis rules out McKee and Ostriker ISM model in particular and evaporative evolution in general unless the supernova rate is at least several times lower than current expectations. For standard Sedov evolutions, the density limit marginally admits evolution in 0.2 cu m, a popular alternative to the McKee and Ostriker model.

  14. LMC P3

    NASA Image and Video Library

    2016-10-10

    This composite image contains data from Chandra (purple) that provides evidence for the survival of a companion star from the blast of a supernova explosion. Chandra's X-rays reveal a point-like source in the supernova remnant at the location of a massive star. The data suggest that mass is being pulled away from the massive star towards a neutron star or a black hole companion. If confirmed, this would be only the third binary system containing both a massive star and a neutron star or black hole ever found in the aftermath of a supernova. This supernova remnant is found embedded in clouds of ionized hydrogen, which are shown in optical light (yellow and cyan) from the MCELS survey, along with additional optical data from the DSS (white).

  15. On the velocity of the Vela pulsar

    NASA Astrophysics Data System (ADS)

    Gvaramadze, V.

    2001-04-01

    It is shown that if the shell of the Vela supernova remnant is responsible for nearly all the scattering of the Vela pulsar, then the scintillation and proper motion velocities of the pulsar can only be reconciled with each other in the case of nonzero transverse velocity of the scattering material. A possible origin of large-scale transverse motions in the shell of the Vela supernova remnant is discussed.

  16. A 3D View of a Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2017-06-01

    The outlined regions mark the 57 knots in Tycho selected by the authors for velocity measurements. Magenta regions have redshifted line-of-sight velocities (moving away from us); cyan regions have blueshifted light-of-sight velocities (moving toward us). [Williams et al. 2017]The Tycho supernova remnant was first observed in the year 1572. Nearly 450 years later, astronomers have now used X-ray observations of Tycho to build the first-ever 3D map of a Type Ia supernova remnant.Signs of ExplosionsSupernova remnants are spectacular structures formed by the ejecta of stellar explosions as they expand outwards into the surrounding interstellar medium.One peculiarity of these remnants is that they often exhibit asymmetries in their appearance and motion. Is this because the ejecta are expanding into a nonuniform interstellar medium? Or was the explosion itself asymmetric? The best way we can explore this question is with detailed observations of the remnants.Histograms of the velocity in distribution of the knots in the X (green), Y (blue) and Z (red) directions (+Z is away from the observer). They show no evidence for asymmetric expansion of the knots. [Williams et al. 2017]Enter TychoTo this end, a team of scientists led by Brian Williams (Space Telescope Science Institute and NASA Goddard SFC) has worked to map out the 3D velocities of the ejecta in the Tycho supernova remnant. Tycho is a Type Ia supernova thought to be caused by the thermonuclear explosion of a white dwarf in a binary system that was destabilized by mass transfer from its companion.After 450 years of expansion, the remnant now has the morphological appearance of a roughly circular cloud of clumpy ejecta. The forward shock wave from the supernova, however, is known to have twice the velocity on one side of the shell as on the other.To better understand this asymmetry, Williams and collaborators selected a total of 57 knots in Tychos ejecta, spread out around the remnant. They then used 12 years of Chandra X-ray observations to measure both the knots proper motion in the plane of the sky and their line-of-sight velocity. These two measurements were then combined to build a full 3D map of the motion of the ejecta.3D hydrodynamical simulations of Tycho, stopped at the current epoch. These show that both initially smooth (top) and initially clumpy (bottom) ejecta models are consistent with the current observations of the morphology and dynamics of Tychos ejecta. [Adapted from Williams et al. 2017]Symmetry and ClumpsWilliams and collaborators found that the knots have total velocities that range from 2400 to 6600 km/s. Unlike the forward shock of the supernova, Tychos ejecta display no asymmetries in their motion which suggests that the explosion itself was symmetric. The more likely explanation is a density gradient in the interstellar medium, which could slow the shock wave on one side of the remnant without yet affecting the motion of the clumps of ejecta.As a final exploration, the authors attempt to address the origin of Tychos clumpiness. The fact that some of Tychos ejecta knots precede its outer edge has raised the question of whether the ejecta started out clumpy, or if they began smooth and only clumped during expansion. Williams and collaborators matched the morphological and dynamical data to simulations, demonstrating that neither scenario can be ruled out at this time.This first 3D map of a Type Ia supernova represents an important step in our ability to understand these stellar explosions. The authors suggest that well be able to expand on this map in the future with additional observations from Chandra, as well as with new data from future X-ray observatories that will be able to detect fainter emission.CitationBrian J. Williams et al 2017 ApJ 842 28. doi:10.3847/1538-4357/aa7384

  17. An absence of ex-companion stars in the type Ia supernova remnant SNR 0509-67.5.

    PubMed

    Schaefer, Bradley E; Pagnotta, Ashley

    2012-01-11

    A type Ia supernova is thought to begin with the explosion of a white dwarf star. The explosion could be triggered by the merger of two white dwarfs (a 'double-degenerate' origin), or by mass transfer from a companion star (the 'single-degenerate' path). The identity of the progenitor is still controversial; for example, a recent argument against the single-degenerate origin has been widely rejected. One way to distinguish between the double- and single-degenerate progenitors is to look at the centre of a known type Ia supernova remnant to see whether any former companion star is present. A likely ex-companion star for the progenitor of the supernova observed by Tycho Brahe has been identified, but that claim is still controversial. Here we report that the central region of the supernova remnant SNR 0509-67.5 (the site of a type Ia supernova 400 ± 50 years ago, based on its light echo) in the Large Magellanic Cloud contains no ex-companion star to a visual magnitude limit of 26.9 (an absolute magnitude of M(V) = +8.4) within a region of radius 1.43 arcseconds. (This corresponds to the 3σ maximum distance to which a companion could have been 'kicked' by the explosion.) This lack of any ex-companion star to deep limits rules out all published single-degenerate models for this supernova. The only remaining possibility is that the progenitor of this particular type Ia supernova was a double-degenerate system.

  18. PSR J0538+2817 as the remnant of the first supernova explosion in a massive binary

    NASA Astrophysics Data System (ADS)

    Gvaramadze, V. V.

    It is generally accepted that the radio pulsar PSR J 0538 2817 is associated with the supernova remnant SNR S 147 The only problem for the association is the obvious discrepancy Kramer et al 2003 between the kinematic age of the system of sim 30 kyr estimated from the angular offset of the pulsar from the geometric center of the SNR and pulsar s proper motion and the characteristic age of the pulsar of sim 600 kyr To reconcile these ages one can assume that the pulsar was born with a spin period close to the present one Kramer et al 2003 Romani Ng 2003 We propose an alternative explanation of the age discrepancy based on the fact that PSR J 0538 2817 could be the stellar remnant of the first supernova explosion in a massive binary system and therefore could be as old as indicated by its characteristic age Our proposal implies that S 147 is the diffuse remnant of the second supernova explosion that disrupted the binary system and that a much younger second neutron star not necessarily manifesting itself as a radio pulsar should be associated with S 147 We use the existing observational data on the system PSR J 0538 2817 SNR S 147 to suggest that the progenitor of the supernova that formed S 147 was a Wolf-Rayet star so that the supernova explosion occurred within a wind bubble surrounded by a massive shell and to constrain the parameters of the binary system We also restrict the magnitude and direction of the kick velocity received by the young neutron star at birth and find that the kick vector

  19. PSR J0538+2817 As The Remnant Of The First Supernova Explosion in a Massive Binary

    NASA Astrophysics Data System (ADS)

    Gvaramadze, V. V.

    2006-08-01

    It is generally accepted that the radio pulsar PSR J0538+2817 is associated with the supernova remnant (SNR) S147. The only problem for the association is the obvious discrepancy (Kramer et al. 2003) between the kinematic age of the system of ~30 kyr (estimated from the angular offset of the pulsar from the geometric center of the SNR and pulsar's proper motion) and the characteristic age of the pulsar of ~600 kyr. To reconcile these ages one can assume that the pulsar was born with a spin period close to the present one (Kramer et al. 2003; Romani & Ng 2003). We propose an alternative explanation of the age discrepancy based on the fact that PSR J0538+2817 could be the stellar remnant of the first supernova explosion in a massive binary system and therefore could be as old as indicated by its characteristic age. Our proposal implies that S147 is the diffuse remnant of the second supernova explosion (that disrupted the binary system) and that a much younger second neutron star (not necessarily manifesting itself as a radio pulsar) should be associated with S147. We use the existing observational data on the system PSR J0538+2817/SNR S147 to suggest that the progenitor of the supernova that formed S147 was a Wolf-Rayet star (so that the supernova explosion occurred within a wind bubble surrounded by a massive shell) and to constrain the parameters of the binary system. We also restrict the magnitude and direction of the kick velocity received by the young neutron star at birth and find that the kick vector should not strongly deviate from the orbital plane of the binary system.

  20. Supernova remnant evolution in wind bubbles: A closer look at Kes 27

    NASA Astrophysics Data System (ADS)

    Dwarkadas, V. V.; Dewey, D.

    2013-03-01

    Massive Stars (>8M⊙) lose mass in the form of strong winds. These winds accumulate around the star, forming wind-blown bubbles. When the star explodes as a supernova (SN), the resulting shock wave expands within this wind-blown bubble, rather than the interstellar medium. The properties of the resulting remnant, its dynamics and kinematics, the morphology, and the resulting evolution, are shaped by the structure and properties of the wind-blown bubble. In this article we focus on Kes 27, a supernova remnant (SNR) that has been proposed by [1] to be evolving in a wind-blown bubble, explore its properties, and investigate whether the X-Ray properties could be ascribed to evolution of a SNR in a wind-blown bubble. Our initial model does not support the scenario proposed by [1], due to the fact that the reflected shock is expanding into much lower densities.

  1. High Energy Observational Investigations of Supernova Remnants and their Interactions with Surroundings

    NASA Astrophysics Data System (ADS)

    Hui, Chung-Yue

    2013-09-01

    Here we review the effort of Fermi Asian Network (FAN) in exploring the supernova remnants (SNRs) with state-of-art high energy observatories, including Fermi Gamma-ray Space Telescope and Chandra X-ray Observatory, in the period of 2011- 2012. Utilizing the data from Fermi LAT, we have discovered the GeV emission at the position of the Galactic SNR Kes 17 which provides evidence for the hadronic acceleration. Our study also sheds light on the propagation of cosmic rays from their acceleration site to the intersteller medium. We have also launched an identification campaign of SNR candidates in the Milky Way, in which a new SNR G308.3-1.4 have been uncovered with our Chandra observation. Apart from the remnant, we have also discovered an associated compact object at its center. The multiwavelength properties of this X-ray source suggest it can possibly be the compact binary that survived a supernova explosion.

  2. A comparison of models for supernova remnants including cosmic rays

    NASA Astrophysics Data System (ADS)

    Kang, Hyesung; Drury, L. O'C.

    1992-11-01

    A simplified model which can follow the dynamical evolution of a supernova remnant including the acceleration of cosmic rays without carrying out full numerical simulations has been proposed by Drury, Markiewicz, & Voelk in 1989. To explore the accuracy and the merits of using such a model, we have recalculated with the simplified code the evolution of the supernova remnants considered in Jones & Kang, in which more detailed and accurate numerical simulations were done using a full hydrodynamic code based on the two-fluid approximation. For the total energy transferred to cosmic rays the two codes are in good agreement, the acceleration efficiency being the same within a factor of 2 or so. The dependence of the results of the two codes on the closure parameters for the two-fluid approximation is also qualitatively similar. The agreement is somewhat degraded in those cases where the shock is smoothed out by the cosmic rays.

  3. High-Resolution X-Ray Spectroscopy of the Galactic Supernova Remnant Puppis A with the XMM-Newton RGS

    NASA Technical Reports Server (NTRS)

    Katsuda, Satoru; Tsunemi, Hiroshi; Mori, Koji; Uchida, Hiroyuki; Petre, Robert; Yamada, Shinya; Akamatsu, Hiroki; Konami, Saori; Tamagawa, Toru

    2012-01-01

    We present high-resolution X-ray spectra of cloud-shock interaction regions in the eastern and northern rims of the Galactic supernova remnant Puppis A, using the Reflection Grating Spectrometer onboard the XMM-Newton satellite. A number of emission lines including K(alpha) triplets of He-like N, O , and Ne are clearly resolved for the first time. Intensity ratios of forbidden to resonance lines in the triplets are found to be higher than predictions by thermal emission models having plausible plasma parameters. The anomalous line ratios cannot be reproduced by effects of resonance scattering, recombination, or inner-shell ionization processes, but could be explained by charge-exchange emission that should arise at interfaces between the cold/warm clouds and the hot plasma. Our observations thus provide observational support for charge-exchange X-ray emission in supernova remnants.

  4. Fermi-Lat and WMAP Observations of the Puppis a Supernova Remnant

    NASA Technical Reports Server (NTRS)

    Hewitt, John William; Grondin, M. H.; Lemoine-Goumard, M.; Reposeur, T.; Ballet, J.; Tanaka, T.

    2012-01-01

    We report the detection of GeV gamma-ray emission from the supernova remnant Puppis A with the Fermi Gamma-Ray Space Telescope. Puppis A is among the faintest supernova remnants yet detected at GeV energies, with a luminosity of only 2.7×10(exp 34) (D/2.2 kpc)(exp 2) erg s(exp -1) between 1 and 100 GeV. The gamma-ray emission from the remnant is spatially extended, with a morphology matching that of the radio and X-ray emission, and is well described by a simple power law with an index of 2.1. We attempt to model the broadband spectral energy distribution, from radio to gamma-rays, using standard nonthermal emission mechanisms. To constrain the relativistic electron population we use 7 years of WMAP data to extend the radio spectrum up to 93 GHz. Both leptonic and hadronic dominated models can reproduce the nonthermal spectral energy distribution, requiring a total content of cosmic ray (CR) electrons and protons accelerated in Puppis A of at least WCR is approx. (1 - 5)×10 (exp 49) erg.

  5. X-Ray Measured Dynamics of Tycho's Supernova Remnant

    NASA Technical Reports Server (NTRS)

    Katsuda, Satoru; Petre, Robert; Hughes, John; Hwang, Una; Yamaguchi, Hiroya; Hayato, Asami; Mori, Koji; Tsunemi, Hiroshi

    2010-01-01

    We present X-ray proper-motion measurements of the forward shock and reverse-shocked ejecta in Tycho's supernova remnant, based on three sets of archival Chandra data taken in 2000, 2003, and 2007. We find that the proper motion of the edge of the remnant (i.e., the forward shock and protruding ejecta knots) varies from 0.''20 yr-1 (expansion index m = 0.33, where R = tm ) to 0.''40 yr-1 (m = 0.65) with azimuthal angle in 2000-2007 measurements, and 0.''14 yr-1 (m = 0.26) to 0.''40 yr-1 (m = 0.65) in 2003-2007 measurements. The azimuthal variation of the proper motion and the average expansion index of [approx]0.5 are consistent with those derived from radio observations. We also find proper motion and expansion index of the reverse-shocked ejecta to be 0.''21-0.''31 yr-1 and 0.43-0.64, respectively. From a comparison of the measured m-value with Type Ia supernova evolutionary models, we find a pre-shock ambient density around the remnant of [less, similar]0.2 cm-3.

  6. OXYGEN-RICH SUPERNOVA REMNANT IN THE LARGE MAGELLANIC CLOUD

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This is a NASA Hubble Space Telescope image of the tattered debris of a star that exploded 3,000 years ago as a supernova. This supernova remnant, called N132D, lies 169,000 light-years away in the satellite galaxy, the Large Magellanic Cloud. A Hubble Wide Field Planetary Camera 2 image of the inner regions of the supernova remnant shows the complex collisions that take place as fast moving ejecta slam into cool, dense interstellar clouds. This level of detail in the expanding filaments could only be seen previously in much closer supernova remnants. Now, Hubble's capabilities extend the detailed study of supernovae out to the distance of a neighboring galaxy. Material thrown out from the interior of the exploded star at velocities of more than four million miles per hour (2,000 kilometers per second) plows into neighboring clouds to create luminescent shock fronts. The blue-green filaments in the image correspond to oxygen-rich gas ejected from the core of the star. The oxygen-rich filaments glow as they pass through a network of shock fronts reflected off dense interstellar clouds that surrounded the exploded star. These dense clouds, which appear as reddish filaments, also glow as the shock wave from the supernova crushes and heats the clouds. Supernova remnants provide a rare opportunity to observe directly the interiors of stars far more massive than our Sun. The precursor star to this remnant, which was located slightly below and left of center in the image, is estimated to have been 25 times the mass of our Sun. These stars 'cook' heavier elements through nuclear fusion, including oxygen, nitrogen, carbon, iron etc., and the titanic supernova explosions scatter this material back into space where it is used to create new generations of stars. This is the mechanism by which the gas and dust that formed our solar system became enriched with the elements that sustain life on this planet. Hubble spectroscopic observations will be used to determine the exact chemical composition of this nuclear- processed material, and thereby test theories of stellar evolution. The image shows a region of the remnant 50 light-years across. The supernova explosion should have been visible from Earth's southern hemisphere around 1,000 B.C., but there are no known historical records that chronicle what would have appeared as a 'new star' in the heavens. This 'true color' picture was made by superposing images taken on 9-10 August 1994 in three of the strongest optical emission lines: singly ionized sulfur (red), doubly ionized oxygen (green), and singly ionized oxygen (blue). Photo credit: Jon A. Morse (STScI) and NASA Investigating team: William P. Blair (PI; JHU), Michael A. Dopita (MSSSO), Robert P. Kirshner (Harvard), Knox S. Long (STScI), Jon A. Morse (STScI), John C. Raymond (SAO), Ralph S. Sutherland (UC-Boulder), and P. Frank Winkler (Middlebury). Image files in GIF and JPEG format may be accessed via anonymous ftp from oposite.stsci.edu in /pubinfo: GIF: /pubinfo/GIF/N132D.GIF JPEG: /pubinfo/JPEG/N132D.jpg The same images are available via World Wide Web from links in URL http://www.stsci.edu/public.html.

  7. An X-Ray and Radio Study of the Varying Expansion Velocities in Tycho's Supernova Remnant

    NASA Technical Reports Server (NTRS)

    Williams, Brian J.; Chomiuk, Laura; Hewitt, John W.; Blondin, John M.; Borkowski, Kazimierz J.; Ghavamian, Parviz; Petre, Robert; Reynolds, Stephen P.

    2016-01-01

    We present newly obtained X-ray and radio observations of Tycho's supernova remnant using Chandra and the Karl G. Jansky Very Large Array in 2015 and 2013/14, respectively. When combined with earlier epoch observations by these instruments, we now have time baselines for expansion measurements of the remnant of 12-15 year in the X-rays and 30 year in the radio. The remnant's large angular size allows for proper motion measurements at many locations around the periphery of the blast wave. We find, consistent with earlier measurements, a clear gradient in the expansion velocity of the remnant, despite its round shape. The proper motions on the western and southwestern sides of the remnant are about a factor of two higher than those in the east and northeast. We showed in an earlier work that this is related to an offset of the explosion site from the geometric center of the remnant due to a density gradient in the ISM, and using our refined measurements reported here, we find that this offset is approximately 23'' towards the northeast. An explosion center offset in such a circular remnant has implications for searches for progenitor companions in other remnants.

  8. Some Arguments in Support of the Association of PSR B1706-44 with the Supernova Remnant G343.1-2.3

    NASA Astrophysics Data System (ADS)

    Bock, D. C.-J.; Gvaramadze, V. V.

    We present some arguments in support of the association of the pulsar PSR B1706-44 with the supernova remnant G343.1-2.3, based on the idea that these objects could be the result of a supernova explosion within a mushroom-like cavity (created by the supernova progenitor wind breaking out of the parent molecular cloud). We suggest that in addition to the known bright "half" of G343.1-2.3 there should exist a more extended and weaker component, such that the actual shape of G343.1 2.3 is similar to that of the well-known SNR VRO 42.05.01. We have found such a component in archival radio data.

  9. Diffuse remnants of supernova explosions of moving massive stars

    NASA Astrophysics Data System (ADS)

    Gvaramadze, V. V.

    The modification of the ambient interstellar medium by the wind of massive stars (the progenitors of most of supernovae) results in that the structure and evolution of diffuse supernova remnants (SNRs) significantly deviate from those derived from standard models of SNRs based of the Sedov-Taylor solution. The stellar proper motion and the regular interstellar magnetic field affect the symmetry of the processed medium and cause the SNR to be non-spherically-symmetric. We show that taking into account these effects allows us to explain the diverse morphologies of the known SNRs (the particular attention is paid to the elongated axisymmetric SNRs and the SNRs consisting of two partially overlapping shells) and to infer the ``true" supernova explosion sites in some peculiar SNRs (therefore to search for new neutron stars associated with them).

  10. Dance into the fire: dust survival inside supernova remnants

    NASA Astrophysics Data System (ADS)

    Micelotta, Elisabetta R.; Dwek, Eli; Slavin, Jonathan D.

    2016-06-01

    Core collapse supernovae (CCSNe) are important sources of interstellar dust, potentially capable of producing 1 M_{⊙}) of dust in their explosively expelled ejecta. However, unlike other dust sources, the dust has to survive the passage of the reverse shock, generated by the interaction of the supernova blast wave with its surrounding medium. Knowledge of the net amount of dust produced by CCSNe is crucial for understanding the origin and evolution of dust in the local and high-redshift universe. Our goal is to identify the dust destruction mechanisms in the ejecta, and derive the net amount of dust that survives the passage of the reverse shock. To do so, we have developed analytical models for the evolution of a supernova blast wave and of the reverse shock, and the simultaneous processing of the dust inside the cavity of the supernova remnant. We have applied our models to the special case of the clumpy ejecta of the remnant of Cassiopeia A (Cas A), assuming that the dust (silicates and carbon grains) resides in cool oxygen-rich ejecta clumps which are uniformly distributed within the remnant and surrounded by a hot X-ray emitting plasma (smooth ejecta). The passage of the reverse shock through the clumps gives rise to a relative gas-grain motion and also destroys the clumps. While residing in the ejecta clouds, dust is processed via kinetic sputtering, which is terminated either when the grains escape the clumps, or when the clumps are destroyed by the reverse shock. In either case, grain destruction proceeds thereafter by thermal sputtering in the hot shocked smooth ejecta. We find that 12 and 16 percent of silicate and carbon dust, respectively, survive the passage of the reverse shock by the time the shock has reached the center of the remnant. These fractions depend on the morphology of the ejecta and the medium into which the remnant is expanding, as well as the composition and size distribution of the grains that formed in the ejecta. Results will therefore differ for different types of supernovae. I will discuss our models and results and briefly illustrate the impact of the capabilities of the Athena+ X-ray mission on the variety of astrophysical problems involving the processing of dust particles in extreme environments characterized by the presence of shocked X-ray emitting gas.

  11. Toward Connecting Core-Collapse Supernova Theory with Observations: Nucleosynthetic Yields and Distribution of Elements in a 15 M⊙ Blue Supergiant Progenitor with SN 1987A Energetics

    NASA Astrophysics Data System (ADS)

    Plewa, Tomasz; Handy, Timothy; Odrzywolek, Andrzej

    2014-09-01

    We compute and discuss the process of nucleosynthesis in a series of core-collapse explosion models of a 15 solar mass, blue supergiant progenitor. We obtain nucleosynthetic yields and study the evolution of the chemical element distribution from the moment of core bounce until young supernova remnant phase. Our models show how the process of energy deposition due to radioactive decay modifies the dynamics and the core ejecta structure on small and intermediate scales. The results are compared against observations of young supernova remnants including Cas A and the recent data obtained for SN 1987A. We compute and discuss the process of nucleosynthesis in a series of core-collapse explosion models of a 15 solar mass, blue supergiant progenitor. We obtain nucleosynthetic yields and study the evolution of the chemical element distribution from the moment of core bounce until young supernova remnant phase. Our models show how the process of energy deposition due to radioactive decay modifies the dynamics and the core ejecta structure on small and intermediate scales. The results are compared against observations of young supernova remnants including Cas A and the recent data obtained for SN 1987A. The work has been supported by the NSF grant AST-1109113 and DOE grant DE-FG52-09NA29548. This research used resources of the National Energy Research Scientific Computing Center, which is supported by the U.S. DoE under Contract No. DE-AC02-05CH11231.

  12. A more direct measure of supernova rates in starburst galaxies

    NASA Technical Reports Server (NTRS)

    Van Buren, Dave; Greenhouse, Matthew A.

    1994-01-01

    We determine ages for young supernova remnants in the starburst galaxies M82 and NGC 253 by applying Chevalier's model for radio emission from supernova blast waves expanding into the ejecta of their precursor stars. Absolute ages are determined by calibrating the model with radio observations of Cas A. We derive supernova rates of 0.10 and 0.08/yr for M82 and NGC 253, respectively. Assuming L (sub FIR) to be proportional to the supernova rate, we find r(sub SN) approximately equal 2 x 10(exp -12) x L(sub FIR), solar yr(exp -1) for these archetypal starburst galaxies. This approach is unique in that the supernova rate is derived from direct observation of supernova remnants rather than from star formation rates and an assumed initial mass function (IMF). We suggest that the approach presented here can be used to derive star-formation rates that are more directly related to observable quantities than those derived by other methods. We find that the supernova rate, far infrared (FIR) luminosity, and dynamical mass of the M82 starburst place few constraints on the initial mass function (IMF) slope and mass limits.

  13. X-Ray Ejecta Kinematics of the Galactic Core-Collapse Supernova Remnant G292.0+1.8

    NASA Astrophysics Data System (ADS)

    Bhalerao, Jayant; Park, Sangwook; Dewey, Daniel; Hughes, John P.; Mori, Koji; Lee, Jae-Joon

    2015-02-01

    We report on the results from the analysis of our 114 ks Chandra High Energy Transmision Grating Spectrometer observation of the Galactic core-collapse supernova remnant G292.0+1.8. To probe the three-dimensional structure of the clumpy X-ray emitting ejecta material in this remnant, we measured Doppler shifts in emission lines from metal-rich ejecta knots projected at different radial distances from the expansion center. We estimate radial velocities of ejecta knots in the range of -2300 lsim vr lsim 1400 km s-1. The distribution of ejecta knots in velocity versus projected-radius space suggests an expanding ejecta shell with a projected angular thickness of ~90'' (corresponding to ~3 pc at d = 6 kpc). Based on this geometrical distribution of the ejecta knots, we estimate the location of the reverse shock approximately at the distance of ~4 pc from the center of the supernova remnant, putting it in close proximity to the outer boundary of the radio pulsar wind nebula. Based on our observed remnant dynamics and the standard explosion energy of 1051 erg, we estimate the total ejecta mass to be lsim8 M ⊙, and we propose an upper limit of lsim35 M ⊙ on the progenitor's mass.

  14. The Magellanic Cloud supernova remnants

    NASA Astrophysics Data System (ADS)

    Dopita, M. A.

    1984-09-01

    The first supernova remnant (SNR) in the Magellanic Clouds was discovered by Mathewson and Healey (1964). Surveys for SNR in the Magellanic Clouds are discussed, taking into account the selection procedure initially used, current optical selection criteria for SNR, the launching of the Einstein Observatory, and the information obtainable by a detailed study of the discovered SNR. Attention is also given to the oxygen-rich SNR, the nonradiative shock SNR, the evolved radiative SNR, and conclusions based on the obtained results.

  15. Exploring the Diffuse X-ray Emission of Supernova Remnant Kesteven 69 with XMM-Newton

    NASA Astrophysics Data System (ADS)

    Seo, Kyoung-Ae; Hui, Chung Yue

    2013-06-01

    We have investigated the X-ray emission from the shock-heated plasma of the Galactic supernova remnant Kesteven 69 with XMM-Newton. Assuming the plasma is at collisional ionization equilibrium, a plasma temperature and a column absorption are found to be kT ~ 0.62 keV and NH ~ 2.85 ×10^22 cm-2 respectively by imaging spectroscopy. Together with the deduced emission measure, we place constraints on its Sedov parameters.

  16. Multi-epoch very long baseline interferometric observations of the nuclear starburst region of NGC 253: Improved modeling of the supernova and star formation rates

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

    Rampadarath, H.; Morgan, J. S.; Tingay, S. J.

    2014-01-01

    The results of multi-epoch observations of the southern starburst galaxy, NGC 253, with the Australian Long Baseline Array at 2.3 GHz are presented. As with previous radio interferometric observations of this galaxy, no new sources were discovered. By combining the results of this survey with Very Large Array observations at higher frequencies from the literature, spectra were derived and a free-free absorption model was fitted of 20 known sources in NGC 253. The results were found to be consistent with previous studies. The supernova remnant, 5.48-43.3, was imaged with the highest sensitivity and resolution to date, revealing a two-lobed morphology.more » Comparisons with previous observations of similar resolution give an upper limit of 10{sup 4} km s{sup –1} for the expansion speed of this remnant. We derive a supernova rate of <0.2 yr{sup –1} for the inner 300 pc using a model that improves on previous methods by incorporating an improved radio supernova peak luminosity distribution and by making use of multi-wavelength radio data spanning 21 yr. A star formation rate of SFR(M ≥ 5 M {sub ☉}) < 4.9 M {sub ☉} yr{sup –1} was also estimated using the standard relation between supernova and star formation rates. Our improved estimates of supernova and star formation rates are consistent with studies at other wavelengths. The results of our study point to the possible existence of a small population of undetected supernova remnants, suggesting a low rate of radio supernova production in NGC 253.« less

  17. The Proper Motion of the Central Compact Object RX J0822-4300 in the Supernova Remnant Puppis A

    NASA Technical Reports Server (NTRS)

    Becker, Werner; Prinz, Tobias; Winkler, P. Frank; Petre, Robert

    2012-01-01

    Using the High Resolution Camera (HRC) aboard the Chandra X-ray Observatory, we have re-examined the proper motion of the central compact object RX J0822-4300 in the supernova remnant Puppis A. New data from 2010 August, combined with three archival data sets from as early as 1999 December, provide a baseline of 3886 days (more than 10 1/2 years) to perform the measurement. Correlating the four positions of RX J0822-4300 measured in each data set implies a projected proper motion of mu = 71 +/- 12 mas/yr. For a distance of 2 kpc this proper motion is equivalent to a recoil velocity of 672 +/- 115 km/s. The position angle is found to be 244 +/- 11 degrees. Both the magnitude and direction of the proper motion are in agreement with RX J0822-4300 originating near the optical expansion center of the supernova remnant. For a displacement of 371 +/- 31 arcsec between its birth place and today's position we deduce an age of (5.2 +/- 1.0) 10(exp 3) yrs for RX J0822-4300. The age inferred from the neutron star proper motion and filament motions can be considered as two independent measurements of the same quantity. They average to 4450 +/- 750 yrs for the age of the supernova remnant Puppis A.

  18. Explaining the morphology of supernova remnant (SNR) 1987A with the jittering jets explosion mechanism

    NASA Astrophysics Data System (ADS)

    Bear, Ealeal; Soker, Noam

    2018-07-01

    We find that the remnant of supernova (SN) 1987A shares some morphological features with four supernova remnants (SNRs) that have signatures of shaping by jets, and from that we strengthen the claim that jets played a crucial role in the explosion of SN 1987A. Some of the morphological features appear also in planetary nebulae (PNe) where jets are observed. The clumpy ejecta brings us to support the claim that the jittering jets explosion mechanism can account for the structure of the remnant of SN 1987A, i.e. SNR 1987A. We conduct a preliminary attempt to quantify the fluctuations in the angular momentum of the mass that is accreted on to the newly born neutron star via an accretion disc or belt. The accretion disc/belt launches jets that explode core collapse supernovae (CCSNe). The relaxation time of the accretion disc/belt is comparable to the duration of a typicalfigu jet-launching episode in the jittering jets explosion mechanism, and hence the disc/belt has no time to relax. We suggest that this might explain the two unequal opposite jets that later lead to the unequal sides of the elongated structures in some SNRs of CCSNe. We reiterate our earlier call for a paradigm shift from a neutrino-driven explosion to a jet-driven explosion of CCSNe.

  19. Explaining the morphology of supernova remnant (SNR) 1987A with the jittering jets explosion mechanism

    NASA Astrophysics Data System (ADS)

    Bear, Ealeal; Soker, Noam

    2018-04-01

    We find that the remnant of supernova (SN) 1987A shares some morphological features with four supernova remnants (SNRs) that have signatures of shaping by jets, and from that we strengthen the claim that jets played a crucial role in the explosion of SN 1987A. Some of the morphological features appear also in planetary nebulae (PNe) where jets are observed. The clumpy ejecta bring us to support the claim that the jittering jets explosion mechanism can account for the structure of the remnant of SN 1987A, i.e., SNR 1987A. We conduct a preliminary attempt to quantify the fluctuations in the angular momentum of the mass that is accreted on to the newly born neutron star via an accretion disk or belt. The accretion disk/belt launches the jets that explode core collapse supernovae (CCSNe). The relaxation time of the accretion disk/belt is comparable to the duration of a typical jet-launching episode in the jittering jets explosion mechanism, and hence the disk/belt has no time to relax. We suggest that this might explain two unequal opposite jets that later lead to unequal sides of the elongated structures in some SNRs of CCSNe. We reiterate our earlier call for a paradigm shift from neutrino-driven explosion to a jet-driven explosion of CCSNe.

  20. Action Replay of Powerful Stellar Explosion

    NASA Astrophysics Data System (ADS)

    2008-03-01

    Astronomers have made the best ever determination of the power of a supernova explosion that was visible from Earth long ago. By observing the remnant of a supernova and a light echo from the initial outburst, they have established the validity of a powerful new method for studying supernovas. Using data from NASA's Chandra X-ray Observatory, ESA's XMM-Newton Observatory, and the Gemini Observatory, two teams of researchers studied the supernova remnant and the supernova light echo that are located in the Large Magellanic Cloud (LMC), a small galaxy about 160,000 light years from Earth. They concluded that the supernova occurred about 400 years ago (in Earth’s time frame), and was unusually bright and energetic. X-ray Image of SNR 0509-67.5 X-ray Image of SNR 0509-67.5 This result is the first time two methods - X-ray observations of a supernova remnant and optical observations of the expanding light echoes from the explosion - have both been used to estimate the energy of a supernova explosion. Up until now, scientists had only made such an estimate using the light seen soon after a star exploded, or using remnants that are several hundred years old, but not from both. "People didn't have advanced telescopes to study supernovas when they went off hundreds of years ago," said Armin Rest of Harvard University, who led the light echo observations using Gemini. "But we've done the next best thing by looking around the site of the explosion and constructing an action replay of it." People Who Read This Also Read... Milky Way's Super-efficient Particle Accelerators Caught in The Act Oldest Known Objects Are Surprisingly Immature Discovery of Most Recent Supernova in Our Galaxy NASA Unveils Cosmic Images Book in Braille for Blind Readers In 2004, scientists used Chandra to determine that a supernova remnant, known as SNR 0509-67.5 in the LMC, was a so-called Type Ia supernova, caused by a white dwarf star in a binary system that reaches a critical mass and explodes. In the new optical study, an estimate of the explosion's energy came from studying an echo of the original light of the explosion. Just as sound bounces off walls of a canyon, so too can light waves create an echo by bouncing off dust clouds in space. The light from these echoes travels a longer path than the light that travels straight toward us, and so can be seen hundreds of years after the supernova itself. First seen by the Cerro-Tololo Inter-American Observatory in Chile, the light echoes were observed in greater detail by Gemini Observatory in Chile. The optical spectra of the light echo were used to confirm that the supernova was a Type Ia and to unambiguously determine the particular class of explosion and therefore its energy. The Chandra data, along with XMM data obtained in 2000, were then independently used to calculate the amount of energy involved in the original explosion, using an analysis of the supernova remnant and state-of-the-art explosion models. Their conclusion confirmed the results from the optical data, namely that the explosion was an especially energetic and bright variety of Type Ia supernova. This agreement provides strong evidence that the detailed explosion models are accurate. "Having these two methods agree lets us breathe a sigh of relief," said Carlos Badenes of Princeton University who led the Chandra and XMM study. "It looks like we're on the right track with trying to understand these big explosions. Their stellar debris really can retain a memory of what created them hundreds of years earlier." Both methods estimated a similar time since the explosion of about 400 years. An extra constraint on the age comes from the lack of recorded historical evidence for a recent supernova in the LMC. Because this star appears in the Southern Hemisphere, it likely would have been seen by navigators who noted similarly bright celestial events if it had occurred less than about 400 years ago. Because Type Ia supernovas have nearly uniform intrinsic brightness, they are used as important tools by scientists to study the expansion of the universe and the nature of dark energy. "It's crucial to know that the basic assumptions about these explosions are correct, so they're not used just as black-boxes to measure distances," said Badenes. This work is also being extended to other supernova remnants and light echoes. "This is the first case where the conclusions that are drawn from the supernova remnant about the original explosion can be directly tested by looking at the original event itself," said Rest. "We'll be able to learn a lot about supernovas in our own galaxy by using this technique." These results appear in two recently accepted papers in The Astrophysical Journal. The first discusses the spectrum obtained by Gemini, led by Rest. The second, with Badenes as first author, details the Chandra and XMM observations of SNR 0509-67.5. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass.

  1. On the Anomalously Large Extension of the Pulsar Wind Nebula HESS J1825-137

    NASA Astrophysics Data System (ADS)

    Khangulyan, Dmitry; Koldoba, Alexander V.; Ustyugova, Galina V.; Bogovalov, Sergey V.; Aharonian, Felix

    2018-06-01

    The very high energy gamma-ray emission reported from a number of pulsar wind nebulae (PWNe) is naturally explained by the inverse Compton scattering of multi-TeV electrons. However, the physical dimensions of some gamma-ray-emitting PWNe significantly exceed the scales anticipated by the standard hydrodynamical paradigm of PWN formation. The most “disturbing” case in this regard is HESS J1825-137, which extends to distances of r ≈ 70 pc from the central pulsar PSR J1826‑1334. If the gamma-ray emission is indeed produced inside the PWN, but not by electrons that escaped the nebula and diffuse in the interstellar medium (ISM), the formation of such an anomalously extended plerion could be realized, in a diluted environment with the hydrogen number density {n}{{ISM}}≤slant {10}-2 {cm}}-3. In this paper, we explore an alternative scenario assuming that the pulsar responsible for the formation of the nebula initially had a very short rotation period. In this case, the sizes of both the PWN and the surrounding supernova remnant depend on the initial pulsar period, the braking index, and the ISM density. To check the feasibility of this scenario, we study the parameter space that would reproduce the size of HESS J1825-137. We show that this demand can be achieved if the braking index is small, n≤slant 2, and the pulsar birth period is short, {P}{{b}}≃ 1 {ms}. This scenario can reproduce the wind termination position, which is expected at {R}{{TS}}≃ 0.03 {pc}, only in a dense environment with {n}{{ISM}}≥slant 1 {cm}}-3. The requirement of the dense surrounding gas is supported by the presence of molecular clouds found in the source vicinity.

  2. The Case of the Neutron Star With a Wayward Wake

    NASA Astrophysics Data System (ADS)

    2006-06-01

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

  3. Gamma-Ray Bursts and Their Links with Supernovae and Cosmology

    NASA Technical Reports Server (NTRS)

    Meszaros, Peter; Gehrels, Neil

    2012-01-01

    Gamma-ray bursts are the most luminous explosions in the Universe, whose origin and mechanism are the focus of intense interest. They appear connected to supernova remnants from massive stars or the merger of their remnants, and their brightness makes them temporarily detectable out to the largest distances yet explored in the universe. After pioneering breakthroughs from space and ground experiments, their study is entering a new phase with observations from the recently launched Fermi satellite, as well as the prospect of detections or limits from large neutrino and gravitational wave detectors. The interplay between such observations and theoretical models of gamma-ray bursts is reviewed, as well as their connections to supernovae and cosmology.

  4. Gamma Ray Bursts and Their Links With Supernovae and Cosmology

    NASA Technical Reports Server (NTRS)

    Meszaros, Peter; Gehrels, Neil

    2012-01-01

    Gamma-ray bursts are the most luminous explosions in the Universe, whose origin and mechanism is the focus of intense interest. They appear connected to supernova remnants from massive stars or the merger of their remnants, and their brightness makes them temporarily detectable out to the largest distances yet explored in the Universe. After pioneering breakthroughs from space and ground experiments, their study is entering a new phase with observations from the recently launched Fermi satellite, as well as the prospect of detections or limits from large neutrino and gravitational wave detectors. The interplay between such observations and theoretical models of gamma-ray bursts is reviewed, as well as their connections to supernovae and cosmology.

  5. The slow X-ray pulsar SXP 1062 and associated supernova remnant in the Wing of the Small Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Oskinova, L. M.; Guerrero, M. A.; Hénault-Brunet, V.; Sun, W.; Chu, Y.-H.; Evans, C.; Gallagher, J. S.; Gruendl, R. A.; Reyes-Iturbide, J.

    2013-03-01

    SXP 1062 is an exceptional case of a young neutron star in a wind-fed high-mass X-ray binary associated with a supernova remnant. A unique combination of measured spin period, its derivative, luminosity and young age makes this source a key probe for the physics of accretion and neutron star evolution. Theoretical models proposed to explain the properties of SXP 1062 shall be tested with new data.

  6. The Association of PSR B1757-24 and the SNR G5.4-1.2

    NASA Astrophysics Data System (ADS)

    Gvaramadze, V. V.

    The association of PSR B1757-24 and the supernova remnant (SNR) G5.4-1.2 was recently questioned by Thorsett et al. (2002) on the basis of proper motion measurements of the pulsar and the "incorrect" orientation of the vector of pulsar transverse velocity (inferred from the orientation of the cometary-shaped pulsar wind nebula). We show, however, that the association could be real if both objects are the remnants of an off-centered cavity supernova explosion.

  7. Temperature relaxation in supernova remnants, revisited

    NASA Technical Reports Server (NTRS)

    Itoh, H.

    1984-01-01

    Some supernova remnants are expanding into a partially neutral medium. The neutral atoms which are engulfed by the fast blast shock are collisionally ionized to eject low-energy secondary electrons. Calculations are conducted of the temperature relaxation through Coulomb collisions among the secondary electrons, the shocked electrons, and the ions, assuming that the three species have Maxwellian velocity distributions. The results are applied to a self-similar blast wave. If the efficiency of collisionless electron heating at the shock front is high in young remnants such as Tycho, the secondary electrons may be much cooler than both the shocked electrons and the ions. In this case, the emergent X-ray continuum spectrum will have a two-temperature, or a power-law, appearance. This effect may have been observed in the bright rim of the remnant of SN 1006.

  8. X-Rays form the Vela-Puppis Complex

    NASA Technical Reports Server (NTRS)

    Bunner, A. N.

    1971-01-01

    A review of X-ray observations in the vicinity of the Gum nebula is presented. There is little doubt that the filamentary nebula Stromlo 16, the radio source Vela X, and the extended X-ray object Vel XR-2 are indications of the same, relatively nearby, supernova remnant. X-ray absorption measurements are consistent with a distance of 500 + or - 100 pc. The observed X-ray spectra have not yet distinguished between thermal bremsstrahlung and synchrotron radiation as the source mechanism. A search for low energy X-ray emission lines, both within the 5 deg diameter remnant and in the larger Gum nebula, may provide an important test for models of supernova remnant evolution.

  9. Investigating the galactic Supernova Remnant Kes 78 with XMM-Newton

    NASA Astrophysics Data System (ADS)

    Miceli, M.; Bamba, A.; Orlando, S.; Bocchino, F.

    2016-06-01

    The galactic supernova remnant Kes 78 is associated with a HESS gamma-ray source and its X-ray emission has been recently revealed by Suzaku observations which have found indications for a hard X-ray component in the spectra. We analyzed an XMM-Newton EPIC observation of Kes 78 and studied the spatial distribution of the physical and chemical properties of the X-ray emitting plasma. The EPIC data unveiled a very complex morphology for the soft X-ray emission. We performed image analysis and spatially resolved spectral analysis finding indications for the interaction of the remnant with a local molecular cloud. Finally, we investigated the origin of the hard X-ray emitting component.

  10. Investigating the Galactic supernova remnant Kes 78 with XMM-Newton

    NASA Astrophysics Data System (ADS)

    Miceli, Marco; Bamba, Aya; Orlando, Salvatore; Bocchino, Fabrizio

    2016-06-01

    The galactic supernova remnant Kes 78 is associated with a HESS gamma-ray source and its X-ray emission has been recently revealed by Suzaku observations which have found indications for a hard X-ray component in the spectra. We analyzed an XMM-Newton EPIC observation of Kes 78 and studied the spatial distribution of the physical and chemical properties of the X-ray emitting plasma. The EPIC data unveiled a very complex morphology for the soft X-ray emission. We performed image analysis and spatially resolved spectral analysis finding indications for the interaction of the remnant with a local molecular cloud. Finally, we investigated the origin of the hard X-ray emitting component.

  11. Onion-shell model for cosmic ray electrons and radio synchrotron emission in supernova remnants

    NASA Technical Reports Server (NTRS)

    Beck, R.; Drury, L. O.; Voelk, H. J.; Bogdan, T. J.

    1985-01-01

    The spectrum of cosmic ray electrons, accelerated in the shock front of a supernova remnant (SNR), is calculated in the test-particle approximation using an onion-shell model. Particle diffusion within the evolving remnant is explicity taken into account. The particle spectrum becomes steeper with increasing radius as well as SNR age. Simple models of the magnetic field distribution allow a prediction of the intensity and spectrum of radio synchrotron emission and their radial variation. The agreement with existing observations is satisfactory in several SNR's but fails in other cases. Radiative cooling may be an important effect, especially in SNR's exploding in a dense interstellar medium.

  12. VLBI of supernovae and gamma-ray bursts

    NASA Astrophysics Data System (ADS)

    Bartel, N.; Karimi, B.; Bietenholz, M. F.

    2017-04-01

    Supernovae and gamma-ray bursts (GRBs) are among the brightest events in the universe. Excluding Type Ia supernovae and short GRBs, they are the result of the core collapse of a massive star with material being ejectedwith speeds of several 1000 km/s to nearly the speed of light, and with a neutron star or a black hole left over as the compact remnant of the explosion. Synchrotron radiation in the radio is generated in a shell when the ejecta interact with the surrounding medium and possibly also in the central region near the compact remnant itself. VLBI has allowed resolving some of these sources and monitoring their expansion in detail, thereby revealing characteristics of the dying star, the explosion, the expanding shock front, and the expected compact remnant. We report on updates of some of the most interesting results that have been obtained with VLBI so far. Movies of supernovae are available from our website. They show the evolution from shortly after the explosion to decades thereafter, in one case revealing an emerging compact central source, which may be associated with shock interaction near the explosion center or with the stellar corpse itself, a neutron star or a black hole.

  13. Echoes of a Stellar Ending

    NASA Image and Video Library

    2012-03-14

    Listed as Cassiopeia A, this remnant of the supernova is one of the brightest radio sources in the known universe. More recently, NASA WISE telescope detected infrared echoes of the flash of light rippling outwards from the supernova.

  14. The Progenitor of the New COMPTEL/ROSAT Supernova Remnant in Vela

    NASA Technical Reports Server (NTRS)

    Chen, Wan; Gehrels, Neil

    1999-01-01

    We show that (1) the newly discovered supernova remnant (SNR) GROJ0852-4642/RXJ0852.0-4622 was created by a core-collapse supernova of a massive star and (2) the same supernova event that produced the Ti-44 detected by COMPTEL from this source is probably also responsible for a large fraction of the observed Al-26 emission in the Vela region detected by the same instrument. The first conclusion is based on the fact that the remnant is currently expanding too slowly given its young age for it to be caused by a Type la supernova. If the current SNR shell expansion speed is greater than 3000 km/s, a 15 solar mass. Type II supernova with a moderate kinetic energy exploding at about 150 pc away is favored. If the SNR expansion speed is lower than 2000 km/s, as derived naively from X-ray data, a much more energetic supernova is required to have occurred at approximately 250 pc away in a dense environment at the edge of the Gum Nebula. This progenitor has a preferred ejecta mass of less than or equal to 10(Solar Mass), and therefore it is probably a Type Ib or Type Ic supernova. However, the required high ambient density of n(sub H) greater than or equal to 100 cu cm in this scenario is difficult to reconcile with the regional CO data. A combination of our estimates of the age/energetics of the new SNR and the almost perfect positional coincidence of the new SNR with the centroid of the COMPTEL Al-26 emission feature of the Vela region strongly favors a causal connection. If confirmed, this will be the first case in which both Ti-44 and Al-26 are detected from the same young SNR, and together they can be used to select preferred theoretical core-collapse supernova models.

  15. Mapping Calcium Rich Ejecta in Two Type Ia Supernovae

    NASA Astrophysics Data System (ADS)

    Fesen, Robert

    2016-10-01

    Type Ia supernovae (SNe Ia) are thermonuclear explosions of white dwarfs (WDs) in close binary systems with either a non-degenerate or WD companion. SN Ia explosion computations are quite challenging, involving a complex interplay of turbulent hydrodynamics, nuclear burning, conduction, radiative transfer in iron-group rich material and possibly magnetic fields leading to significant uncertainties. Several key questions about expansion asymmetries and the overall characteristics of SNe Ia could be resolved if one could obtain direct observations of the internal kinematics and elemental distributions of young SN Ia remnants.We propose to use WFC3/UVIS to obtain images of the normal Type Ia supernova remnant 0519-69.0 and the overluminous Type Ia supernova remnant 0509-67.5 in the LMC. The Ca II on-band F390M filter and off-band F336W and FQ422M filters will be used to determine the spatial extent and density distributions of the Ca-rich ejecta via resonance line absorption. Differences in the observed on and off band Ca II fluxes for LMC stars located behind these young 400 - 600 yr old remnants will yield calcium column density estimates for multiple lines-of-sight within these remnants. These results will be compared to the calcium distribution seen in SN 1885, a subluminous SN Ia in M31, already imaged by HST.The resulting calcium density distribution maps for both a normal and overluminous SN Ia events will provide powerful insights regarding the structure and kinematics of calcium-rich ejecta in three different type Ia subclass events, and unique empirical data with which to test current SN Ia explosion models.

  16. Neutron Star/supernova Remnant Associations

    NASA Astrophysics Data System (ADS)

    Gvaramadze, V. V.

    We propose a new approach for studying the neutron star/supernova remnant associations, based on the idea that the (diffuse) supernova remnants (SNRs) can be products of an off-centred supernova (SN) explosion in a preexisting bubble created by the wind of a moving massive star. A cavity SN explosion of a moving star results in a considerable offset of the neutron star (NS) birth-place from the geometrical centre of the SNR. Therefore: a) the high transverse velocities inferred for a number of NSs (e.g. PSR B 1610-50, PSR B 1757-24, SGR 0525-66) through their association with SNRs can be reduced; b) the proper motion vector of a NS should not necessarily point away from the geometrical centre of the associated SNR. Taking into account of these two facts allow us to enlarge the circle of possible NS/SNR associations, and could significantly affect the results of previous studies of NS/SNR associations. The possibilities of our approach are illustrated with the example of the association between PSR B 1706-44 and SNR G 343.1-2.3. We show that this association could be real if both objects are the remnants of a SN exploded within a mushroom-like cavity (created by the SN progenitor wind breaking out of the parent molecular cloud and expanding into an intercloud medium of a much less density). We also show that the SN explosion sites in some middle-aged (shell-like) SNRs could be marked by (compact) nebulae of thermal X-ray emission. The possible detection of such nebulae within middle-aged SNRs could be used for the re-estimation of implied transverse velocities of known NSs or for the search of new stellar remnants possibly associated with these SNRs.

  17. X-ray Observations of Cosmic Ray Acceleration

    NASA Technical Reports Server (NTRS)

    Petre, Robert

    2012-01-01

    Since the discovery of cosmic rays, detection of their sources has remained elusive. A major breakthrough has come through the identification of synchrotron X-rays from the shocks of supernova remnants through imaging and spectroscopic observations by the most recent generation of X-ray observatories. This radiation is most likely produced by electrons accelerated to relativistic energy, and thus has offered the first, albeit indirect, observational evidence that diffusive shock acceleration in supernova remnants produces cosmic rays to TeV energies, possibly as high as the "knee" in the cosmic ray spectrum. X-ray observations have provided information about the maximum energy to which these shOCks accelerate electrons, as well as indirect evidence of proton acceleration. Shock morphologies measured in X-rays have indicated that a substantial fraction of the shock energy can be diverted into particle acceleration. This presentation will summarize what we have learned about cosmic ray acceleration from X-ray observations of supernova remnants over the past two decades.

  18. Hard X-ray Emission and Efficient Particle Acceleration by Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Vink, Jacco

    2009-05-01

    I discuss the non-thermal X-ray emission from young supernova remnants. Over the last decade it has become clear from both X-ray and γ-ray observations that young supernovae accelerate particles up to 100 TeV. In soft X-rays the accelerated >10 TeV electrons produce synchrotron radiation, coming from narrow filaments located at the shock fronts. The width of these filaments shows that the magnetic fields are relatively high, thus providing evidence for magnetic field amplification. The synchrotron radiation of several remnants is known to extend into the hard X-ray regime. In particular Cas A, has a spectrum that appears as a power law up to almost 100 TeV. This is very surprising, as a steepening is expected going from the soft to the hard X-ray band. The spectrum is likely a result of many superimposed individual spectra, each steepening at different energies. This implies considerable spatial variation in hard X-rays, an obvious target for Simbol-X. The variations will be important to infer local shock acceleration properties, but also magnetic field fluctuations may cause spatial and temporal variations. Finally, I draw the attention to super bubbles and supernovae as sources of cosmic rays. As such they may be sources of hard X-ray emission. In particular, supernovae exploding inside the dense red supergiants winds of their progenitors ares promising candidates for hard X-ray emission.

  19. Energy Dependence of Synchrotron X-Ray Rims in Tycho's Supernova Remnant

    NASA Technical Reports Server (NTRS)

    Tran, Aaron; Williams, Brian J.; Petre, Robert; Ressler, Sean M.; Reynolds, Stephen P.

    2015-01-01

    Several young supernova remnants exhibit thin X-ray bright rims of synchrotron radiation at their forward shocks. Thin rims require strong magnetic field amplification beyond simple shock compression if rim widths are only limited by electron energy losses. But, magnetic field damping behind the shock could produce similarly thin rims with less extreme field amplification. Variation of rim width with energy may thus discriminate between competing influences on rim widths. We measured rim widths around Tycho's supernova remnant in 5 energy bands using an archival 750 ks Chandra observation. Rims narrow with increasing energy and are well described by either loss-limited or damped scenarios, so X-ray rim width-energy dependence does not uniquely specify a model. But, radio counterparts to thin rims are not loss-limited and better reflect magnetic field structure. Joint radio and X-ray modeling favors magnetic damping in Tycho's SNR with damping lengths approximately 1-5% of remnant radius and magnetic field strengths approximately 50-400 micron G assuming Bohm diffusion. X-ray rim widths are approximately 1% of remnant radius, somewhat smaller than inferred damping lengths. Electron energy losses are important in all models of X-ray rims, suggesting that the distinction between loss-limited and damped models is blurred in soft X-rays. All loss-limited and damping models require magnetic fields approximately greater than 20 micron G, arming the necessity of magnetic field amplification beyond simple compression.

  20. Dark Energy Survey Group

    Science.gov Websites

    -Chuan Pan, Companions in Type Ia SNe Remnants 2015-03 Daniel Kasen, Type Ia SNe Models 2014-06 Marisa March, DES Supernovae 2014-06 David Chamulak, Supernova Explosion Models 2011-04 Gene Byrd 2010-04 Liz

  1. A Supernova Shockwaves

    NASA Image and Video Library

    2007-06-13

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

  2. Cassiopeia A: Death Becomes Her

    NASA Image and Video Library

    2005-06-10

    This false-color image from three of NASA Great Observatories provides one example of a star that died in a fiery supernova blast. Called Cassiopeia A, this supernova remnant is located 10,000 light-years away in the constellation Cassiopeia.

  3. G306.3-0.9: A Newly Discovered Young Galactic Supernova Remnant

    NASA Technical Reports Server (NTRS)

    Reynolds, Mark T.; Loi, Syheh T.; Murphy, Tara; Miller, Jon M.; Maitra, Dipankar; Gueltekin, Kayhan; Gehrels, Neil; Kennea, Jamie A.; Siegel, Michael H.; Gelbord, Jonathan; hide

    2013-01-01

    We present X-ray and radio observations of the new Galactic supernova remnant (SNR) G306.3-0.9, recently discovered by Swift. Chandra imaging reveals a complex morphology, dominated by a bright shock. The X-ray spectrum is broadly consistent with a young SNR in the Sedov phase, implying an age of 2500 yr for a distance of 8 kpc, plausibly identifying this as one of the 20 youngest Galactic SNRs. Australia Telescope Compact Array imaging reveals a prominent ridge of radio emission that correlates with the X-ray emission. We find a flux density of 160 mJy at 1 GHz, which is the lowest radio flux recorded for a Galactic SNR to date. The remnant is also detected at 24µm, indicating the presence of irradiated warm dust. The data reveal no compelling evidence for the presence of a compact stellar remnant.

  4. Impacto ambiental de los remanentes de supernova

    NASA Astrophysics Data System (ADS)

    Dubner, G. M.

    2015-08-01

    The explosion of a supernovae (SN) represents the sudden injection of about ergs of thermal and mechanical energy in a small region of space, causing the formation of powerful shock waves that propagate through the interstellar medium at speeds of several thousands of km/s. These waves sweep, compress and heat the interstellar material that they encounter, forming the supernova remnants. Their evolution over thousands of years change forever, irreversibly, not only the physical but also the chemical properties of a vast region of space that can span hundreds of parsecs. This contribution briefly analyzes the impact of these explosions, discussing the relevance of some phenomena usually associated with SNe and their remnants in the light of recent theoretical and observational results.

  5. Approximate supernova remnant dynamics with cosmic ray production

    NASA Technical Reports Server (NTRS)

    Voelk, H. J.; Drury, L. O.; Dorfi, E. A.

    1985-01-01

    Supernova explosions are the most violent and energetic events in the galaxy and have long been considered probably sources of Cosmic Rays. Recent shock acceleration models treating the Cosmic Rays (CR's) as test particles nb a prescribed Supernova Remnant (SNR) evolution, indeed indicate an approximate power law momentum distribution f sub source (p) approximation p(-a) for the particles ultimately injected into the Interstellar Medium (ISM). This spectrum extends almost to the momentum p = 1 million GeV/c, where the break in the observed spectrum occurs. The calculated power law index approximately less than 4.2 agrees with that inferred for the galactic CR sources. The absolute CR intensity can however not be well determined in such a test particle approximation.

  6. AN X-RAY AND RADIO STUDY OF THE VARYING EXPANSION VELOCITIES IN TYCHO’S SUPERNOVA REMNANT

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

    Williams, Brian J.; Chomiuk, Laura; Hewitt, John W.

    2016-06-01

    We present newly obtained X-ray and radio observations of Tycho’s supernova remnant using Chandra and the Karl G. Jansky Very Large Array in 2015 and 2013/14, respectively. When combined with earlier epoch observations by these instruments, we now have time baselines for expansion measurements of the remnant of 12–15 years in the X-rays and 30 years in the radio. The remnant’s large angular size allows for proper motion measurements at many locations around the periphery of the blast wave. Consistent with earlier measurements, we find a clear gradient in the expansion velocity of the remnant, despite its round shape. Themore » proper motions on the western and southwestern sides of the remnant are about a factor of two higher than those in the east and northeast. We showed in an earlier work that this is related to an offset of the explosion site from the geometric center of the remnant due to a density gradient in the ISM, and using our refined measurements reported here, we find that this offset is ∼23″ toward the northeast. An explosion center offset in such a circular remnant has implications for searches for progenitor companions in other remnants.« less

  7. Evolution and Spectrum of the Radio Emission of Tycho's Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Vinyaikin, E. N.

    2018-02-01

    The radio spectrum of Tycho's Supernova Remnant is constructed at frequencies 12.6-143 000 MHz for epoch 2010.3, taking into account the secular decrease in the radio flux density of the remnant at the rate d = -(0.46 ± 0.03)%/year: S_ν ^{3C10} (t = 2010.3) = (43.1 ± 1.8 Jy)(ν [GHz])^{ - (0.592 ± 0.019) + (0.041 ± 0.012)log (ν [GHz])} . The spectrum has positive curvature. The presence of a low-frequency turnover in the spectrum of the radio source 3C10 with its maximum at 7.7 MHz is predicted, due to absorption in the interstellar medium in the direction toward the source.

  8. Dynamics of supernova remnants in the Galactic centre.

    NASA Astrophysics Data System (ADS)

    Bortolas, E.; Mapelli, M.; Spera, M.

    The Galactic centre (GC) is a unique place to study the extreme dynamical processes occurring near a super-massive black hole (SMBH). Here we simulate a large set of binaries orbiting the SMBH while the primary member undergoes a supernova (SN) explosion, in order to study the impact of SN kicks on the orbits of stars and dark remnants in the GC. We find that SN explosions are efficient in scattering neutron stars and other light stars on new (mostly eccentric) orbits, while black holes (BHs) tend to retain memory of the orbit of their progenitor star. SN kicks are thus unable to eject BHs from the GC: a cusp of dark remnants may be lurking in the central parsec of our Galaxy.

  9. Detection of radio emission from optically identified supernova remnants in M31

    NASA Technical Reports Server (NTRS)

    Dickel, J. R.; Dodorico, S.; Felli, M.; Dopita, M.

    1982-01-01

    The Very Large Array was used to conduct a radio search at a wavelength of 20 cm for ten optically identified supernova remnants (SNRs) in M31. Five SNRs were detected, and for the other objects, upper limits to the emission were determined. On the average, the surface brightness of an SNR in M31 appears to be fainter than that of an SNR in the Galaxy. It is suggested that the median surface brightness at a given diameter is higher in late-type spirals than in Sb systems.

  10. Soft X-ray emission from the Lupus Loop and Sn 1006 supernova remnants

    NASA Technical Reports Server (NTRS)

    Winkler, P. F., Jr.; Hearn, D. R.; Richardson, J. A.; Behnken, J. M.

    1979-01-01

    X-ray maps of the Lupus region have been obtained in a raster scan observation from SAS 3. These show the Lupus Loop to be a faint extended source of soft X-rays with a temperature about 2.5 million K. The most prominent feature of the region is the A.D. 1006 supernova remnant, which is unexpectedly bright at 0.2-1.0 keV. One speculative interpretation of the low-energy flux from SN 1006 is as blackbody radiation from a hot neutron star.

  11. Integral Field Spectroscopy of Supernova Remnant 1E0102–7219 Reveals Fast-moving Hydrogen and Sulfur-rich Ejecta

    NASA Astrophysics Data System (ADS)

    Seitenzahl, Ivo R.; Vogt, Frédéric P. A.; Terry, Jason P.; Ghavamian, Parviz; Dopita, Michael A.; Ruiter, Ashley J.; Sukhbold, Tuguldur

    2018-02-01

    We study the optical emission from heavy element ejecta in the oxygen-rich young supernova remnant 1E 0102.2–7219 (1E 0102) in the Small Magellanic Cloud. We have used the Multi-Unit Spectroscopic Explorer optical integral field spectrograph at the Very Large Telescope on Cerro Paranal and the wide field spectrograph (WiFeS) at the ANU 2.3 m telescope at Siding Spring Observatory to obtain deep observations of 1E 0102. Our observations cover the entire extent of the remnant from below 3500 Å to 9350 Å. Our observations unambiguously reveal the presence of fast-moving ejecta emitting in [S II], [S III], [Ar III], and [Cl II]. The sulfur-rich ejecta appear more asymmetrically distributed compared to oxygen or neon, a product of carbon burning. In addition to the forbidden line emission from products of oxygen burning (S, Ar, Cl), we have also discovered Hα and Hβ emission from several knots of low surface brightness, fast-moving ejecta. The presence of fast-moving hydrogen points toward a progenitor that had not entirely shed its hydrogen envelope prior to the supernova. The explosion that gave rise to 1E 0102 is therefore commensurate with a Type IIb supernova.

  12. High-energy particle acceleration in the shell of a supernova remnant.

    PubMed

    Aharonian, F A; Akhperjanian, A G; Aye, K-M; Bazer-Bachi, A R; Beilicke, M; Benbow, W; Berge, D; Berghaus, P; Bernlöhr, K; Bolz, O; Boisson, C; Borgmeier, C; Breitling, F; Brown, A M; Gordo, J Bussons; Chadwick, P M; Chitnis, V R; Chounet, L-M; Cornils, R; Costamante, L; Degrange, B; Djannati-Ataï, A; Drury, L O'C; Ergin, T; Espigat, P; Feinstein, F; Fleury, P; Fontaine, G; Funk, S; Gallant, Y A; Giebels, B; Gillessen, S; Goret, P; Guy, J; Hadjichristidis, C; Hauser, M; Heinzelmann, G; Henri, G; Hermann, G; Hinton, J A; Hofmann, W; Holleran, M; Horns, D; De Jager, O C; Jung, I; Khélifi, B; Komin, Nu; Konopelko, A; Latham, I J; Le Gallou, R; Lemoine, M; Lemière, A; Leroy, N; Lohse, T; Marcowith, A; Masterson, C; McComb, T J L; De Naurois, M; Nolan, S J; Noutsos, A; Orford, K J; Osborne, J L; Ouchrif, M; Panter, M; Pelletier, G; Pita, S; Pohl, M; Pühlhofer, G; Punch, M; Raubenheimer, B C; Raue, M; Raux, J; Rayner, S M; Redondo, I; Reimer, A; Reimer, O; Ripken, J; Rivoal, M; Rob, L; Rolland, L; Rowell, G; Sahakian, V; Saugé, L; Schlenker, S; Schlickeiser, R; Schuster, C; Schwanke, U; Siewert, M; Sol, H; Steenkamp, R; Stegmann, C; Tavernet, J-P; Théoret, C G; Tluczykont, M; Van Der Walt, D J; Vasileiadis, G; Vincent, P; Visser, B; Völk, H J; Wagner, S J

    2004-11-04

    A significant fraction of the energy density of the interstellar medium is in the form of high-energy charged particles (cosmic rays). The origin of these particles remains uncertain. Although it is generally accepted that the only sources capable of supplying the energy required to accelerate the bulk of Galactic cosmic rays are supernova explosions, and even though the mechanism of particle acceleration in expanding supernova remnant (SNR) shocks is thought to be well understood theoretically, unequivocal evidence for the production of high-energy particles in supernova shells has proven remarkably hard to find. Here we report on observations of the SNR RX J1713.7 - 3946 (G347.3 - 0.5), which was discovered by ROSAT in the X-ray spectrum and later claimed as a source of high-energy gamma-rays of TeV energies (1 TeV = 10(12) eV). We present a TeV gamma-ray image of the SNR: the spatially resolved remnant has a shell morphology similar to that seen in X-rays, which demonstrates that very-high-energy particles are accelerated there. The energy spectrum indicates efficient acceleration of charged particles to energies beyond 100 TeV, consistent with current ideas of particle acceleration in young SNR shocks.

  13. The properties of the progenitor, neutron star, and pulsar wind in the supernova remnant Kes 75

    NASA Astrophysics Data System (ADS)

    Gelfand, J. D.; Slane, P. O.; Temim, T.

    2014-03-01

    By studying composite supernova remnants (SNRs), remnants which contain a pulsar wind nebula (PWN), it is possible to estimate physical properties of the progenitor explosion, central neutron star, and its pulsar wind that are difficult to measure directly. This is best done by fitting the dynamical and broadband spectral properties of a PWN with an evolutionary model for a PWN inside an SNR. We apply such a model to the composite SNR Kes 75, whose associated pulsar PSR J1846-0258 is thought to have an extremely strong surface magnetic field. If ˜ 3 M_⊙ of mass was ejected in the supernova, our model suggests a normal or slightly subenergetic supernova in a low density environment. Additionally, for the measured pre-outburst braking index of p=2.65, our model prefers an age of {˜ 430} years and an initial spin period P_0 ˜ 0.2 s. Lastly, the magnetization of the pulsar wind and energy spectrum of particles injected at the termination shock are similar to those observed from other PWNe powered by less magnetized neutron stars. While further study is needed to verify these results, they are nominally inconsistent with strong neutron star magnetic fields resulting from very fast initial rotation.

  14. An ASCA Study of the Composite Supernova Remnant G18.95-1.1

    NASA Technical Reports Server (NTRS)

    Harrus, Ilana

    2000-01-01

    This is the final report on the work done on Supernova Remnant (SNR) G18-95-1.1. The data were taken on April, 2. 1998 and delivered a couple of months later to the Principal Investigator (PI: Dr. Ilana Harrus). We received a CD-ROM containing the results of the standard processing pipeline and all the files needed for the analysis. We have analyzed the data and presented a poster on this object at the 194th American Astronomical Society Meeting in Chicago (June 1999). A copy of the poster is appended to this report. The poster presentation triggered several discussions and we are summarizing the analysis results and those discussions in a paper to be submitted soon to the Astrophysical Journal. We have appended the draft of the paper to this report. It must be noted that the paper is still in its early stages. In particular more work is needed in the physical implications of the results of the spectral analysis and in the comparison with theoretical models to understand the curious morphology of the remnant. The project should be completed within the next two months. Attachment: "ASCA study of the centrally-peaked thermal supernova remnant: G18.95-1.1".

  15. Fermi LAT discovery of GeV gamma-ray emission from the young supernova remnan Cassiopeia A

    DOE PAGES

    Abdo, A. A.

    2010-01-27

    Here, we report on the first detection of GeV high-energy gamma-ray emission from a young supernova remnant (SNR) with the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope. Our observations reveal a source with no discernible spatial extension detected at a significance level of 12.2σ above 500 MeV at a location that is consistent with the position of the remnant of the supernova explosion that occurred around 1680 in the Cassiopeia constellation—Cassiopeia A (Cas A). The gamma-ray flux and spectral shape of the source are consistent with a scenario in which the gamma-ray emission originates from relativistic particles acceleratedmore » in the shell of this remnant. The total content of cosmic rays (electrons and protons) accelerated in Cas A can be estimated as W CR sime (1-4) × 1049 erg thanks to the well-known density in the remnant assuming that the observed gamma ray originates in the SNR shell(s). Finally, the magnetic field in the radio-emitting plasma can be robustly constrained as B ≥ 0.1 mG, providing new evidence of the magnetic field amplification at the forward shock and the strong field in the shocked ejecta.« less

  16. Hard X-ray Emission and Efficient Particle Acceleration by Supernova Remnants

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

    Vink, Jacco

    I discuss the non-thermal X-ray emission from young supernova remnants. Over the last decade it has become clear from both X-ray and {gamma}-ray observations that young supernovae accelerate particles up to 100 TeV. In soft X-rays the accelerated >10 TeV electrons produce synchrotron radiation, coming from narrow filaments located at the shock fronts. The width of these filaments shows that the magnetic fields are relatively high, thus providing evidence for magnetic field amplification.The synchrotron radiation of several remnants is known to extend into the hard X-ray regime. In particular Cas A, has a spectrum that appears as a power lawmore » up to almost 100 TeV. This is very surprising, as a steepening is expected going from the soft to the hard X-ray band. The spectrum is likely a result of many superimposed individual spectra, each steepening at different energies. This implies considerable spatial variation in hard X-rays, an obvious target for Simbol-X. The variations will be important to infer local shock acceleration properties, but also magnetic field fluctuations may cause spatial and temporal variations.Finally, I draw the attention to super bubbles and supernovae as sources of cosmic rays. As such they may be sources of hard X-ray emission. In particular, supernovae exploding inside the dense red supergiants winds of their progenitors ares promising candidates for hard X-ray emission.« less

  17. Dead Star Rumbles

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Composite of Supernova Remnant Cassiopeia A This Spitzer Space Telescope composite shows the supernova remnant Cassiopeia A (white ball) and surrounding clouds of dust (gray, orange and blue). It consists of two processed images taken one year apart. Dust features that have not changed over time appear gray, while those that have changed are colored blue or orange. Blue represents an earlier time and orange, a later time.

    These observations illustrate that a blast of light from Cassiopeia A is waltzing outward through the dusty skies. This dance, called an 'infrared echo,' began when the remnant erupted about 50 years ago.

    Cassiopeia A is the remnant of a once massive star that died in a violent supernova explosion 325 years ago. It consists of a dead star, called a neutron star, and a surrounding shell of material that was blasted off as the star died. This remnant is located 10,000 light-years away in the northern constellation Cassiopeia.

    An infrared echo is created when a star explodes or erupts, flashing light into surrounding clumps of dust. As the light zips through the dust clumps, it heats them up, causing them to glow successively in infrared, like a chain of Christmas bulbs lighting up one by one. The result is an optical illusion, in which the dust appears to be flying outward at the speed of light. This apparent motion can be seen here by the shift in colored dust clumps.

    Echoes are distinct from supernova shockwaves, which are made up material that is swept up and hurled outward by exploding stars.

    This infrared echo is the largest ever seen, stretching more than 50 light-years away from Cassiopeia A. If viewed from Earth, the entire movie frame would take up the same amount of space as two full moons.

    Hints of an older infrared echo from Cassiopeia A's supernova explosion hundreds of years ago can also be seen.

    The earlier Spitzer image was taken on November 30, 2003, and the later, on December 2, 2004.

  18. MISSING BLACK HOLES UNVEIL THE SUPERNOVA EXPLOSION MECHANISM

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

    Belczynski, Krzysztof; Wiktorowicz, Grzegorz; Fryer, Chris L.

    2012-09-20

    It is firmly established that the stellar mass distribution is smooth, covering the range 0.1-100 M{sub Sun }. It is to be expected that the masses of the ensuing compact remnants correlate with the masses of their progenitor stars, and thus it is generally thought that the remnant masses should be smoothly distributed from the lightest white dwarfs to the heaviest black holes (BHs). However, this intuitive prediction is not borne out by observed data. In the rapidly growing population of remnants with observationally determined masses, a striking mass gap has emerged at the boundary between neutron stars (NSs) andmore » BHs. The heaviest NSs reach a maximum of two solar masses, while the lightest BHs are at least five solar masses. Over a decade after the discovery, the gap has become a significant challenge to our understanding of compact object formation. We offer new insights into the physical processes that bifurcate the formation of remnants into lower-mass NSs and heavier BHs. Combining the results of stellar modeling with hydrodynamic simulations of supernovae, we both explain the existence of the gap and also put stringent constraints on the inner workings of the supernova explosion mechanism. In particular, we show that core-collapse supernovae are launched within 100-200 ms of the initial stellar collapse, implying that the explosions are driven by instabilities with a rapid (10-20 ms) growth time. Alternatively, if future observations fill in the gap, this will be an indication that these instabilities develop over a longer (>200 ms) timescale.« less

  19. NASA's Great Observatories May Unravel 400-Year Old Supernova Mystery

    NASA Astrophysics Data System (ADS)

    2004-10-01

    Four hundred years ago, sky watchers, including the famous astronomer Johannes Kepler, best known as the discoverer of the laws of planetary motion, were startled by the sudden appearance of a "new star" in the western sky, rivaling the brilliance of the nearby planets. Kepler's Supernova Remnant Multiple Images of Kepler's Supernova Remnant Modern astronomers, using NASA's three orbiting Great Observatories, are unraveling the mysteries of the expanding remains of Kepler's supernova, the last such object seen to explode in our Milky Way galaxy. When a new star appeared Oct. 9, 1604, observers could use only their eyes to study it. The telescope would not be invented for another four years. A team of modern astronomers has the combined abilities of NASA's Great Observatories, the Spitzer Space Telescope (SST), Hubble Space Telescope (HST), and Chandra X-ray Observatory, to analyze the remains in infrared radiation, visible light, and X-rays. Ravi Sankrit and William Blair of the Johns Hopkins University in Baltimore lead the team. The combined image unveils a bubble-shaped shroud of gas and dust, 14 light-years wide and expanding at 4 million mph. Observations from each telescope highlight distinct features of the supernova, a fast-moving shell of iron-rich material, surrounded by an expanding shock wave sweeping up interstellar gas and dust. Interview with Dr. Ravi Sankrit Interview with Dr. Ravi Sankrit "Multi-wavelength studies are absolutely essential for putting together a complete picture of how supernova remnants evolve," Sankrit said. Sankrit is an associate research scientist, Center for Astrophysical Sciences at Hopkins and lead for HST astronomer observations. "For instance, the infrared data are dominated by heated interstellar dust, while optical and X-ray observations sample different temperatures of gas," Blair added. Blair is a research professor, Physics and Astronomy Department at Hopkins and lead astronomer for SST observations. "A range of observations is needed to help us understand the complex relationship that exists among the various components," Blair said. The explosion of a star is a catastrophic event. The blast rips the star apart and unleashes a roughly spherical shock wave that expands outward at more than 22 million mph like an interstellar tsunami. The shock wave spreads out into surrounding space, sweeping up any tenuous interstellar gas and dust into an expanding shell. The stellar ejecta from the explosion initially trail behind the shock wave. It eventually catches up with the inner edge of the shell and is heated to X-ray temperatures. Kepler's Supernova Remnant Hubble Optical Image of Kepler's Supernova Remnant Visible-light images from Hubble's Advanced Camera for Surveys reveal where the supernova shock wave is slamming into the densest regions of surrounding gas. The bright glowing knots are dense clumps that form behind the shock wave. Sankrit and Blair compared their HST observations with those taken with ground-based telescopes to obtain a more accurate distance to the supernova remnant of about 13,000 light-years. Kepler's Supernova Remnant Spitzer Infrared Image of Kepler's Supernova Remnant The astronomers used the SST to probe for material that radiates in infrared light, which shows heated microscopic dust particles that have been swept up by the supernova shock wave. SST is sensitive enough to detect both the densest regions seen by HST and the entire expanding shock wave, a spherical cloud of material. Instruments on SST also reveal information about the chemical composition and physical environment of the expanding clouds of gas and dust ejected into space. This dust is similar to dust which was part of the cloud of dust and gas that formed the sun and planets in our solar system. Interview with Dr. William Blair Interview with Dr. William Blair The Chandra X-ray data show regions of very hot gas. The hottest gas, higher-energy X-rays, is located primarily in the regions directly behind the shock front. These regions also show up in the HST observations and also align with the faint rim of material seen in the SST data. Cooler X-ray gas, lower-energy X-rays, resides in a thick interior shell and marks the location of the material expelled from the exploded star. There have been six known supernovas in our Milky Way over the past 1,000 years. Kepler's is the only one, which astronomers do not know what type of star exploded. By combining information from all three Great Observatories, astronomers may find the clues they need. "It's really a situation where the total is greater than the sum of the parts," Blair said. "When the analysis is complete, we will be able to answer several questions about this enigmatic object." Information and images from this research is available on the Web at: http://www.nasa.gov http://hubblesite.org/newscenter/newsdesk/archive/releases/2004/29/ http://chandra.harvard.edu and http://www.spitzer.caltech.edu/

  20. On Neutron Star/Supernova Remnant Association

    NASA Astrophysics Data System (ADS)

    Gvaramadze, V. V.

    It is pointed out that a cavity supernova (SN) explosion of a moving massive star could result in a significant offset of the neutron star (NS) birth-place from the geometrical centre of the supernova remnant (SNR). Therefore: a) the high implied transverse velocities of a number of NSs (e.g. PSR B1610-50, PSR B1706-44, PSR B1757-24, SGR 0526-66) could be reduced; b) the proper motion vector of a NS should not necessarily point away from the geometrical centre of the associated SNR; c) the circle of possible NS/SNR associations could be enlarged. An observational test is discussed, which could provide a determination of the true birth-places of NSs associated with middle-aged SNRs, and thereby provide more reliable estimates of their transverse velocities.

  1. The Case of Missing Iron in Cassiopeia A

    NASA Image and Video Library

    2014-02-19

    When astronomers first looked at images of a supernova remnant called Cassiopeia A, captured by NASA NuSTAR. The mystery of Cassiopeia A Cas A, a massive star that exploded in a supernova more than 11,000 years ago continues to confound scientists.

  2. 84 gigahertz observations of five Crab-like supernova remnants

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

    Salter, C. J.; Reynolds, S. P.; Hogg, D. E.

    1989-03-01

    Flux density measurements at 3.6 mm have been made to extend the frequency coverage for three Crablike remnants and two Crablike components within remnants whose large-scale morphologies show shell-type structure. All five objects show flat, polarized, nonthermal radio spectra and associated X-ray emission characteristic of this class. The flux density is found to be lower than expected on the basis of an extrapolation of the spectrum from lower frequencies. If this is due to steepening caused by evolutionary effects, severe constraints can be put on the characteristics of the objects showing spectral steepening: all must be less than 2000 yrmore » old, and the supernovae in which they were born must all have had very unusual properties. 30 refs.« less

  3. The Peculiar, Asymmetric Core-Collapse Supernova Remnant G350.1-0.3

    NASA Astrophysics Data System (ADS)

    Reynolds, Stephen

    2017-09-01

    We propose a 200 ks observation of one of the most peculiar supernova remnants known: G350.1-0.3. This mysterious object resembles no other known SNR in radio or X-rays, It contains a compact central object (CCO) which may or may not be related. Previous spectral analyses are contradictory, but there appears to be strong iron emission and an extreme overabundance of nickel. Age estimates suggest it could be as young as 600 years old. Our proposed observation should be able to measure expansion since 2009, confirming or refuting the age estimate, and will allow spectroscopy on small scales to confirm enhanced abundances and search for shocked ambient material and nonthermal emission. If the CCO originated at the remnant center, its motion will also be detected.

  4. Distant Supernova Remnant Imaged by Chandra's High Resolution Camera

    NASA Astrophysics Data System (ADS)

    1999-09-01

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

  5. X-ray imaging and spectroscopic study of the SNR Kes 73 hosting the magnetar 1E 1841-045

    NASA Astrophysics Data System (ADS)

    Kumar, H. S.; Safi-Harb, S.; Slane, P. O.; Gotthelf, E. V.

    2014-01-01

    We present the first detailed Chandra and XMM-Newton study of the young Galactic supernova remnant (SNR) Kes 73 associated with the anomalous X-ray pulsar (AXP) 1E 1841-045. Images of the remnant in the radio (20 cm), infrared (24 μm), and X-rays (0.5-7 keV) reveal a spherical morphology with a bright western limb. High-resolution Chandra images show bright diffuse emission across the remnant, with several small-scale clumpy and knotty structures filling the SNR interior. The overall Chandra and XMM-Newton spectrum of the SNR is best described by a two-component thermal model with the hard component characterized by a low ionization timescale, suggesting that the hot plasma has not yet reached ionization equilibrium. The soft component is characterized by enhanced metal abundances from Mg, Si, and S, suggesting the presence of metal-rich supernova ejecta. We discuss the explosion properties of the supernova and infer the mass of its progenitor star. Such studies shed light on our understanding of SNRs associated with highly magnetized neutron stars.

  6. Planck intermediate results: XXXI. Microwave survey of Galactic supernova remnants

    DOE PAGES

    Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; ...

    2016-02-09

    The all-sky Planck survey in 9 frequency bands was used in this paper to search for emission from all 274 known Galactic supernova remnants. Of these, 16 were detected in at least two Planck frequencies. The radio-through-microwave spectral energy distributions were compiled to determine the mechanism for microwave emission. In only one case, IC 443, is there high-frequency emission clearly from dust associated with the supernova remnant. In all cases, the low-frequency emission is from synchrotron radiation. As predicted for a population of relativistic particles with energy distribution that extends continuously to high energies, a single power law is evidentmore » for many sources, including the Crab and PKS 1209-51/52. A decrease in flux density relative to the extrapolation of radio emission is evident in several sources. Their spectral energy distributions can be approximated as broken power laws, S ν ∝ ν -α, with the spectral index, α, increasing by 0.5–1 above a break frequency in the range 10–60 GHz. Finally, the break could be due to synchrotron losses.« less

  7. Search for a Radio Pulsar in the Remnant of Supernova 1987A

    NASA Astrophysics Data System (ADS)

    Zhang, S.-B.; Dai, S.; Hobbs, G.; Staveley-Smith, L.; Manchester, R. N.; Russell, C. J.; Zanardo, G.; Wu, X.-F.

    2018-06-01

    We have observed the remnant of supernova SN 1987A (SNR 1987A), located in the Large Magellanic Cloud (LMC), to search for periodic and/or transient radio emission with the Parkes 64 m-diameter radio telescope. We found no evidence of a radio pulsar in our periodicity search and derived 8σ upper bounds on the flux density of any such source of 31 μJy at 1.4 GHz and 21 μJy at 3 GHz. Four candidate transient events were detected with greater than 7σ significance, with dispersion measures (DMs) in the range 150 to 840 cm-3 pc. For two of them, we found a second pulse at slightly lower significance. However, we cannot at present conclude that any of these are associated with a pulsar in SNR 1987A. As a check on the system, we also observed PSR B0540-69, a young pulsar which also lies in the LMC. We found eight giant pulses at the DM of this pulsar. We discuss the implications of these results for models of the supernova remnant, neutron star formation and pulsar evolution.

  8. PROBING X-RAY ABSORPTION AND OPTICAL EXTINCTION IN THE INTERSTELLAR MEDIUM USING CHANDRA OBSERVATIONS OF SUPERNOVA REMNANTS

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

    Foight, Dillon R.; Slane, Patrick O.; Güver, Tolga

    We present a comprehensive study of interstellar X-ray extinction using the extensive Chandra supernova remnant (SNR) archive and use our results to refine the empirical relation between the hydrogen column density and optical extinction. In our analysis, we make use of the large, uniform data sample to assess various systematic uncertainties in the measurement of the interstellar X-ray absorption. Specifically, we address systematic uncertainties that originate from (i) the emission models used to fit SNR spectra; (ii) the spatial variations within individual remnants; (iii) the physical conditions of the remnant such as composition, temperature, and non-equilibrium regions; and (iv) themore » model used for the absorption of X-rays in the interstellar medium. Using a Bayesian framework to quantify these systematic uncertainties, and combining the resulting hydrogen column density measurements with the measurements of optical extinction toward the same remnants, we find the empirical relation N {sub H} = (2.87 ± 0.12) × 10{sup 21} A {sub V} cm{sup 2}, which is significantly higher than the previous measurements.« less

  9. Dust in a Type Ia Supernova Progenitor: Spitzer Spectroscopy of Kepler's Supernova Remnant

    NASA Technical Reports Server (NTRS)

    Williams, Brian J.; Borkowski, Kazimierz; Reynolds, Stephen P.; Ghavamian, Parviz; Blair, William P.; Long, Knox S.; Sankrit, Ravi

    2012-01-01

    Characterization of the relatively poorly-understood progenitor systems of Type Ia supernovae is of great importance in astrophysics, particularly given the important cosmological role that these supernovae play. Kepler's Supernova Remnant, the result of a Type Ia supernova, shows evidence for an interaction with a dense circumstellar medium (CSM), suggesting a single-degenerate progenitor system. We present 7.5-38 micron IR spectra of the remnant, obtained with the Spitzer Space Telescope, dominated by emission from warm dust. Broad spectral features at 10 and 18 micron, consistent with various silicate particles, are seen throughout. These silicates were likely formed in the stellar outflow from the progenitor system during the AGB stage of evolution, and imply an oxygen-rich chemistry. In addition to silicate dust, a second component, possibly carbonaceous dust, is necessary to account for the short-wavelength IRS and IRAC data. This could imply a mixed chemistry in the atmosphere of the progenitor system. However, non-spherical metallic iron inclusions within silicate grains provide an alternative solution. Models of collisionally-heated dust emission from fast shocks (> 1000 km/s) propagating into the CSM can reproduce the majority of the emission associated with non-radiative filaments, where dust temperatures are approx 80-100 K, but fail to account for the highest temperatures detected, in excess of 150 K. We find that slower shocks (a few hundred km/s) into moderate density material (n(sub o) approx 50-100 / cubic cm) are the only viable source of heating for this hottest dust. We confirm the finding of an overall density gradient, with densities in the north being an order of magnitude greater than those in the south.

  10. Suzaku Finds "Fossil" Fireballs from Supernovae

    NASA Image and Video Library

    2017-12-08

    Suzaku Finds "Fossil" Fireballs from Supernovae In a supernova remnant known as the Jellyfish Nebula, Suzaku detected X-rays from fully ionized silicon and sulfur -- an imprint of higher-temperature conditions immediately following the star's explosion. The nebula is about 65 light-years across. (12/30/2009) Credit: JAXA/NASA/Suzaku To learn more go to: www.nasa.gov/mission_pages/astro-e2/news/fossil-fireballs...

  11. Supernova Collisions with the Heliosphere

    NASA Astrophysics Data System (ADS)

    Fields, Brian D.; Athanassiadou, Themis; Johnson, Scott R.

    2008-05-01

    Nearby supernova explosions—within a few tens of pc of the solar system—have become a subject of intense scrutiny, due to the discovery of live undersea 60Fe from an event 2.8 Myr ago. A key open question concerns the delivery of supernova ejecta to the Earth, in particular penetration of the heliosphere by the supernova remnant (SNR). We present the first systematic numerical hydrodynamical study of the interaction between a supernova blast and the solar wind. Our simulations explore dynamic pressure regimes that are factors >=10 above those in other studies of the heliosphere under exotic conditions, for supernovae exploding at a range of distances through different interstellar environments, and interacting with solar winds of varying strengths. Our results are qualitatively consistent with the structure of the contemporary heliosphere modeled by previous work, but compressed to within the inner solar system. We demonstrate that key characteristics of the resulting heliospheric structure follow simple scaling laws that can be understood in terms of pressure-balance arguments, and which are in agreement with previous work. Our models show that a 10 pc supernova event, incident on a solar-wind outflow with the mean observed properties, compresses the heliopause to just beyond 1 AU. We also demonstrate scenarios where the supernova remnant compresses the heliopause to within 1 AU, in which cases supernova material will be directly deposited on Earth. Since 8 pc marks the nominal "kill radius" for severe biosphere damage, any extinction-level events should have left terrestrial deposits of supernova debris. We conclude with a brief discussion of the effect of our approximations and the impact of additional physics.

  12. Youngest Stellar Explosion in Our Galaxy Discovered

    NASA Astrophysics Data System (ADS)

    2008-05-01

    Astronomers have found the remains of the youngest supernova, or exploded star, in our Galaxy. The supernova remnant, hidden behind a thick veil of gas and dust, was revealed by the National Science Foundation's Very Large Array (VLA) and NASA's Chandra X-Ray Observatory, which could see through the murk. The object is the first example of a "missing population" of young supernova remnants. 1985 and 2008 VLA Images Move cursor over image to blink. VLA Images of G1.9+0.3 in 1985 and 2008: Circle for size comparison. CREDIT: Green, et al., NRAO/AUI/NSF From observing supernovae in other galaxies, astronomers have estimated that about three such stellar explosions should occur in our Milky Way every century. However, the most recent one known until now occurred around 1680, creating the remnant called Cassiopeia A. The newly-discovered object is the remnant of an explosion only about 140 years ago. "If the supernova rate estimates are correct, there should be the remnants of about 10 supernova explosions in the Milky Way that are younger than Cassiopeia A," said David Green of the University of Cambridge in the UK, who led the VLA study. "It's great to finally track one of them down." Supernova explosions, which mark the violent death of a star, release tremendous amounts of energy and spew heavy elements such as calcium and iron into interstellar space. They thus seed the clouds of gas and dust from which new stars and planets are formed and, through their blast shocks, can even trigger such formation. The lack of evidence for young supernova remnants in the Milky Way had caused astronomers to wonder if our Galaxy, which appears otherwise normal, differed in some unknown way from others. Alternatively, scientists thought that the "missing" Milky Way supernovae perhaps indicated that their understanding of the relationship between supernovae and other galactic processes was in error. The astronomers made their discovery by measuring the expansion of the debris from the star's explosion. They did this by comparing images of the object, called G1.9+0.3, made more than two decades apart. In 1985, astronomers led by Green observed G1.9+0.3 with the VLA and identified it as a supernova remnant. At that time, they estimated its age as between 400 and 1,000 years. It is near the center of our Galaxy, roughly 25,000 light-years from Earth. In 2007, another team of astronomers, led by Stephen Reynolds of North Carolina State University, observed the object with the Chandra X-Ray Observatory. To their surprise, their image showed the object to be about 16 percent larger than in the 1985 VLA image. "This is a huge difference. It means the explosion debris is expanding very quickly, which in turn means the object is much younger than we originally thought," Reynolds explained. However, this expansion measurement came from comparing a radio image to an X-ray image. To make an "apples to apples" comparison, the scientists sought and were quickly granted observing time on the VLA. "I've never seen a large astronomical institution move so fast," said Reynolds. Their new VLA observations confirmed the supernova remnant's rapid expansion. The discovery provides scientists with a valuable source of new information about exploding stars. "Our previous situation was as if someone studying humans could look at babies and at adults, but could not study teenagers. Now, we're filling in that gap," said Reynolds. The object already has provided surprises. The velocities of its explosion debris and extreme energies of its particles are unprecedented. "No other object in the Galaxy has properties like this," said Reynolds. "Finding G1.9+0.3 is extremely important for learning more about how some stars explode and what happens in the aftermath," he added. The discovery was possible because radio and X-ray telescopes, unlike visible-light telescopes, can penetrate the thick clouds of gas and dust in our Galaxy. "Looking out of the Milky Way, we can see some supernova explosions with optical telescopes across half of the Universe, but when they're in this murk, we can miss them in our own cosmic back yard," Reynolds said. "Fortunately, the expanding gas cloud from the explosion shines brightly in radio waves and X-rays for thousands of years. X-ray and radio telescopes can see through all that obscuration and show us what we've been missing," he added. Because of the obscuration, no one could have seen the original explosion 140 years ago. The astronomers are reporting their results in papers published in the Astrophysical Journal Letters and Monthly Notices of the Royal Astronomical Society. Background Information: Supernova Explosions Supernova explosions are the violent death throes of stars. These explosions release in one event as much energy as is being released by all the rest of the stars in a galaxy -- typically 100 billion or so. Supernovae seen in other galaxies can outshine the rest of their galaxy for days. The supernovae that have occurred in our own Galaxy and were not obscured by the gas and dust that obscured G1.9+0.3 have often provided a spectacular sight. Historical records indicate that ancient astronomers noted supernova explosions at least as early as A.D. 393, and probably earlier. The pre-telescopic astronomers Tycho Brahe and Johannes Kepler made extensive observations of supernovae in 1572 and 1604. Chinese astronomers noted that a supernova in 1054 was bright enough to be seen in the daytime. A supernova in 1006 remained visible for two years. Supernovae that result from the deaths of stars much more massive than the Sun enrich the galaxy with chemical elements that are produced in the cores of those stars before they explode. The heavy elements, such as carbon, oxygen, iron, siicon and calcium, that make up planets and their inhabitants were made available by supernova explosions. In addition to enriching the material between stars with heavy elements, supernovae stir up that material through the shock energy of the explosion. This is thought to help trigger the process of star formation in interstellar clouds of gas and dust. Many astronomers believe that our own Solar System is the result of such a supernova shock. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

  13. Infrared emission from the supernova remnant Puppis A: Dust and gas parameters

    NASA Technical Reports Server (NTRS)

    Arendt, Richard G.; Dwek, Eli; Petre, R

    1989-01-01

    The infrared (IR) spectra of collisionally heated dust at several regions across the supernova remnant (SNR) Puppis A were modelled. Through the comparison of the actual and model spectra, the possible range of gas density and temperature within these areas was narrowed down. From the models, information on the minimum and maximum dust grain sizes and the amount of sputtering which has occurred was found. Finally the mass of gas and dust, the IR luminosity, the effective thickness, and the length of time since the dust was swept up by the SNR were derived for these regions.

  14. Analysis of LAC Observations of Clusters of Galaxies and Supernova Remnants

    NASA Technical Reports Server (NTRS)

    Hughes, J.

    1996-01-01

    The following publications are included and serve as the final report: The X-ray Spectrum of Abell 665; Clusters of Galaxies; Ginga Observation of an Oxygen-rich Supernova Remnant; Ginga Observations of the Coma Cluster and Studies of the Spatial Distribution of Iron; A Measurement of the Hubble Constant from the X-ray Properties and the Sunyaev-Zel'dovich Effect of Abell 2218; Non-polytropic Model for the Coma Cluster; and Abundance Gradients in Cooling Flow Clusters: Ginga LAC (Large Area Counter) and Einstein SSS (Solid State Spectrometer) Spectra of A496, A1795, A2142, and A2199.

  15. Exploding Stars and Stripes

    NASA Astrophysics Data System (ADS)

    2011-03-01

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

  16. XMM-Newton observations of the non-thermal supernova remnant HESS J1731-347 (G353.6-0.7)

    NASA Astrophysics Data System (ADS)

    Doroshenko, V.; Pühlhofer, G.; Bamba, A.; Acero, F.; Tian, W. W.; Klochkov, D.; Santangelo, A.

    2017-12-01

    We report on the analysis of XMM-Newton observations of the non-thermal shell-type supernova remnant HESS J1731-347 (G353.6-0.7). For the first time the complete remnant shell has been covered in X-rays, which allowed direct comparison with radio and TeV observations. We carried out a spatially resolved spectral analysis of XMM-Newton data and confirmed the previously reported non-thermal power-law X-ray spectrum of the source with negligible variations of spectral index across the shell. On the other hand, the X-ray absorption column is strongly variable and correlates with the CO emission thus confirming that the absorbing material must be in the foreground and reinforcing the previously suggested lower limit on distance. Finally, we find that the X-ray emission of the remnant is suppressed towards the Galactic plane, which points to lower shock velocities in this region, likely due to the interaction of the shock with the nearby molecular cloud.

  17. G0.9 + 0.1 and the emerging class of composite supernova remnants

    NASA Technical Reports Server (NTRS)

    Helfand, D. J.; Becker, R. H.

    1987-01-01

    High-resolution, multifrequency maps of a bright extended radio source near the Galactic center have revealed it to be a classic example of a composite supernova remnant. A steep-spectrum shell of emission, about 8 arcmin in diameter, surrounds a flat-spectrum, highly polarized Crab-like core about 2 arcmin across. The two components have equal flux densities at about 6 cm, marking this source as having the highest core-to-shell ratio among the about 10 composite remnants identified to date. X-ray and far-infrared data on the source are used to constrain the energetics and evolutionary state of the remnant and its putative central pulsar. It is argued that the total energy contained in the Crab-like components requires that the pulsars powering them were all born with periods shorter than 50 ms, and that if a substantial number of neutron stars with slow initial rotation rates exist, their birthplaces have not yet been found.

  18. A Spatially Resolved Plerionic X-Ray Nebula around PSR B0540-69.

    PubMed

    Gotthelf; Wang

    2000-04-01

    We present a high-resolution Chandra X-ray observation of PSR B0540-69, the Crab-like 50 ms pulsar in the Large Magellanic Cloud. We use phase-resolved imaging to decompose the extended X-ray emission, as expected of a synchrotron nebula, from the pointlike emission of the pulsar. The image of the pulsed X-ray emission shows a well-defined point-spread function of the observation, while the resolved nebula has a morphology and size remarkably similar to the Crab nebula, including evidence for a jetlike feature from PSR B0540-69. The patchy outer shell, which most likely represents the expanding blast wave of the supernova, is reminiscent of that seen in radio. Based on morphology, size, and energetics, there can be little doubt that SNR B0540-69 is an analogous system to the Crab but located in our neighboring galaxy.

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

    NASA Technical Reports Server (NTRS)

    Immler, Stefan; Kuntz, K. D.

    2005-01-01

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

  20. Type II supernovae as a significant source of interstellar dust.

    PubMed

    Dunne, Loretta; Eales, Stephen; Ivison, Rob; Morgan, Haley; Edmunds, Mike

    2003-07-17

    Large amounts of dust (>10(8)M(o)) have recently been discovered in high-redshift quasars and galaxies corresponding to a time when the Universe was less than one-tenth of its present age. The stellar winds produced by stars in the late stages of their evolution (on the asymptotic giant branch of the Hertzsprung-Russell diagram) are thought to be the main source of dust in galaxies, but they cannot produce that dust on a short enough timescale (&<1 Gyr) to explain the results in the high-redshift galaxies. Supernova explosions of massive stars (type II) are also a potential source, with models predicting 0.2-4M(o) of dust. As massive stars evolve rapidly, on timescales of a few Myr, these supernovae could be responsible for the high-redshift dust. Observations of supernova remnants in the Milky Way, however, have hitherto revealed only 10(-7)-10(-3)M(o) each, which is insufficient to explain the high-redshift data. Here we report the detection of approximately 2-4M(o) of cold dust in the youngest known Galactic supernova remnant, Cassiopeia A. This observation implies that supernovae are at least as important as stellar winds in producing dust in our Galaxy and would have been the dominant source of dust at high redshifts.

  1. Implications of supernova remnant origin model of galactic cosmic rays on gamma rays from young supernova remnants

    NASA Astrophysics Data System (ADS)

    Banik, Prabir; Bhadra, Arunava

    2017-06-01

    It is widely believed that Galactic cosmic rays are originated in supernova remnants (SNRs), where they are accelerated by a diffusive shock acceleration (DSA) process in supernova blast waves driven by expanding SNRs. In recent theoretical developments of the DSA theory in SNRs, protons are expected to accelerate in SNRs at least up to the knee energy. If SNRs are the true generators of cosmic rays, they should accelerate not only protons but also heavier nuclei with the right proportions, and the maximum energy of the heavier nuclei should be the atomic number (Z ) times the mass of the proton. In this work, we investigate the implications of the acceleration of heavier nuclei in SNRs on energetic gamma rays produced in the hadronic interaction of cosmic rays with ambient matter. Our findings suggest that the energy conversion efficiency has to be nearly double for the mixed cosmic ray composition compared to that of pure protons to explain observations. In addition, the gamma-ray flux above a few tens of TeV would be significantly higher if cosmic ray particles could attain energies Z times the knee energy in lieu of 200 TeV, as suggested earlier for nonamplified magnetic fields. The two stated maximum energy paradigms will be discriminated in the future by upcoming gamma-ray experiments like the Cherenkov telescope array (CTA).

  2. High Velocity Gas in the Line of Sight to the Vela SNR

    NASA Technical Reports Server (NTRS)

    Nichols, Joy S.; Slavin, Jonathan D.

    2004-01-01

    One of the best objects for study of the structure, kinematics, and evolutionary status of a middle-aged supernova remnant (SNR) is the VELA SNR, due to its proximity, extensive optical filamentary structure, and an abundance of hot background stars for absorption line research. The VELA remnant is 7.3 degrees in diameter, based on x-ray imagery with ROSAT, with the pulsar nearly centered in the remnant. The western region of the remnant has much lower x-ray surface brightness than the remainder of the remnant and in fact escaped earlier detection with previous instrumentation. The remnant is believed to be about 11,000 years old.

  3. The evolution of supernova remnants in different galactic environments, and its effects on supernova statistics

    NASA Technical Reports Server (NTRS)

    Kafatos, M.; Sofia, S.; Bruhweiler, F.; Gull, T. R.

    1980-01-01

    Examination of the interaction between supernova (SN) ejecta and the various environments in which the explosive event might occur shows that only a small fraction of the many SNs produce observable supernova remnants (SNRs). This fraction, which is found to depend weakly upon the lower mass limit of the SN progenitors, and more strongly on the specfic characteristics of the associated interstellar medium, decreases from approximately 15 percent near the galctic center to 10 percent at Rgal approximately 10 kpc and drops nearly to zero for Rgal 15 kpc. Generally, whether a SNR is detectable is determined by the density of the ambient interstellar medium in which it is embeeede. The presence of large, low density cavities arpund stellar associations due to the combined effects of stellar winds and supernova shells strongly suggests that a large portion of the detectable SNRs have runway stars as their progenitors. These results explain the differences between the substantially larger SN rates in the galaxy derived both from pulsar statistics and from observations of SN events in external galaxies, when compared to the substantially smaller SN rates derived form galactic SNR statistics.

  4. Evolution of Supernova Remnants Near the Galactic Center

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

    Yalinewich, A.; Piran, T.; Sari, R.

    Supernovae near the Galactic center (GC) evolve differently from regular Galactic supernovae. This is mainly due to the environment into which the supernova remnants (SNRs) propagate. SNRs near the GC propagate into a wind swept environment with a velocity directed away from the GC, and a graded density profile. This causes these SNRs to be non-spherical, and to evolve faster than their Galactic counterparts. We develop an analytic theory for the evolution of explosions within a stellar wind, and verify it using a hydrodynamic code. We show that such explosions can evolve in one of three possible morphologies. Using thesemore » results we discuss the association between the two SNRs (SGR East and SGR A’s bipolar radio/X-ray lobes) and the two neutron stars (the Cannonball and SGR J1745-2900) near the GC. We show that, given the morphologies of the SNR and positions of the neutron stars, the only possible association is between SGR A’s bipolar radio/X-ray lobes and SGR J1745-2900. If a compact object was created in the explosion of SGR East, it remains undetected, and the SNR of the supernova that created the Cannonball has already disappeared.« less

  5. Measurements of Amplified Magnetic Field and Cosmic-Ray Content in Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Uchiyama, Yasunobu

    Supernova explosions drive collisionless shocks in the interstellar (or circumstellar) medium. Such shocks are mediated by plasma waves, resulting in the shock transition on a scale much smaller than the collisional mean free path. Galactic cosmic rays are widely considered to be accelerated at collisionless shocks in supernova remnants via diffusive shock acceleration. New high-energy data coming from the X-ray and gamma-ray satellites and from imaging air Cerenkov telescopes are making possible to study physics of particle acceleration at supernova shocks, such as magnetic field amplification which is considered to be realized as part of shock acceleration process and the energy content of cosmic-ray particles in the supernova shell. In particular, GeV observations with the Fermi Gamma-ray Space Telescope offer the prime means to establish the origin of the gamma-rays, and to measure the cosmic-ray content. Moreover they provide a new opportunity to learn about how particle acceleration responds to environ-mental effects. I will present recent observational results from the Chandra and Suzaku X-ray satellites and new results from the LAT onboard Fermi, and discuss their implications to the origin of galactic cosmic rays.

  6. ROSAT PSPC and HRI Observations of Supernova Remnant G292.0+1.8

    NASA Technical Reports Server (NTRS)

    Hughes, John P.

    1999-01-01

    The supernova remnant G292.0+1.8 was observed by the ROSAT PSPC for 18 ksec as part of this grant. Considerable effort was put into the analysis of the PSPC spectra. The major work went into nonequilibrium ionization joint spectral fits with the Einstein SSS and EXOSAT ME data which indicated that the two spatial regions of this remnant (a central bar and a plateau region covering a larger extent) had similar abundances, but different excitation conditions (temperature and ionization state), an important conclusion, if true. Unfortunately as this work was being finished, new ASCA data revealed the presence of a previously unknown, spectrally hard X-ray source near the center of the remnant which contaminated the SSS and ME data and as a consequence made our detailed spectral analysis done up until then un-publishable. We searched for evidence of this hard source in the PSPC data both spectrally and using timing searches (for a pulsar), but found nothing significant. ROSAT HRI data were also obtained on this remnant. These data were compared to the Einstein HRI data to search for evidence of spectral variations with position and possible expansion of the X-ray remnant. One feature in the remnant appears to have changed in brightness although it is not clear what is the cause of the change. No evidence for the hard ASCA source was apparent in the HRI data.

  7. Chandra Detection of a Pulsar Wind Nebula Associated With Supernova Remnant 3C 396

    NASA Technical Reports Server (NTRS)

    Olbert, C. M.; Keohane, J. W.; Arnaud, K. A.; Dyer, K. K.; Reynolds, S. P.; Safi-Harb, S.

    2003-01-01

    We present a 100 ks observation of the Galactic supernova remnant 3C396 (G39.2-0.3) with the Chandra X-Ray Observatory that we compare to a 20cm map of the remnant from the Very Large Array. In the Chandra images, a nonthermal nebula containing an embedded pointlike source is apparent near the center of the remnant which we interpret as a synchrotron pulsar wind nebula surrounding a yet undetected pulsar. From the 2-10 keV spectrum for the nebula (N(sub H) = 5.3 plus or minus 0.9 x 10(exp 22) per square centimeter, GAMMA =1.5 plus or minus 0.3) we derive an unabsorbed x-ray flux of S(sub z)=1.62 x 10(exp -12) erg per square centimeter per second, and from this we estimate the spin-down power of the neutron star to be E(sup dot) = 7.2 x 10(exp 36) ergs per second. The central nebula is morphologically complex, showing bent, extended structure. The radio and X-ray shells of the remnant correlate poorly on large scales, particularly on the eastern half of the remnant, which appears very faint in X-ray images. At both radio and X-ray wavelengths the western half of the remnant is substantially brighter than the east.

  8. A distance estimate to the Cygnus Loop based on the distances to two stars located within the remnant

    NASA Astrophysics Data System (ADS)

    Fesen, Robert A.; Neustadt, Jack M. M.; Black, Christine S.; Milisavljevic, Dan

    2018-04-01

    Underlying nearly every quantitative discussion of the Cygnus Loop supernova remnant is uncertainty about its distance. Here, we present optical images and spectra of nebulosities around two stars whose mass-loss material appears to have interacted with the remnant's expanding shock front and thus can be used to estimate the Cygnus Loop's distance. Narrow passband images reveal a small emission-line nebula surrounding an M4 red giant near the remnant's eastern nebula NGC 6992. Optical spectra of the nebula show it to be shock-heated with significantly higher electron densities than seen in the remnant's filaments. This along with a bow-shaped morphology suggests it is likely red giant mass-loss material shocked and accelerated by passage of the Cygnus Loop's blast wave. We also identify a B7 V star located along the remnant's northwestern limb, which also appears to have interacted with the remnant's shock wave. It lies within a small arc of nebulosity in an unusually complex region of curved and distorted filaments along the remnant's northern shock front suggestive of a localized disturbance of the shock front due to the B star's stellar winds. Based on the assumption that these two stars lie inside the remnant, combined with an estimated distance to a molecular cloud situated along the remnant's western limb, we propose a distance to the Cygnus Loop of 1.0 ± 0.2 kpc. Although larger than several recent estimates of 500-800 pc, a distance ≃1 kpc helps resolve difficulties with the remnant's postshock cosmic ray and gas pressure ratio and estimated supernova explosion energy.

  9. AN X-RAY INVESTIGATION OF THREE SUPERNOVA REMNANTS IN THE LARGE MAGELLANIC CLOUD

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

    Klimek, Matthew D.; Points, S. D.; Smith, R. C.

    2010-12-20

    We have investigated three supernova remnants (SNRs) in the LMC using multi-wavelength data. These SNRs are generally fainter than the known sample (see Section 4) and may represent a previously missed population. One of our SNRs is the second LMC remnant analyzed which is larger than any Galactic remnant for which a definite size has been established. The analysis of such a large remnant contributes to the understanding of the population of highly evolved SNRs. We have obtained X-ray images and spectra of three of these recently identified SNRs using the XMM-Newton observatory. These data, in conjunction with pre-existing opticalmore » emission-line images and spectra, were used to determine the physical conditions of the optical- and X-ray-emitting gas in the SNRs. We have compared the morphologies of the SNRs in the different wavebands. The physical properties of the warm ionized shell were determined from the H{alpha} surface brightness and the SNR expansion velocity. The X-ray spectra were fit with a thermal plasma model and the physical conditions of the hot gas were derived from the model fits. Finally, we have compared our observations with simulations of SNR evolution.« less

  10. Helium in supernova remnants

    NASA Astrophysics Data System (ADS)

    Danziger, I. J.; Leibowitz, E.

    1983-02-01

    Observational data for supernova remnants (SNR) which exhibit He abundances exceeding the normal value of 0.10 are examingd. Attention is given to the Crab, Cas A, and Puppis A nebular O, N, and He abundances, sizes, and ages. The overabundances of He and N detected in the Crab and Cas A nebulae are suggested to have arisen from swept-up interstellar matter. Therefore, the He abundances in interstellar matter may be calculated from data on old SNR. However, the Larger and Smaller Magellanic clouds display lowered abundances, which may be due to stratification caused by ionization. The method is useful for SNRs located within 5 mpc of the local group of galaxies.

  11. The hydrodynamics of off-center explosions. [of supernovae

    NASA Technical Reports Server (NTRS)

    Fryxell, B. A.

    1979-01-01

    The behavior of off-center supernova explosions is investigated using a two-dimensional hydrodynamic code. An important application of these calculations is the possible formation of high-velocity pulsars. The dependence of the final velocity of the collapsed remnant on the location and energy of the explosion is computed. The largest remnant velocities result from explosions located at a mass fraction of 0.5. An explosion energy 50% greater than the binding energy of the star ejects 0.51 solar masses, producing a 1.4 solar mass remnant with a velocity of 400 km/s. However, this energy must be generated in a very small region of the star in order to create the required asymmetry in the explosion. Because of this, a specific energy of about 10 to the 20th ergs/g is needed. Nuclear reactions can produce no more than about 5 x 10 to the 17th erg/g, and it is unclear how the energy produced in gravitational collapse models can be sufficiently localized. Unless a supernova mechanism can be found which can produce enough energy in a small region of the star, off-center explosions do not provide a satisfactory explanation for high-velocity pulsars.

  12. A Search for a Surviving White Dwarf Companion in SN 1006

    NASA Astrophysics Data System (ADS)

    Kerzendorf, W. E.; Strampelli, G.; Shen, K. J.; Schwab, J.; Pakmor, R.; Do, T.; Buchner, J.; Rest, A.

    2018-05-01

    Multiple channels have been proposed to produce Type Ia supernovae, with many scenarios suggesting that the exploding white dwarf accretes from a binary companion pre-explosion. In almost all cases, theory suggests that this companion will survive. However, no such companion has been unambiguously identified in ancient supernova remnants - possibly falsifying the accretion scenario. Existing surveys, however, have only looked for stars as faint as ≈0.1L⊙ and thus might have missed a surviving white dwarf companion. In this work, we present very deep DECAM imaging (u, g, r, z) of the Type Ia supernova remnant SN 1006 specifically to search for a potential surviving white dwarf companion. We find no object that is consistent with a relatively young cooling white dwarf within the inner half of the SN 1006 remnant. We find that if there is a companion white dwarf, it must be redder than the standard white dwarf cooling track, or it must have formed long ago and cooled undisturbed for >108 yr. We conclude that our findings are consistent with the complete destruction of the secondary (such as in a merger) or an anomalously red or very dim surviving companion white dwarf.

  13. TYCHO SN 1572: A NAKED Ia SUPERNOVA REMNANT WITHOUT AN ASSOCIATED AMBIENT MOLECULAR CLOUD

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

    Tian, W. W.; Leahy, D. A., E-mail: tww@bao.ac.cn

    The historical supernova remnant (SNR) Tycho SN 1572 originates from the explosion of a normal Type Ia supernova that is believed to have originated from a carbon-oxygen white dwarf in a binary system. We analyze the 21 cm continuum, H I, and {sup 12}CO-line data from the Canadian Galactic Plane Survey in the direction of SN 1572 and the surrounding region. We construct H I absorption spectra to SN 1572 and three nearby compact sources. We conclude that SN 1572 has no molecular cloud interaction, which argues against previous claims that a molecular cloud is interacting with the SNR. Thismore » new result does not support a recent claim that dust, newly detected by AKARI, originates from such an SNR-cloud interaction. We suggest that the SNR has a kinematic distance of 2.5-3.0 kpc based on a nonlinear rotational curve model. Very high energy {gamma}-ray emission from the remnant has been detected by the VERITAS telescope, so our result shows that its origin should not be an SNR-cloud interaction. Both radio and X-ray observations support that SN 1572 is an isolated Type Ia SNR.« less

  14. PSR B 1706-44 and the SNR G 343.1-2.3 as the remnants of a cavity supernova explosion

    NASA Astrophysics Data System (ADS)

    Bock, D. C.-J.; Gvaramadze, V. V.

    2002-11-01

    The possible association of the supernova remnant (SNR) G 343.1-2.3 with the pulsar PSR B 1706-44 (superposed on the arclike ``shell" of the SNR) has been questioned by some authors on the basis of an inconsistency between the implied and measured (scintillation) transverse velocities of the pulsar, the absence of any apparent interaction between the pulsar and the SNR's ``shell'', and some other indirect arguments. We suggest, however, that this association could be real if both objects are the remnants of a supernova (SN) which exploded within a mushroom-like cavity (created by the SN progenitor wind breaking out of the parent molecular cloud). This suggestion implies that the actual shape of the SNR's shell is similar to that of the well-known SNR VRO 42.05.01 and that the observed bright arc corresponds to the ``half'' of the SNR located inside the cloud. We report the discovery in archival radio data of an extended ragged radio arc to the southeast of the bright arc which we interpret as the ``half'' of the SN blast wave expanding in the intercloud medium.

  15. Particle Acceleration, Magnetic Field Generation and Emission from Relativistic Jets and Supernova Remnants

    NASA Technical Reports Server (NTRS)

    Nishikawa, K.-I.; Hartmann, D. H.; Hardee, P.; Hededal, C.; Mizunno, Y.; Fishman, G. J.

    2006-01-01

    We performed numerical simulations of particle acceleration, magnetic field generation, and emission from shocks in order to understand the observed emission from relativistic jets and supernova remnants. The investigation involves the study of collisionless shocks, where the Weibel instability is responsible for particle acceleration as well as magnetic field generation. A 3-D relativistic particle-in-cell (RPIC) code has been used to investigate the shock processes in electron-positron plasmas. The evolution of theWeibe1 instability and its associated magnetic field generation and particle acceleration are studied with two different jet velocities (0 = 2,5 - slow, fast) corresponding to either outflows in supernova remnants or relativistic jets, such as those found in AGNs and microquasars. Slow jets have intrinsically different structures in both the generated magnetic fields and the accelerated particle spectrum. In particular, the jet head has a very weak magnetic field and the ambient electrons are strongly accelerated and dragged by the jet particles. The simulation results exhibit jitter radiation from inhomogeneous magnetic fields, generated by the Weibel instability, which has different spectral properties than standard synchrotron emission in a homogeneous magnetic field.

  16. A New Supernova Remnant Coincident with the Slow X-Ray Pulsar AX J1845-0258.

    PubMed

    Gaensler; Gotthelf; Vasisht

    1999-11-20

    We report on Very Large Array observations in the direction of the recently discovered slow X-ray pulsar AX J1845-0258. In the resulting images, we find a 5&arcmin; shell of radio emission; the shell is linearly polarized with a nonthermal spectral index. We classify this source as a previously unidentified, young (<8000 yr) supernova remnant (SNR), G29.6+0.1, which we propose is physically associated with AX J1845-0258. The young age of G29.6+0.1 is then consistent with the interpretation that anomalous X-ray pulsars (AXPs) are isolated, highly magnetized neutron stars ("magnetars"). Three of the six known AXPs can now be associated with SNRs; we conclude that AXPs are young ( less, similar10,000 yr) objects and that they are produced in at least 5% of core-collapse supernovae.

  17. Chandra X-Ray Observatory Image of Cassiopeia A

    NASA Technical Reports Server (NTRS)

    1999-01-01

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

  18. History of Chandra X-Ray Observatory

    NASA Image and Video Library

    1999-08-01

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

  19. Gamma-ray astronomy and the origin of cosmic rays

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1978-01-01

    New surveys of galactic gamma ray emission together with millimeter wave radio surveys indicated that cosmic rays were produced as the result of supernova explosions in our galaxy with the most intense production occurring in a Great Galactic Ring about 35,000 light years in diameter where supernova remnants and pulsars were concentrated.

  20. Compact radio sources in the starburst galaxy M82 and the Sigma-D relation for supernova remnants

    NASA Technical Reports Server (NTRS)

    Huang, Z. P.; Thuan, T. X.; Chevalier, R. A.; Condon, J. J.; Yin, Q. F.

    1994-01-01

    We have obtained an 8.4 GHz Very Large Array (VLA) A-array map of the starburst galaxy M82 with a resolution Full Width at Half Maximum (FWHM) approximately 0.182 sec. About 50 compact radio sources in the central region of M82 were detected with a peak surface brightness approximately greater than 10(exp -17) W/Hz/sq m/sr. Comparison with previous observations shows that most sources are declining in flux. Three previously visible sources have faded into the background of our map (approximately less than 0.2 mJy/beam), while a few sources, including the second and third brightest radio sources in M82, may have increased slightly in flux over the last decade. No new radio supernova was found. The birth rate of the compact radio sources is estimated to be 0.11 + or - 0.05/yr. We attribute the population of such bright, small supernova remnants (SNRs) in M82 to the high pressure in the central region that can truncate the mass loss during a red supergiant phase or allow dense ionized clouds to be present. The compact radio sources obey a Sigma(radio surface brightness) - D(diameter) relation which is remarkably similar to that followed by supernova remnants in the Galaxy and the Magellanic Clouds and by two of the strongest known extragalactic radio supernovae: SN 1986J and SN 1979C. A least-squares fit to the SNR data gives: Sigma(sub 8.4 GHz) (W/Hz/sq m/sr) = 4.4 x 10(exp -16) D(sub pc)(exp -3.5 +/- 0.1) covering seven orders of magnitude in Sigma. Possible selection effects are discussed and a theoretical discussion of the correlation is presented.

  1. The SN 393-SNR RX J1713.7-3946 (G347.3-0.5) Connection

    NASA Astrophysics Data System (ADS)

    Fesen, Robert A.; Kremer, Richard; Patnaude, Daniel; Milisavljevic, Dan

    2012-02-01

    Although the connection of the Chinese "guest" star of 393 AD with the Galactic supernova remnant RX J1713.7-3946 (G347.3-0.5) made by Wang et al. in 1997 is consistent with the remnant's relatively young properties and the guest star's projected position within the "tail" of the constellation Scorpius, there are difficulties with such an association. The brief Chinese texts concerning the 393 AD guest star make no comment about its apparent brightness, stating only that it disappeared after eight months. However, at the remnant's current estimated 1-1.3 kpc distance and A V ~= 3, its supernova (SN) should have been a visually bright object at maximum light (-3.5 to -5.0 mag) if MV = - 17 to -18 and would have remained visible for over a year. The peak brightness sime0 mag adopted by Wang et al. and others would require the RX J1713.7-3946 supernova to have been a very subluminous event similar to or fainter than SN 2005cs in M51. We also note problems connecting SN 393 with a European record in which the Roman poet Claudian describes a visually brilliant star in the heavens around 393 AD that could be readily seen even in midday. Although several authors have suggested this account may be a reference to the Chinese supernova of 393, Scorpius would not be visible near midday in March when the Chinese first reported the 393 guest star. We review both the Chinese and Roman accounts and calculate probable visual brightnesses for a range of SN subtypes and conclude that neither the Chinese nor the Roman descriptions are easily reconciled with an expected RX J1713.7-3946 supernova brightness and duration.

  2. New Evidence Links Stellar Remains to Oldest Recorded Supernova

    NASA Astrophysics Data System (ADS)

    2006-09-01

    Recent observations have uncovered evidence that helps to confirm the identification of the remains of one of the earliest stellar explosions recorded by humans. The new study shows that the supernova remnant RCW 86 is much younger than previously thought. As such, the formation of the remnant appears to coincide with a supernova observed by Chinese astronomers in 185 A.D. The study used data from NASA's Chandra X-ray Observatory and the European Space Agency's XMM-Newton Observatory, "There have been previous suggestions that RCW 86 is the remains of the supernova from 185 A.D.," said Jacco Vink of University of Utrecht, the Netherlands, and lead author of the study. "These new X-ray data greatly strengthen the case." When a massive star runs out of fuel, it collapses on itself, creating a supernova that can outshine an entire galaxy. The intense explosion hurls the outer layers of the star into space and produces powerful shock waves. The remains of the star and the material it encounters are heated to millions of degrees and can emit intense X-ray radiation for thousands of years. Animation of a Massive Star Explosion Animation of a Massive Star Explosion In their stellar forensic work, Vink and colleagues studied the debris in RCW 86 to estimate when its progenitor star originally exploded. They calculated how quickly the shocked, or energized, shell is moving in RCW 86, by studying one part of the remnant. They combined this expansion velocity with the size of the remnant and a basic understanding of how supernovas expand to estimate the age of RCW 86. "Our new calculations tell us the remnant is about 2,000 years old," said Aya Bamba, a coauthor from the Institute of Physical and Chemical Research (RIKEN), Japan. "Previously astronomers had estimated an age of 10,000 years." The younger age for RCW 86 may explain an astronomical event observed almost 2000 years ago. In 185 AD, Chinese astronomers (and possibly the Romans) recorded the appearance of a new bright star. The Chinese noted that it sparkled like a star and did not appear to move in the sky, arguing against it being a comet. Also, the observers noticed that the star took about eight months to fade, consistent with modern observations of supernovas. RCW 86 had previously been suggested as the remnant from the 185 AD event, based on the historical records of the object's position. However, uncertainties about the age provided significant doubt about the association. "Before this work I had doubts myself about the link, but our study indicates that the age of RCW 86 matches that of the oldest known supernova explosion in recorded history," said Vink. "Astronomers are used to referencing results from 5 or 10 years ago, so it's remarkable that we can build upon work from nearly 2000 years ago." The smaller age estimate for the remnant follows directly from a higher expansion velocity. By examining the energy distribution of the X-rays, a technique known as spectroscopy, the team found most of the X-ray emission was caused by high-energy electrons moving through a magnetic field. This is a well-known process that normally gives rise to low-energy radio emission. However, only very high shock velocities can accelerate the electrons to such high energies that X-ray radiation is emitted. "The energies reached in this supernova remnant are extremely high," said Andrei Bykov, another team member from the Ioffe Institute, St. Peterburg, Russia. "In fact, the particle energies are greater than what can be achieved by the most modern particle accelerators." The difference in age estimates for RCW 86 is due to differences in expansion velocities measured for the supernova remnant. The authors speculate that these variations arise because RCW 86 is expanding into an irregular bubble blown by a wind from the progenitor star before it exploded. In some directions, the shock wave has encountered a dense region outside the bubble and slowed down, whereas in other regions the shock remains inside the bubble and is still moving rapidly. These regions give the most accurate estimate of the age. The study describing these results appeared in the September 1 issue of The Astrophysical Journal Letters. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory, Cambridge, Mass., controls science and flight operations from the Chandra X-ray Center, Cambridge, Mass. XMM-Newton is an European Space Agency science mission managed at the European Space Research and Technology Centre, Noordwijk, the Netherlands for the Directorate of the Scientific Programme. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

  3. A broadband study of the emission from the composite supernova remnant MSH 11-62

    DOE PAGES

    Slane, Patrick; Hughes, John P.; Temim, Tea; ...

    2012-03-30

    MSH 11-62 (G291.0-0.1) is a composite supernova remnant for which radio and X-ray observations have identified the remnant shell as well as its central pulsar wind nebula. Our observations suggest a relatively young system expanding into a low-density region. We present a study of MSH 11-62 using observations with the Chandra, XMM -Newton, and Fermi observatories, along with radio observations from the Australia Telescope Compact Array. We also identify a compact X-ray source that appears to be the putative pulsar that powers the nebula, and show that the X-ray spectrum of the nebula bears the signature of synchrotron losses asmore » particles diffuse into the outer nebula. Using data from the Fermi Large Area Telescope, we identify γ-ray emission originating from MSH 11-62. Furthermore, with density constraints from the new X-ray measurements of the remnant, we model the evolution of the composite system in order to constrain the properties of the underlying pulsar and the origin of the γ-ray emission.« less

  4. A Broadband Study of the Emission from the Composite Supernova Remnant MSH 11-62

    NASA Technical Reports Server (NTRS)

    Slane, Patrick; Hughes, John P.; Temim, Tea; Rousseau, Romain; Castro, Daniel; Foight, Dillon; Gaensler, B. M.; Funk, Stefan; Lemoine-Goumard, Marianne; Gelfand, Joseph D.; hide

    2012-01-01

    MSH 11-62 (G29U)-Q.1) is a composite supernova remnant for which radio and X-ray observations have identified the remnant shell as well as its central pulsar wind nebula. The observations suggest a relatively young system expanding into a low-density region. Here, we present a study of MSH ll-62 using observations with the Chandra, XMM-Newton, and Fermi observatories, along with radio observations from the Australia Telescope Compact Array. We identify a compact X-ray source that appears to be the putative pulsar that powers the nebula, and show that the X-ray spectrum of the nebula bears the signature of synchrotron losses as particles diffuse into the outer nebula. Using data from the Fermi Large Area Telescope, we identify gamma-ray emission originating from MSH 11-62. With density constraints from the new X-ray measurements of the remnant, we model the evolution of the composite system in order to constrain the properties of the underlying pulsar and the origin of the gamma-ray emission.

  5. High Resolution X-Ray Spectroscopy and Imaging of Supernova Remnant N132D

    NASA Technical Reports Server (NTRS)

    Behar, Ehud; Rasmussen, Andrew; Griffiths, R. Gareth; Dennerl, Konrad; Audard, Marc; Aschenbach, Bernd

    2000-01-01

    The observation of the supernova remnant N132D by the scientific instruments on board the XMM-Newton satellite is presented. The X-rays from N132D are dispersed into a detailed line-rich spectrum using the Reflection Grating Spectrometers. Spectral lines of C, N, O, Ne, Mg, Si, S, and Fe are identified. Images of the remnant, in narrow wavelength bands, produced by the European Photon Imaging Cameras reveal a complex spatial structure of the ionic distribution. While K - shell Fe seems to originate near the centre, all of the other ions are observed along the shell. An emission excess of O(6+) over O(7+) is detected on the northeastern edge of the remnant. This can be a sign of hot ionising conditions, or it can reflect a relatively cool region. Spectral fitting of the CCD spectrum suggests high temperatures in this region, but a detailed analysis of the atomic processes involved in producing the O(6+) spectral lines leads to the conclusion that the intensities of these lines alone cannot provide a conclusive distinction between the two scenarios.

  6. Dust masses for SN 1980K, SN1993J and Cassiopeia A from red-blue emission line asymmetries

    NASA Astrophysics Data System (ADS)

    Bevan, Antonia; Barlow, M. J.; Milisavljevic, D.

    2017-03-01

    We present Monte Carlo line transfer models that investigate the effects of dust on the very late time emission line spectra of the core-collapse supernovae SN 1980K and SN 1993J and the young core collapse supernova remnant Cassiopeia A. Their blueshifted emission peaks, resulting from the removal by dust of redshifted photons emitted from the far sides of the remnants, and the presence of extended red emission wings are used to constrain dust compositions and radii and to determine the masses of dust in the remnants. We estimate dust masses of between 0.08 and 0.15 M⊙ for SN 1993J at year 16, 0.12 and 0.30 M⊙ for SN 1980K at year 30 and ∼1.1 M⊙ for Cas A at year ∼330. Our models for the strong oxygen forbidden lines of Cas A require the overall modelled profiles to be shifted to the red by between 700 and 1000 km s-1, consistent with previous estimates for the shift of the dynamical centroid of this remnant.

  7. High-resolution radio and X-ray observations of the supernova remnant W28

    NASA Technical Reports Server (NTRS)

    Andrews, M. D.; Basart, J. P.; Lamb, R. C.; Becker, R. H.

    1983-01-01

    The present study has the objective to report the first high resolution radio and X-ray observations of the central part of the galactic supernova remnant, W28, taking into account the possible association of the remnant with the unidentified gamma-ray source, 2CG 006-00. This gamma-ray source is approximately two-thirds as bright as the Crab pulsar above 100 MeV, and has a somewhat flatter spectrum. Both the radio and X-ray observations reveal previously unknown aspects of W28 which support the possibility of W28 being a gamma-ray source. The radio data show a flat-spectrum, nonthermal component reminiscent of the Crab Nebula and Vela, both of which are confirmed gamma-ray sources. The X-ray observations reveal a compact source within W28, again suggestive of both the Crab and Vela. If the similarities among W28, the Crab Nebula, and the Vela remnant are valid, the gamma-ray source 2CG 00-00 should be studied for periodicity, the conclusive signature of a compact source of emission.

  8. 9500 Nights of Mid-Infrared Observations of SN 1987A: the birth of the remnant

    NASA Astrophysics Data System (ADS)

    Bouchet, Patrice; Danziger, John

    2014-01-01

    The one-in-a-life-time event Supernova SN 1987A, the brightest supernova seen since Kepler's in 1604, has given us a unique opportunity to study the mechanics of a supernova explosion and now to witness the birth of a supernova remnant. A violent encounter is underway between the fastest-moving debris and the circumstellar ring: shocks excite ``hotspots''. ATCA/ANTF, Gemini, VLT, HST, Spitzer, Chandra, and recently ALMA observations have been so far organized to help understanding the several emission mechanisms at work. In the mid-infrared SN 1987A has transformed from a SN with the bulk of its radiation from the ejecta to a SNR whose emission is dominated by the interaction of the blast wave with the surrounding interstellar medium, a process in which kinetic energy is converted into radiative energy. Currently this remnant emission is dominated by material in or near the inner equatorial ring (ER). We give here a brief history of our mid-infrared observations, and present our last data obtained with the SPITZER infrared satellite and the ESO VLT and Gemini telescopes: we show how together with Chandra observations, they contribute to the understanding of this fascinating object. We argue also that our imaging observations suggest that warm dust is still present in the ejecta, and we dispute the presence of huge amount of very cold dust in it, as it has been claimed on the basis of data obtained with the HERSCHELl satellite.

  9. Time-dependent shock acceleration of particles. Effect of the time-dependent injection, with application to supernova remnants

    NASA Astrophysics Data System (ADS)

    Petruk, O.; Kopytko, B.

    2016-11-01

    Three approaches are considered to solve the equation which describes the time-dependent diffusive shock acceleration of test particles at the non-relativistic shocks. At first, the solution of Drury for the particle distribution function at the shock is generalized to any relation between the acceleration time-scales upstream and downstream and for the time-dependent injection efficiency. Three alternative solutions for the spatial dependence of the distribution function are derived. Then, the two other approaches to solve the time-dependent equation are presented, one of which does not require the Laplace transform. At the end, our more general solution is discussed, with a particular attention to the time-dependent injection in supernova remnants. It is shown that, comparing to the case with the dominant upstream acceleration time-scale, the maximum momentum of accelerated particles shifts towards the smaller momenta with increase of the downstream acceleration time-scale. The time-dependent injection affects the shape of the particle spectrum. In particular, (I) the power-law index is not solely determined by the shock compression, in contrast to the stationary solution; (II) the larger the injection efficiency during the first decades after the supernova explosion, the harder the particle spectrum around the high-energy cutoff at the later times. This is important, in particular, for interpretation of the radio and gamma-ray observations of supernova remnants, as demonstrated on a number of examples.

  10. Discovery of recombining plasma from the faintest GeV supernova remnant HB 21 and a possible scenario for cosmic rays escaping from supernova remnant shocks

    NASA Astrophysics Data System (ADS)

    Suzuki, Hiromasa; Bamba, Aya; Nakazawa, Kazuhiro; Furuta, Yoshihiro; Sawada, Makoto; Yamazaki, Ryo; Koyama, Katsuji

    2018-06-01

    We present an X-ray study of the GeV gamma-ray supernova remnant (SNR) HB 21 with Suzaku. HB 21 is interacting with molecular clouds, and is the faintest in the GeV band among known GeV SNRs. We discovered strong radiative recombination continua of Si and S from the center of the remnant, which provide direct evidence of a recombining plasma (RP). The total emission can be explained with the RP and ionizing plasma components. The electron temperature and recombination timescale of the RP component were estimated as 0.17 (0.15-0.18) keV and 3.2 (2.0-4.8) × 1011 s cm-3, respectively. The estimated age of the RP (˜170 kyr) is the longest among known recombining GeV SNRs, because of a very low density of electrons (˜0.05 cm-3). We have examined the dependencies of GeV spectral indices on each of RP ages and SNR diameters for nine recombining GeV SNRs. Both showed possible positive correlations, indicating that both the parameters can be good indicators of properties of accelerated protons, for instance the degree of escape from SNR shocks. A possible scenario for a process of proton escape is introduced: interaction with molecular clouds makes weaker magnetic turbulence and cosmic-ray protons escape, simultaneously cooling down the thermal electrons and generating an RP.

  11. Dust Destruction in the Supernova Remnant N49: Additional WiFeS Integral Field data AnalysisRachel Quigley, Rachael Huxford, Parviz Ghavamian, Mike Dopita

    NASA Astrophysics Data System (ADS)

    Quigley, Rachel; Ghavamian, Parviz

    2018-01-01

    Abstract:The supernova remnant N49, located in the Large Magellanic Cloud (LMC), is widely researched because of its relatively young age and its location near a dense, dusty molecular cloud in the interstellar medium (ISM). N49 has entered into its radiative phase more quickly than to be expected for the age of this remnant. As a consequence, N49 is showing signs that the diffuse hot interior is starting to cool and recombine. Using existing integral field spectra of SNR N49, different Fe emission lines and other spectral lines were extracted via python tools, following a similar approach to Dopita et al. (2016). At optical wavelengths, the dependence of [OIII]5007/4363 ratio on shock velocity is evident. This diagnostic is important because the [OIII]-emitting zone in low-velocity shocks of the cooling post-shock gas is hot. As the shock velocity increases, the temperature indicated by the [OIII] parameter falls. The dependence of Fe depletion lines on shock velocity is rather weak. Using [FeIII]:[OIII] diagnostic, the properties of dust destruction and production of dust in the SNR can be determined. Using this method, line ratios for other emission lines can be compared to the MAPPINGS predictions of Allen et al. (2008) to study the range of shock speeds present in the supernova remnant, where radiative shocks are driven into interstellar gas.

  12. EVIDENCE FOR PARTICLE ACCELERATION TO THE KNEE OF THE COSMIC RAY SPECTRUM IN TYCHO'S SUPERNOVA REMNANT

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

    Eriksen, Kristoffer A.; Hughes, John P.; Badenes, Carles

    2011-02-20

    Supernova remnants (SNRs) have long been assumed to be the source of cosmic rays (CRs) up to the 'knee' of the CR spectrum at 10{sup 15} eV, accelerating particles to relativistic energies in their blast waves by the process of diffusive shock acceleration (DSA). Since CR nuclei do not radiate efficiently, their presence must be inferred indirectly. Previous theoretical calculations and X-ray observations show that CR acceleration significantly modifies the structure of the SNR and greatly amplifies the interstellar magnetic field. We present new, deep X-ray observations of the remnant of Tycho's supernova (SN 1572, henceforth Tycho), which reveal amore » previously unknown, strikingly ordered pattern of non-thermal high-emissivity stripes in the projected interior of the remnant, with spacing that corresponds to the gyroradii of 10{sup 14}-10{sup 15} eV protons. Spectroscopy of the stripes shows the plasma to be highly turbulent on the (smaller) scale of the Larmor radii of TeV energy electrons. Models of the shock amplification of magnetic fields produce structure on the scale of the gyroradius of the highest energy CRs present, but they do not predict the highly ordered pattern we observe. We interpret the stripes as evidence for acceleration of particles to near the knee of the CR spectrum in regions of enhanced magnetic turbulence, while the observed highly ordered pattern of these features provides a new challenge to models of DSA.« less

  13. Two evolved supernova remnants with newly identified Fe-rich cores in the Large Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Kavanagh, P. J.; Sasaki, M.; Bozzetto, L. M.; Points, S. D.; Crawford, E. J.; Dickel, J.; Filipović, M. D.; Haberl, F.; Maggi, P.; Whelan, E. T.

    2016-02-01

    Aims: We present a multi-wavelength analysis of the evolved supernova remnants MCSNR J0506-7025 and MCSNR J0527-7104 in the Large Magellanic Cloud. Methods: We used observational data from XMM-Newton, the Australian Telescope Compact Array, and the Magellanic Cloud Emission Line Survey to study their broad-band emission and used Spitzer and H I data to gain a picture of the environment into which the remnants are expanding. We performed a multi-wavelength morphological study and detailed radio and X-ray spectral analyses to determine their physical characteristics. Results: Both remnants were found to have bright X-ray cores, dominated by Fe L-shell emission, which is consistent with reverse shock-heated ejecta with determined Fe masses in agreement with Type Ia explosion yields. A soft X-ray shell, which is consistent with swept-up interstellar medium, was observed in MCSNR J0506-7025, suggestive of a remnant in the Sedov phase. Using the spectral fit results and the Sedov self-similar solution, we estimated the age of MCSNR J0506-7025 to be ~16-28 kyr, with an initial explosion energy of (0.07-0.84) × 1051 erg. A soft shell was absent in MCSNR J0527-7104, with only ejecta emission visible in an extremely elongated morphology that extends beyond the optical shell. We suggest that the blast wave has broken out into a low density cavity, allowing the shock heated ejecta to escape. We find that the radio spectral index of MCSNR J0506-7025 is consistent with the standard -0.5 for supernova remnants. Radio polarisation at 6 cm indicates a higher degree of polarisation along the western front and at the eastern knot with a mean fractional polarisation across the remnant of P ≅ (20 ± 6)%. Conclusions: The detection of Fe-rich ejecta in the remnants suggests that both resulted from Type Ia explosions. The newly identified Fe-rich cores in MCSNR J0506-7025 and MCSNR J0527-7104 make them members of the expanding class of evolved Fe-rich remnants in the Magellanic Clouds. Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA.

  14. Point X-ray sources in the SNR G 315.4-2.30 (MSH 14-63, RCW 86)

    NASA Astrophysics Data System (ADS)

    Gvaramadze, V. V.; Vikhlinin, A. A.

    2003-04-01

    We report the results of a search for a point X-ray source (stellar remnant) in the southwest protrusion of the supernova remnant G 315.4-2.30 (MSH 14-63, RCW 86) using the archival data of the Chandra X-ray Observatory. The search was motivated by a hypothesis that G 315.4-2.30 is the result of an off-centered cavity supernova explosion of a moving massive star, which ended its evolution just near the edge of the main-sequence wind-driven bubble. This hypothesis implies that the southwest protrusion in G 315.4-2.30 is the remainder of a pre-existing bow shock-like structure created by the interaction of the supernova progenitor's wind with the interstellar medium and that the actual location of the supernova blast center is near the center of this hemispherical structure. We have discovered two point X-ray sources in the ``proper" place. One of the sources has an optical counterpart with the photographic magnitude 13.38+/-0.40, while the spectrum of the source can be fitted with an optically thin plasma model. We interpret this source as a foreground active star of late spectral type. The second source has no optical counterpart to a limiting magnitude ~ 21. The spectrum of this source can be fitted almost equally well with several simple models (power law: photon index =1.87; two-temperature blackbody: kT1 =0.11 keV, R1 =2.34 km and kT2 =0.71 keV, R2 =0.06 km; blackbody plus power law: kT =0.07 keV, photon index =2.3). We interpret this source as a candidate stellar remnant (neutron star), while the photon index and non-thermal luminosity of the source (almost the same as those of the Vela pulsar and the recently discovered pulsar PSR J 0205+6449 in the supernova remnant 3C 58) suggest that it can be a young ``ordinary" pulsar.

  15. Fermi-LAT Observations of Supernova Remnants Kesteven 79

    NASA Astrophysics Data System (ADS)

    Auchettl, Katie; Slane, Patrick; Castro, Daniel

    2014-03-01

    In this paper, we report on the detection of γ-ray emission coincident with the Galactic supernova remnant (SNR) Kesteven 79 (Kes 79). We analyzed approximately 52 months of data obtained with the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. Kes 79 is thought to be interacting with adjacent molecular clouds, based on the presence of strong 12CO J = 1 → 0 and HCO+ J = 1 → 0 emission and the detection of 1720 MHz line emission toward the east of the remnant. Acceleration of cosmic rays is expected to occur at SNR shocks, and SNRs interacting with dense molecular clouds provide a good testing ground for detecting and analyzing the production of γ-rays from the decay of π0 into two γ-ray photons. This analysis investigates γ-ray emission coincident with Kes 79, which has a detection significance of ~7σ. Additionally, we present an investigation of the spatial and spectral characteristics of Kes 79 using multiple archival XMM-Newton observations of this remnant. We determine the global X-ray properties of Kes 79 and estimate the ambient density across the remnant. We also performed a similar analysis for Galactic SNR Kesteven 78 (Kes 78), but due to large uncertainties in the γ-ray background model, no conclusion can be made about an excess of GeV γ-ray associated with the remnant.

  16. The Progenitor Systems and Explosion Mechanisms of Supernovae

    NASA Astrophysics Data System (ADS)

    Milisavljevic, D.

    2013-10-01

    Supernovae are among the most powerful explosions in the universe. They affect the energy balance, global structure, and chemical make-up of galaxies, they produce neutron stars, black holes, and some gamma-ray bursts, and they have been used as cosmological yardsticks to detect the accelerating expansion of the universe. Fundamental properties of these cosmic engines, however, remain uncertain. In this review we discuss the progress made over the last two decades in understanding supernova progenitor systems and explosion mechanisms. We also comment on anticipated future directions of research and highlight alternative methods of investigation using young supernova remnants.

  17. The diffuse source at the center of LMC SNR 0509–67.5 is a background galaxy at z = 0.031

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

    Pagnotta, Ashley; Walker, Emma S.; Schaefer, Bradley E., E-mail: pagnotta@amnh.org

    2014-06-20

    Type Ia supernovae (SNe Ia) are well-known for their use in the measurement of cosmological distances, but our continuing lack of concrete knowledge about their progenitor stars is both a matter of debate and a source of systematic error. In our attempts to answer this question, we presented unambiguous evidence that LMC SNR 0509–67.5, the remnant of an SN Ia that exploded in the Large Magellanic Cloud 400 ± 50 yr ago, did not have any point sources (stars) near the site of the original supernova explosion, from which we concluded that this particular supernova must have had a progenitormore » system consisting of two white dwarfs. There is, however, evidence of nebulosity near the center of the remnant, which could have been left over detritus from the less massive WD, or could have been a background galaxy unrelated to the supernova explosion. We obtained long-slit spectra of the central nebulous region using GMOS on Gemini South to determine which of these two possibilities is correct. The spectra show Hα emission at a redshift of z = 0.031, which implies that the nebulosity in the center of LMC SNR 0509–67.5 is a background galaxy, unrelated to the supernova.« less

  18. Pulsar Wind Nebulae inside Supernova Remnants as Cosmic-Ray PeVatrons

    NASA Astrophysics Data System (ADS)

    Ohira, Yutaka; Kisaka, Shota; Yamazaki, Ryo

    2018-07-01

    We propose that cosmic ray PeVatrons are pulsar wind nebulae (PWNe) inside supernova remnants (SNRs). The PWN initially expands into the freely expanding stellar ejecta. Then, the PWN catches up with the shocked region of the SNR, where particles can be slightly accelerated by the back and forth motion between the PWN and the SNR, and some particles diffuse into the PWN. Afterwards the PWN is compressed by the SNR, where the particles in the PWN are accelerated by the adiabatic compression. Using a Monte Carlo simulation, we show that particles accelerated by the SNR to 0.1 PeV can be reaccelerated to 1 PeV until the end of the PWN compression.

  19. Pulsar Wind Nebulae inside Supernova Remnants as Cosmic-Ray PeVatrons

    NASA Astrophysics Data System (ADS)

    Ohira, Yutaka; Kisaka, Shota; Yamazaki, Ryo

    2018-05-01

    We propose that cosmic-ray PeVatrons are pulsar wind nebulae (PWNe) inside supernova remnants (SNRs). The PWN initially expands into the freely expanding stellar ejecta. Then, the PWN catches up with the shocked region of the SNR, where particles can be slightly accelerated by the back and forth motion between the PWN and the SNR, and some particles diffuse into the PWN. Afterwards the PWN is compressed by the SNR, where the particles in the PWN are accelerated by the adiabatic compression. Using a Monte Carlo simulation, we show that particles accelerated by the SNR to 0.1 PeV can be reaccelerated to 1 PeV until the end of the PWN compression.

  20. A Python Calculator for Supernova Remnant Evolution

    NASA Astrophysics Data System (ADS)

    Leahy, D. A.; Williams, J. E.

    2017-05-01

    A freely available Python code for modeling supernova remnant (SNR) evolution has been created. This software is intended for two purposes: to understand SNR evolution and to use in modeling observations of SNR for obtaining good estimates of SNR properties. It includes all phases for the standard path of evolution for spherically symmetric SNRs. In addition, alternate evolutionary models are available, including evolution in a cloudy ISM, the fractional energy-loss model, and evolution in a hot low-density ISM. The graphical interface takes in various parameters and produces outputs such as shock radius and velocity versus time, as well as SNR surface brightness profile and spectrum. Some interesting properties of SNR evolution are demonstrated using the program.

  1. Gamma Rays at Very High Energies

    NASA Astrophysics Data System (ADS)

    Aharonian, Felix

    This chapter presents the elaborated lecture notes on Gamma Rays at Very High Energies given by Felix Aharonian at the 40th Saas-Fee Advanced Course on "Astrophysics at Very High Energies". Any coherent description and interpretation of phenomena related to gammarays requires deep knowledge of many disciplines of physics like nuclear and particle physics, quantum and classical electrodynamics, special and general relativity, plasma physics, magnetohydrodynamics, etc. After giving an introduction to gamma-ray astronomy the author discusses the astrophysical potential of ground-based detectors, radiation mechanisms, supernova remnants and origin of the galactic cosmic rays, TeV emission of young supernova remnants, gamma-emission from the Galactic center, pulsars, pulsar winds, pulsar wind nebulae, and gamma-ray loud binaries.

  2. Spitzer Observations of Dust Destruction in the Puppis A Supernova Remnant

    NASA Technical Reports Server (NTRS)

    Arendt, Richard G.; Dwek, Eli,; Blair, William P.; Ghavamian, Parviz; Long, Knox S.

    2010-01-01

    Imaging and spectral observations of the Puppis A supernova remnant (SNR) with the Spitzer Space Telescope confirm that its IR emission is dominated by the thermal continuum emission of swept-up interstellar dust which is collisionally heated by the X-ray emitting gas of the SNR. Line emission is too weak to affect the fluxes measured in broadband observations, and is poorly correlated with the IR or X-ray emission. Modeling of spectra from regions both in the SNR and in the associated ISM show that the ubiquitous polycyclic aromatic hydrocarbons (PAHs) of the ISM are destroyed within the SNR, along with nearly 25% of the mass of graphite and silicate dust grains.

  3. 5@5 - A 5 GeV Energy Threshold Array of Imaging Atmospheric Cherenkov Telescopes at 5 km Altitude

    NASA Astrophysics Data System (ADS)

    Aharonian, F. A.; Konopelko, A. K.; Voelk, H. J.; Quintana, H.

    2000-10-01

    We discuss the concept and the performance of 5@5 - a stereoscopic array of several large imaging atmospheric Cherenkov telescopes installed at a very high mountain elevation of about 5 km a.s.l. or more - for the study of the gamma-ray sky at energies from several GeV to 100 GeV. With its capability to detect the ``standard'' EGRET sources with spectra extending up to 10 GeV in exposure times from 1 to 103 seconds, such a detector may serve as an ideal "Gamma-Ray Timing Explorer" for the study of transient non-thermal phenomena like gamma-radiation from AGN jets, synchrotron flares of microquasars, the high energy (GeV) counterparts of Gamma Ray Bursts, etc. Such an instrument would also allow detailed studies of the spectral characteristics of persistent gamma-ray sources like pulsars, supernova remnants, plerions, radiogalaxies, etc, in the energy region between 10 GeV and 100 GeV, where the capabilities of both the current space-based and ground-based gamma-ray projects are quite limited. The existing technological achievements in the design and construction of multi (1000) pixel, high resolution imagers, as well as of large, 20 m diameter class multi-mirror dishes with rather modest optical requirements, would allow the construction of the "5@5" in a foreseeable future. The Llano de Chajnantor (or the neighboring Cerro Toco) in the Atacama desert of Northern Chile seems an ideal site for such a ``post - CANGAROO/H.E.S.S./MAGIC/VERITAS'' era ground-based gamma-ray detector. The large flat area of that site, which was recently chosen for the installation of one of the most powerful future astronomical instruments - the Atacama Large Millimeter Array (ALMA) - could accomodate also an additional Cherenkov telescope array which requires a relatively compact area with a radius of about 100 m.

  4. Minkowski, Rudolph Leo Bernhard (1895-1976)

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    Born in Strassburg, Germany, worked on atomic spectroscopy at Hamburg and had to flee the Nazi persecution, joined WALTER BAADE on the Mount Wilson Observatory staff, where he began to apply spectroscopy to astronomy. He investigated nebulae, including supernova remnants, especially the Crab nebula. He classified supernovae into Types I and II, leading to their identification as two similar implo...

  5. Interaction of Supernova Blast Waves with Wind-Driven Shells: Formation of "Jets", "Bullets", "Ears", Etc.

    NASA Astrophysics Data System (ADS)

    Gvaramadze, V. V.

    Most of middle-aged supernova remnants (SNRs) have a distorted and complicated appearance which cannot be explained in the framework of the Sedov-Taylor model. We consider three typical examples of such SNRs (Vela SNR, MSH15-52, G309.2-00.6) and show that their structure could be explained as a result of interaction of a supernova (SN) blast wave with the ambient medium preprocessed by the action of the SN progenitor's wind and ionized emission.

  6. Numerical Simulations of Supernova Remnant Evolution in a Cloudy Interstellar Medium

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

    Slavin, Jonathan D.; Smith, Randall K.; Foster, Adam

    The mixed morphology class of supernova remnants has centrally peaked X-ray emission along with a shell-like morphology in radio emission. White and Long proposed that these remnants are evolving in a cloudy medium wherein the clouds are evaporated via thermal conduction once being overrun by the expanding shock. Their analytical model made detailed predictions regarding temperature, density, and emission profiles as well as shock evolution. We present numerical hydrodynamical models in 2D and 3D including thermal conduction, testing the White and Long model and presenting results for the evolution and emission from remnants evolving in a cloudy medium. We findmore » that, while certain general results of the White and Long model hold, such as the way the remnants expand and the flattening of the X-ray surface brightness distribution, in detail there are substantial differences. In particular we find that the X-ray luminosity is dominated by emission from shocked cloud gas early on, leading to a bright peak, which then declines and flattens as evaporation becomes more important. In addition, the effects of thermal conduction on the intercloud gas, which is not included in the White and Long model, are important and lead to further flattening of the X-ray brightness profile as well as lower X-ray emission temperatures.« less

  7. Cosmic Explosions in Three Dimensions

    NASA Astrophysics Data System (ADS)

    Höflich, Peter; Kumar, Pawan; Wheeler, J. Craig

    2011-08-01

    Introduction: 3-D Explosions: a meditation on rotation (and magnetic fields) J. C. Wheeler; Part I. Supernovae: Observations Today: 1. Supernova explosions: lessons from spectropolarimetry L. Wang; 2. Spectropolarimetric observations of Supernovae A. Filippenko and D. C. Leonard; 3. Observed and physical properties of type II plateau supernovae M. Hamuy; 4. SN1997B and the different types of Type Ic Supernovae A. Clocchiatti, B. Leibundgut, J. Spyromilio, S. Benetti, E. Cappelaro, M. Turatto and M. Phillips; 5. Near-infrared spectroscopy of stripped-envelope Supernovae C. L. Gerardy, R. A. Fesen, G. H. Marion, P. Hoeflich and J. C. Wheeler; 6. Morphology of Supernovae remnants R. Fesen; 7. The evolution of Supernova remnants in the winds of massive stars V. Dwarkadas; 8. Types for the galactic Supernovae B. E. Schaefer; Part II. Theory of Thermonuclear Supernovae: 9. Semi-steady burning evolutionary sequences for CAL 83 and CAL 87: supersoft X-ray binaries are Supernovae Ia progenitors S. Starrfield, F. X. Timmes, W. R. Hix, E. M. Sion, W. M. Sparks and S. Dwyer; 10. Type Ia Supernovae progenitors: effects of the spin-up of the white dwarfs S.-C. Yoon and N. Langer; 11. Terrestrial combustion: feedback to the stars E. S. Oran; 12. Non-spherical delayed detonations E. Livne; 13. Numerical simulations of Type Ia Supernovae: deflagrations and detonations V. N. Gamezo, A. M. Khokhlov and E. S. Oran; 14. Type Ia Supernovae: spectroscopic surprises D. Branch; 15. Aspherity effects in Supernovae P. Hoeflich, C. Gerardy and R. Quimby; 16. Broad light curve SneIa: asphericity or something else? A. Howell and P. Nugent; 17. Synthetic spectrum methods for 3-D SN models R. Thomas; 18. A hole in Ia' spectroscopic and polarimetric signatures of SN Ia asymmetry due to a companion star D. Kasen; 19. Hunting for the signatures of 3-D explosions with 1-D synthetic spectra E. Lentz, E. Baron and P. H. Hauschildt; 20. On the variation of the peak luminosity of Type Ia J. W. Truran, E. X. Timmes and E. F. Brown; Part III. Theory of Core Collapse Supernovae: 21. Rotation of core collapse progenitors: single and binary stars N. Langer; 22. Large scale convection and the convective Supernova mechanism S. Colgate and M. E. Herant; 23. Topics in core-collapse Supernova A. Burrows, C. D. Ott and C. Meakin; 24. MHD Supernova jets: the missing link D. Meier and M. Nakamura; 25. Effects of super strong magnetic fields in core collapse Supernovae I. S. Akiyama; 26. Non radial instability of stalled accretion shocks advective-acoustic cycle T. Foglizzo and P. Galletti; 27. Asymmetry effects in Hypernovae K. Maeda, K. Nomoto, J. Deng and P.A. Mazzali; 28. Turbulent MHD jet collimation and thermal driving P. T. Williams; Part IV. Magnetars, N-Stars, Pulsars: 29. Supernova remnants and pulsar wind nebulae R. Chevalier; 30. X-Ray signatures of Supernovae D. Swartz; 31. Asymmetric Supernovae and Neutron Star Kicks D. Lai and D. Q. Lamb; 32. Triggers of magnetar outbursts R. Duncan; 33. Turbulent MHD Jet Collimation and Thermal Driving P. Williams; 34. The interplay between nuclear electron capture and fluid dynamics in core collapse Supernovae W. R. Hix, O. E. B. Messer and A. Mezzacappa; Part V. Gamma-Ray Bursts: 35. GRB 021004 and Gamma-ray burst distances B. E. Schaefer; 36. Gamma-ray bursts as a laboratory for the study of Type Ic Supernovae D. Q. Lamb, T. Q. Donaghy and C. Graziani; 37. The diversity of cosmic explosions: Gamma-ray bursts and Type Ib/c Supernovae E. Berger; 38. A GRB simulation using 3D relativistic hydrodynamics J. Cannizo, N. Gehrels and E. T. Vishniac; 39. The first direct link in the Supernova/GRB connection: GRB 030329 and SN 2003dh T. Matheson; Part VI. Summary: 40. Three-dimensional explosions C. Wheeler.

  8. The Propagation Distance and Sources of Interstellar Turbulence

    NASA Astrophysics Data System (ADS)

    Spangler, S. R.

    2007-07-01

    Turbulence appears to be widely distributed in the interstellar medium, including regions far from obvious generators of this turbulence such as supernova remnants and star formation regions. This indicates that the turbulence must be transported, most likely by propagation at the Alfvén speed, over distances of hundreds of parsecs. This requirement appears contradicted by estimates that the damping length of magnetohydrodynamic waves and turbulence by ion-neutral collisions in the Diffuse Ionized Gas (DIG, the most pervasive phase of the interstellar medium) is less than a parsec. This damping length estimate is not highly model-dependent, and is consistent with calculations positing a balance between radiative cooling and turbulent dissipative heating of the interstellar gas. This problem is even more severe in the Warm Neutral Medium (WNM) phase, where the neutral density fraction is much higher. Three possible resolutions of this matter are proposed. (1) Interstellar turbulence may be generated by highly distributed, local generators rather than greatly separated, powerful generators such as supernova remnants. (2) The turbulence may be generated by powerful and isolated objects like supernova remnants, but then ``percolate'' through the interstellar medium by propagating through channels with a very high degree of ionization. (3) The dissipation of small-scale turbulence may be balanced by a cascade from larger, less damped fluctuations.

  9. High-energy Emission from the Composite Supernova Remnant MSH 15-56

    NASA Technical Reports Server (NTRS)

    Temim, Tea; Slane, Patrick; Castro, Daniel; Plucinsky, Paul; Gelfand, Joseph; Dickel, John R.

    2013-01-01

    MSH 1556 (G326.3-1.8) is a composite supernova remnant (SNR) that consists of an SNR shell and a displaced pulsar wind nebula (PWN) in the radio. We present XMM-Newton and Chandra X-ray observations of the remnant that reveal a compact source at the tip of the radio PWN and complex structures that provide evidence for mixing of the supernova (SN) ejecta with PWN material following a reverse shock interaction. The X-ray spectra are well fitted by a non-thermal power-law model whose photon index steepens with distance from the presumed pulsar, and a thermal component with an average temperature of 0.55 keV. The enhanced abundances of silicon and sulfur in some regions, and the similar temperature and ionization timescale, suggest that much of the X-ray emission can be attributed to SN ejecta that have either been heated by the reverse shock or swept up by the PWN. We find one region with a lower temperature of 0.3 keV that appears to be in ionization equilibrium.Assuming the Sedov model, we derive a number of SNR properties, including an age of 16,500 yr. Modeling of the gamma-ray emission detected by Fermi shows that the emission may originate from the reverse shock-crushed PWN.

  10. XMM-Newton observations of the supernova remnant IC 443. II. Evidence of stellar ejecta in the inner regions

    NASA Astrophysics Data System (ADS)

    Troja, E.; Bocchino, F.; Miceli, M.; Reale, F.

    2008-07-01

    Aims: We investigate the spatial distribution of the physical and chemical properties of the hot X-ray emitting plasma of the supernova remnant IC 443, to derive important constraints on its ionization stage, on the progenitor supernova explosion, on the age of the remnant, and its physical association with a close pulsar wind nebula. Methods: We present XMM-Newton images of IC 443, a median photon energy map, silicon and sulfur equivalent width maps, and a spatially resolved spectral analysis of a set of homogeneous regions. Results: The hard X-ray thermal emission (1.4-5.0 keV) of IC 443 displays a centrally-peaked morphology, its brightness peaks being associated with hot (kT > 1 keV) X-ray emitting plasma. A ring-shaped structure, characterized by high values of equivalent widths and median photon energy, encloses the PWN. Its hard X-ray emission is spectrally characterized by a collisional ionization equilibrium model, and strong emission lines of Mg, Si, and S, requiring oversolar metal abundances. Dynamically, the location of the ejecta ring suggests an SNR age of ~4000 yr. The presence of overionized plasma in the inner regions of IC 443, addressed in previous works, is much less evident in our observations.

  11. Color Composite Image of the Supernova Remnant

    NASA Technical Reports Server (NTRS)

    2000-01-01

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

  12. NASA's Hubble Sees A New Supernova Remnant Light Up

    NASA Image and Video Library

    2011-06-10

    NASA image release June 10, 2011 Astronomers using NASA's Hubble Space Telescope are witnessing the unprecedented transition of a supernova to a supernova remnant, where light from an exploding star in a neighboring galaxy, the Large Magellanic Cloud, reached Earth in February 1987. Named Supernova 1987A, it was the closest supernova explosion witnessed in almost 400 years. The supernova's close proximity to Earth has allowed astronomers to study it in detail as it evolves. Now, the supernova debris, which has faded over the years, is brightening. This means that a different power source has begun to light the debris. The debris of SN 1987A is beginning to impact the surrounding ring, creating powerful shock waves that generate X-rays observed with NASA's Chandra X-ray Observatory. Those X-rays are illuminating the supernova debris and shock heating is making it glow in visible light. The results are being reported in the June 9, 2011, issue of the journal Nature by a team including Robert Kirshner of the Harvard-Smithsonian Center for Astrophysics (CfA), who leads a long-term study of SN 1987A with Hubble. Since its launch in 1990, the Hubble telescope has provided a continuous record of the changes in SN 1987A. Credit: NASA, ESA, and P. Challis (Harvard-Smithsonian Center for Astrophysics) NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Join us on Facebook Find us on Instagram

  13. Nucleosynthesis in Supernovae

    NASA Astrophysics Data System (ADS)

    Thielemann, Friedrich-Karl; Isern, Jordi; Perego, Albino; von Ballmoos, Peter

    2018-04-01

    We present the status and open problems of nucleosynthesis in supernova explosions of both types, responsible for the production of the intermediate mass, Fe-group and heavier elements (with the exception of the main s-process). Constraints from observations can be provided through individual supernovae (SNe) or their remnants (e.g. via spectra and gamma-rays of decaying unstable isotopes) and through surface abundances of stars which witness the composition of the interstellar gas at their formation. With a changing fraction of elements heavier than He in these stars (known as metallicity) the evolution of the nucleosynthesis in galaxies over time can be determined. A complementary way, related to gamma-rays from radioactive decays, is the observation of positrons released in β+-decays, as e.g. from ^{26}Al, ^{44}Ti, ^{56,57}Ni and possibly further isotopes of their decay chains (in competition with the production of e+e- pairs in acceleration shocks from SN remnants, pulsars, magnetars or even of particle physics origin). We discuss (a) the role of the core-collapse supernova explosion mechanism for the composition of intermediate mass, Fe-group (and heavier?) ejecta, (b) the transition from neutron stars to black holes as the final result of the collapse of massive stars, and the relation of the latter to supernovae, faint supernovae, and gamma-ray bursts/hypernovae, (c) Type Ia supernovae and their nucleosynthesis (e.g. addressing the ^{55}Mn puzzle), plus (d) further constraints from galactic evolution, γ-ray and positron observations. This is complemented by the role of rare magneto-rotational supernovae (related to magnetars) in comparison with the nucleosynthesis of compact binary mergers, especially with respect to forming the heaviest r-process elements in galactic evolution.

  14. 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.

  15. Hubble Space Telescope Observations of Oxygen-rich Supernova Remnants in the Magellanic Clouds. III. WFPC2 Imaging of the Young, Crab-like Supernova Remnant SNRO540-69.3

    NASA Technical Reports Server (NTRS)

    Morse, Jon A.; Smith, Nathan; Blair, William P.; Kirshner, Robert P.; Winkler, P. Frank; Hughes, John P.

    2006-01-01

    Hubble Space Telescope images with the Wide Field Planetary Camera 2 of the young, oxygen-rich, Crab-like supernova remnant SNR0540-69.3 in the Large Magellanic Cloud (LMC) reveal details of the emission distribution and the relationship between the expanding ejecta and synchrotron nebula. The emission distributions appear very similar to those seen in the Crab nebula, with the ejecta located in a thin envelope surrounding the synchrotron nebula. The [O III] emission is more extended than other tracers, forming a faint "skin" around the denser filaments and synchrotron nebula, as also observed in the Crab. The [O III] exhibits somewhat different kinematic structure in long-slit spectra, including a more extended high-velocity emission halo not seen in images. Yet even the fastest expansion speeds in SNR 0540 s halo are slow when compared to most other young supernova remnants, though the Crab nebula has similar slow expansion speeds. We show a striking correspondence between the morphology of the synchrotron nebula observed in an optical continuum filter with that recently resolved in Chandra X-ray images. We argue that the multi-component kinematics and filamentary morphology of the optical emission-line features likely result from magnetic Rayleigh-Taylor instabilities that form as the synchrotron nebula expands and sweeps up ejecta, as seen in the Crab nebula. Our images and spectra help to refine our understanding of SNR 0540 in several more detailed respects: they confirm the identification of H(alpha)+[N II] in the red spectrum, they show that the systemic velocity of SNR 0540 is not significantly different from that of the LMC, and they hint at a lower Ne abundance than the Crab (potentially indicating a more massive progenitor star).

  16. ANTARES and KM3NeT programs for the supernova neutrino detection

    NASA Astrophysics Data System (ADS)

    Kulikovskiy, Vladimir

    2017-02-01

    The currently working ANTARES neutrino telescope has capabilities to detect neutrinos produced in astrophysical transient sources. Neutrino alerts are regularly generated to trigger multi-wavelength observatories. Potential sources include gamma-ray bursts, core-collapse supernovae, and flaring active galactic nuclei. In particular, the neutrino detection together with the multi-wavelength observations may reveal hidden jets in the supernova explosions. Supernovae remnants are currently the most promising acceleration sites of the cosmic rays in our Galaxy. The neutrino emission is expected during the cosmic ray interaction with the surrounding matter. The neutrino telescopes in the Northern hemisphere have excellent visibility to the most of the galactic supernovae remnants. Recent results on the search for point-sources with the ANTARES detector and the prospects for the future KM3NeT detector are presented. Although ANTARES and KM3NeT detectors are mainly designed for high energy neutrino detection, the MeV neutrino signal from the supernova can be identified as a simultaneous increase of the counting rate of the optical modules in the detector. The noise from the optical background due to 40K decay in the sea water and the bioluminescence can be significantly reduced by using nanosecond coincidences between the nearby placed photomultipliers. This technique has been tested with the ANTARES storeys, each one consisting of three 10-inch photomultipliers, and it is further optimized for the KM3NeT telescope where the directional optical modules containing 31 3-inch photomultipliers provide very promising expectations.

  17. DESTRUCTION OF INTERSTELLAR DUST IN EVOLVING SUPERNOVA REMNANT SHOCK WAVES

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

    Slavin, Jonathan D.; Dwek, Eli; Jones, Anthony P., E-mail: jslavin@cfa.harvard.edu

    2015-04-10

    Supernova generated shock waves are responsible for most of the destruction of dust grains in the interstellar medium (ISM). Calculations of the dust destruction timescale have so far been carried out using plane parallel steady shocks, however, that approximation breaks down when the destruction timescale becomes longer than that for the evolution of the supernova remnant (SNR) shock. In this paper we present new calculations of grain destruction in evolving, radiative SNRs. To facilitate comparison with the previous study by Jones et al., we adopt the same dust properties as in that paper. We find that the efficiencies of grainmore » destruction are most divergent from those for a steady shock when the thermal history of a shocked gas parcel in the SNR differs significantly from that behind a steady shock. This occurs in shocks with velocities ≳200 km s{sup −1} for which the remnant is just beginning to go radiative. Assuming SNRs evolve in a warm phase dominated ISM, we find dust destruction timescales are increased by a factor of ∼2 compared to those of Jones et al., who assumed a hot gas dominated ISM. Recent estimates of supernova rates and ISM mass lead to another factor of ∼3 increase in the destruction timescales, resulting in a silicate grain destruction timescale of ∼2–3 Gyr. These increases, while not able to resolve the problem of the discrepant timescales for silicate grain destruction and creation, are an important step toward understanding the origin and evolution of dust in the ISM.« less

  18. Destruction of Interstellar Dust in Evolving Supernova Remnant Shock Waves

    NASA Technical Reports Server (NTRS)

    Slavin, Jonathan D.; Dwek, Eli; Jones, Anthony P.

    2015-01-01

    Supernova generated shock waves are responsible for most of the destruction of dust grains in the interstellar medium (ISM). Calculations of the dust destruction timescale have so far been carried out using plane parallel steady shocks, however that approximation breaks down when the destruction timescale becomes longer than that for the evolution of the supernova remnant (SNR) shock. In this paper we present new calculations of grain destruction in evolving, radiative SNRs. To facilitate comparison with the previous study by Jones et al. (1996), we adopt the same dust properties as in that paper. We find that the efficiencies of grain destruction are most divergent from those for a steady shock when the thermal history of a shocked gas parcel in the SNR differs significantly from that behind a steady shock. This occurs in shocks with velocities 200 km s(exp -1) for which the remnant is just beginning to go radiative. Assuming SNRs evolve in a warm phase dominated ISM, we find dust destruction timescales are increased by a factor of approximately 2 compared to those of Jones et al. (1996), who assumed a hot gas dominated ISM. Recent estimates of supernova rates and ISM mass lead to another factor of approximately 3 increase in the destruction timescales, resulting in a silicate grain destruction timescale of approximately 2-3 Gyr. These increases, while not able resolve the problem of the discrepant timescales for silicate grain destruction and creation, are an important step towards understanding the origin, and evolution of dust in the ISM.

  19. Cauldron of Light

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image to view the animation

    In this animation, a seething cauldron of light appears to bubble and ooze around the remains of a giant star that astronomers have been watching tear itself apart for the last 300 years. This movie flips quickly between different observations taken over three years by NASA's Spitzer Space Telescope.

    Beginning in the center, the well-studied Cassiopeia A supernova remnant is shown. Cassiopeia A is the remnant of a once massive star that died in a violent supernova explosion. It consists of a dead star, called a neutron star, and a surrounding shell of material that was blasted off as the star died.

    Panning outward, 'light echoes' create the illusion of motion in the clouds, as different areas of the material are lit up in succession by the light flash of the supernova. A light echo occurs when a star explodes, acting like a cosmic flashbulb. The light from this explosion zips through nearby dust clumps, illuminating and heating them up slightly. This brief period of warming causes them to glow in infrared, like a chain of Christmas bulbs lighting up one by one. The result is an optical illusion, in which the dust appears to be flying outward at the speed of light.

    In reality, the clouds are stationary, at least in the brief time over which these observations were taken. The inclination of the clouds cause some light echoes to appear to expand away from the supernova remnant, while others move towards it or boil in many directions with seeming turbulence.

  20. The Transition of a Type IIL Supernova into a Supernova Remnant: Late-time Observations of SN 2013by

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

    Black, C. S.; Fesen, R. A.; Milisavljevic, D.

    2017-10-10

    We present early-time Swift and Chandra X-ray data along with late-time optical and near-infrared observations of SN 2013by, a Type IIL supernova (SN) that occurred in the nearby spiral galaxy ESO 138−G10 ( D ∼ 14.8 Mpc). Optical and NIR photometry and spectroscopy follow the late-time evolution of the SN from days +89 to +457 post maximum brightness. The optical spectra and X-ray light curves are consistent with the picture of an SN having prolonged interaction with circumstellar material (CSM) that accelerates the transition from SN to supernova remnant (SNR). Specifically, we find SN 2013by’s H α profile exhibits significantmore » broadening (∼10,000 km s{sup −1}) on day +457, the likely consequence of high-velocity, H-rich material being excited by a reverse shock. A relatively flat X-ray light curve is observed that cannot be modeled using Inverse Compton scattering processes alone, but requires an additional energy source most likely originating from the SN-CSM interaction. In addition, we see the first overtone of CO emission near 2.3 μ m on day +152, signaling the formation of molecules and dust in the SN ejecta and is the first time CO has been detected in a Type IIL SN. We compare SN 2013by with Type IIP SNe, whose spectra show the rarely observed SN-to-SNR transition in varying degrees and conclude that Type IIL SNe may enter the remnant phase at earlier epochs than their Type IIP counterparts.« less

  1. A Chandrasekhar Mass Progenitor for the Type Ia Supernova Remnant 3C 397 from the Enhanced Abundances of Nickel and Manganese

    NASA Technical Reports Server (NTRS)

    Yamaguchi, Hiroya; Badenes, Carles; Foster, Adam R.; Bravo, Eduardo; Williams, Brian J.; Maeda, Keiichi; Nobukawa, Masayoshi; Eriksen, Kristoffer A.; Brickhouse, Nancy S.; Petre, Robert; hide

    2015-01-01

    Despite decades of intense efforts, many fundamental aspects of Type Ia supernovae (SNe Ia) remain elusive. One of the major open questions is whether the mass of an exploding white dwarf (WD) is close to the Chandrasekhar limit. Here, we report the detection of strong K-shell emission from stable Fe-peak elements in the Suzaku X-ray spectrum of the Type Ia supernova remnant (SNR) 3C 397. The high Ni/Fe and Mn/Fe mass ratios - (0.11-0.24 and 0.018-0.033, respectively) in the hot plasma component that dominates the K-shell emission lines indicate a degree of neutronization in the supernova ejecta that can only be achieved by electron capture in the dense cores of exploding WDs with a near-Chandrasekhar mass. This suggests a single-degenerate origin for 3C 397, since Chandrasekhar mass progenitors are expected naturally if the WD accretes mass slowly from a companion. Together with other results supporting the double-degenerate scenario, our work adds to the mounting evidence that both progenitor channels make a significant contribution to the SN Ia rate in star-forming galaxies.

  2. How high energy fluxes may affect Rayleigh-Taylor instability growth in young supernova remnants

    NASA Astrophysics Data System (ADS)

    Kuranz, C. C.; Park, H.-S.; Huntington, C. M.; Miles, A. R.; Remington, B. A.; Drake, R. P.; Tranthan, M. A.; Handy, T. A.; Shvarts, D.; Malamud, G.; Shimony, A.; Shvarts, D.; Kline, J.; Flippo, K. A.; Doss, F. W.; Plewa, T.

    2017-10-01

    Energy-transport effects can alter the structure that develops as a supernova evolves into a supernova remnant. The Rayleigh Taylor instability is thought to produce structure at the interface between the stellar ejecta and the circumstellar matter, based on simple models and hydrodynamic simulations. Simulations predict that RT produces structures at this interface, having a range of spatial scales. When the CSM is dense enough, as in the case of SN 1993J, the hot shocked matter can produce significant radiative fluxes that affect the emission from the SNR. Here we report experimental results from the National Ignition Facility to explore how large energy fluxes, which are present in supernovae such as SN 1993J, might affect this structure. We present data and simulations from Rayleigh-Taylor instability experiments in high- and low- energy flux experiments performed at the National Ignition Facility. We also will discuss the apparent, larger role of heat conduction when we closely examined the comparison between the experimental results, and the SNR observations and models. This work is funded by the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, Grant Number DE-NA0002956.

  3. Infrared Emission from Supernova Remnants: Formation and Destruction of Dust

    NASA Astrophysics Data System (ADS)

    Williams, Brian J.; Temim, Tea

    2016-09-01

    We review the observations of dust emission in supernova remnants (SNRs) and supernovae (SNe). Theoretical calculations suggest that SNe, particularly core-collapse, should make significant quantities of dust, perhaps as much as a solar mass. Observations of extragalactic SNe have yet to find anywhere near this amount, but this may be the result of observational limitations. SN 1987A, in the process of transitioning from a SN to an SNR, does show signs of a significant amount of dust forming in its ejecta, but whether this dust will survive the passage of the reverse shock to be injected into the ISM is unknown. IR observations of SNRs have not turned up significant quantities of dust, and the dust that is observed is generally swept up by the forward shock, rather than created in the ejecta. Because the shock waves also destroy dust in the ISM, we explore the question of whether SNe might be net destroyers, rather than net creators of dust in the universe.

  4. Infrared Emission from Supernova Remnants: Formation and Destruction of Dust

    NASA Astrophysics Data System (ADS)

    Williams, Brian J.; Temim, Tea

    We review the observations of dust emission in supernova remnants (SNRs) and supernovae (SNe). Theoretical calculations suggest that SNe, particularly core-collapse, should make significant quantities of dust, perhaps as much as a solar mass. Observations of extragalactic SNe have yet to find anywhere near this amount, but this may be the result of observational limitations. SN 1987A, in the process of transitioning from a SN to an SNR, does show signs of a significant amount of dust forming in its ejecta, but whether this dust will survive the passage of the reverse shock to be injected into the ISM is unknown. IR observations of SNRs have not turned up significant quantities of dust, and the dust that is observed is generally swept up by the forward shock, rather than created in the ejecta. Because the shock waves also destroy dust in the ISM, we explore the question of whether SNe might be net destroyers, rather than net creators of dust in the universe.

  5. Toward Connecting Core-Collapse Supernova Theory with Observations: Nucleosynthetic Yields and Distribution of Elements in a 15 M⊙ Blue Supergiant Progenitor with SN 1987A Energetics

    NASA Astrophysics Data System (ADS)

    Plewa, Tomasz; Handy, Timothy; Odrzywolek, Andrzej

    2014-03-01

    We compute and discuss the process of nucleosynthesis in a series of core-collapse explosion models of a 15 solar mass, blue supergiant progenitor. We obtain nucleosynthetic yields and study the evolution of the chemical element distribution from the moment of core bounce until young supernova remnant phase. Our models show how the process of energy deposition due to radioactive decay modifies the dynamics and the core ejecta structure on small and intermediate scales. The results are compared against observations of young supernova remnants including Cas A and the recent data obtained for SN 1987A. The work has been supported by the NSF grant AST-1109113 and DOE grant DE-FG52-09NA29548. This research used resources of the National Energy Research Scientific Computing Center, which is supported by the U.S. DoE under Contract No. DE-AC02-05CH11231.

  6. A high-resolution X-ray image of Puppis A - Inhomogeneities in the interstellar medium

    NASA Technical Reports Server (NTRS)

    Petre, R.; Kriss, G. A.; Winkler, P. F.; Canizares, C. R.

    1982-01-01

    Eleven HRI exposures from the Einstein Observatory are assembled into an 0.1-4 keV image of the Puppis A supernova remnant which displays a complex morphology that may reflect the structure of the shocked interstellar medium. In addition to showing a density gradient of a factor greater than four across the approximately 30 pc diameter of the remnant perpendicular to the galactic plane, a shell of X-ray emission is seen surrounding the northern half of Puppis A, coincident with the radio shell, whose edge brightness profile indicates direct hot plasma heating by the blast wave rather than evaporation from clouds. The interior structure of the supernova remnant suggests inhomogeneities whose sizes range over 0.1-5 pc, but with moderate density contrast. Although isolated clouds of 10-30/cu cm density are responsible for the two brightest X-ray features, they represent only a small fraction of the Puppis A mass.

  7. X-ray characteristics of the Lupus Loop and SN 1006 supernova remnants

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

    Toor, A.

    1980-01-01

    The spatial extent of the Lupus Loop and spectra for the Lupus Loop and SN1006 supernova remnants have been determined with a rocket-borne payload. The Lupus Loop is an extended source of soft X-rays (approx. 300' diam) that shows a correlation between its brightest x-ray and radio-emission regions. Its spectrum is characterized by a temperature of 350 eV. Thus, the Lupus Loop appears similar to Vela X and Cygnus Loop, although much weaker. Emission from SN1006 is spatially unresolved and exhibits a harder spectrum than that of the Lupus Loop. All spectral data (0.2 to 10 keV) from our observationmore » and previous observations are satisfactorily fit with a power law (index = 2.15). This spectral dependence suggests the possibility that a rotating neutron star is the underlying source of the radiated energy although such an interpretation appears inconsistent with the remnant's morphology.« less

  8. Searches for Continuous Gravitational Waves from Nine Young Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Aasi, J.; Abbott, B. P.; Abbott, R.; Abbott, T.; Abernathy, M. R.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Adya, V.; Affeldt, C.; Agathos, M.; Agatsuma, K.; Aggarwal, N.; Aguiar, O. D.; Ain, A.; Ajith, P.; Alemic, A.; Allen, B.; Allocca, A.; Amariutei, D.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Araya, M. C.; Arceneaux, C.; Areeda, J. S.; Ast, S.; Aston, S. M.; Astone, P.; Aufmuth, P.; Aulbert, C.; Aylott, B. E.; Babak, S.; Baker, P. T.; Baldaccini, F.; Ballardin, G.; Ballmer, S. W.; Barayoga, J. C.; Barbet, M.; Barclay, S.; Barish, B. C.; Barker, D.; Barone, F.; Barr, B.; Barsotti, L.; Barsuglia, M.; Bartlett, J.; Barton, M. A.; Bartos, I.; Bassiri, R.; Basti, A.; Batch, J. C.; Bauer, Th. S.; Baune, C.; Bavigadda, V.; Behnke, B.; Bejger, M.; Belczynski, C.; Bell, A. S.; Bell, C.; Benacquista, M.; Bergman, J.; Bergmann, G.; Berry, C. P. L.; Bersanetti, D.; Bertolini, A.; Betzwieser, J.; Bhagwat, S.; Bhandare, R.; Bilenko, I. A.; Billingsley, G.; Birch, J.; Biscans, S.; Bitossi, M.; Biwer, C.; Bizouard, M. A.; Blackburn, J. K.; Blackburn, L.; Blair, C. D.; Blair, D.; Bloemen, S.; Bock, O.; Bodiya, T. P.; Boer, M.; Bogaert, G.; Bojtos, P.; Bond, C.; Bondu, F.; Bonelli, L.; Bonnand, R.; Bork, R.; Born, M.; Boschi, V.; Bose, Sukanta; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Branchesi, M.; Brau, J. E.; Briant, T.; Bridges, D. O.; Brillet, A.; Brinkmann, M.; Brisson, V.; Brooks, A. F.; Brown, D. A.; Brown, D. D.; Brown, N. M.; Buchman, S.; Buikema, A.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Buskulic, D.; Buy, C.; Cadonati, L.; Cagnoli, G.; Calderón Bustillo, J.; Calloni, E.; Camp, J. B.; Cannon, K. C.; Cao, J.; Capano, C. D.; Carbognani, F.; Caride, S.; Caudill, S.; Cavaglià, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C.; Cesarini, E.; Chakraborty, R.; Chalermsongsak, T.; Chamberlin, S. J.; Chao, S.; Charlton, P.; Chassande-Mottin, E.; Chen, Y.; Chincarini, A.; Chiummo, A.; Cho, H. S.; Cho, M.; Chow, J. H.; Christensen, N.; Chu, Q.; Chua, S.; Chung, S.; Ciani, G.; Clara, F.; Clark, J. A.; Cleva, F.; Coccia, E.; Cohadon, P.-F.; Colla, A.; Collette, C.; Colombini, M.; Cominsky, L.; Constancio, M., Jr.; Conte, A.; Cook, D.; Corbitt, T. R.; Cornish, N.; Corsi, A.; Costa, C. A.; Coughlin, M. W.; Coulon, J.-P.; Countryman, S.; Couvares, P.; Coward, D. M.; Cowart, M. J.; Coyne, D. C.; Coyne, R.; Craig, K.; Creighton, J. D. E.; Creighton, T. D.; Cripe, J.; Crowder, S. G.; Cumming, A.; Cunningham, L.; Cuoco, E.; Cutler, C.; Dahl, K.; Dal Canton, T.; Damjanic, M.; Danilishin, S. L.; D'Antonio, S.; Danzmann, K.; Dartez, L.; Dattilo, V.; Dave, I.; Daveloza, H.; Davier, M.; Davies, G. S.; Daw, E. J.; Day, R.; DeBra, D.; Debreczeni, G.; Degallaix, J.; De Laurentis, M.; Deléglise, S.; Del Pozzo, W.; Denker, T.; Dent, T.; Dereli, H.; Dergachev, V.; De Rosa, R.; DeRosa, R. T.; DeSalvo, R.; Dhurandhar, S.; Díaz, M.; Di Fiore, L.; Di Lieto, A.; Di Palma, I.; Di Virgilio, A.; Dojcinoski, G.; Dolique, V.; Dominguez, E.; Donovan, F.; Dooley, K. L.; Doravari, S.; Douglas, R.; Downes, T. P.; Drago, M.; Driggers, J. C.; Du, Z.; Ducrot, M.; Dwyer, S.; Eberle, T.; Edo, T.; Edwards, M.; Edwards, M.; Effler, A.; Eggenstein, H.-B.; Ehrens, P.; Eichholz, J.; Eikenberry, S. S.; Essick, R.; Etzel, T.; Evans, M.; Evans, T.; Factourovich, M.; Fafone, V.; Fairhurst, S.; Fan, X.; Fang, Q.; Farinon, S.; Farr, B.; Farr, W. M.; Favata, M.; Fays, M.; Fehrmann, H.; Fejer, M. M.; Feldbaum, D.; Ferrante, I.; Ferreira, E. C.; Ferrini, F.; Fidecaro, F.; Fiori, I.; Fisher, R. P.; Flaminio, R.; Fournier, J.-D.; Franco, S.; Frasca, S.; Frasconi, F.; Frei, Z.; Freise, A.; Frey, R.; Fricke, T. T.; Fritschel, P.; Frolov, V. V.; Fuentes-Tapia, S.; Fulda, P.; Fyffe, M.; Gair, J. R.; Gammaitoni, L.; Gaonkar, S.; Garufi, F.; Gatto, A.; Gehrels, N.; Gemme, G.; Gendre, B.; Genin, E.; Gennai, A.; Gergely, L. Á.; Ghosh, S.; Giaime, J. A.; Giardina, K. D.; Giazotto, A.; Gleason, J.; Goetz, E.; Goetz, R.; Gondan, L.; González, G.; Gordon, N.; Gorodetsky, M. L.; Gossan, S.; Gossler, S.; Gouaty, R.; Gräf, C.; Graff, P. B.; Granata, M.; Grant, A.; Gras, S.; Gray, C.; Greenhalgh, R. J. S.; Gretarsson, A. M.; Groot, P.; Grote, H.; Grunewald, S.; Guidi, G. M.; Guido, C. J.; Guo, X.; Gushwa, K.; Gustafson, E. K.; Gustafson, R.; Hacker, J.; Hall, E. D.; Hammond, G.; Hanke, M.; Hanks, J.; Hanna, C.; Hannam, M. D.; Hanson, J.; Hardwick, T.; Harms, J.; Harry, G. M.; Harry, I. W.; Hart, M.; Hartman, M. T.; Haster, C.-J.; Haughian, K.; Heidmann, A.; Heintze, M.; Heinzel, G.; Heitmann, H.; Hello, P.; Hemming, G.; Hendry, M.; Heng, I. S.; Heptonstall, A. W.; Heurs, M.; Hewitson, M.; Hild, S.; Hoak, D.; Hodge, K. A.; Hofman, D.; Hollitt, S. E.; Holt, K.; Hopkins, P.; Hosken, D. J.; Hough, J.; Houston, E.; Howell, E. J.; Hu, Y. M.; Huerta, E.; Hughey, B.; Husa, S.; Huttner, S. H.; Huynh, M.; Huynh-Dinh, T.; Idrisy, A.; Indik, N.; Ingram, D. R.; Inta, R.; Islas, G.; Isler, J. C.; Isogai, T.; Iyer, B. R.; Izumi, K.; Jacobson, M.; Jang, H.; Jaranowski, P.; Jawahar, S.; Ji, Y.; Jiménez-Forteza, F.; Johnson, W. W.; Jones, D. I.; Jones, R.; Jonker, R. J. G.; Ju, L.; K, Haris; Kalogera, V.; Kandhasamy, S.; Kang, G.; Kanner, J. B.; Kasprzack, M.; Katsavounidis, E.; Katzman, W.; Kaufer, H.; Kaufer, S.; Kaur, T.; Kawabe, K.; Kawazoe, F.; Kéfélian, F.; Keiser, G. M.; Keitel, D.; Kelley, D. B.; Kells, W.; Keppel, D. G.; Key, J. S.; Khalaidovski, A.; Khalili, F. Y.; Khazanov, E. A.; Kim, C.; Kim, K.; Kim, N. G.; Kim, N.; Kim, Y.-M.; King, E. J.; King, P. J.; Kinzel, D. L.; Kissel, J. S.; Klimenko, S.; Kline, J.; Koehlenbeck, S.; Kokeyama, K.; Kondrashov, V.; Korobko, M.; Korth, W. Z.; Kowalska, I.; Kozak, D. B.; Kringel, V.; Krishnan, B.; Królak, A.; Krueger, C.; Kuehn, G.; Kumar, A.; Kumar, P.; Kuo, L.; Kutynia, A.; Landry, M.; Lantz, B.; Larson, S.; Lasky, P. D.; Lazzarini, A.; Lazzaro, C.; Lazzaro, C.; Le, J.; Leaci, P.; Leavey, S.; Lebigot, E.; Lebigot, E. O.; Lee, C. H.; Lee, H. K.; Lee, H. M.; Leonardi, M.; Leong, J. R.; Leroy, N.; Letendre, N.; Levin, Y.; Levine, B.; Lewis, J.; Li, T. G. F.; Libbrecht, K.; Libson, A.; Lin, A. C.; Littenberg, T. B.; Lockerbie, N. A.; Lockett, V.; Logue, J.; Lombardi, A. L.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Lough, J.; Lubinski, M. J.; Lück, H.; Lundgren, A. P.; Lynch, R.; Ma, Y.; Macarthur, J.; MacDonald, T.; Machenschalk, B.; MacInnis, M.; Macleod, D. M.; Magaña na-Sandoval, F.; Magee, R.; Mageswaran, M.; Maglione, C.; Mailand, K.; Majorana, E.; Maksimovic, I.; Malvezzi, V.; Man, N.; Mandel, I.; Mandic, V.; Mangano, V.; Mangano, V.; Mansell, G. L.; Mantovani, M.; Marchesoni, F.; Marion, F.; Márka, S.; Márka, Z.; Markosyan, A.; Maros, E.; Martelli, F.; Martellini, L.; Martin, I. W.; Martin, R. M.; Martynov, D.; Marx, J. N.; Mason, K.; Masserot, A.; Massinger, T. J.; Matichard, F.; Matone, L.; Mavalvala, N.; Mazumder, N.; Mazzolo, G.; McCarthy, R.; McClelland, D. E.; McCormick, S.; McGuire, S. C.; McIntyre, G.; McIver, J.; McLin, K.; McWilliams, S.; Meacher, D.; Meadors, G. D.; Meidam, J.; Meinders, M.; Melatos, A.; Mendell, G.; Mercer, R. A.; Meshkov, S.; Messenger, C.; Meyers, P. M.; Mezzani, F.; Miao, H.; Michel, C.; Middleton, H.; Mikhailov, E. E.; Milano, L.; Miller, A.; Miller, J.; Millhouse, M.; Minenkov, Y.; Ming, J.; Mirshekari, S.; Mishra, C.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Moe, B.; Moggi, A.; Mohan, M.; Mohanty, S. D.; Mohapatra, S. R. P.; Moore, B.; Moraru, D.; Moreno, G.; Morriss, S. R.; Mossavi, K.; Mours, B.; Mow-Lowry, C. M.; Mueller, C. L.; Mueller, G.; Mukherjee, S.; Mullavey, A.; Munch, J.; Murphy, D.; Murray, P. G.; Mytidis, A.; Nagy, M. F.; Nardecchia, I.; Nash, T.; Naticchioni, L.; Nayak, R. K.; Necula, V.; Nedkova, K.; Nelemans, G.; Neri, I.; Neri, M.; Newton, G.; Nguyen, T.; Nielsen, A. B.; Nissanke, S.; Nitz, A. H.; Nocera, F.; Nolting, D.; Normandin, M. E. N.; Nuttall, L. K.; Ochsner, E.; O'Dell, J.; Oelker, E.; Ogin, G. H.; Oh, J. J.; Oh, S. H.; Ohme, F.; Oppermann, P.; Oram, R.; O'Reilly, B.; Ortega, W.; O'Shaughnessy, R.; Osthelder, C.; Ott, C. D.; Ottaway, D. J.; Ottens, R. S.; Overmier, H.; Owen, B. J.; Padilla, C.; Pai, A.; Pai, S.; Palashov, O.; Palomba, C.; Pal-Singh, A.; Pan, H.; Pankow, C.; Pannarale, F.; Pant, B. C.; Paoletti, F.; Papa, M. A.; Paris, H.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Patrick, Z.; Pedraza, M.; Pekowsky, L.; Pele, A.; Penn, S.; Perreca, A.; Phelps, M.; Pichot, M.; Piergiovanni, F.; Pierro, V.; Pillant, G.; Pinard, L.; Pinto, I. M.; Pitkin, M.; Poeld, J.; Poggiani, R.; Post, A.; Poteomkin, A.; Powell, J.; Prasad, J.; Predoi, V.; Premachandra, S.; Prestegard, T.; Price, L. R.; Prijatelj, M.; Principe, M.; Privitera, S.; Prix, R.; Prodi, G. A.; Prokhorov, L.; Puncken, O.; Punturo, M.; Puppo, P.; Pürrer, M.; Qin, J.; Quetschke, V.; Quintero, E.; Quiroga, G.; Quitzow-James, R.; Raab, F. J.; Rabeling, D. S.; Rácz, I.; Radkins, H.; Raffai, P.; Raja, S.; Rajalakshmi, G.; Rakhmanov, M.; Ramirez, K.; Rapagnani, P.; Raymond, V.; Razzano, M.; Re, V.; Reed, C. M.; Regimbau, T.; Rei, L.; Reid, S.; Reitze, D. H.; Reula, O.; Ricci, F.; Riles, K.; Robertson, N. A.; Robie, R.; Robinet, F.; Rocchi, A.; Rolland, L.; Rollins, J. G.; Roma, V.; Romano, R.; Romanov, G.; Romie, J. H.; Rosińska, D.; Rowan, S.; Rüdiger, A.; Ruggi, P.; Ryan, K.; Sachdev, S.; Sadecki, T.; Sadeghian, L.; Saleem, M.; Salemi, F.; Sammut, L.; Sandberg, V.; Sanders, J. R.; Sannibale, V.; Santiago-Prieto, I.; Sassolas, B.; Sathyaprakash, B. S.; Saulson, P. R.; Savage, R.; Sawadsky, A.; Scheuer, J.; Schilling, R.; Schmidt, P.; Schnabel, R.; Schofield, R. M. S.; Schreiber, E.; Schuette, D.; Schutz, B. F.; Scott, J.; Scott, S. M.; Sellers, D.; Sengupta, A. S.; Sentenac, D.; Sequino, V.; Sergeev, A.; Serna, G.; Sevigny, A.; Shaddock, D. A.; Shah, S.; Shahriar, M. S.; Shaltev, M.; Shao, Z.; Shapiro, B.; Shawhan, P.; Shoemaker, D. H.; Sidery, T. L.; Siellez, K.; Siemens, X.; Sigg, D.; Silva, A. D.; Simakov, D.; Singer, A.; Singer, L.; Singh, R.; Sintes, A. M.; Slagmolen, B. J. J.; Smith, J. R.; Smith, M. R.; Smith, R. J. E.; Smith-Lefebvre, N. D.; Son, E. J.; Sorazu, B.; Souradeep, T.; Staley, A.; Stebbins, J.; Steinke, M.; Steinlechner, J.; Steinlechner, S.; Steinmeyer, D.; Stephens, B. C.; Steplewski, S.; Stevenson, S.; Stone, R.; Strain, K. A.; Straniero, N.; Strigin, S.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sutton, P. J.; Swinkels, B.; Szczepanczyk, M.; Szeifert, G.; Tacca, M.; Talukder, D.; Tanner, D. B.; Tápai, M.; Tarabrin, S. P.; Taracchini, A.; Taylor, R.; Tellez, G.; Theeg, T.; Thirugnanasambandam, M. P.; Thomas, M.; Thomas, P.; Thorne, K. A.; Thorne, K. S.; Thrane, E.; Tiwari, V.; Tomlinson, C.; Tonelli, M.; Torres, C. V.; Torrie, C. I.; Travasso, F.; Traylor, G.; Tse, M.; Tshilumba, D.; Ugolini, D.; Unnikrishnan, C. S.; Urban, A. L.; Usman, S. A.; Vahlbruch, H.; Vajente, G.; Vajente, G.; Valdes, G.; Vallisneri, M.; van Bakel, N.; van Beuzekom, M.; van den Brand, J. F. J.; van den Broeck, C.; van der Sluys, M. V.; van Heijningen, J.; van Veggel, A. A.; Vass, S.; Vasúth, M.; Vaulin, R.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, J.; Veitch, P. J.; Venkateswara, K.; Verkindt, D.; Vetrano, F.; Viceré, A.; Vincent-Finley, R.; Vinet, J.-Y.; Vitale, S.; Vo, T.; Vocca, H.; Vorvick, C.; Vousden, W. D.; Vyatchanin, S. P.; Wade, A. R.; Wade, L.; Wade, M.; Walker, M.; Wallace, L.; Walsh, S.; Wang, H.; Wang, M.; Wang, X.; Ward, R. L.; Warner, J.; Was, M.; Weaver, B.; Wei, L.-W.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Welborn, T.; Wen, L.; Wessels, P.; Westphal, T.; Wette, K.; Whelan, J. T.; White, D. J.; Whiting, B. F.; Wilkinson, C.; Williams, L.; Williams, R.; Williamson, A. R.; Willis, J. L.; Willke, B.; Wimmer, M.; Winkler, W.; Wipf, C. C.; Wittel, H.; Woan, G.; Worden, J.; Xie, S.; Yablon, J.; Yakushin, I.; Yam, W.; Yamamoto, H.; Yancey, C. C.; Yang, Q.; Yvert, M.; Zadrożny, A.; Zanolin, M.; Zendri, J.-P.; Zhang, Fan; Zhang, L.; Zhang, M.; Zhang, Y.; Zhao, C.; Zhou, M.; Zhu, X. J.; Zucker, M. E.; Zuraw, S.; Zweizig, J.

    2015-11-01

    We describe directed searches for continuous gravitational waves (GWs) in data from the sixth Laser Interferometer Gravitational-wave Observatory (LIGO) science data run. The targets were nine young supernova remnants not associated with pulsars; eight of the remnants are associated with non-pulsing suspected neutron stars. One target's parameters are uncertain enough to warrant two searches, for a total of 10. Each search covered a broad band of frequencies and first and second frequency derivatives for a fixed sky direction. The searches coherently integrated data from the two LIGO interferometers over time spans from 5.3-25.3 days using the matched-filtering {F}-statistic. We found no evidence of GW signals. We set 95% confidence upper limits as strong (low) as 4 × 10-25 on intrinsic strain, 2 × 10-7 on fiducial ellipticity, and 4 × 10-5 on r-mode amplitude. These beat the indirect limits from energy conservation and are within the range of theoretical predictions for neutron-star ellipticities and r-mode amplitudes.

  9. Improved optical spectrophotometry of supernova remnants in M33

    NASA Technical Reports Server (NTRS)

    Blair, W. P.; Kirshner, R. P.

    1985-01-01

    Optical spectra of SNRs in M33 have been used to investigate abundance gradients and SNR evolution in this galaxy. Abundances of O, N, and S are derived from the spectra using new shock models by Dopita et al. (1984). The results for N and S show abundance gradients similar to those in NGC 300 and the Galaxy. The O abundances may be affected by possible contamination from H II regions and low-velocity shocks. Electron densities derived from the forbidden S II 6717 A/6731 A line ratio are used with a pressure equilibrium argument to estimate the initial explosion energy for each SNR. Evolutionary models for the remnants are investigated, and the distribution of the number of remnants with diameter is found to be consistent with free expansion of the SNRs to diameters of about 26 pc. The results may also be consistent with Sedov evolution if the ranges of initial supernova energies and surrounding interstellar medium densities are large enough.

  10. Observations of the young supernova remnant RX J1713.7–3946 with the Fermi Large Area Telescope

    DOE PAGES

    Abdo, A. A.; Ackermann, M.; Ajello, M.; ...

    2011-05-23

    Here, we present observations of the young supernova remnant (SNR) RX J1713.7–3946 with the Fermi Large Area Telescope (LAT). We clearly detect a source positionally coincident with the SNR. The source is extended with a best-fit extension of 0°.55 ± 0°.04 matching the size of the non-thermal X-ray and TeV gamma-ray emission from the remnant. The positional coincidence and the matching extended emission allow us to identify the LAT source with SNR RX J1713.7–3946. The spectrum of the source can be described by a very hard power law with a photon index of Γ = 1.5 ± 0.1 that coincidesmore » in normalization with the steeper H.E.S.S.-detected gamma-ray spectrum at higher energies. The broadband gamma-ray emission is consistent with a leptonic origin as the dominant mechanism for the gamma-ray emission.« less

  11. OBSERVATIONS OF THE YOUNG SUPERNOVA REMNANT RX J1713.7-3946 WITH THE FERMI LARGE AREA TELESCOPE

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

    Abdo, A. A.; Ackermann, M.; Ajello, M.

    We present observations of the young supernova remnant (SNR) RX J1713.7-3946 with the Fermi Large Area Telescope (LAT). We clearly detect a source positionally coincident with the SNR. The source is extended with a best-fit extension of 0.{sup 0}55 {+-} 0.{sup 0}04 matching the size of the non-thermal X-ray and TeV gamma-ray emission from the remnant. The positional coincidence and the matching extended emission allow us to identify the LAT source with SNR RX J1713.7-3946. The spectrum of the source can be described by a very hard power law with a photon index of {Gamma} = 1.5 {+-} 0.1 thatmore » coincides in normalization with the steeper H.E.S.S.-detected gamma-ray spectrum at higher energies. The broadband gamma-ray emission is consistent with a leptonic origin as the dominant mechanism for the gamma-ray emission.« less

  12. FERMI LAT DISCOVERY OF EXTENDED GAMMA-RAY EMISSIONS IN THE VICINITY OF THE HB 3 SUPERNOVA REMNANT

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

    Katagiri, H.; Yoshida, K.; Ballet, J.

    2016-02-20

    We report the discovery of extended gamma-ray emission measured by the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope in the region of the supernova remnant (SNR) HB 3 (G132.7+1.3) and the W3 II complex adjacent to the southeast of the remnant. W3 is spatially associated with bright {sup 12}CO (J = 1–0) emission. The gamma-ray emission is spatially correlated with this gas and the SNR. We discuss the possibility that gamma rays originate in interactions between particles accelerated in the SNR and interstellar gas or radiation fields. The decay of neutral pions produced in nucleon–nucleon interactions between accelerated hadrons and interstellar gas provides amore » reasonable explanation for the gamma-ray emission. The emission from W3 is consistent with irradiation of the CO clouds by the cosmic rays accelerated in HB 3.« less

  13. NASA's Fermi Proves Supernova Remnants Produce Cosmic Rays

    NASA Image and Video Library

    2017-12-08

    The W44 supernova remnant is nestled within and interacting with the molecular cloud that formed its parent star. Fermi's LAT detects GeV gamma rays (magenta) produced when the gas is bombarded by cosmic rays, primarily protons. Radio observations (yellow) from the Karl G. Jansky Very Large Array near Socorro, N.M., and infrared (red) data from NASA's Spitzer Space Telescope reveal filamentary structures in the remnant's shell. Blue shows X-ray emission mapped by the Germany-led ROSAT mission. To read more go to: 1.usa.gov/14V14qi NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram Credit: NASA/DOE/Fermi LAT Collaboration, NRAO/AUI, JPL-Caltech, ROSAT

  14. A population of isolated hard X-ray sources near the supernova remnant Kes 69

    NASA Astrophysics Data System (ADS)

    Bocchino, F.; Bykov, A. M.; Chen, Y.; Krassilchtchikov, A. M.; Levenfish, K. P.; Miceli, M.; Pavlov, G. G.; Uvarov, Yu. A.; Zhou, X.

    2012-05-01

    Recent X-ray observations of the supernova remnant (SNR) IC 443 interacting with molecular clouds detected a new population of hard X-ray sources related to the remnant itself, which has been proposed to be fast ejecta fragments propagating within the dense environment. Encouraged by these studies, we obtained a deep XMM-Newton observation of the SNR Kes 69, which also shows signs of a shock-cloud interaction. We report on the detection of 18 hard X-ray sources in the field of Kes 69, which is a number sognificantly higher than expected for the Galactic source population in the field. The sources are spatially correlated with CO emission from the cloud in the remnant environment. The spectra of 3 of the 18 sources can be described as hard power-laws with photon indices smaller than two plus line emission associated with K-shell transitions. We discuss the two most promising scenarios for the interpretation of the sources, namely fast ejecta fragments (as in IC 443) and cataclysmic variables. While most of the observational evidence is consistent with the former interpretation, we cannot rule out the latter.

  15. Kepler's Supernova Remnant: A View from Chandra X-Ray Observatory

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    [figure removed for brevity, see original site] Figure 1

    Each top panel in the composite above shows the entire remnant. Each color in the composite represents a different region of the electromagnetic spectrum, from X-rays to infrared light. The X-ray and infrared data cannot be seen with the human eye. Astronomers have color-coded those data so they can be seen in these images.

    The bottom panels are close-up views of the remnant. In the bottom, center image, Hubble sees fine details in the brightest, densest areas of gas. The region seen in these images is outlined in the top, center panel.

    The images indicate that the bubble of gas that makes up the supernova remnant appears different in various types of light. Chandra reveals the hottest gas [colored blue and colored green], which radiates in X-rays. The blue color represents the higher-energy gas; the green, the lower-energy gas. Hubble shows the brightest, densest gas [colored yellow], which appears in visible light. Spitzer unveils heated dust [colored red], which radiates in infrared light.

  16. Is the Link Between the Observed Velocities of Neutron Stars and their Progenitors a Simple Mass Relationship?

    NASA Astrophysics Data System (ADS)

    Bray, J. C.

    2017-11-01

    While the imparting of velocity `kicks' to compact remnants from supernovae is widely accepted, the relationship of the `kick' to the progenitor is not. We propose the `kick' is predominantly a result of conservation of momentum between the ejected and compact remnant masses. We propose the `kick' velocity is given by v kick = α(M ejecta/M remnant)+β, where α and β are constants we wish to determine. To test this we use the BPASS v2 (Binary Population and Spectral Synthesis) code to create stellar populations from both single star and binary star evolutionary pathways. We then use our Remnant Ejecta and Progenitor Explosion Relationship (REAPER) code to apply `kicks' to neutron stars from supernovae in these models using a grid of α and β values, (from 0 to 200 km s-1 in steps of 10 km s-1), in three different `kick' orientations, (isotropic, spin-axis aligned and orthogonal to spin-axis) and weighted by three different Salpeter initial mass functions (IMF's), with slopes of -2.0, -2.35 and -2.70. We compare our synthetic 2D and 3D velocity probability distributions to the distributions provided by Hobbs et al. (1995).

  17. Radio to Gamma-Ray Emission from Shell-Type Supernova Remnants: Predictions from Non-Linear Shock Acceleration Models

    NASA Technical Reports Server (NTRS)

    Baring, Matthew G.; Ellison, Donald C.; Reynolds, Stephen P.; Grenier, Isabelle A.; Goret, Philippe

    1998-01-01

    Supernova remnants (SNRs) are widely believed to be the principal source of galactic cosmic rays, produced by diffusive shock acceleration in the environs of the remnant's expanding blast wave. Such energetic particles can produce gamma-rays and lower energy photons via interactions with the ambient plasma. The recently reported observation of TeV gamma-rays from SN1006 by the CANGAROO Collaboration, combined with the fact that several unidentified EGRET sources have been associated with known radio/optical/X-ray-emitting remnants, provides powerful motivation for studying gamma-ray emission from SNRs. In this paper, we present results from a Monte Carlo simulation of non-linear shock structure and acceleration coupled with photon emission in shell-like SNRs. These non-linearities are a by-product of the dynamical influence of the accelerated cosmic rays on the shocked plasma and result in distributions of cosmic rays which deviate from pure power-laws. Such deviations are crucial to acceleration efficiency considerations and impact photon intensities and spectral shapes at all energies, producing GeV/TeV intensity ratios that are quite different from test particle predictions.

  18. Supernova Remnant W49B

    NASA Image and Video Library

    2017-12-08

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

  19. INTEGRAL Studies of Nonthermal Emission From the Supernova Remnants Cassiopeia A, CTA 1, and MSH 11-61A

    NASA Technical Reports Server (NTRS)

    Sturner, S. J.; Beckmann, V.; Bykov, A.; Lebrun, F.; Terrier, R.

    2004-01-01

    We present the initial results from our study of the nonthermal continuum emission from the supernova remnants Cassiopeia A, MSB 11-61-4, a d CT-4 1. We used the INTEGRAL Core Program data to conduct this study. During the INTEGRAL mission a significant fraction of the total observing time (e.g. 35% in year one) is allocated to the Core Program and is analyzed under the auspices of the INTEGRAL Science Working Team. We report no statistically significant detections thus far but we will continue to analyze the data as more is taken. The results so far are consistent with previous measurements from e.g. RXTE and ASCA.

  20. Discovery of Gamma-Ray Emission from the Supernova Remnant Kes 17 with Fermi Large Area Telescope

    NASA Astrophysics Data System (ADS)

    Wu, J. H. K.; Wu, E. M. H.; Hui, C. Y.; Tam, P. H. T.; Huang, R. H. H.; Kong, A. K. H.; Cheng, K. S.

    2011-10-01

    We report the discovery of GeV emission at the position of supernova remnant Kes 17 by using the data from the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. Kes 17 can be clearly detected with a significance of ~12σ in the 1-20 GeV range. Moreover, a number of γ-ray sources were detected in its vicinity. The γ-ray spectrum of Kes 17 can be described well by a simple power law with a photon index of Γ ~ 2.4. Together with the multiwavelength evidence for its interactions with the nearby molecular cloud, the γ-ray detection suggests that Kes 17 is a candidate acceleration site for cosmic rays.

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

    NASA Astrophysics Data System (ADS)

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

    2003-06-01

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

  2. Detection of a new extended soft X-ray source H1538-32 - A possible old supernova remnant

    NASA Technical Reports Server (NTRS)

    Riegler, G. R.; Agrawal, P. C.; Gull, S. F.

    1980-01-01

    The discovery in the Lupus region of a new, extended soft X-ray source, H1538-32, is reported, having a distance of approximately 340 pc, and a luminosity of 1 to 2 x 10 to the 34th ergs/sec. The observed energy spectrum of the source is well fitted either by a thermal bremsstrahlung spectrum with Gaunt factor but without line emission, or by a coronal plasma model which includes the X-ray emission lines of various elements and the continuum as outlined by Raymond and Smith (1977). On the basis of the extended nature of the source and its thermal spectrum, it is suggested that H1538-32 may be an old supernova remnant.

  3. RXTE Observations of Cas A

    NASA Technical Reports Server (NTRS)

    Rothschild, R. E.; Lingenfelter, R. E.; Heindl, W. A.; Blanco, P. R.; Pelling, M. R.; Gruber, D. E.; Allen, G. E.; Jahoda, K.; Swank, J. H.; Woosley, S. E.; hide

    1997-01-01

    The exciting detection by the COMPTEL instrument of the 1157 keV Ti-44 line from the supernova remnant Cas A sets important new constraints on supernova dynamics and nucleosynthesis. The Ti-44 decay also produces x-ray lines at 68 and 78 keV, whose flux should be essentially the same as that of the gamma ray line. The revised COMPTEL flux of 4 x l0(exp -5) cm(exp -2)s(exp -1) is very near the sensitivity limit for line detection by the HEXTE instrument on RXTE. We report on the results from two RXTE observations - 20 ks during In Orbit Checkout in January 1996 and 200 ks in April 1996. We also find a strong continuum emission suggesting cosmic ray electron acceleration in the remnant.

  4. Combined ultraviolet studies of astronomical source

    NASA Technical Reports Server (NTRS)

    Dupress, A. K.; Baliunas, S. L.; Blair, W. P.; Hartmann, L. W.; Huchra, J. P.; Raymond, J. C.; Smith, G. H.; Soderblom, D. R.

    1985-01-01

    As part of its Ultraviolet Studies of Astronomical Sources the Smithsonian Astrophysical Observatory for the period 1 Feb. 1985 to 31 July 1985 observed the following: the Cygnus Loop; oxygen-rich supernova remnants in 1E0102-72; the Large Magellanic Cloud supernova remnants; P Cygni profiles in dwarf novae; soft X-ray photoionization of interstellar gas; spectral variations in AM Her stars; the mass of Feige 24; atmospheric inhomogeneities in Lambda Andromedae and FF Aquarii; photometric and spectroscopic observation of Capella; Alpha Orionis; metal deficient giant stars; M 67 giants; high-velocity winds from giant stars; accretion disk parameters in cataclysmic variables; chromospheric emission of late-type dwarfs in visual binaries; chromospheres and transient regions of stars in the Ursa Major group; and low-metallicity blue galaxies.

  5. Detection of 16 gamma-ray pulsars through blind frequency searches using the Fermi LAT.

    PubMed

    Abdo, A A; Ackermann, M; Ajello, M; Anderson, B; Atwood, W B; Axelsson, M; Baldini, L; Ballet, J; Barbiellini, G; Baring, M G; Bastieri, D; Baughman, B M; Bechtol, K; Bellazzini, R; Berenji, B; Bignami, G F; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A W; Bregeon, J; Brez, A; Brigida, M; Bruel, P; Burnett, T H; Caliandro, G A; Cameron, R A; Caraveo, P A; Casandjian, J M; Cecchi, C; Celik, O; Chekhtman, A; Cheung, C C; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; Conrad, J; Cutini, S; Dermer, C D; de Angelis, A; de Luca, A; de Palma, F; Digel, S W; Dormody, M; do Couto e Silva, E; Drell, P S; Dubois, R; Dumora, D; Farnier, C; Favuzzi, C; Fegan, S J; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Gehrels, N; Germani, S; Giebels, B; Giglietto, N; Giommi, P; Giordano, F; Glanzman, T; Godfrey, G; Grenier, I A; Grondin, M-H; Grove, J E; Guillemot, L; Guiriec, S; Gwon, C; Hanabata, Y; Harding, A K; Hayashida, M; Hays, E; Hughes, R E; Jóhannesson, G; Johnson, R P; Johnson, T J; Johnson, W N; Kamae, T; Katagiri, H; Kataoka, J; Kawai, N; Kerr, M; Knödlseder, J; Kocian, M L; Kuss, M; Lande, J; Latronico, L; Lemoine-Goumard, M; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Madejski, G M; Makeev, A; Marelli, M; Mazziotta, M N; McConville, W; McEnery, J E; Meurer, C; Michelson, P F; Mitthumsiri, W; Mizuno, T; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nolan, P L; Norris, J P; Nuss, E; Ohsugi, T; Omodei, N; Orlando, E; Ormes, J F; Paneque, D; Parent, D; Pelassa, V; Pepe, M; Pesce-Rollins, M; Pierbattista, M; Piron, F; Porter, T A; Primack, J R; Rainò, S; Rando, R; Ray, P S; Razzano, M; Rea, N; Reimer, A; Reimer, O; Reposeur, T; Ritz, S; Rochester, L S; Rodriguez, A Y; Romani, R W; Ryde, F; Sadrozinski, H F-W; Sanchez, D; Sander, A; Saz Parkinson, P M; Scargle, J D; Sgrò, C; Siskind, E J; Smith, D A; Smith, P D; Spandre, G; Spinelli, P; Starck, J-L; Strickman, M S; Suson, D J; Tajima, H; Takahashi, H; Takahashi, T; Tanaka, T; Thayer, J G; Thompson, D J; Tibaldo, L; Tibolla, O; Torres, D F; Tosti, G; Tramacere, A; Uchiyama, Y; Usher, T L; Van Etten, A; Vasileiou, V; Vilchez, N; Vitale, V; Waite, A P; Wang, P; Watters, K; Winer, B L; Wolff, M T; Wood, K S; Ylinen, T; Ziegler, M

    2009-08-14

    Pulsars are rapidly rotating, highly magnetized neutron stars emitting radiation across the electromagnetic spectrum. Although there are more than 1800 known radio pulsars, until recently only seven were observed to pulse in gamma rays, and these were all discovered at other wavelengths. The Fermi Large Area Telescope (LAT) makes it possible to pinpoint neutron stars through their gamma-ray pulsations. We report the detection of 16 gamma-ray pulsars in blind frequency searches using the LAT. Most of these pulsars are coincident with previously unidentified gamma-ray sources, and many are associated with supernova remnants. Direct detection of gamma-ray pulsars enables studies of emission mechanisms, population statistics, and the energetics of pulsar wind nebulae and supernova remnants.

  6. THE ABSENCE OF EX-COMPANIONS IN TYPE Ia SUPERNOVA REMNANTS

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

    Di Stefano, R.; Kilic, Mukremin, E-mail: rd@cfa.harvard.edu, E-mail: kilic@ou.edu

    Type Ia supernovae (SNe Ia) play important roles in our study of the expansion and acceleration of the universe, but because we do not know the exact nature or natures of the progenitors, there is a systematic uncertainty that must be resolved if SNe Ia are to become more precise cosmic probes. No progenitor system has ever been identified either in the pre- or post-explosion images of a Ia event. There have been recent claims for and against the detection of ex-companion stars in several SNe Ia remnants. These studies, however, usually ignore the angular momentum gain of the progenitormore » white dwarf (WD), which leads to a spin-up phase and a subsequent spin-down phase before explosion. For spin-down timescales greater than 10{sup 5} years, the donor star could be too dim to detect by the time of explosion. Here we revisit the current limits on ex-companion stars to SNR 0509-67.5, a 400-year-old remnant in the Large Magellanic Cloud. If the effects of possible angular momentum gain on the WD are included, a wide range of single-degenerate progenitor models are allowed for this remnant. We demonstrate that the current absence of evidence for ex-companion stars in this remnant, as well as other SNe Ia remnants, does not necessarily provide the evidence of absence for ex-companions. We discuss potential ways to identify such ex-companion stars through deep imaging observations.« less

  7. Dust in Supernovae and Supernova Remnants I: Formation Scenarios

    NASA Astrophysics Data System (ADS)

    Sarangi, A.; Matsuura, M.; Micelotta, E. R.

    2018-04-01

    Supernovae are considered as prime sources of dust in space. Observations of local supernovae over the past couple of decades have detected the presence of dust in supernova ejecta. The reddening of the high redshift quasars also indicate the presence of large masses of dust in early galaxies. Considering the top heavy IMF in the early galaxies, supernovae are assumed to be the major contributor to these large amounts of dust. However, the composition and morphology of dust grains formed in a supernova ejecta is yet to be understood with clarity. Moreover, the dust masses inferred from observations in mid-infrared and submillimeter wavelength regimes differ by two orders of magnitude or more. Therefore, the mechanism responsible for the synthesis of molecules and dust in such environments plays a crucial role in studying the evolution of cosmic dust in galaxies. This review summarises our current knowledge of dust formation in supernova ejecta and tries to quantify the role of supernovae as dust producers in a galaxy.

  8. THE SN 393-SNR RX J1713.7-3946 (G347.3-0.5) CONNECTION

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

    Fesen, Robert A.; Milisavljevic, Dan; Kremer, Richard

    Although the connection of the Chinese 'guest' star of 393 AD with the Galactic supernova remnant RX J1713.7-3946 (G347.3-0.5) made by Wang et al. in 1997 is consistent with the remnant's relatively young properties and the guest star's projected position within the 'tail' of the constellation Scorpius, there are difficulties with such an association. The brief Chinese texts concerning the 393 AD guest star make no comment about its apparent brightness, stating only that it disappeared after eight months. However, at the remnant's current estimated 1-1.3 kpc distance and A{sub V} {approx_equal} 3, its supernova (SN) should have been amore » visually bright object at maximum light (-3.5 to -5.0 mag) if M{sub V} = - 17 to -18 and would have remained visible for over a year. The peak brightness {approx_equal}0 mag adopted by Wang et al. and others would require the RX J1713.7-3946 supernova to have been a very subluminous event similar to or fainter than SN 2005cs in M51. We also note problems connecting SN 393 with a European record in which the Roman poet Claudian describes a visually brilliant star in the heavens around 393 AD that could be readily seen even in midday. Although several authors have suggested this account may be a reference to the Chinese supernova of 393, Scorpius would not be visible near midday in March when the Chinese first reported the 393 guest star. We review both the Chinese and Roman accounts and calculate probable visual brightnesses for a range of SN subtypes and conclude that neither the Chinese nor the Roman descriptions are easily reconciled with an expected RX J1713.7-3946 supernova brightness and duration.« less

  9. LAD Early Career Prize Talk:Laboratory astrophysics experiments investigating the effects of high energy fluxes on Rayleigh-Taylor instability growth relevant to young supernova remnants

    NASA Astrophysics Data System (ADS)

    Kuranz, Carolyn C.; Drake, R. Paul; Park, Hye Sook; Huntington, Channing; Miles, Aaron R.; Remington, Bruce A.; Plewa, Tomek; Trantham, Matt; Shvarts, Dov; Raman, Kumar; MacLaren, Steven; Wan, Wesley; Doss, Forrest; Kline, John; Flippos, Kirk; Malamud, Guy; Handy, Timothy; Prisbey, Shon; Grosskopf, Michael; Krauland, Christine; Klein, Sallee; Harding, Eric; Wallace, Russell; Marion, Donna; Kalantar, Dan

    2017-06-01

    Energy-transport effects can alter the structure that develops as a supernova evolves into a supernova remnant. The Rayleigh Taylor (RT) instability is thought to produce structure at the interface between the stellar ejecta and the circumstellar matter (CSM), based on simple models and hydrodynamic simulations. When a blast wave emerges from an exploding star, it drives a forward shock into the CSM and a reverse shock forms in the expanding stellar ejecta, creating a young supernova remnant (SNR). As mass accumulates in the shocked layers, the interface between these two shocks decelerates, becoming unstable to the RT instability. Simulations predict that RT produces structures at this interface, having a range of spatial scales. When the CSM is dense enough, as in the case of SN 1993J, the hot shocked matter can produce significant radiative fluxes that affect the emission from the SNR. Here we report experimental results from the National Ignition Facility (NIF) to explore how large energy fluxes, which are present in supernovae such as SN 1993J, might affect this structure. The experiment used NIF to create a RT unstable interface subject to a high energy flux by the emergence of a blast wave into lower-density matter, in analogy to the SNR. We also preformed and with a low energy flux to compare the affect of the energy flux on the instability growth. We found that the RT growth was reduced in the experiments with a high energy flux. In analyzing the comparison with SN 1993J, we discovered that the energy fluxes produced by heat conduction appear to be larger than the radiative energy fluxes, and large enough to have dramatic consequences. No reported astrophysical simulations have included radiation and heat conduction self-consistently in modeling SNRs.

  10. Broadband Observations and Modeling of the Shell-Type Supernova Remnant G347.3-0.5

    NASA Technical Reports Server (NTRS)

    Ellison, Donald C.; Slane, Patrick O.; Gaensler, Bryan M.

    2002-01-01

    The supernova remnant G347.3-0.5 emits a featureless power law in X-rays, thought to indicate shock acceleration of electrons to high energies. We here produce a broadband spectrum of the bright northwest limb of this source by combining radio observations from the Australia Telescope Compact Array (ATCA), X-ray observations from the Advanced Satellite for Cosmology and Astrophysics (ASCA), and TeV gamma-ray observations from the CANGAROO imaging Cerenkov telescope. We assume that this emission is produced by an electron population generated by diffusive shock acceleration at the remnant forward shock. The nonlinear aspects of the particle acceleration force a connection between the widely different wavelength bands and between the electrons and the unseen ions, presumably accelerated simultaneously with the electrons. This allows us to infer the relativistic proton spectrum and estimate ambient parameters such as the supernova explosion energy, magnetic field, matter density in the emission region, and efficiency of the shock acceleration process. We find convincing evidence that the shock acceleration is efficient, placing greater than 25% of the shock kinetic energy flux into relativistic ions. Despite this high efficiency, the maximum electron and proton energies, while depending somewhat on assumptions for the compression of the magnetic field in the shock, are well below the observed 'knee' at 10(exp 15) eV in the Galactic cosmic-ray spectrum.

  11. The supernova remnant W49B as seen with H.E.S.S. and Fermi-LAT

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

    Abdalla, H.; Abramowski, A.; Aharonian, F.

    The supernova remnant (SNR) W49B originated from a core-collapse supernova that occurred between one and four thousand years ago, and subsequently evolved into a mixed-morphology remnant, which is interacting with molecular clouds (MC). Gamma-ray observations of SNR-MC associations are a powerful tool to constrain the origin of Galactic cosmic rays, as they can probe the acceleration of hadrons through their interaction with the surrounding medium and subsequent emission of non-thermal photons. Here, we report the detection of a γ-ray source coincident with W49B at very high energies (VHE; E > 100 GeV) with the H.E.S.S. Cherenkov telescopes together with amore » study of the source with five years of Fermi-LAT high-energy γ-ray (0.06–300 GeV) data. The smoothly connected, combined source spectrum, measured from 60 MeV to multi-TeV energies, shows two significant spectral breaks at 304 ± 20 MeV and 8.4 -2.5 +2.2 GeV; the latter is constrained by the joint fit from the two instruments. The detected spectral features are similar to those observed in several other SNR-MC associations and are found to be indicative of γ-ray emission produced through neutral-pion decay.« less

  12. The supernova remnant W49B as seen with H.E.S.S. and Fermi-LAT

    DOE PAGES

    Abdalla, H.; Abramowski, A.; Aharonian, F.; ...

    2018-04-01

    The supernova remnant (SNR) W49B originated from a core-collapse supernova that occurred between one and four thousand years ago, and subsequently evolved into a mixed-morphology remnant, which is interacting with molecular clouds (MC). Gamma-ray observations of SNR-MC associations are a powerful tool to constrain the origin of Galactic cosmic rays, as they can probe the acceleration of hadrons through their interaction with the surrounding medium and subsequent emission of non-thermal photons. Here, we report the detection of a γ-ray source coincident with W49B at very high energies (VHE; E > 100 GeV) with the H.E.S.S. Cherenkov telescopes together with amore » study of the source with five years of Fermi-LAT high-energy γ-ray (0.06–300 GeV) data. The smoothly connected, combined source spectrum, measured from 60 MeV to multi-TeV energies, shows two significant spectral breaks at 304 ± 20 MeV and 8.4 -2.5 +2.2 GeV; the latter is constrained by the joint fit from the two instruments. The detected spectral features are similar to those observed in several other SNR-MC associations and are found to be indicative of γ-ray emission produced through neutral-pion decay.« less

  13. Probing the local environment of the supernova remnant HESS J1731-347 with CO and CS observations

    NASA Astrophysics Data System (ADS)

    Maxted, N.; Burton, M.; Braiding, C.; Rowell, G.; Sano, H.; Voisin, F.; Capasso, M.; Pühlhofer, G.; Fukui, Y.

    2018-02-01

    The shell-type supernova remnant HESS J1731 - 347 emits TeV gamma-rays, and is a key object for the study of the cosmic ray acceleration potential of supernova remnants. We use 0.5-1 arcmin Mopra CO/CS(1-0) data in conjunction with H I data to calculate column densities towards the HESS J1731 - 347 region. We trace gas within at least four Galactic arms, typically tracing total (atomic+molecular) line-of-sight H column densities of 2-3× 1022 cm-2. Assuming standard X-factor values and that most of the H I/CO emission seen towards HESS J1731 - 347 is on the near-side of the Galaxy, X-ray absorption column densities are consistent with H I+CO-derived column densities foreground to, but not beyond, the Scutum-Crux Galactic arm, suggesting a kinematic distance of ˜3.2 kpc for HESS J1731 - 347. At this kinematic distance, we also find dense, infrared-dark gas traced by CS(1-0) emission coincident with the north of HESS J1731 - 347, the nearby H II region G353.43-0.37 and the nearby unidentified gamma-ray source HESS J1729 - 345. This dense gas lends weight to the idea that HESS J1729 - 345 and HESS J1731 - 347 are connected, perhaps via escaping cosmic-rays.

  14. Observation of Extended Very High Energy Emission from the Supernova Remnant IC 443 with VERITAS

    NASA Astrophysics Data System (ADS)

    Acciari, V. A.; Aliu, E.; Arlen, T.; Aune, T.; Bautista, M.; Beilicke, M.; Benbow, W.; Bradbury, S. M.; Buckley, J. H.; Bugaev, V.; Butt, Y.; Byrum, K.; Cannon, A.; Celik, O.; Cesarini, A.; Chow, Y. C.; Ciupik, L.; Cogan, P.; Colin, P.; Cui, W.; Daniel, M. K.; Dickherber, R.; Duke, C.; Dwarkadas, V. V.; Ergin, T.; Fegan, S. J.; Finley, J. P.; Finnegan, G.; Fortin, P.; Fortson, L.; Furniss, A.; Gall, D.; Gibbs, K.; Gillanders, G. H.; Godambe, S.; Grube, J.; Guenette, R.; Gyuk, G.; Hanna, D.; Hays, E.; Holder, J.; Horan, D.; Hui, C. M.; Humensky, T. B.; Imran, A.; Kaaret, P.; Karlsson, N.; Kertzman, M.; Kieda, D.; Kildea, J.; Konopelko, A.; Krawczynski, H.; Krennrich, F.; Lang, M. J.; LeBohec, S.; Maier, G.; McCann, A.; McCutcheon, M.; Millis, J.; Moriarty, P.; Ong, R. A.; Otte, A. N.; Pandel, D.; Perkins, J. S.; Pohl, M.; Quinn, J.; Ragan, K.; Reyes, L. C.; Reynolds, P. T.; Roache, E.; Rose, H. J.; Schroedter, M.; Sembroski, G. H.; Smith, A. W.; Steele, D.; Swordy, S. P.; Theiling, M.; Toner, J. A.; Valcarcel, L.; Varlotta, A.; Vassiliev, V. V.; Vincent, S.; Wagner, R. G.; Wakely, S. P.; Ward, J. E.; Weekes, T. C.; Weinstein, A.; Weisgarber, T.; Williams, D. A.; Wissel, S.; Wood, M.; Zitzer, B.

    2009-06-01

    We present evidence that the very high energy (VHE, E > 100 GeV) gamma-ray emission coincident with the supernova remnant IC 443 is extended. IC 443 contains one of the best studied sites of supernova remnant/molecular cloud interaction and the pulsar wind nebula CXOU J061705.3+222127, both of which are important targets for VHE observations. VERITAS observed IC 443 for 37.9 hr during 2007 and detected emission above 300 GeV with an excess of 247 events, resulting in a significance of 8.3 standard deviations (σ) before trials and 7.5σ after trials in a point-source search. The emission is centered at 6h16m51s + 22°30'11'' (J2000) ±0fdg03stat ± 0fdg08sys, with an intrinsic extension of 0fdg16 ± 0fdg03stat ± 0fdg04sys. The VHE spectrum is well fit by a power law (dN/dE = N 0 × (E/TeV)-Γ) with a photon index of 2.99 ± 0.38stat ± 0.3sys and an integral flux above 300 GeV of (4.63 ± 0.90stat ± 0.93sys) × 10-12 cm-2 s-1. These results are discussed in the context of existing models for gamma-ray production in IC 443.

  15. Shocks in Dense Clouds in the Vela Supernova Remnant: FUSE

    NASA Technical Reports Server (NTRS)

    Nichols, Joy; Sonneborn, George (Technical Monitor)

    2002-01-01

    We have obtained 8 LWRS FUSE spectra to study a recently identified interaction of the Vela supernova remnant with a dense cloud region along its western edge. The goal is to quantify the temperature, ionization, density, and abundance characteristics associated with this shock/dense cloud interface by means of UV absorption line studies. Our detection of high-velocity absorption line C I at +90 to +130 km/s with IUE toward a narrow region interior to the Vela SNR strongly suggests the Vela supernova remnant is interacting with a dense ISM or molecular cloud. The shock/dense cloud interface is suggested by (1) the rarity of detection of high-velocity C I seen in IUE spectra, (2) its very limited spatial distribution in the remnant, and (3) a marked decrease in X-ray emission in the region immediately west of the position of these stars where one also finds a 100 micron emission ridge in IRAS images. We have investigated the shock physics and general properties of this interaction region through a focussed UV absorption line study using FUSE spectra. We have FUSE data on OVI absorption lines observed toward 8 stars behind the Vela supernova remnant (SNR). We compare the OVI observations with IUE observations of CIV absorption toward the same stars. Most of the stars, which are all B stars, have complex continua making the extraction of absorption lines difficult. Three of the stars, HD 72088, HD 72089 and HD 72350, however, are rapid rotators (v sin i less than 100 km/s) making the derivation of absorption column densities much easier. We have measured OVI and CIV column densities for the "main component" (i.e. the low velocity component) for these stars. In addition, by removing the H2 line at 1032.35A (121.6 km/s relative to OVI), we find high velocity components of OVI at approximately 150 km/s that we attribute to the shock in the Vela SNR. The column density ratios and magnitudes are compared to both steady shock models and results of hydrodynamical SNR modeling. We find that the models require the shock to be relatively slow (approximately 100 - 170 km/s) to match the FUSE data. We discuss the implications of our results for models of the evolution of the Vela SNR.

  16. Dead Star Rumbles

    NASA Image and Video Library

    2005-06-10

    This Spitzer Space Telescope composite shows the supernova remnant Cassiopeia A white ball and surrounding clouds of dust gray, orange and blue. It consists of two processed images taken one year apart.

  17. Deep View of the Large Magellanic Cloud with Six Years of Fermi-LAT Observations

    NASA Technical Reports Server (NTRS)

    Ackermann, M.; Albert, A.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Bloom, E. D.; hide

    2016-01-01

    Context. The nearby Large Magellanic Cloud (LMC) provides a rare opportunity of a spatially resolved view of an external star-forming galaxy in gamma-rays. The LMC was detected at 0.1-100 GeV as an extended source with CGRO/EGRET and using early observations with the Fermi-LAT. The emission was found to correlate with massive star-forming regions and to be particularly bright towards 30 Doradus. Aims. Studies of the origin and transport of cosmic rays (CRs) in the Milky Way are frequently hampered by line-of-sight confusion and poor distance determination. The LMC offers a complementary way to address these questions by revealing whether and how the gamma-ray emission is connected to specific objects, populations of objects, and structures in the galaxy. Methods. We revisited the gamma-ray emission from the LMC using about 73 months of Fermi-LAT P7REP data in the 0.2-100 GeV range. We developed a complete spatial and spectral model of the LMC emission, for which we tested several approaches: a simple geometrical description, template-fitting, and a physically driven model for CR-induced interstellar emission. Results. In addition to identifying PSR J0540-6919 through its pulsations, we find two hard sources positionally coincident with plerion N 157B and supernova remnant N 132D, which were also detected at TeV energies with H.E.S.S. We detect an additional soft source that is currently unidentified. Extended emission dominates the total flux from the LMC. It consists of an extended component of about the size of the galaxy and additional emission from three to four regions with degree-scale sizes. If it is interpreted as CRs interacting with interstellar gas, the large-scale emission implies a large-scale population of approximately 1-100 GeV CRs with a density of approximately 30% of the local Galactic value. On top of that, the three to four small-scale emission regions would correspond to enhancements of the CR density by factors 2 to 6 or higher, possibly more energetic and younger populations of CRs compared to the large-scale population. An alternative explanation is that this is emission from an unresolved population of at least two dozen objects, such as pulsars and their nebulae or supernova remnants. This small-scale extended emission has a spatial distribution that does not clearly correlate with known components of the LMC, except for a possible relation to cavities and supergiant shells. Conclusions. The Fermi-LAT GeV observations allowed us to detect individual sources in the LMC. Three of the newly discovered sources are associated with rare and extreme objects. The 30 Doradus region is prominent in GeV gamma-rays because PSR J0540-6919 and N 157B are strong emitters. The extended emission from the galaxy has an unexpected spatial distribution, and observations at higher energies and in radio may help to clarify its origin.

  18. Deep view of the Large Magellanic Cloud with six years of Fermi -LAT observations

    DOE PAGES

    Ackermann, M.

    2016-01-27

    Context. The nearby Large Magellanic Cloud (LMC) provides a rare opportunity of a spatially resolved view of an external star-forming galaxy in -rays. The LMC was detected at 0.1–100 GeV as an extended source with CGRO/EGRET and using early observations with the Fermi-LAT. The emission was found to correlate with massive star-forming regions and to be particularly bright towards 30 Doradus. Aims. Studies of the origin and transport of cosmic rays (CRs) in the Milky Way are frequently hampered by line-of-sight confusion and poor distance determination. The LMC offers a complementary way to address these questions by revealing whether andmore » how the -ray emission is connected to specific objects, populations of objects, and structures in the galaxy. Methods. We revisited the -ray emission from the LMC using about 73 months of Fermi-LAT P7REP data in the 0.2–100 GeV range. We developed a complete spatial and spectral model of the LMC emission, for which we tested several approaches: a simple geometrical description, template-fitting, and a physically driven model for CR-induced interstellar emission. Results. In addition to identifying PSR J0540-6919 through its pulsations, we find two hard sources positionally coincident with plerion N 157B and supernova remnant N 132D, which were also detected at TeV energies with H.E.S.S. We detect an additional soft source that is currently unidentified. Extended emission dominates the total flux from the LMC. It consists of an extended component of about the size of the galaxy and additional emission from three to four regions with degree-scale sizes. If it is interpreted as CRs interacting with interstellar gas, the large-scale emission implies a large-scale population of ~1–100GeV CRs with a density of ~30% of the local Galactic value. On top of that, the three to four small-scale emission regions would correspond to enhancements of the CR density by factors 2 to 6 or higher, possibly more energetic and younger populations of CRs compared to the large-scale population. An alternative explanation is that this is emission from an unresolved population of at least two dozen objects, such as pulsars and their nebulae or supernova remnants. This small-scale extended emission has a spatial distribution that does not clearly correlate with known components of the LMC, except for a possible relation to cavities and supergiant shells. Conclusions. The Fermi-LAT GeV observations allowed us to detect individual sources in the LMC. Three of the newly discovered sources are associated with rare and extreme objects. The 30 Doradus region is prominent in GeV -rays because PSR J0540-6919 and N 157B are strong emitters. The extended emission from the galaxy has an unexpected spatial distribution, and observations at higher energies and in radio may help to clarify its origin. Key words. Gamma« less

  19. Hubble Solves Mystery on Source of Supernova in Nearby Galaxy

    NASA Image and Video Library

    2017-12-08

    NASA image release January 11, 2012 Using NASA's Hubble Space Telescope, astronomers have solved a longstanding mystery on the type of star, or so-called progenitor, that caused a supernova in a nearby galaxy. The finding yields new observational data for pinpointing one of several scenarios that could trigger such outbursts. Based on previous observations from ground-based telescopes, astronomers knew that a kind of supernova called a Type Ia created a remnant named SNR 0509-67.5, which lies 170,000 light-years away in the Large Magellanic Cloud galaxy. The type of system that leads to this kind of supernova explosion has long been a high importance problem with various proposed solutions but no decisive answer. All these solutions involve a white dwarf star that somehow increases in mass to the highest limit. Astronomers failed to find any companion star near the center of the remnant, and this rules out all but one solution, so the only remaining possibility is that this one Type Ia supernova came from a pair of white dwarfs in close orbit. To read more go to: www.nasa.gov/mission_pages/hubble/science/supernova-sourc... Image Credit: NASA, ESA, CXC, SAO, the Hubble Heritage Team (STScI/AURA), and J. Hughes (Rutgers University) NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  20. Hubble Space Telescope Image, Supernova Remnant Cassiopeia A

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The colorful streamers that float across the sky in this photo taken by NASA's Hubble Space Telescope (HST) were created by the universe's biggest firecracker, the titanic supernova explosion of a massive star. The light from the exploding star reached Earth 320 years ago, nearly a century before the United States celebrated its birth with a bang. The dead star's shredded remains are called Cassiopeia A, or 'Cas A' for short. Cas A is the youngest known supernova remnant in our Milky Way Galaxy and resides 10,000 light-years away in the constellation Cassiopeia, so the star actually blew up 10,000 years before the light reached Earth in the late 1600s. This HST image of Cas A shows for the first time that the debris is arranged into thousands of small, cooling knots of gas. This material eventually will be recycled into building new generations of stars and planets. Our own Sun and planets are constructed from the debris of supernovae that exploded billions of years ago. This photo shows the upper rim of the super nova remnant's expanding shell. Near the top of the image are dozens of tiny clumps of matter. Each small clump, originally just a small fragment of the star, is tens of times larger than the diameter of our solar system. The colors highlight parts of the debris where chemical elements are glowing. The dark blue fragments, for example, are richest in oxygen; the red material is rich in sulfur. The images were taken with the Wide Field and Planetary Camera 2 in January 2000 and January 2002. Image Credit: NASA and HST team (Stoics/AURA). Acknowledgment: R. Fesen (Darmouth) and J. Morse ( Univ. of Colorado).

  1. Maximum Energies of Shock-Accelerated Electrons in Young Shell Supernova Remnants

    NASA Technical Reports Server (NTRS)

    Reynolds, Stephen P.; Keohane, Jonathan W.; White, Nicholas E. (Technical Monitor)

    1999-01-01

    Young supernova remnants (SNRs) are often assumed to be the source of cosmic rays up to energies approaching the slight steepening in the cosmic ray spectrum at around 1000 TeV, known as the "knee." We show that the observed X-ray emission of 14 radio-bright shell remnants, including all five historical shells, can be used to put limits on E(sub max), the energy at which the electron energy distribution must steepen from its slope at radio-emitting energies. Most of the remnants show thermal spectra, so any synchrotron component must fall below the observed X-ray fluxes. We obtain upper limits on E(sub max) by considering the most rapid physically plausible cutoff in the relativistic electron distribution, an exponential, which is as sharp or sharper than found in any more elaborate models. This maximally curved model then gives us the highest possible E(sub max) consistent with not exceeding observed X-rays. Our results are thus independent of particular models for the electron spectrum in SNRs. Assuming homogeneous emitting volumes with a constant magnetic field strength of 10 uG, no object could reach 1000 TeV, and only one, Kes 73, has an upper limit on E(sub max), above 100 TeV. All the other remnants have limits at or below 80 TeV. E(sub max) is probably set by the finite remnant lifetime rather than by synchrotron losses for remnants younger than a few thousand years, so that an observed electron steepening should be accompanied by steepening at the same energy for protons. More complicated, inhomogeneous models could allow higher values of E(sub max) in parts of the remnant, but the emission-weighted average value, that characteristic of typical electrons, should obey these limits. The young remnants are not expected to improve much over their remaining lives at producing the highest energy Galactic cosmic rays; if they cannot, this picture of cosmic-ray origin may need major alteration.

  2. SN 1985f - Death of a Wolf-Rayet star

    NASA Technical Reports Server (NTRS)

    Begelman, M. C.; Sarazin, C. L.

    1986-01-01

    The optical spectrum of SN 1985f has been analyzed, and the supernova ejecta is shown to contain approximately 5 or more solar masses of oxygen and very little hydrogen. It is suggested that the explosion resulted from the pair instability supernova of a WO Wolf-Rayet star of about 50 solar masses, and that the optical luminosity of the supernova is powered by the radioactive decay of Co-56 synthesized in the explosion. As calculated from the rate of the optical emission decay, the explosion occurred about 350 days before its discovery in February, 1985. It is believed that some of the oxygen-rich supernova remnants may also have been produced by explosions of WO stars.

  3. INTERACTION BETWEEN THE SUPERNOVA REMNANT HB 3 AND THE NEARBY STAR-FORMING REGION W3

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

    Zhou, Xin; Yang, Ji; Fang, Min

    We performed millimeter observations of CO lines toward the supernova remnant (SNR) HB 3. Substantial molecular gas around −45 km s{sup −1} is detected in the conjunction region between the SNR HB 3 and the nearby W3 complex. This molecular gas is distributed along the radio continuum shell of the remnant. Furthermore, the shocked molecular gas indicated by line wing broadening features is also distributed along the radio shell and inside it. By both morphological correspondence and dynamical evidence, we confirm that the SNR HB 3 interacts with the −45 km s{sup −1} molecular cloud (MC), in essence, with the nearby H ii region/MC complexmore » W3. The redshifted line wing broadening features indicate that the remnant is located at the nearside of the MC. With this association, we could place the remnant at the same distance as the W3/W4 complex, which is 1.95 ± 0.04 kpc. The spatial distribution of aggregated young stellar object candidates shows a correlation with the shocked molecular strip associated with the remnant. We also find a binary clump of CO at ( l = 132.°94, b = 1.°12) around −51.5 km s{sup −1} inside the projected extent of the remnant, and it is associated with significant mid-infrared emission. The binary system also has a tail structure resembling the tidal tails of interacting galaxies. According to the analysis of CO emission lines, the larger clump in this binary system is about stable, and the smaller clump is significantly disturbed.« less

  4. XMM-Newton observation of the supernova remnant Kes 78 (G32.8-0.1): Evidence of shock-cloud interaction

    NASA Astrophysics Data System (ADS)

    Miceli, M.; Bamba, A.; Orlando, S.; Zhou, P.; Safi-Harb, S.; Chen, Y.; Bocchino, F.

    2017-03-01

    Context. The Galactic supernova remnant Kes 78 is surrounded by dense molecular clouds, whose projected position overlaps with the extended HESS γ-ray source HESS J1852-000. The X-ray emission from the remnant has recently been revealed by Suzaku observations, which have shown indications for a hard X-ray component in the spectra that might be associated with synchrotron radiation. Aims: We describe the spatial distribution of the physical properties of the X-ray emitting plasma and reveal the effects of the interaction of the remnant with the inhomogeneous ambient medium. We also investigate the origin of the γ-ray emission, which may be inverse-Compton radiation associated with X-ray synchrotron-emitting electrons or hadronic emission originating from the impact of high-energy protons on the nearby clouds. Methods: We analyzed an XMM-Newton EPIC observation of Kes 78 by performing image analysis and spatially resolved spectral analysis on a set of three regions. We tested our findings against the observations of the 12CO and 13CO emission in the environment of the remnant. Results: We reveal the complex X-ray morphology of Kes 78 and find variations in the spectral properties of the plasma, with significantly denser and cooler material at the eastern edge of the remnant, which we interpret as a signature of interaction with a molecular cloud. We also exclude that narrow filaments emit the X-ray synchrotron radiation. Conclusions: Assuming that the very high energy γ-ray emission is associated with Kes 78, the lack of synchrotron emission rules out a leptonic origin. A hadronic origin is further supported by evidence of interaction of the remnant with a dense molecular cloud in its eastern limb.

  5. Kinematics of the Galactic Supernova Remnant G109.1-1.0 (CTB 109)

    NASA Astrophysics Data System (ADS)

    Sánchez-Cruces, M.; Rosado, M.; Fuentes-Carrera, I.; Ambrocio-Cruz, P.

    2018-01-01

    We present direct images in the H α and [S II] λλ6717,6731 Å lines of the Galactic supernova remnant (SNR) G109.1-1.0 (CTB 109). We confirm that the filaments detected are the optical counterpart of the X-ray and radio SNR due to their high [S II]/H α line ratios. We study for the first time the kinematics of the optical counterpart of SNR CTB 109 using the Universidad Nacional Autónoma de México scanning Fabry-Perot interferometer PUMA. We estimate a systemic velocity of VLSR = -50 ± 6 km s-1 for this remnant and an expansion velocity of Vexp = 230 ± 5 km s-1. From this velocity and taking into account previous studies of the kinematics of objects at that Galactic longitude, we derive a distance to SNR CTB 109 of 3.1 ± 0.2 kpc, locating it in the Perseus arm. Using the [S II] λ6717/[S II] λ6731 line ratio, we find an electronic density value around ne = 580 cm-3. Considering that this remnant is evolving in a low-density medium with higher-density cloudlets responsible for the optical emission, we determine the age and energy deposited in the ISM by the supernova explosion (E0) in both the Sedov-Taylor phase and the radiative phase. For both cases, the age is thousands of years and E0 is rather typical of SNRs containing simple pulsars, so that the energy released to the ISM cannot be used to distinguish between SNRs hosting typical pulsars from those hosting powerful magnetars, like CTB 109.

  6. A speckle hologram of the interstellar plasma

    NASA Technical Reports Server (NTRS)

    Desai, K. M.; Gwinn, C. R.; Reynolds, J.; King, E. A.; Jauncey, D.; Flanagan, C.; Nicolson, G.; Preston, R. A.; Jones, D. L.

    1992-01-01

    Observations of a speckle hologram of scattering material along the line of sight to the Vela pulsar indicate that this material is concentrated in the Vela supernova remnant, deep within the Gum Nebula. The speckle hologram is observed through the amplitude and phase variations of the interferometric cross-power spectrum with time and frequency. These variations describe the density fluctuations of the interstellar plasma, in a holographic fashion. The decorrelation due to the phase variations of the speckles yields the angular size of the scattering disk; comparison with the bandwidth of their amplitude variations yields a characteristic distance from earth to the scattering material of 0.81 +/- 0.03 of the distance from earth to the pulsar. This result is consistent with theories of irregularities associated with particle acceleration in shocks in supernova remnants.

  7. Investigating the X-ray and Gamma-ray Properties of the Galactic Supernova Remnants Kes 69, 3C 396, 3C 400.2

    NASA Astrophysics Data System (ADS)

    Ergin, Tülün; Sezer, Aytap; Yamazaki, Ryo

    2016-06-01

    Kes 69, 3C 396, and 3C 400.2 are mixed-morphology (MM) Galactic supernova remnants (SNRs), where Kes 69 and 3C 396 are interacting with molecular clouds (MCs). Previous X-ray studies showed that the emission from these SNRs is thermal. It has been suggested that MM SNRs interacting with MCs are potential candidates for recombining plasma (RP) in X-rays and hadronic gamma-ray emission. Recently, Chandra observations revealed signs of RP in 3C 400.2. Our preliminary analyses show that the X-ray emission of NW and SE region of 3C 400.2 arises from recombining plasma. We detected GeV gamma-ray emission from Kes 69 and 3C 396 above 5σ

  8. Observation of Nonthermal Emission from the Supernova Remnant IC443 with RXTE

    NASA Technical Reports Server (NTRS)

    Sturner, S. J.; Keohane, J. W.; Reimer, O.

    2002-01-01

    In this paper we present analysis of X-ray spectra from the supernova remnant IC443 obtained using the PCA on RXTE. The spectra in the 3 - 20 keV band are well fit by a two-component model consisting of thermal and nonthermal components. We compare these results with recent results of other X-ray missions and discuss the need for a cut-off in the nonthermal spectrum. Recent Chandra and XMM-Newton observations suggest that much of the nonthermal emission from IC443 can be attributed to a pulsar wind nebula. We present the results of our search for periodic emission in the RXTE PCA data. We then discuss the origin o f the nonthermal component and its possible association with the unidentified EGRET source.

  9. SN1987A: The Birth of a Supernova Remnant

    NASA Technical Reports Server (NTRS)

    McCray, Richard

    2003-01-01

    This grant was intended to support the development of theoretical models needed to interpret and understand the observations by the Hubble Space Telescope and the Chandra X-ray telescope of the rapidly developing remnant of Supernova 1987A. In addition, we carried out a few investigations of related topics. The project was spectacularly successful. The models that we developed provide the definitive framework for predicting and interpreting this phenomenon. Following is a list of publications based on our work. Some of these papers include results of both theoretical modeling supported by this project and also analysis of data supported by the Space Telescope Science Institute and the Chandra X-ray Observatory. We first list papers published in refereed journals, then conference proceedings and book chapters, and also an educational web site.

  10. Rossi X-Ray Timing Explorer All-Sky Monitor Localization of SGR 1627-41

    NASA Astrophysics Data System (ADS)

    Smith, Donald A.; Bradt, Hale V.; Levine, Alan M.

    1999-07-01

    The fourth unambiguously identified soft gamma repeater (SGR), SGR 1627-41, was discovered with the BATSE instrument on 1998 June 15. Interplanetary Network (IPN) measurements and BATSE data constrained the location of this new SGR to a 6° segment of a narrow (19") annulus. We present two bursts from this source observed by the All-Sky Monitor (ASM) on the Rossi X-Ray Timing Explorer. We use the ASM data to further constrain the source location to a 5' long segment of the BATSE/IPN error box. The ASM/IPN error box lies within 0.3 arcmin of the supernova remnant G337.0-0.1. The probability that a supernova remnant would fall so close to the error box purely by chance is ~5%.

  11. Detection of 16 Gamma-Ray Pulsars Through Blind Frequency Searches Using the Fermi LAT

    DOE PAGES

    Abdo, A. A.; Ackermann, M.; Ajello, M.; ...

    2009-07-02

    Pulsars are rapidly rotating, highly magnetized neutron stars emitting radiation across the electromagnetic spectrum. Although there are more than 1800 known radio pulsars, until recently only seven were observed to pulse in gamma rays, and these were all discovered at other wavelengths. The Fermi Large Area Telescope (LAT) makes it possible to pinpoint neutron stars through their gamma-ray pulsations. In this paper, we report the detection of 16 gamma-ray pulsars in blind frequency searches using the LAT. Most of these pulsars are coincident with previously unidentified gamma-ray sources, and many are associated with supernova remnants. Finally, direct detection of gamma-raymore » pulsars enables studies of emission mechanisms, population statistics, and the energetics of pulsar wind nebulae and supernova remnants.« less

  12. GeV-gamma-ray emission regions

    NASA Image and Video Library

    2017-12-08

    NASA's Fermi Closes on Source of Cosmic Rays New images from NASA's Fermi Gamma-ray Space Telescope show where supernova remnants emit radiation a billion times more energetic than visible light. The images bring astronomers a step closer to understanding the source of some of the universe's most energetic particles -- cosmic rays. Fermi mapped GeV-gamma-ray emission regions (magenta) in the W44 supernova remnant. The features clearly align with filaments detectable in other wavelengths. This composite merges X-rays (blue) from the Germany-led ROSAT mission, infrared (red) from NASA's Spitzer Space Telescope, and radio (orange) from the Very Large Array near Socorro, N.M. Credit: NASA/DOE/Fermi LAT Collaboration, ROSAT, JPL-Caltech, and NRAO/AUI For more information: www.nasa.gov/mission_pages/GLAST/news/cosmic-rays-source....

  13. 1051 Ergs: The Evolution of Shell Supernova Remnants

    DTIC Science & Technology

    1997-11-15

    progress in these matters . For convenience, and also to avoid conventional labels (e.g., “Sedov”), most of the workshop was organized around chron...setting the stage,” so that many preliminary matters had been resolved or focused. The web site continues to be acces- sible for review of the...acting with circumstellar matter (Chevalier 1982b). The inter- action between the supernova ejecta and circumstellar matter generates a double-shock

  14. A Chandrasekhar mass progenitor for the Type Ia supernova remnant 3C 397 from the enhanced abundances of nickel and manganese

    DOE PAGES

    Yamaguchi, Hiroya; Badenes, Carles; Foster, Adam R.; ...

    2015-03-12

    Despite decades of intense efforts, many fundamental aspects of Type Ia supernovae (SNe Ia) remain elusive. One of the major open questions is whether the mass of an exploding white dwarf (WD) is close to the Chandrasekhar limit. Here, we report the detection of strong K-shell emission from stable Fe-peak elements in the Suzaku X-ray spectrum of the Type Ia supernova remnant (SNR) 3C 397. The high Ni/Fe and Mn/Fe mass ratios (0.11–0.24 and 0.018–0.033, respectively) in the hot plasma component that dominates the K-shell emission lines indicate a degree of neutronization in the supernova ejecta that can only bemore » achieved by electron capture in the dense cores of exploding WDs with a near-Chandrasekhar mass. This suggests a single-degenerate origin for 3C 397, since Chandrasekhar mass progenitors are expected naturally if the WD accretes mass slowly from a companion. Altogether with other results supporting the double-degenerate scenario, our work adds to the mounting evidence that both progenitor channels make a significant contribution to the SN Ia rate in star-forming galaxies.« less

  15. Interstellar Lithium and Rubidium in the Diffuse Gas Near IC 443

    NASA Astrophysics Data System (ADS)

    Ritchey, Adam M.; Taylor, C. J.; Federman, S. R.; Lambert, D. L.

    2011-01-01

    We present an analysis of interstellar lithium and rubidium from observations made with the Hobby-Eberly Telescope at McDonald Observatory of the Li I λ6707 and Rb I λ7800 absorption lines along four lines of sight through the supernova remnant IC 443. The observations probe interstellar material polluted by the ejecta of a core-collapse (Type II) supernova and can thus be used to constrain the contribution from massive stars to the synthesis of lithium and rubidium. Production of 7Li is expected to occur through neutrino spallation in the helium and carbon shells of the progenitor star during the terminal supernova explosion, while both 6Li and 7Li are synthesized via spallation and fusion reactions involving cosmic rays accelerated by the remnant. Gamma-ray emission from IC 443 provides strong evidence for the interaction of accelerated cosmic rays with the ambient atomic and molecular gas. Rubidium is also produced by massive stars through the weak s-process in the He- and C-burning shells and the r-process during core collapse. We examine interstellar 7Li/6Li isotope ratios as well as Li/K and Rb/K ratios along each line of sight, and discuss the implications of our results in the context of nucleosynthesis associated with Type II supernovae.

  16. Deep Radio Imaging with MERLIN of the Supernova Remnants in M82

    NASA Astrophysics Data System (ADS)

    Muxlow, T. W. B.; Pedlar, A.; Riley, J. D.; McDonald, A. R.; Beswick, R. J.; Wills, K. A.

    An 8 day MERLIN deep integration at 5GHz of the central region of the starburst galaxy M82 has been used to investigate the radio structure of a number of supernova remnants in unprecedented detail revealing new shells and partial shell structures for the first time. In addition, by comparing the new deep 2002 image with an astrometrically aligned image from 36 hours of data taken in 1992, it has been possible to directly measure the expansion velocities of 4 of the most compact remnants in M82. For the two most compact remnants, 41.95+575 and 43.31+592, expansion velocities of 2800 ± 300 km s-1 and 8750 ± 400 km s-1 have been derived. These confirm and refine the measured expansion velocities which have been derived from VLBI multi-epoch studies. For remnants 43.18+583 and 44.01+596, expansion velocities of 10500 ± 750 km s -1 and 2400 ± 250 km s-1 have been measured for the first time. In addition, the peak of the radio emission for SNR 45.17+612 has moved between the two epochs implying velocities around 7500km s-1. The relatively compact remnants in M82 are thus found to be expanding over a wide range of velocities which appear unrelated to their size. The new 2002 map is the most sensitive high-resolution image yet made of M82, achieving an rms noise level of 17µJy beam-1. This establishes a first epoch for subsequent deep studies of expansion velocities for many SNR within M82.

  17. Morphological and spectral properties of the W51 region measured with the MAGIC telescopes

    NASA Astrophysics Data System (ADS)

    Aleksić, J.; Alvarez, E. A.; Antonelli, L. A.; Antoranz, P.; Asensio, M.; Backes, M.; Barres de Almeida, U.; Barrio, J. A.; Bastieri, D.; Becerra González, J.; Bednarek, W.; Berger, K.; Bernardini, E.; Biland, A.; Blanch, O.; Bock, R. K.; Boller, A.; Bonnoli, G.; Borla Tridon, D.; Bretz, T.; Cañellas, A.; Carmona, E.; Carosi, A.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Cossio, L.; Covino, S.; Da Vela, P.; Dazzi, F.; De Angelis, A.; De Caneva, G.; De Cea del Pozo, E.; De Lotto, B.; Delgado Mendez, C.; Diago Ortega, A.; Doert, M.; Domínguez, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Eisenacher, D.; Elsaesser, D.; Ferenc, D.; Fonseca, M. V.; Font, L.; Fruck, C.; García López, R. J.; Garczarczyk, M.; Garrido, D.; Giavitto, G.; Godinović, N.; González Muñoz, A.; Gozzini, S. R.; Hadasch, D.; Häfner, D.; Herrero, A.; Hildebrand, D.; Hose, J.; Hrupec, D.; Huber, B.; Jankowski, F.; Jogler, T.; Kadenius, V.; Kellermann, H.; Klepser, S.; Krähenbühl, T.; Krause, J.; La Barbera, A.; Lelas, D.; Leonardo, E.; Lewandowska, N.; Lindfors, E.; Lombardi, S.; López, M.; López-Coto, R.; López-Oramas, A.; Lorenz, E.; Makariev, M.; Maneva, G.; Mankuzhiyil, N.; Mannheim, K.; Maraschi, L.; Mariotti, M.; Martínez, M.; Mazin, D.; Meucci, M.; Miranda, J. M.; Mirzoyan, R.; Moldón, J.; Moralejo, A.; Munar-Adrover, P.; Niedzwiecki, A.; Nieto, D.; Nilsson, K.; Nowak, N.; Orito, R.; Paiano, S.; Paneque, D.; Paoletti, R.; Pardo, S.; Paredes, J. M.; Partini, S.; Perez-Torres, M. A.; Persic, M.; Pilia, M.; Pochon, J.; Prada, F.; Prada Moroni, P. G.; Prandini, E.; Puerto Gimenez, I.; Puljak, I.; Reichardt, I.; Reinthal, R.; Rhode, W.; Ribó, M.; Rico, J.; Rügamer, S.; Saggion, A.; Saito, K.; Saito, T. Y.; Salvati, M.; Satalecka, K.; Scalzotto, V.; Scapin, V.; Schultz, C.; Schweizer, T.; Shore, S. N.; Sillanpää, A.; Sitarek, J.; Snidaric, I.; Sobczynska, D.; Spanier, F.; Spiro, S.; Stamatescu, V.; Stamerra, A.; Steinke, B.; Storz, J.; Strah, N.; Sun, S.; Surić, T.; Takalo, L.; Takami, H.; Tavecchio, F.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Tibolla, O.; Torres, D. F.; Treves, A.; Uellenbeck, M.; Vogler, P.; Wagner, R. M.; Weitzel, Q.; Zabalza, V.; Zandanel, F.; Zanin, R.

    2012-05-01

    Context. The W51 complex hosts the supernova remnant W51C which is known to interact with the molecular clouds in the star forming region W51B. In addition, a possible pulsar wind nebula CXO J192318.5+140305 was found likely associated with the supernova remnant. Gamma-ray emission from this region was discovered by Fermi/LAT (between 0.2 and 50 GeV) and H.E.S.S. (>1 TeV). The spatial distribution of the events could not be used to pinpoint the location of the emission among the pulsar wind nebula, the supernova remnant shell and/or the molecular cloud. However, the modeling of the spectral energy distribution presented by the Fermi/LAT collaboration suggests a hadronic emission mechanism. The possibility that the gamma-ray emission from such an object is of hadronic origin can contribute to solvingthe long-standing problem of the contribution to galactic cosmic rays by supernova remnants. Aims: Our aim is to determine the morphology of the very-high-energy gamma-ray emission of W51 and measure its spectral properties. Methods: We performed observations of the W51 complex with the MAGIC telescopes for more than 50 h. The energy range accessible with MAGIC extends from 50 GeV to several TeV, allowing for the first spectral measurement at these energies. In addition, the good angular resolution in the medium (few hundred GeV) to high (above 1 TeV) energies allow us to perform morphological studies. We look for underlying structures by means of detailed morphological studies. Multi-wavelength data from this source have been sampled to model the emission with both leptonic and hadronic processes. Results: We detect an extended emission of very-high-energy gamma rays, with a significance of 11 standard deviations. We extend the spectrum from the highest Fermi/LAT energies to ~5 TeV and find that it follows a single power law with an index of 2.58 ± 0.07stat ± 0.22syst. The main part of the emission coincides with the shocked cloud region, while we find a feature extending towards the pulsar wind nebula. The possible contribution of the pulsar wind nebula, assuming a point-like source, shows no dependence on energy and it is about 20% of the overall emission. The broad band spectral energy distribution can be explained with a hadronic model that implies proton acceleration above 100 TeV. This result, together with the morphology of the source, tentatively suggests that we observe ongoing acceleration of ions in the interaction zone between supernova remnant and cloud.

  18. Cosmic Ray Production in Supernovae

    NASA Astrophysics Data System (ADS)

    Bykov, A. M.; Ellison, D. C.; Marcowith, A.; Osipov, S. M.

    2018-02-01

    We give a brief review of the origin and acceleration of cosmic rays (CRs), emphasizing the production of CRs at different stages of supernova evolution by the first-order Fermi shock acceleration mechanism. We suggest that supernovae with trans-relativistic outflows, despite being rather rare, may accelerate CRs to energies above 10^{18} eV over the first year of their evolution. Supernovae in young compact clusters of massive stars, and interaction powered superluminous supernovae, may accelerate CRs well above the PeV regime. We discuss the acceleration of the bulk of the galactic CRs in isolated supernova remnants and re-acceleration of escaped CRs by the multiple shocks present in superbubbles produced by associations of OB stars. The effects of magnetic field amplification by CR driven instabilities, as well as superdiffusive CR transport, are discussed for nonthermal radiation produced by nonlinear shocks of all speeds including trans-relativistic ones.

  19. Cassiopeia A Comes Alive Across Time and Space

    NASA Astrophysics Data System (ADS)

    2009-01-01

    Two new efforts have taken a famous supernova remnant from the static to the dynamic. A new movie of data from NASA's Chandra X-ray Observatory shows changes in time never seen before in this type of object. And, an unprecedented and dramatic three-dimensional visualization of the same remnant by a separate team is being released. Nearly ten years ago, Chandra's "First Light" image of Cassiopeia A (Cas A) revealed previously unseen structures and detail. Now, after eight years of observation, scientists have been able to construct a movie that tracks the remnant's expansion and changes over time. "With Chandra, we have watched Cas A over a relatively small amount of its life, but so far the show has been amazing," said Daniel Patnaude of the Smithsonian Astrophysical Observatory in Cambridge, Mass. "And, we can use this to learn more about the aftermath of the star's explosion." A separate, but equally fascinating visualization featuring Cas A was presented, along with the Patnaude team's results, at a press conference at the American Astronomical Society meeting in Long Beach, Calif. Based on data from Chandra, NASA's Spitzer Space Telescope, and ground-based optical telescopes, Tracey Delaney and her colleagues have created the first threedimensional fly-through of a supernova remnant. Cas A animation Brief Time-lapse Movie of Cassiopeia A "We have always wanted to know how the pieces we see in two dimensions fit together with each other in real life," said Delaney of the Massachusetts Institute of Technology. "Now we can see for ourselves with this 'hologram' of supernova debris." This ground-breaking visualization of Cas A was made possible through a collaboration with the Astronomical Medicine project based at Harvard. The goal of this project is to bring together the best techniques from two very different fields, astronomy and medical imaging. "Right now, we are focusing on improving three-dimensional visualization in both astronomy and medicine,"said Harvard's Alyssa Goodman who heads the Astronomical Medicine project. "This project with Cas A is exactly what we have hoped would come out of it." People Who Read This Also Read... Ghost Remains After Black Hole Eruption Galaxies Coming of Age in Cosmic Blobs A New Way To Weigh Giant Black Holes NASA Announces 2009 Astronomy and Astrophysics Fellows While these are stunning visuals, both the data movie from Patnaude and the 3-D model from Delaney are, more importantly, rich resources for science. The two teams are trying to get a much more complete understanding of how this famous supernova explosion and its remnant work. Patnaude and his team have measured the expansion velocity of features in Cas A from motions in the movie, and find it is slower than expected based on current theoretical models. Patnaude thinks the explanation for this mysterious loss of energy is cosmic ray acceleration. Using estimates of the properties of the supernova explosion, including its energy and dynamics, Patnaude's group show that about 30% of the energy in this supernova has gone into accelerating cosmic rays, energetic particles that are generated, in part, by supernova remnants and constantly bombard the Earth's atmosphere. The flickering in the movie provides valuable new information about where the acceleration of these particles occurs. Likewise, the new 3-D model of Cas A provides researchers with unique ability to study this remnant. With this new tool, Delaney and colleagues found two components to the explosion, a spherical component from the outer layers of the star and a flattened component from the inner layers of the star. Cas A animation 3-D Visualization of Cassiopeia A Notable features of the model are high-velocity plumes from this internal material that are shooting out from the explosion. Plumes, or jets, of silicon appear in the northeast and southwest, while plumes of iron are seen in the southeast and north. Astronomers had known about the plumes and jets before, but did not know that they all came out in a broad, disk-like structure. The implication of this work is that astronomers who build models of supernova explosions must now consider that the outer layers of the star come off spherically, but the inner layers come out more disk like with high-velocity jets in multiple directions. Cassiopeia A is the remains of a star thought to have exploded about 330 years ago, and is one of the youngest remnants in the Milky Way galaxy. The study of Cas A and remnants like it help astronomers better understand how the explosions that generate them seed interstellar gas with heavy elements, heat it with the energy of their radiation, and trigger blast waves from which new stars form. Larry Rudnick, from the University of Minnesota, led the Spitzer part of the Delaney study. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass.

  20. Supernova Remnants As Laboratories For Determining The Properties Of Ejecta Dust And The Processing Of Dust Grains In Shocks

    NASA Astrophysics Data System (ADS)

    Dwek, Eli; Temim, Tea

    Recent infrared satellites, such as the Spitzer, Herschel, and WISE, have obtained a wealth of spectral and broadband data on the infrared (IR) emission from dust in supernova remnants (SNRs). Supernovae (SNe) are important producers of newly condensed dust during the early free-expansion phase of their evolution, and the dominant destroyers of dust during the subsequent remnant phase of their evolution. The infrared observations hold the key for determining their role in the origin and evolution of dust in the universe. We propose to model the composition, abundance, and size distribution of the dust in select Galactic and Magellanic Cloud remnants. As explained in detail below, the remnants were selected for the availability of IR and X-ray observations. All selected remnants have Spitzer IRS spectral data in the 5-35 μm regions which allow us to determine the effect of grain processing in the shock. Some have spectral maps that allow the distinction between the IR emission from SN-condensed and swept up circumstellar and interstellar dust. All remnants have also been covered by Spitzer, Herschel, and WISE imaging, and have existing X-ray Chandra and/or XMM observations. The dust in some remnants is radiatively-heated by a pulsar wind nebula, and in others collisionally- heated by shocked X-ray or line emitting gas. We will use physical models to calculate the radiative and collisional heating of SNR dust, the equilibrium or fluctuating dust temperatures, and the resulting IR emission for various dust compositions and size distributions. Specific examples of Cas A, SN1987A, the Crab Nebula, and Puppis A, are discussed in detail to illustrate our modeling approach. Our study will be the first comprehensive and physical analysis of a large sample of SNRs in different evolutionary states and different astrophysical environments. They will cover a wide range of interactions between the dust grains and their surroundings, including the radioactively- powered and/or shocked SN ejecta, hard X-rays and EUV radiation fields, and shocked circumstel- lar/interstellar gas. Our study will shed light on the evolution of dust grains from their explosive formation sites, through their violent injection into the ISM, and ultimate demise or survival as they travel through a network of interstellar shock waves. It will constitute a major advance in our understanding of the origin and evolution of dust in the Milky Way, in galaxies in general, and especially in the early universe.

  1. Supernova remnants in the GC region

    NASA Astrophysics Data System (ADS)

    Asvarov, Abdul

    2016-07-01

    Along with the central Black hole the processes of active star formation play very important role in the energetics of the Galactic center region. The SNe and their remnants (SNRs) are the main ingredients of the processes of star formation. SNRs are also the sources of electromagnetic radiation of all wavelengths from the optical to hard gamma rays. In the presented work we consider the physics of supernova remnants evolving in extreme environmental conditions which are typical for the region of the Galactic center. Because of the high density and strong inhomogeneity of the surrounding medium these objects remain practically invisible at almost all wavelengths. We model evolution of SNR taking into account the pressure of the surrounding medium and the gravitational field of the matter (stars, compact clouds, dark matter) inside the remnant. As it is well established, considerable portion of the kinetic energy of the SNR can be converted into the cosmic ray particles by diffusive shock acceleration mechanism. Therefore the effect of particle acceleration is also included in the model (with the effectiveness of acceleration as a free parameter). Using the observed radiation fluxes at different wavelengths we attempt to obtain limits on the parameters of the model of the Galactic Center, namely, the frequency of star birth, the average density of the matter and radiation field, etc.

  2. ASCA Observations of LMC SNRS

    NASA Technical Reports Server (NTRS)

    Hughes, John P.

    1999-01-01

    We present our first results from a study of the supernova remnants (SNRs) in the Large Magellanic Cloud (LMC) using data from ASCA. The three remnants we have analyzed to date, 0509-67.5, 0519-69.0, and N103B, are among the smallest, and presumably also the youngest, in the Cloud. The X-ray spectra of these SNRs show strong K(alpha) emission lines of silicon, sulfur, argon, and calcium with no evidence for corresponding lines of oxygen, neon, or magnesium. The dominant feature in the spectra is a broad blend of emission lines around 1 keV which we attribute to L-shell emission lines of iron. Model calculations (Nomoto, Thielemann, & Yokoi 1984) show that the major products of nucleosynthesis in Type Ia supernovae (SNs) are the elements from silicon to iron, as observed here. The calculated nucleosynthetic yields from Type Ib and II SNs are shown to be qualitatively inconsistent with the data. We conclude that the SNs which produced these remnants were of Type Ia. This finding also confirms earlier suggestions that the class of Balmer-dominated remnants arise from Type Ia SN explosions. Based an these early results from the LMC SNR sample, we find that roughly one-half of the SNRs produced in the LMC within the last approximately 1500 yr came from Type Ia SNs.

  3. A Chandra X-Ray Survey of Ejecta in the Cassiopeia A Supernova Remnant

    NASA Technical Reports Server (NTRS)

    Hwang, Una; Laming, J. Martin

    2011-01-01

    We present a survey of the X-ray emitting ejecta in the Cassiopeia A supernova remnant based on an extensive analysis of over 6000 spectral regions extracted on 2.5-10" angular scales using the Chandra 1 Ms observation. We interpret these results in the context of hydrodynamical models for the evolution of the remnant. The distributions of fitted temperature and ionization age are highly peaked and suggest that the ejecta were subjected to multiple secondary shocks. Based on the fitted emission measure and element abundances, and an estimate of the emitting volume, we derive masses for the X-ray emitting ejecta as well as showing the distribution of the mass of various elements over the remnant. The total shocked Fe mass appears to be roughly 0.14 Solar Mass, which accounts for nearly all of the mass expected in Fe ejecta. We find two populations of Fe ejecta, that associated with normal Si-burning and that associated with alpha-rich freeze-out, with a mass ratio of approximately 2:1. Surprisingly, essentially all of this Fe (both components) is well outside the central regions of the SNR, presumably having been ejected by hydrodynamic instabilities during the explosion. We discuss this, and its implications for the neutron star kick.

  4. SUPERNOVAE, NEUTRON STARS, AND TWO KINDS OF NEUTRINO

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

    Chiu, H.Y.

    1962-08-15

    The role of neutrinos in the core of a star that has undergone a supernova explosion is discussed. The existence of neutron stars, the Schwarzchild singularity in general relativity, and the meaning of conservation of baryons in the neighborhood of a Schwarzchild singularity are also considered. The problem of detection of neutron stars is discussed. It is concluded that neutron stars are the most plausible alternative for the remnant of the core of a supernova. The neutrino emission processes are divided into two groups: the neutrino associated with the meson (mu) and the production of electron neutrinos. (C.E.S.)

  5. No hot and luminous progenitor for Tycho's supernova

    NASA Astrophysics Data System (ADS)

    Woods, T. E.; Ghavamian, P.; Badenes, C.; Gilfanov, M.

    2017-11-01

    Type Ia supernovae have proven vital to our understanding of cosmology, both as standard candles and for their role in galactic chemical evolution; however, their origin remains uncertain. The canonical accretion model implies a hot and luminous progenitor that would ionize the surrounding gas out to a radius of 10-100 pc for 100,000 years after the explosion. Here, we report stringent upper limits on the temperature and luminosity of the progenitor of Tycho's supernova (SN 1572), determined using the remnant itself as a probe of its environment. Hot, luminous progenitors that would have produced a greater hydrogen ionization fraction than that measured at the radius of the present remnant ( 3 pc) can thus be excluded. This conclusively rules out steadily nuclear-burning white dwarfs (supersoft X-ray sources), as well as disk emission from a Chandrasekhar-mass white dwarf accreting approximately greater than 10-8 M⊙ yr-1 (recurrent novae; M⊙ is equal to one solar mass). The lack of a surrounding Strömgren sphere is consistent with the merger of a double white dwarf binary, although other more exotic scenarios may be possible.

  6. Acceleration of cosmic rays in supernova-remnants

    NASA Technical Reports Server (NTRS)

    Dorfi, E. A.; Drury, L. O.

    1985-01-01

    It is commonly accepted that supernova-explosions are the dominant source of cosmic rays up to an energy of 10 to the 14th power eV/nucleon. Moreover, these high energy particles provide a major contribution to the energy density of the interstellar medium (ISM) and should therefore be included in calculations of interstellar dynamic phenomena. For the following the first order Fermi mechanism in shock waves are considered to be the main acceleration mechanism. The influence of this process is twofold; first, if the process is efficient (and in fact this is the cas) it will modify the dynamics and evolution of a supernova-remnant (SNR), and secondly, the existence of a significant high energy component changes the overall picture of the ISM. The complexity of the underlying physics prevented detailed investigations of the full non-linear selfconsistent problem. For example, in the context of the energy balance of the ISM it has not been investigated how much energy of a SN-explosion can be transfered to cosmic rays in a time-dependent selfconsistent model. Nevertheless, a lot of progress was made on many aspects of the acceleration mechanism.

  7. X-ray observations of the supernova remnant MSH 11-54

    NASA Technical Reports Server (NTRS)

    Agrawal, P. C.; Riegler, G. R.

    1980-01-01

    Soft X-ray observations of the X-ray source H1122-59 in the 0.4-2 keV band made with the low-energy detector 1 of the HEAO A-2 experiment are described. Based on positional coincidence, the source is identified with the supernova remnant MSH-11-54, thus confirming the report of Share et al. (1980). The object is a bright source in the 0.4-2 keV band with an X-ray flux of 9 x 10 to the -11th ergs/sq cm s near the earth. The measured source spectrum implies a plasma temperature of 4 million K and X-ray luminosity in the 0.4-2 keV band of 10 to the 37th ergs/s using a distance of 10 kpc for MSH 11-54. The X-ray observations, interpreted in terms of an adiabatic shock wave model, give a shock velocity of about 560 km/s and a supernova age of about 2300 yr, in good agreement with the age derived from the radio observations.

  8. Spitzer Observations of Dust Destruction in the Puppis A Supernova Remnant

    NASA Technical Reports Server (NTRS)

    Arendt, Richard G.; Dweek, Eli; Blair, William P.; Ghavamian, Parviz; Hwang, Una; Long, Knox X.; Petre, Robert; Rho, Jeonghee; Winkler, P. Frank

    2010-01-01

    The interaction of the Puppis A supernova remnant (SNR) with a neighboring molecular cloud provides a unique opportunity to measure the amount of grain destruction in an SNR shock. Spitzer Space Telescope MIPS imaging of the entire SNR at 24, 70, and 160 micrometers shows an extremely good correlation with X-ray emission, indicating that the SNR's IR radiation is dominated by the thermal emission of swept-up interstellar dust, collisionally heated by the hot shocked gas. Spitzer IRS spectral observations targeted both the Bright Eastern Knot (BEK) of the SNR where a small cloud has been engulfed by the supernova blast wave and outlying portions of the associated molecular cloud that are yet to be hit by the shock front. Modeling the spectra from both regions reveals the composition and the grain size distribution of the interstellar dust, both in front of and behind the SNR shock front. The comparison shows that the ubiquitous polycyclic aromatic hydrocarbons of the interstellar medium are destroyed within the BEK, along with nearly 25% of the mass of graphite and silicate dust grains.

  9. Cassiopeia A supernova

    NASA Image and Video Library

    2017-12-08

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

  10. Discovery of X-Ray-Emitting O-Ne-Mg-Rich Ejecta in the Galactic Supernova Remnant Puppis A

    NASA Technical Reports Server (NTRS)

    Katsuda, Satoru; Hwang, Una; Petre, Robert; Park, Sangwook; Mori, Koji; Tsunemi, Hiroshi

    2010-01-01

    We report on the discovery of X-ray-emitting O-Ne-Mg-rich ejecta in the middle-aged Galactic O-rich supernova remnant Puppis A with Chandra and XMM-Newton. We use line ratios to identify a low-ionization filament running parallel to the northeastern edge of the remnant that requires super-solar abundances, particularly for O, Ne, and Mg, which we interpret to be from O-Ne-Mg-rich ejecta. Abundance ratios of Ne/O, Mg/O, and Fe/O are measured to be [approx]2, [approx]2, and <0.3 times the solar values. Our spatially resolved spectral analysis from the northeastern rim to the western rim otherwise reveals sub-solar abundances consistent with those in the interstellar medium. The filament is coincident with several optically emitting O-rich knots with high velocities. If these are physically related, the filament would be a peculiar fragment of ejecta. On the other hand, the morphology of the filament suggests that it may trace ejecta heated by a shock reflected strongly off the dense ambient clouds near the northeastern rim.

  11. Supernova VLBI

    NASA Astrophysics Data System (ADS)

    Bartel, N.

    2009-08-01

    We review VLBI observations of supernovae over the last quarter century and discuss the prospect of imaging future supernovae with space VLBI in the context of VSOP-2. From thousands of discovered supernovae, most of them at cosmological distances, ˜50 have been detected at radio wavelengths, most of them in relatively nearby galaxies. All of the radio supernovae are Type II or Ib/c, which originate from the explosion of massive progenitor stars. Of these, 12 were observed with VLBI and four of them, SN 1979C, SN 1986J, SN 1993J, and SN 1987A, could be imaged in detail, the former three with VLBI. In addition, supernovae or young supernova remnants were discovered at radio wavelengths in highly dust-obscured galaxies, such as M82, Arp 299, and Arp 220, and some of them could also be imaged in detail. Four of the supernovae so far observed were sufficiently bright to be detectable with VSOP-2. With VSOP-2 the expansion of supernovae can be monitored and investigated with unsurpassed angular resolution, starting as early as the time of the supernova's transition from its opaque to transparent stage. Such studies can reveal, in a movie, the aftermath of a supernova explosion shortly after shock break out.

  12. Three Great Eyes on Kepler Supernova Remnant

    NASA Image and Video Library

    2004-10-06

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

  13. Spectroscopic mapping of the physical properties of supernova remnant N 49

    NASA Astrophysics Data System (ADS)

    Pauletti, D.; Copetti, M. V. F.

    2016-10-01

    Context. Physical conditions inside a supernova remnant can vary significantly between different positions. However, typical observational data of supernova remnants are integrated data or contemplate specific portions of the remnant. Aims: We study the spatial variation in the physical properties of the N 49 supernova remnant based on a spectroscopic mapping of the whole nebula. Methods: Long-slit spectra were obtained with the slit (~4' × 1.03″) aligned along the east-west direction from 29 different positions spaced by 2″ in declination. A total of 3248 1D spectra were extracted from sections of 2″ of the 2D spectra. More than 60 emission lines in the range 3550 Å to 8920 Å were measured in these spectra. Maps of the fluxes and of intensity ratios of these emission lines were built with a spatial resolution of 2″ × 2″. Results: An electron density map has been obtained using the [S II] λ6716 /λ6731 line ratio. Values vary from ~500 cm-3 at the northeast region to more than 3500 cm-3 at the southeast border. We calculated the electron temperature using line ratio sensors for the ions S+, O++, O+, and N+. Values are about 3.6 × 104 K for the O++ sensor and about 1.1 × 104 K for other sensors. The Hα/Hβ ratio map presents a ring structure with higher values that may result from collisional excitation of hydrogen. We detected an area with high values of [N II] λ6583/Hα extending from the remnant center to its northeastern border, which may be indicating an overabundance of nitrogen in the area due to contamination by the progenitor star. We found a radial dependence in many line intensity ratio maps. We observed an increase toward the remnant borders of the intensity ratio of any two lines in which the numerator comes before in the sequence [O III] λ5007, [O III] λ4363, [Ar III] λ7136, [Ne III] λ3869, [O II] λ7325, [O II] λ3727, He II λ4686, Hβ λ4861, [N II] λ6583, He I λ6678, [S II] λ6731, [S II] λ6716, [O I] λ6300, [Ca II] λ7291, Ca II λ3934, and [N I] λ5199. Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia, e Inovação (MCTI) da República Federativa do Brasil, the US National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU).Maps as FITS files are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/595/A10

  14. The Fermi Gamma-Ray Space Telescope, Exploding Stars, Neutron Stars, and Black Holes

    NASA Technical Reports Server (NTRS)

    Thompson, David J.

    2010-01-01

    Since August, 2008, the Fermi Gamma-ray Space Telescope has been scanning the sky, producing a full-sky image every three hours. These cosmic gamma-rays come from extreme astrophysical phenomena, many related to exploding stars (supernovae) or what these explosions leave behind: supernova remnants, neutron stars, and black holes. This talk uses sample Fermi results, plus simple demonstrations, to illustrate the exotic properties of these endpoints of stellar evolution.

  15. SHADOWS OF OUR FORMER COMPANIONS: HOW THE SINGLE-DEGENERATE BINARY TYPE IA SUPERNOVA SCENARIO AFFECTS REMNANTS

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

    Gray, William J.; Raskin, Cody; Owen, J. Michael

    2016-12-10

    Here we present three-dimensional high-resolution simulations of Type Ia supernova in the presence of a non-degenerate companion. We find that the presence of a nearby companion leaves a long-lived hole in the supernova ejecta. In particular, we aim to study the long-term evolution of this hole as the supernova ejecta interacts with the surrounding interstellar medium (ISM). Using estimates for the X-ray emission, we find that the hole generated by the companion remains for many centuries after the interaction between the ejecta and the ISM. We also show that the hole is discernible over a wide range of viewing anglesmore » and companion masses.« less

  16. Dance of the Light Echoes

    NASA Technical Reports Server (NTRS)

    2008-01-01

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

    This composite image from NASA's Spitzer Space Telescope shows the remnant of a star that exploded, called Cassiopeia A (center) and its surrounding 'light echoes' -- dances of light through dusty clouds, created when stars blast apart. The light echoes are colored and the surrounding clouds of dust are gray.

    In figure 1, dramatic changes are highlighted in phenomena referred to as light echoes (colored areas) around the Cassiopeia A supernova remnant (center). Cassiopeia A is the remnant of a once massive star that died in a violent supernova explosion. It consists of a dead star, called a neutron star, and a surrounding shell of material that was blasted off as the star died.

    A light echo occurs when a star explodes, acting like a cosmic flashbulb. The light from this explosion zips through nearby dust clumps, illuminating and heating them up slightly. This brief period of warming causes them to glow in infrared, like a chain of Christmas bulbs lighting up one by one. The result is an optical illusion, in which the dust appears to be flying outward at the speed of light. In figure 1, this apparent motion can be seen here by the shift in colored dust clumps

    Cassiopeia A is the remnant of a once massive star that died in a violent supernova explosion. It consists of a dead star, called a neutron star, and a surrounding shell of material that was blasted off as the star died. This remnant is located 11,000 light-years away in the northern constellation Cassiopeia.

    This composite consists of six processed images taken over a time span of three years. Dust features that have not changed over time appear gray, while those that have changed are colored blue or orange. Bluer colors represent an earlier time and redder ones, a later time. The progression of the light echo through the dust can be seen here by the shift in colored dust clumps.

    This light echo is the largest ever seen, stretching more than 300 light-years away from Cassiopeia A. If viewed from Earth, the entire frame would take up the same amount of space as seven full moons. The supernova remnant is located 11,000 light-years away in the northern constellation Cassiopeia.

    The earliest Spitzer image shown here was taken in February 2005, and the latest one in January 2008. The image was processed to emphasize the light echo by enhancing the areas that change, which appear in color, and dimming regions that remain constant, seen in grayscale. Spurious color artifacts such as diffraction spikes around stars were removed by hand.

  17. Distances to supernova remnants G20.4 + 0.1, G24.7 - 0.6, and G28.6 - 0.1 and new molecular cloud associations

    NASA Astrophysics Data System (ADS)

    Ranasinghe, S.; Leahy, D. A.

    2018-06-01

    Accurate distances to supernova remnants (SNRs) are crucial in determining their size, age, luminosity, and evolutionary state. To determine distances, we chose three SNRs from the VLA (Very Large Array) Galactic Plane Survey for extraction of H I absorption spectra. Analysing H I absorption spectra, 13CO emission spectra, and H I and 13CO channel maps, kinematic velocities (or their limits) to the three SNRs were calculated. The three SNRs are probably associated with molecular clouds and the new distance to G20.4 + 0.1, G24.7 - 0.6, and G28.6 - 0.1 are 7.8 ± 0.5 kpc, 3.8 ± 0.2 kpc, and 9.6 ± 0.3 kpc, respectively.

  18. The impact of supernova fragments on the evolution of multisupernova remnants

    NASA Technical Reports Server (NTRS)

    Franco, J.; Ferrara, A.; Rozyczka, M.; Tenorio-Tgale, G.; Cox, D. P.

    1993-01-01

    Analytical approximations and 2D hydrodynamical simulations are used to examine the interaction of supernova fragments with the internal structure of large multisupernova remnants (MSRs). The fragments are thermalized by reverse shocks generated in the interaction with the MSR interior, which is assumed to be hot and rarefied. The evolution is divided into two stages: before and after reaching a reference distance, R(E), from the explosion site. As the density of the expanding fragment drops, the reverse shock accelerates, and, when the distance R(E) is reached, it begins to effectively erode the fragment. At some selected evolutionary times, the X-ray emission from the shocked fragment is also calculated. The direct bombardment of the MRS shell by the shocked fragment has a series of important consequences: it excites, punctures, and deforms the expanding shell.

  19. The Complex Shell and Pulsar-Wind Nebula in the Young Supernova Remnant Kes 75

    NASA Astrophysics Data System (ADS)

    Borkowski, Kazimierz

    2015-09-01

    Kes 75 (G29.7-0.3) may be the youngest supernova remnant/pulsar-wind nebula (SNR/PWN) in the Galaxy, 400 - 900 years old. As such, it can illuminate early stages of PWN/SNR interaction and the nature of the immediate SN environment. The pulsar is unusual with some magnetar-like properties. Spectral studies are complex and conflicting, but Chandra can provide basic dynamical information: the expansion rate of the shell since earlier observations in 2000 and 2006, information crucial to a better age determination, model discrimination, and interpretation of the very large asymmetry (only about half the SNR shell is detectable). Our 150 ks proposed observation should allow rates to be measured to 15% or better. We shall also monitor the PWN for any morphological and spectral changes.

  20. A model of the pre-Sedov expansion phase of supernova remnant-ambient plasma coupling and X-ray emission from SN 1987A

    NASA Technical Reports Server (NTRS)

    Spicer, D. S.; Maran, S. P.; Clark, R. W.

    1990-01-01

    This paper examines the mechanism responsible for coupling supernova (SN) remnant to the ambient medium during the pre-Sedov or the so-called free expansion phase, immediately following the progenitor explosion. A theory is developed for the interaction of an SN piston with the ambient medium during the pre-Sedov phase. The possibility of X-ray production by the high-speed portion of the piston during this phase is investigated. The relevant observations of high-energy emissions from the SN 1987A, including the X-ray spectrum, luminosity, and temporal development, are considered. It is shown that the commonly assumed snowplow model for SNR evolution is valid, because of the action of a variety of collisionless two-stream instabilities that permit the coupling of the ambient plasma with SNR.

  1. Distances to Supernova Remnants G31.9+0.0 and G54.4−0.3 Associated with Molecular Clouds

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

    Ranasinghe, S.; Leahy, D. A.

    2017-07-10

    New distances to the supernova remnants (SNRs) G31.9+0.0 and G54.4−0.3 have been found. The analysis method uses H i absorption spectra and CO channel maps. Individual H i channel maps are used to verify absorption features in the H i absorption spectrum or to determine if they have noise. Both of the SNRs are associated with molecular clouds so accurate kinematic velocities are determined. The H iabsorption is used to resolve the kinematic distance ambiguity. The resulting new distance for G31.9+0.0 is 7.1 ± 0.4 kpc and for G54.4−0.3 it is 6.6 ± 0.6 kpc. These are significant revisions tomore » the previous values.« less

  2. ANTIMATTER PRODUCTION IN SUPERNOVA REMNANTS

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

    Kachelriess, M.; Ostapchenko, S.; Tomas, R.

    2011-06-01

    We calculate the energy spectra of cosmic rays (CRs) and their secondaries produced in a supernova remnant (SNR) taking into account the time dependence of the SNR shock. We model the trajectories of charged particles as a random walk with a prescribed diffusion coefficient, accelerating the particles at each shock crossing. Secondary production by CRs colliding with gas is included as a Monte Carlo process. We find that SNRs produce less antimatter than suggested previously: the positron/electron ratio F{sub e}{sup +}/F{sub e}{sup +}{sub +e}{sup -} and the antiproton/proton ratio F{sub p-bar/}F{sub p-bar+p} are a few percent and few x 10{supmore » -5}, respectively. Moreover, the obtained positron/electron ratio decreases with energy, while the antiproton/proton ratio rises at most by a factor of two above 10 GeV.« less

  3. Separated before birth: pulsars B2020+28 and B2021+51 as the remnants of runaway stars

    NASA Astrophysics Data System (ADS)

    Gvaramadze, V. V.

    2007-08-01

    Astrometric data on the pulsars B2020+28 and B2021+51 suggest that they originated within several parsecs of each other in the direction of the Cyg OB2 association. It was proposed that the pulsars share their origin in a common massive binary and were separated at the birth of the second pulsar following the asymmetric supernova explosion. We consider a different scenario for the origin of the pulsar pair based on a possibility that the pulsars were separated before their birth and that they are the remnants of runaway stars ejected (with velocities similar to those of the pulsars) from the core of Cyg OB2 due to strong three- or four-body dynamical encounters. Our scenario does not require any asymmetry in supernova explosions.

  4. Gamma-ray emission from the shell of supernova remnant W44 revealed by the Fermi LAT.

    PubMed

    Abdo, A A; Ackermann, M; Ajello, M; Baldini, L; Ballet, J; Barbiellini, G; Baring, M G; Bastieri, D; Baughman, B M; Bechtol, K; Bellazzini, R; Berenji, B; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A W; Bregeon, J; Brez, A; Brigida, M; Bruel, P; Burnett, T H; Buson, S; Caliandro, G A; Cameron, R A; Caraveo, P A; Casandjian, J M; Cecchi, C; Celik, O; Chekhtman, A; Cheung, C C; Chiang, J; Ciprini, S; Claus, R; Cognard, I; Cohen-Tanugi, J; Cominsky, L R; Conrad, J; Cutini, S; Dermer, C D; de Angelis, A; de Palma, F; Digel, S W; do Couto e Silva, E; Drell, P S; Dubois, R; Dumora, D; Espinoza, C; Farnier, C; Favuzzi, C; Fegan, S J; Focke, W B; Fortin, P; Frailis, M; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Gehrels, N; Germani, S; Giavitto, G; Giebels, B; Giglietto, N; Giordano, F; Glanzman, T; Godfrey, G; Grenier, I A; Grondin, M-H; Grove, J E; Guillemot, L; Guiriec, S; Hanabata, Y; Harding, A K; Hayashida, M; Hays, E; Hughes, R E; Jackson, M S; Jóhannesson, G; Johnson, A S; Johnson, T J; Johnson, W N; Kamae, T; Katagiri, H; Kataoka, J; Katsuta, J; Kawai, N; Kerr, M; Knödlseder, J; Kocian, M L; Kramer, M; Kuss, M; Lande, J; Latronico, L; Lemoine-Goumard, M; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Lyne, A G; Madejski, G M; Makeev, A; Mazziotta, M N; McEnery, J E; Meurer, C; Michelson, P F; Mitthumsiri, W; Mizuno, T; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nakamori, T; Nolan, P L; Norris, J P; Noutsos, A; Nuss, E; Ohsugi, T; Omodei, N; Orlando, E; Ormes, J F; Paneque, D; Parent, D; Pelassa, V; Pepe, M; Pesce-Rollins, M; Piron, F; Porter, T A; Rainò, S; Rando, R; Razzano, M; Reimer, A; Reimer, O; Reposeur, T; Rochester, L S; Rodriguez, A Y; Romani, R W; Roth, M; Ryde, F; Sadrozinski, H F-W; Sanchez, D; Sander, A; Saz Parkinson, P M; Scargle, J D; Sgrò, C; Siskind, E J; Smith, D A; Smith, P D; Spandre, G; Spinelli, P; Stappers, B W; Stecker, F W; Strickman, M S; Suson, D J; Tajima, H; Takahashi, H; Takahashi, T; Tanaka, T; Thayer, J B; Thayer, J G; Theureau, G; Thompson, D J; Tibaldo, L; Tibolla, O; Torres, D F; Tosti, G; Tramacere, A; Uchiyama, Y; Usher, T L; Vasileiou, V; Venter, C; Vilchez, N; Vitale, V; Waite, A P; Wang, P; Winer, B L; Wood, K S; Yamazaki, R; Ylinen, T; Ziegler, M

    2010-02-26

    Recent observations of supernova remnants (SNRs) hint that they accelerate cosmic rays to energies close to ~10(15) electron volts. However, the nature of the particles that produce the emission remains ambiguous. We report observations of SNR W44 with the Fermi Large Area Telescope at energies between 2 x 10(8) electron volts and 3 x10(11) electron volts. The detection of a source with a morphology corresponding to the SNR shell implies that the emission is produced by particles accelerated there. The gamma-ray spectrum is well modeled with emission from protons and nuclei. Its steepening above approximately 10(9) electron volts provides a probe with which to study how particle acceleration responds to environmental effects such as shock propagation in dense clouds and how accelerated particles are released into interstellar space.

  5. Observations of Non Typical Masers at the RT-22 Radio Telescope in 2004-2013

    NASA Astrophysics Data System (ADS)

    Shulga, V. M.; Antyufeyev, O. V.; Zubrin, S. Y.; Myshenko, V. V.; Piddyachiy, V. I.; Korolev, A. M.; Patoka, O. M.

    2017-06-01

    Purpose: Some peculiarities of emission of Class I methanol masers on the 80-71A+ transition at 95 GHz in sources closely associated with protostar-forming regions and in supernova remnants are studied. Here belongs the investigation of SiO (J=2-1) maser variability in R Cassiopeiae, too. Design/methodology/approach: Search for Class I methanol masers is based on the idea of coincidence of regions of their emission with sources of OH masing transition in the bottom level of energy at frequency of 1720 MHz (2Π3/2 J=3/2 F=2-1). Findings: Two methanol masers on transition 80-71A+ (95 GHz) in the supernova remnants IC 443 and Kes 79 are detected. Variabilities of SiO maser emission on transition J=2-1 in R Cassiopeiae are shown for the first time. Conclusions: Variability of methanol and SiO masers is their general feature. On the example of three objects, the possibility of using the 1720 MHz OH maser as an indicator in the search for Class I methanol masers is shown. Especially it is important in the study of methanol maser emission in supernova remnants that has been proved to be true by detection of methanol masers on transition 80-71A+ (95 GHz) in IC 443 and Kes 79. Features of spectra variability of emission in R Cassiopeiae testify to formation and disappearance of SiO (J=2-1) masers.

  6. History of Chandra X-Ray Observatory

    NASA Image and Video Library

    1999-08-01

    This x-ray image of the Cassiopeia A (CAS A) supernova remnant is the official first light image of the Chandra X-Ray Observatory (CXO). The 5,000-second image was made with the Advanced Charged Coupled Device (CCD) Image Spectrometer (ACIS). Two shock waves are visible: A fast outer shock and a slower irner shock. The inner shock wave is believed to be due to the collision of ejecta from the supernova explosion with a circumstellar shell of material, heating it to a temperature of 10 million-degrees Celsius. The outer shock wave is analogous to an awesome sonic boom resulting from this collision The x-rays reveal a bright object near the center, which may be the long-sought neutron star or black hole remnant of the explosion that produced Cassiopeia A. Cassiopeia A is the 320-year-old remnant of a massive star that exploded. Located in the constellation Cassiopeia, it is 10 light-years across and 10,000 light-years from Earth. A supernova occurs when a massive star has used up its nuclear fuel and the pressure drops in the central core of the star. The matter in the core is crushed by gravity to higher and higher densities, and temperatures reach billions of degrees. Under these extreme conditions, nuclear reactions occur violently and catastrophically, reversing the collapse. A thermonuclear shock wave races through the now expanding stellar debris, fusing lighter elements into heavier ones and producing a brilliant visual outburst.

  7. Hubble Sees Stars and a Stripe in Celestial Fireworks

    NASA Image and Video Library

    2017-12-08

    Release date: July 1, 2008 SN 1006 Supernova Remnant (Hubble) A delicate ribbon of gas floats eerily in our galaxy. A contrail from an alien spaceship? A jet from a black-hole? Actually this image, taken by NASA's Hubble Space Telescope, is a very thin section of a supernova remnant caused by a stellar explosion that occurred more than 1,000 years ago. On or around May 1, 1006 A.D., observers from Africa to Europe to the Far East witnessed and recorded the arrival of light from what is now called SN 1006, a tremendous supernova explosion caused by the final death throes of a white dwarf star nearly 7,000 light-years away. The supernova was probably the brightest star ever seen by humans, and surpassed Venus as the brightest object in the night time sky, only to be surpassed by the moon. It was visible even during the day for weeks, and remained visible to the naked eye for at least two and a half years before fading away. It wasn't until the mid-1960s that radio astronomers first detected a nearly circular ring of material at the recorded position of the supernova. The ring was almost 30 arcminutes across, the same angular diameter as the full moon. The size of the remnant implied that the blast wave from the supernova had expanded at nearly 20 million miles per hour over the nearly 1,000 years since the explosion occurred. In 1976, the first detection of exceedingly faint optical emission of the supernova remnant was reported, but only for a filament located on the northwest edge of the radio ring. A tiny portion of this filament is revealed in detail by the Hubble observation. The twisting ribbon of light seen by Hubble corresponds to locations where the expanding blast wave from the supernova is now sweeping into very tenuous surrounding gas. The hydrogen gas heated by this fast shock wave emits radiation in visible light. Hence, the optical emission provides astronomers with a detailed "snapshot" of the actual position and geometry of the shock front at any given time. Bright edges within the ribbon correspond to places where the shock wave is seen exactly edge on to our line of sight. Today we know that SN 1006 has a diameter of nearly 60 light-years, and it is still expanding at roughly 6 million miles per hour. Even at this tremendous speed, however, it takes observations typically separated by years to see significant outward motion of the shock wave against the grid of background stars. In the Hubble image as displayed, the supernova would have occurred far off the lower right corner of the image, and the motion would be toward the upper left. SN 1006 resides within our Milky Way Galaxy. Located more than 14 degrees off the plane of the galaxy's disk, there is relatively little confusion with other foreground and background objects in the field when trying to study this object. In the Hubble image, many background galaxies (orange extended objects) far off in the distant universe can be seen dotting the image. Most of the white dots are foreground or background stars in our Milky Way galaxy. This image is a composite of hydrogen-light observations taken with Hubble's Advanced Camera for Surveys in February 2006 and Wide Field Planetary Camera 2 observations in blue, yellow-green, and near-infrared light taken in April 2008. The supernova remnant, visible only in the hydrogen-light filter was assigned a red hue in the Heritage color image. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA) Acknowledgment: W. Blair (Johns Hopkins University) To learn more about the Hubble Space Telescope go here: www.nasa.gov/mission_pages/hubble/main/index.html NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  8. Dusty Dead Star

    NASA Image and Video Library

    2010-03-29

    A composite image from NASA Chandra and Spitzer space telescopes shows the dusty remains of a collapsed star, a supernova remnant called G54.1+0.3. The white source at the center is a dead star called a pulsar.

  9. An Explosion of Infrared Color

    NASA Image and Video Library

    2010-12-09

    This oddly colorful nebula is the supernova remnant IC 443 as seen by NASA Wide-field Infrared Survey Explorer; the Jellyfish nebula is particularly interesting because it provides a look into how stellar explosions interact with their environment.

  10. Merging white dwarfs and thermonuclear supernovae.

    PubMed

    van Kerkwijk, M H

    2013-06-13

    Thermonuclear supernovae result when interaction with a companion reignites nuclear fusion in a carbon-oxygen white dwarf, causing a thermonuclear runaway, a catastrophic gain in pressure and the disintegration of the whole white dwarf. It is usually thought that fusion is reignited in near-pycnonuclear conditions when the white dwarf approaches the Chandrasekhar mass. I briefly describe two long-standing problems faced by this scenario, and the suggestion that these supernovae instead result from mergers of carbon-oxygen white dwarfs, including those that produce sub-Chandrasekhar-mass remnants. I then turn to possible observational tests, in particular, those that test the absence or presence of electron captures during the burning.

  11. Pulsar recoil by large-scale anisotropies in supernova explosions.

    PubMed

    Scheck, L; Plewa, T; Janka, H-Th; Kifonidis, K; Müller, E

    2004-01-09

    Assuming that the neutrino luminosity from the neutron star core is sufficiently high to drive supernova explosions by the neutrino-heating mechanism, we show that low-mode (l=1,2) convection can develop from random seed perturbations behind the shock. A slow onset of the explosion is crucial, requiring the core luminosity to vary slowly with time, in contrast to the burstlike exponential decay assumed in previous work. Gravitational and hydrodynamic forces by the globally asymmetric supernova ejecta were found to accelerate the remnant neutron star on a time scale of more than a second to velocities above 500 km s(-1), in agreement with observed pulsar proper motions.

  12. Hubble views a spectacular supernova with interstellar material over 160,000 light-years away

    NASA Image and Video Library

    2017-12-08

    This NASA/ESA Hubble Space Telescope image captures the remnants of a long-dead star. These rippling wisps of ionized gas, named DEM L316A, are located some 160,000 light-years away within one of the Milky Way’s closest galactic neighbors — the Large Magellanic Cloud (LMC). The explosion that formed DEM L316A was an example of an especially energetic and bright variety of supernova, known as a Type Ia. Such supernova events are thought to occur when a white dwarf star steals more material than it can handle from a nearby companion, and becomes unbalanced. The result is a spectacular release of energy in the form of a bright, violent explosion, which ejects the star’s outer layers into the surrounding space at immense speeds. As this expelled gas travels through the interstellar material, it heats up and ionizes it, producing the faint glow that Hubble’s Wide Field Camera 3 has captured here. The LMC orbits the Milky Way as a satellite galaxy and is the fourth largest in our group of galaxies, the Local Group. DEM L316A is not the only supernova remnant in the LMC; Hubble came across another one in 2010 with SNR 0509, and in 2013 it snapped SNR 0519. Image credit: ESA (European Space Agency)/Hubble & NASA, Y. Chu

  13. No surviving evolved companions of the progenitor of SN 1006.

    PubMed

    González Hernández, Jonay I; Ruiz-Lapuente, Pilar; Tabernero, Hugo M; Montes, David; Canal, Ramon; Méndez, Javier; Bedin, Luigi R

    2012-09-27

    Type Ia supernovae are thought to occur when a white dwarf made of carbon and oxygen accretes sufficient mass to trigger a thermonuclear explosion. The accretion could be slow, from an unevolved (main-sequence) or evolved (subgiant or giant) star (the single-degenerate channel), or rapid, as the primary star breaks up a smaller orbiting white dwarf (the double-degenerate channel). A companion star will survive the explosion only in the single-degenerate channel. Both channels might contribute to the production of type Ia supernovae, but the relative proportions of their contributions remain a fundamental puzzle in astronomy. Previous searches for remnant companions have revealed one possible case for SN 1572 (refs 8, 9), although that has been questioned. More recently, observations have restricted surviving companions to be small, main-sequence stars, ruling out giant companions but still allowing the single-degenerate channel. Here we report the results of a search for surviving companions of the progenitor of SN 1006 (ref. 14). None of the stars within 4 arc minutes of the apparent site of the explosion is associated with the supernova remnant, and we can firmly exclude all giant and subgiant stars from being companions of the progenitor. In combination with previous results, our findings indicate that fewer than 20 per cent of type Ia supernovae occur through the single-degenerate channel.

  14. Is supernova 1987A a stripped asymptotic-branch giant in a binary system?

    NASA Technical Reports Server (NTRS)

    Joss, P. C.; Podsiadlowski, PH.; Hsu, J. J. L.; Rappaport, S.

    1988-01-01

    It is proposed that the progenitor of supernova 1987A was a previously undetected red star in orbit about a blue supergiant. The progenitor was the remnant of an asymptotic-branch giant that had lost most of its hydrogen-rich envelope to its blue companion by type C mass transfer. A detailed evolutionary model strongly supports the feasibility of this proposition. It is found that the original mass of the supernova precursor was 10-15 solar (unless a large fraction of the mass was ejected from the binary sytem), and its final mass, just before the supernova event, was 3-6 solar. The system remained bound, with a new orbital period of 3-10 yr and an eccentricity of 0.1-0.4. This picture can provide plausible qualitative explanations for several anomalies in the observational properties of this supernova.

  15. Massive stars in their death throes.

    PubMed

    Eldridge, John J

    2008-12-13

    The study of the stars that explode as supernovae used to be a forensic study, working backwards from the remnants of the star. This changed in 1987 when the first progenitor star was identified in pre-explosion images. Currently, there are eight detected progenitors with another 21 non-detections, for which only a limit on the pre-explosion luminosity can be placed. This new avenue of supernova research has led to many interesting conclusions, most importantly that the progenitors of the most common supernovae, type IIP, are red supergiants, as theory has long predicted. However, no progenitors have been detected thus far for the hydrogen-free type Ib/c supernovae, which, given the expected progenitors, is an unlikely result. Also, observations have begun to show evidence that luminous blue variables, which are among the most massive stars, may directly explode as supernovae. These results contradict the current stellar evolution theory. This suggests that we may need to update our understanding.

  16. Neutrino Emission from Supernovae

    NASA Astrophysics Data System (ADS)

    Janka, Hans-Thomas

    Supernovae are the most powerful cosmic sources of MeV neutrinos. These elementary particles play a crucial role when the evolution of a massive star is terminated by the collapse of its core to a neutron star or a black hole and the star explodes as supernova. The release of electron neutrinos, which are abundantly produced by electron captures, accelerates the catastrophic infall and causes a gradual neutronization of the stellar plasma by converting protons to neutrons as dominant constituents of neutron star matter. The emission of neutrinos and antineutrinos of all flavors carries away the gravitational binding energy of the compact remnant and drives its evolution from the hot initial to the cold final state. The absorption of electron neutrinos and antineutrinos in the surroundings of the newly formed neutron star can power the supernova explosion and determines the conditions in the innermost supernova ejecta, making them an interesting site for the nucleosynthesis of iron-group elements and trans-iron nuclei.

  17. Kepler Beyond Planets: Finding Exploding Stars (Type Ia Supernova from a White Dwarf Merger)

    NASA Image and Video Library

    2018-03-26

    This frame from an animation shows the merger of two white dwarfs. A white dwarf is an extremely dense remnant of a star that can no longer burn nuclear fuel at its core. This is another way that a "type Ia" supernova occurs. Stellar explosions forge and distribute materials that make up the world in which we live, and also hold clues to how fast the universe is expanding. By understanding supernovae, scientists can unlock mysteries that are key to what we are made of and the fate of our universe. But to get the full picture, scientists must observe supernovae from a variety of perspectives, especially in the first moments of the explosion. That's really difficult -- there's no telling when or where a supernova might happen next. An animation is available at https://photojournal.jpl.nasa.gov/catalog/PIA22353

  18. Supernova Relic Neutrinos and the Supernova Rate Problem: Analysis of Uncertainties and Detectability of ONeMg and Failed Supernovae

    NASA Astrophysics Data System (ADS)

    Mathews, Grant J.; Hidaka, Jun; Kajino, Toshitaka; Suzuki, Jyutaro

    2014-08-01

    Direct measurements of the core collapse supernova rate (R SN) in the redshift range 0 <= z <= 1 appear to be about a factor of two smaller than the rate inferred from the measured cosmic massive star formation rate (SFR). This discrepancy would imply that about one-half of the massive stars that have been born in the local observed comoving volume did not explode as luminous supernovae. In this work, we explore the possibility that one could clarify the source of this "supernova rate problem" by detecting the energy spectrum of supernova relic neutrinos with a next generation 106 ton water Čerenkov detector like Hyper-Kamiokande. First, we re-examine the supernova rate problem. We make a conservative alternative compilation of the measured SFR data over the redshift range 0 <=z <= 7. We show that by only including published SFR data for which the dust obscuration has been directly determined, the ratio of the observed massive SFR to the observed supernova rate R SN has large uncertainties {\\sim }1.8^{+1.6}_{-0.6} and is statistically consistent with no supernova rate problem. If we further consider that a significant fraction of massive stars will end their lives as faint ONeMg SNe or as failed SNe leading to a black hole remnant, then the ratio reduces to {\\sim }1.1^{+1.0}_{-0.4} and the rate problem is essentially solved. We next examine the prospects for detecting this solution to the supernova rate problem. We first study the sources of uncertainty involved in the theoretical estimates of the neutrino detection rate and analyze whether the spectrum of relic neutrinos can be used to independently identify the existence of a supernova rate problem and its source. We consider an ensemble of published and unpublished core collapse supernova simulation models to estimate the uncertainties in the anticipated neutrino luminosities and temperatures. We illustrate how the spectrum of detector events might be used to establish the average neutrino temperature and constrain SN models. We also consider supernova ν-process nucleosynthesis to deduce constraints on the temperature of the various neutrino flavors. We study the effects of neutrino oscillations on the detected neutrino energy spectrum and also show that one might distinguish the equation of state (EoS) as well as the cause of the possible missing luminous supernovae from the detection of supernova relic neutrinos. We also analyze a possible enhanced contribution from failed supernovae leading to a black hole remnant as a solution to the supernova rate problem. We conclude that indeed it might be possible (though difficult) to measure the neutrino temperature, neutrino oscillations, and the EoS and confirm this source of missing luminous supernovae by the detection of the spectrum of relic neutrinos.

  19. Supernova relic neutrinos and the supernova rate problem: Analysis of uncertainties and detectability of ONeMg and failed supernovae

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

    Mathews, Grant J.; Hidaka, Jun; Kajino, Toshitaka

    2014-08-01

    Direct measurements of the core collapse supernova rate (R{sub SN}) in the redshift range 0 ≤ z ≤ 1 appear to be about a factor of two smaller than the rate inferred from the measured cosmic massive star formation rate (SFR). This discrepancy would imply that about one-half of the massive stars that have been born in the local observed comoving volume did not explode as luminous supernovae. In this work, we explore the possibility that one could clarify the source of this 'supernova rate problem' by detecting the energy spectrum of supernova relic neutrinos with a next generation 10{supmore » 6} ton water Čerenkov detector like Hyper-Kamiokande. First, we re-examine the supernova rate problem. We make a conservative alternative compilation of the measured SFR data over the redshift range 0 ≤z ≤ 7. We show that by only including published SFR data for which the dust obscuration has been directly determined, the ratio of the observed massive SFR to the observed supernova rate R{sub SN} has large uncertainties ∼1.8{sub −0.6}{sup +1.6} and is statistically consistent with no supernova rate problem. If we further consider that a significant fraction of massive stars will end their lives as faint ONeMg SNe or as failed SNe leading to a black hole remnant, then the ratio reduces to ∼1.1{sub −0.4}{sup +1.0} and the rate problem is essentially solved. We next examine the prospects for detecting this solution to the supernova rate problem. We first study the sources of uncertainty involved in the theoretical estimates of the neutrino detection rate and analyze whether the spectrum of relic neutrinos can be used to independently identify the existence of a supernova rate problem and its source. We consider an ensemble of published and unpublished core collapse supernova simulation models to estimate the uncertainties in the anticipated neutrino luminosities and temperatures. We illustrate how the spectrum of detector events might be used to establish the average neutrino temperature and constrain SN models. We also consider supernova ν-process nucleosynthesis to deduce constraints on the temperature of the various neutrino flavors. We study the effects of neutrino oscillations on the detected neutrino energy spectrum and also show that one might distinguish the equation of state (EoS) as well as the cause of the possible missing luminous supernovae from the detection of supernova relic neutrinos. We also analyze a possible enhanced contribution from failed supernovae leading to a black hole remnant as a solution to the supernova rate problem. We conclude that indeed it might be possible (though difficult) to measure the neutrino temperature, neutrino oscillations, and the EoS and confirm this source of missing luminous supernovae by the detection of the spectrum of relic neutrinos.« less

  20. The first Fermi LAT supernova remnant catalog

    DOE PAGES

    Acero, F.

    2016-05-16

    To uniformly determine the properties of supernova remnants (SNRs) at high energies, we have developed the first systematic survey at energies from 1 to 100 GeV using data from the Fermi Large Area Telescope. Based on the spatial overlap of sources detected at GeV energies with SNRs known from radio surveys, we classify 30 sources as likely GeV SNRs. We also report 14 marginal associations and 245 flux upper limits. A mock catalog in which the positions of known remnants are scrambled in Galactic longitude, allows us to determine an upper limit of 22% on the number of GeV candidatesmore » falsely identified as SNRs. We have also developed a method to estimate spectral and spatial systematic errors arising from the diffuse interstellar emission model, a key component of all Galactic Fermi LAT analyses. By studying remnants uniformly in aggregate, we measure the GeV properties common to these objects and provide a crucial context for the detailed modeling of individual SNRs. Combining our GeV results with multiwavelength (MW) data, including radio, X-ray, and TeV, demonstrates the need for improvements to previously sufficient, simple models describing the GeV and radio emission from these objects. As a result, we model the GeV and MW emission from SNRs in aggregate to constrain their maximal contribution to observed Galactic cosmic rays.« less

  1. THE FIRST FERMI LAT SUPERNOVA REMNANT CATALOG

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

    Acero, F.; Ballet, J.; Ackermann, M.

    2016-05-01

    To uniformly determine the properties of supernova remnants (SNRs) at high energies, we have developed the first systematic survey at energies from 1 to 100 GeV using data from the Fermi Large Area Telescope (LAT). Based on the spatial overlap of sources detected at GeV energies with SNRs known from radio surveys, we classify 30 sources as likely GeV SNRs. We also report 14 marginal associations and 245 flux upper limits. A mock catalog in which the positions of known remnants are scrambled in Galactic longitude allows us to determine an upper limit of 22% on the number of GeV candidates falsely identifiedmore » as SNRs. We have also developed a method to estimate spectral and spatial systematic errors arising from the diffuse interstellar emission model, a key component of all Galactic Fermi LAT analyses. By studying remnants uniformly in aggregate, we measure the GeV properties common to these objects and provide a crucial context for the detailed modeling of individual SNRs. Combining our GeV results with multiwavelength (MW) data, including radio, X-ray, and TeV, we demonstrate the need for improvements to previously sufficient, simple models describing the GeV and radio emission from these objects. We model the GeV and MW emission from SNRs in aggregate to constrain their maximal contribution to observed Galactic cosmic rays.« less

  2. Fermi Large Area Telescope Detection of Gamma-Ray Emission from the Direction of Supernova iPTF14hls

    NASA Astrophysics Data System (ADS)

    Yuan, Qiang; Liao, Neng-Hui; Xin, Yu-Liang; Li, Ye; Fan, Yi-Zhong; Zhang, Bing; Hu, Hong-Bo; Bi, Xiao-Jun

    2018-02-01

    The remnant of a supernova explosion is widely believed to be the acceleration site of high-energy cosmic-ray particles. The acceleration timescale is, however, typically very long. Here, we report the detection of a variable γ-ray source with the Fermi Large Area Telescope, which is positionally and temporally consistent with a peculiar supernova, iPTF14hls. A quasi-stellar object SDSS J092054.04+504251.5, which is probably a blazar candidate according to the infrared data, is found in the error circle of the γ-ray source. More data about the γ-ray source and SDSS J092054.04+504251.5 are needed to confirm their association. On the other hand, if the association between the γ-ray source and the supernova is confirmed, this would be the first time detecting high-energy γ-ray emission from a supernova, suggesting very fast particle acceleration by supernova explosions.

  3. Discovery of a 50 millisecond pulsar in the Large Magellanic Cloud

    NASA Technical Reports Server (NTRS)

    Seward, F. D.; Harnden, F. R., Jr.; Helfand, D. J.

    1984-01-01

    The present investigation is concerned with the discovery of a new pulsed X-ray source in the Large Magellanic Cloud (LMC) supernova remnant 0540 - 693. The SNR 0540 - 693 is one of three suspected Crab-like remnants in the LMC. The existing X-ray, optical, and radio observations of the remnant itself are discussed, and an analysis is conducted of the implications of the period, period derivative, and X-ray pulse shape of the new source. It is concluded that the pulsed X-ray source is almost certainly a young, isolated pulsar. Many of its properties are very similar to those of the Crab pulsar.

  4. Three Great Eyes on Kepler's Supernova Remnant

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site] Composite

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

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

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

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

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

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

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

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

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

  5. Stellar Debris in the Large Magellanic Cloud

    NASA Image and Video Library

    2006-12-08

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

  6. Dusty Death of a Massive Star

    NASA Image and Video Library

    2006-06-06

    NASA Spitzer Space Telescope shows the supernova remnant 1E0102.2-7219 sits next to the nebula N76 in a bright, star-forming region of the Small Magellanic Cloud, a satellite galaxy to our Milky Way galaxy.

  7. Spatially-resolved Spectroscopy of the IC443 Pulsar Wind Nebula and Environs

    NASA Astrophysics Data System (ADS)

    Swartz, Douglas A.; Weisskopf, M. C.; Zavlin, V.; Bucciantini, N.; Clarke, T. E.; Karovska, M.; Pavlov, G. G.; van der Horst, A.; Yukita, M.

    2013-04-01

    Deep Chandra ACIS observations of the region around the putative pulsar, CXO J061705.3+222127, in the supernova remnant IC443 confirm that (1) the spectrum and flux of the central object are consistent with a rotation-powered pulsar interpretation, (2) the non-thermal surrounding nebula is likely powered by a pulsar wind, and (3) the thermal-dominated spectrum at greater distances is consistent with emission from the supernova remnant. The observations further reveal, for the first time, a ring-like morphology surrounding the pulsar and a jet-like structure oriented roughly north-south across the ring and through the pulsar location. The cometary shape of the nebula, suggesting motion towards the southwest, appears to be subsonic; there is no evidence for a strong bow shock and the ring, presumably formed at a wind termination shock, is not distorted by motion through the ambient medium.

  8. Astrophysics. The exceptionally powerful TeV γ-ray emitters in the Large Magellanic Cloud.

    PubMed

    2015-01-23

    The Large Magellanic Cloud, a satellite galaxy of the Milky Way, has been observed with the High Energy Stereoscopic System (H.E.S.S.) above an energy of 100 billion electron volts for a deep exposure of 210 hours. Three sources of different types were detected: the pulsar wind nebula of the most energetic pulsar known, N 157B; the radio-loud supernova remnant N 132D; and the largest nonthermal x-ray shell, the superbubble 30 Dor C. The unique object SN 1987A is, unexpectedly, not detected, which constrains the theoretical framework of particle acceleration in very young supernova remnants. These detections reveal the most energetic tip of a γ-ray source population in an external galaxy and provide via 30 Dor C the unambiguous detection of γ-ray emission from a superbubble. Copyright © 2015, American Association for the Advancement of Science.

  9. Spatially-resolved Spectroscopy of the IC443 Pulsar Wind Nebula and Environs

    NASA Technical Reports Server (NTRS)

    Swartz, D. A.; Weisskopf, M. C.; Zavlin, V. E.; Bucciantini, N.; Clarke, T. E.; Karovska, M.; Pavlov, G. G.; O'Dell, S. L.; vanderHorst, A J.; Yukita, M.

    2013-01-01

    Deep Chandra ACIS observations of the region around the putative pulsar, CXOU J061705.3+222117, in the supernova remnant IC443 reveal, for the first time, a ring-like morphology surrounding the pulsar and a jet-like structure oriented roughly north-south across the ring and through the pulsar location. The observations further confirm that (1) the spectrum and flux of the central object are consistent with a rotation-powered pulsar interpretation, (2) the non-thermal surrounding nebula is likely powered by the pulsar wind, and (3) the thermal-dominated spectrum at greater distances is consistent with emission from the supernova remnant. The cometary shape of the nebula, suggesting motion towards the southwest (or, equivalently, flow of ambient medium to the northeast), appears to be subsonic; there is no evidence for a strong bow shock, and the circular ring is not distorted by motion through the ambient medium.

  10. Non-linear acceleration at supernova remnant shocks and the hardening in the cosmic ray spectrum

    NASA Astrophysics Data System (ADS)

    Recchia, S.; Gabici, S.

    2018-02-01

    In the last few years, several experiments have shown that the cosmic ray spectrum below the knee is not a perfect power law. In particular, the proton and helium spectra show a spectral hardening by ˜0.1-0.2 in spectral index at particle energies of ˜ 200-300 GeV nucleon-1. Moreover, the helium spectrum is found to be harder than that of protons by ˜0.1 and some evidence for a similar hardening was also found in the spectra of heavier elements. Here, we consider the possibility that the hardening may be the result of a dispersion in the slope of the spectrum of cosmic rays accelerated at supernova remnant shocks. Such a dispersion is indeed expected within the framework of non-linear theories of diffusive shock acceleration, which predict steeper (harder) particle spectra for larger (smaller) cosmic ray acceleration efficiencies.

  11. Hidden Markov model tracking of continuous gravitational waves from young supernova remnants

    NASA Astrophysics Data System (ADS)

    Sun, L.; Melatos, A.; Suvorova, S.; Moran, W.; Evans, R. J.

    2018-02-01

    Searches for persistent gravitational radiation from nonpulsating neutron stars in young supernova remnants are computationally challenging because of rapid stellar braking. We describe a practical, efficient, semicoherent search based on a hidden Markov model tracking scheme, solved by the Viterbi algorithm, combined with a maximum likelihood matched filter, the F statistic. The scheme is well suited to analyzing data from advanced detectors like the Advanced Laser Interferometer Gravitational Wave Observatory (Advanced LIGO). It can track rapid phase evolution from secular stellar braking and stochastic timing noise torques simultaneously without searching second- and higher-order derivatives of the signal frequency, providing an economical alternative to stack-slide-based semicoherent algorithms. One implementation tracks the signal frequency alone. A second implementation tracks the signal frequency and its first time derivative. It improves the sensitivity by a factor of a few upon the first implementation, but the cost increases by 2 to 3 orders of magnitude.

  12. The γ-ray emission produced by protons that escape from supernova remnant G349.7+0.2

    NASA Astrophysics Data System (ADS)

    Zhang, Xiao; Li, Hui; Chen, Yang

    2016-10-01

    G349.7+0.2 is an interacting supernova remnant (SNR) expanding in a dense medium. Recently, a very strong γ-ray source coincident with this SNR has been revealed by Fermi-LAT and H.E.S.S. observations which shows a broken power-law-like spectrum. An escaping-diffusion model, including the power-law and δ-function injection, is applied to this source which can naturally explain the spectral feature in both the GeV and TeV regime. We use the Markov Chain Monte Carlo method to constrain the model parameters and find that the correction factor of slow diffusion around this SNR, χ ˜ 0.01 for power-law injection and χ ˜ 0.1 for δ-function injection, can fit the data best with reasonable molecular cloud mass. This slow diffusion is also consistent with previous results from both phenomenological models and theoretical predication.

  13. On the nature of the TeV emission from the supernova remnant SN 1006

    NASA Astrophysics Data System (ADS)

    Araya, Miguel; Frutos, Francisco

    2012-10-01

    We present a model for the non-thermal emission from the historical supernova remnant SN 1006. We constrain the synchrotron parameters of the model with archival radio and hard X-ray data. Our stationary emission model includes two populations of electrons, which is justified by multifrequency images of the object. From the set of parameters that predict the correct synchrotron flux we select those which are able to account, either partly or entirely, for the gamma-ray emission of the source as seen by HESS. We use the results from this model as well as the latest constraints imposed by the Fermi observatory and conclude that the TeV emission cannot be accounted for by π0 decay from high-energy ions with a single power-law distribution, of the form dN proton /dEp∝Ep-s, and s ≳ 2.

  14. Proper motion of the radio pulsar B1727-47 and its association with the supernova remnant RCW 114

    NASA Astrophysics Data System (ADS)

    Shternin, P. S.; Yu, M.; Kirichenko, A. Yu; Shibanov, Yu A.; Danilenko, A. A.; Voronkov, M. A.; Zyuzin, D. A.

    2017-12-01

    We report preliminary results of the analysis of the proper motion of the bright radio pulsar B1727-47. Using archival Parkes timing data, as well as original and archival ATCA interferometry observations, we, for the first time, constrain the pulsar proper motion at the level of 148±11 mas yr-1. The backward extrapolation of the proper motion vector to the pulsar birth epoch points at the center of the Galactic supernova remnant RCW 114 suggesting the genuine association between the two objects. We discuss the implications of the association and argue that the distance to the system is less than 1 kpc. This value is at least two times lower than the dispersion measure distance estimates. This suggests that the existing Galaxy electron density models are incomplete in the direction to the pulsar.

  15. Energetics and Birth Rates of Supernova Remnants in the Large Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Leahy, D. A.

    2017-03-01

    Published X-ray emission properties for a sample of 50 supernova remnants (SNRs) in the Large Magellanic Cloud (LMC) are used as input for SNR evolution modeling calculations. The forward shock emission is modeled to obtain the initial explosion energy, age, and circumstellar medium density for each SNR in the sample. The resulting age distribution yields a SNR birthrate of 1/(500 yr) for the LMC. The explosion energy distribution is well fit by a log-normal distribution, with a most-probable explosion energy of 0.5× {10}51 erg, with a 1σ dispersion by a factor of 3 in energy. The circumstellar medium density distribution is broader than the explosion energy distribution, with a most-probable density of ˜0.1 cm-3. The shape of the density distribution can be fit with a log-normal distribution, with incompleteness at high density caused by the shorter evolution times of SNRs.

  16. Kinematics of the Ultra-High-Velocity Gas in the Expanding Molecular Shell Adjacent to the W44 Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Yamada, Masaya; Oka, Tomoharu; Tanaka, Kunihiko; Nomura, Mariko; Takekawa, Shunya; Iwata, Yuhei; Tokuyama, Sekito; Tanabe, Keisuke; Tsujimoto, Shiho; Furusawa, Maiko

    2017-01-01

    High-velocity compact cloud (HVCC) is a peculiar category of molecular clouds detected in the central molecular zone of our Galaxy (Oka et al. 1998, 2007, and 2012). They are characterized by compact appearances (d < 5 pc) and very large velocity widths (Δ V > 50 km s-1). Some of them show high CO J=3-2/J=1-0 intensity ratios (>= 1.5), indicating that they consist of dense and warm molecular gas. Dispite a number of efforts, we have not reached a comprehensive interpretation of HVCCs. Recently, we detected an extraordinaly broad velocity width feature, the `Bullet', in the molecular cloud interacting with the W44 supernova remnant. The Bullet shares essential properties with HVCCs. Because of its proximity, a close inspection of the Bullet must contribute to the understanding of HVCCs.

  17. Grain Destruction in a Supernova Remnant Shock Wave

    NASA Technical Reports Server (NTRS)

    Raymond, John C.; Ghavamian, Parviz; Williams, Brian J.; Blair, William P.; Borkowski, Kazimierz J.; Gaetz, Terrance J.; Sankrit, Ravi

    2014-01-01

    Dust grains are sputtered away in the hot gas behind shock fronts in supernova remnants, gradually enriching the gas phase with refractory elements. We have measured emission in C IV (lambda)1550 from C atoms sputtered from dust in the gas behind a non-radiative shock wave in the northern Cygnus Loop. Overall, the intensity observed behind the shock agrees approximately with predictions from model calculations that match the Spitzer 24 micron and the X-ray intensity profiles. Thus these observations confirm the overall picture of dust destruction in SNR shocks and the sputtering rates used in models. However, there is a discrepancy in that the CIV intensity 10'' behind the shock is too high compared to the intensities at the shock and 25'' behind it. Variations in the density, hydrogen neutral fraction and the dust properties over parsec scales in the pre- shock medium limit our ability to test dust destruction models in detail.

  18. Toward the Understanding of the Physical Origin of Recombining Plasma in the Supernova Remnant IC 443

    NASA Astrophysics Data System (ADS)

    Matsumura, Hideaki; Tanaka, Takaaki; Uchida, Hiroyuki; Okon, Hiromichi; Tsuru, Takeshi Go

    2017-12-01

    We perform a spatially resolved spectroscopic analysis of X-ray emission from the supernova remnant (SNR) IC 443 with Suzaku. All of the spectra are well reproduced by a model consisting of a collisional ionization equilibrium (CIE) and two recombining plasma (RP) components. Although previous X-ray studies found an RP in the northeastern region, this is the first report on RPs in the other parts of the remnant. The electron temperature, kT e , of the CIE component is almost uniform at ∼0.2 keV across the remnant. The CIE plasma has metal abundances consistent with solar and is concentrated toward the rim of the remnant, suggesting that it is of shocked interstellar medium origin. The two RP components have different kT e : one in the range of 0.16–0.28 keV and the other in the range of 0.48–0.67 keV. The electron temperatures of both RP components decrease toward the southeast, where the SNR shock is known to be interacting with a molecular cloud. We also find the normalization ratio of the lower-kT e RP to higher-kT e RP components increases toward the southeast. Both results suggest the X-ray emitting plasma in the southeastern region is significantly cooled by some mechanism. One of the plausible cooling mechanisms is a thermal conduction between the hot plasma and the molecular cloud. If the cooling proceeds faster than the recombination timescale of the plasma, the same mechanism can account for the recombining plasma as well.

  19. A Deep X-Ray View of the Synchrotron-dominated Supernova Remnant G330.2+1.0

    NASA Astrophysics Data System (ADS)

    Williams, Brian J.; Hewitt, John W.; Petre, Robert; Temim, Tea

    2018-03-01

    We present moderately deep (125 ks) XMM-Newton observations of supernova remnant G330.2+1.0. This remnant is one of only a few known that fall into the “synchrotron-dominated” category, with the emission almost entirely dominated by a nonthermal continuum. Previous X-ray observations could only characterize the spectra of a few regions. Here, we examine the spectra from 14 regions surrounding the entire rim, finding that the spectral properties of the nonthermal emission do not vary significantly in any systematic way from one part of the forward shock to another, unlike several other remnants of this class. We confirm earlier findings that the power-law index, Γ, ranges from about 2.1–2.5, while the absorbing column density is generally between (2.0–2.6) × 1022 cm‑2. Fits with the srcut model find values of the roll-off frequency in the range of 1017.1–1017.5 Hz, implying energies of accelerated electrons of ∼100 TeV. These values imply a high shock velocity of ∼4600 km s‑1, favoring a young age of the remnant. Diffuse emission from the interior is nonthermal in origin as well, and fits to these regions yield similar values to those along the rim, also implying a young age. Thermal emission is present in the east, and the spectrum is consistent with a ∼650 km s‑1 shock wave encountering interstellar or circumstellar material with a density of ∼1 cm‑3.

  20. A Suzaku Study of Ejecta Structure and Origin of Hard X-ray Emission in the Supernova Remnant G156.2+5.7

    NASA Technical Reports Server (NTRS)

    Uchida, Hiroyuki; Tsunemi, Hiroshi; Katsuda, Satoru; Mori, Koji; Petre, Robert; Yamaguchi, Hiroya

    2012-01-01

    We report an X-ray study of the evolved Galactic supernova remnant (SNR) G1S6.2+S.7 based on six pointing observations with Suzaku. The remnant's large extent (100' in diameter) allows us to investigate its radial structure in the northwestern and eastern directions from the apparent center. The X-ray spectra. were well fit with a two-component non-equilibrium ionization model representing the swept-up interstellar medium (ISM) and the metal-rich ejecta. We found prominent central concentrations of Si, S and Fe from the ejecta component; the lighter elements of O, Ne and Mg were distributed more uniformly. The temperature of the ISM component suggests a slow shock (610-960 km/s), hence the remnant's age is estimated to be 7,000-15,000 yr, assuming its distance to be approx. 1.1 kpc. G1S6.2+5.7 has also been thought to emit hard, non-thermal X-rays, despite being considerably older than any other such remnant. In response to a recent discovery of a background cluster of galaxies (2XMM J045637.2+522411), we carefully excluded its contribution, and reexamined the origin of the hard X-ray emission. We found that the residual hard X-ray emission is consistent with the expected level of the cosmic X-ray background. Thus, no robust evidence for the non-thermal emission was obtained from G156.2+5.7. These results are consistent with the picture of an evolved SNR.

  1. Physical Conditions in Shocked Interstellar Gas Interacting with the Supernova Remnant IC 443

    NASA Astrophysics Data System (ADS)

    Ritchey, Adam M.; Federman, Steven Robert; Jenkins, Edward B.; Caprioli, Damiano; Wallerstein, George

    2018-06-01

    We present the results of a detailed investigation into the physical conditions in interstellar material interacting with the supernova remnant IC 443. Our analysis is based on an examination of high-resolution HST/STIS spectra of two stars probing predominantly neutral gas located both ahead of and behind the supernova shock front. The pre-shock neutral gas is characterized by densities and temperatures typical of diffuse interstellar clouds, while the post-shock material exhibits a range of more extreme physical conditions, including high temperatures (>104 K) in some cases, which may require a sudden heating event to explain. The ionization level is enhanced in the high-temperature post-shock material, which could be the result of enhanced radiation from shocks or from an increase in cosmic-ray ionization. The gas-phase abundances of refractory elements are also enhanced in the high-pressure gas, suggesting efficient destruction of dust grains by shock sputtering. Observations of highly-ionized species at very high velocity indicate a post-shock temperature of 107 K for the hot X-ray emitting plasma of the remnant’s interior, in agreement with studies of thermal X-ray emission from IC 443.

  2. Radio emission from embryonic superluminous supernova remnants

    NASA Astrophysics Data System (ADS)

    Omand, Conor M. B.; Kashiyama, Kazumi; Murase, Kohta

    2018-02-01

    It has been widely argued that Type-I superluminous supernovae (SLSNe-I) are driven by powerful central engines with a long-lasting energy injection after the core-collapse of massive progenitors. One of the popular hypotheses is that the hidden engines are fast-rotating pulsars with a magnetic field of B ˜ 1013-1015 G. Murase, Kashiyama & Mészáros proposed that quasi-steady radio/submm emission from non-thermal electron-positron pairs in nascent pulsar wind nebulae can be used as a relevant counterpart of such pulsar-driven supernovae (SNe). In this work, focusing on the nascent SLSN-I remnants, we examine constraints that can be placed by radio emission. We show that the Atacama Large Millimeter/submillimetre Array can detect the radio nebula from SNe at DL ˜ 1 Gpc in a few years after the explosion, while the Jansky Very Large Array can also detect the counterpart in a few decades. The proposed radio follow-up observation could solve the parameter degeneracy in the pulsar-driven SN model for optical/UV light curves, and could also give us clues to young neutron star scenarios for SLSNe-I and fast radio bursts.

  3. The Population of Supernova Remnants in M51

    NASA Astrophysics Data System (ADS)

    Long, Knox S.; Blair, William P.; Kuntz, K. D.; Winkler, P. Frank

    2017-08-01

    The nearby, actively star-forming, nearly face-on spiral galaxy, M51 (NGC 5194/5), has been the site of four supernovae since 1941. As a result it should have a rich population of young supernova remnants (SNRs). Here we describe a search for optical SNRs in M51 among the 298 X-ray sources discovered inside the D25 contour in deep Chandra observations. The search uses interference filter images obtained with the WFC3 on Hubble Space Telescope and more recent images from GMOS on Gemini North. Of 80 emission nebulae identified in the HST images as SNR candidates based on elevated [SII]: Ha ratios compared to HII regions, 40 have X-ray counterparts. The diameters of the SNRs and SNR candidates detected with HST are systematically smaller than seen in SNR populations of other galaxies at comparable distances. However, this is most likely an instrumental effect, which our ongoing analysis of the new GMOS images will correct. At that point, we will be able to make of fair multi-wavelength comparison of the SNR population in M51 with other nearby, actively star-forming spiral galaxies, such as M83 and NGC6946.

  4. Distance Measurement Solves Astrophysical Mysteries

    NASA Astrophysics Data System (ADS)

    2003-08-01

    Location, location, and location. The old real-estate adage about what's really important proved applicable to astrophysics as astronomers used the sharp radio "vision" of the National Science Foundation's Very Long Baseline Array (VLBA) to pinpoint the distance to a pulsar. Their accurate distance measurement then resolved a dispute over the pulsar's birthplace, allowed the astronomers to determine the size of its neutron star and possibly solve a mystery about cosmic rays. "Getting an accurate distance to this pulsar gave us a real bonanza," said Walter Brisken, of the National Radio Astronomy Observatory (NRAO) in Socorro, NM. Monogem Ring The Monogem Ring, in X-Ray Image by ROSAT satellite CREDIT: Max-Planck Institute, American Astronomical Society (Click on Image for Larger Version) The pulsar, called PSR B0656+14, is in the constellation Gemini, and appears to be near the center of a circular supernova remnant that straddles Gemini and its neighboring constellation, Monoceros, and is thus called the Monogem Ring. Since pulsars are superdense, spinning neutron stars left over when a massive star explodes as a supernova, it was logical to assume that the Monogem Ring, the shell of debris from a supernova explosion, was the remnant of the blast that created the pulsar. However, astronomers using indirect methods of determining the distance to the pulsar had concluded that it was nearly 2500 light-years from Earth. On the other hand, the supernova remnant was determined to be only about 1000 light-years from Earth. It seemed unlikely that the two were related, but instead appeared nearby in the sky purely by a chance juxtaposition. Brisken and his colleagues used the VLBA to make precise measurements of the sky position of PSR B0656+14 from 2000 to 2002. They were able to detect the slight offset in the object's apparent position when viewed from opposite sides of Earth's orbit around the Sun. This effect, called parallax, provides a direct measurement of distance. "Our measurements showed that the pulsar is about 950 light-years from Earth, essentially the same distance as the supernova remnant," said Steve Thorsett, of the University of California, Santa Cruz. "That means that the two almost certainly were created by the same supernova blast," he added. With that problem solved. the astronomers then turned to studying the pulsar's neutron star itself. Using a variety of data from different telescopes and armed with the new distance measurement, they determined that the neutron star is between 16 and 25 miles in diameter. In such a small size, it packs a mass roughly equal to that of the Sun. The next result of learning the pulsar's actual distance was to provide a possible answer to a longstanding question about cosmic rays. Cosmic rays are subatomic particles or atomic nuclei accelerated to nearly the speed of light. Shock waves in supernova remnants are thought to be responsible for accelerating many of these particles. Scientists can measure the energy of cosmic rays, and had noted an excess of such rays in a specific energy range. Some researchers had suggested that the excess could come from a single supernova remnant about 1000 light-years away whose supernova explosion was about 100,000 years ago. The principal difficulty with this suggestion was that there was no accepted candidate for such a source. "Our measurement now puts PSR B0656+14 and the Monogem Ring at exactly the right place and at exactly the right age to be the source of this excess of cosmic rays," Brisken said. With the ability of the VLBA, one of the telescopes of the NRAO, to make extremely precise position measurements, the astronomers expect to improve the accuracy of their distance determination even more. "This pulsar is becoming a fascinating laboratory for studying astrophysics and nuclear physics," Thorsett said. In addition to Brisken and Thorsett, the team of astronomers includes Aaron Golden of the National University of Ireland, Robert Benjamin of the University of Wisconsin, and Miller Goss of NRAO. The scientists are reporting their results in papers appearing in the Astrophysical Journal Letters in August. The VLBA is a continent-wide system of ten radio- telescope antennas, ranging from Hawaii in the west to the U.S. Virgin Islands in the east, providing the greatest resolving power, or ability to see fine detail, in astronomy. Dedicated in 1993, the VLBA is operated from the NRAO's Array Operations Center in Socorro, New Mexico. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

  5. New Hubble Observations of Supernova 1987A Trace Shock Wave

    NASA Image and Video Library

    2017-12-08

    Image release September 2, 2010 ABOUT THIS IMAGE: This image shows the entire region around supernova 1987A. The most prominent feature in the image is a ring with dozens of bright spots. A shock wave of material unleashed by the stellar blast is slamming into regions along the ring's inner regions, heating them up, and causing them to glow. The ring, about a light-year across, was probably shed by the star about 20,000 years before it exploded. An international team of astronomers using the Hubble Space Telescope reports a significant brightening of the emissions from Supernova 1987A. The results, which appear in this week's Science magazine, are consistent with theoretical predictions about how supernovae interact with their immediate galactic environment. The team observed the supernova remnant in optical, ultraviolet, and near-infrared light. They studied the interaction between the ejecta from the stellar explosion and a glowing 6-trillion-mile-diameter ring of gas encircling the supernova remnant. The gas ring was probably shed some 20,000 years before the supernova exploded. Shock waves resulting from the impact of the ejecta onto the ring have brightened 30 to 40 pearl-like "hot spots" in the ring. These blobs likely will grow and merge together in the coming years to form a continuous, glowing circle. "We are seeing the effect a supernova can have in the surrounding galaxy, including how the energy deposited by these stellar explosions changes the dynamics and chemistry of the environment," said University of Colorado at Boulder Research Associate Kevin France of the Center for Astrophysics and Space Astronomy. "We can use these new data to understand how supernova processes regulate the evolution of galaxies." Discovered in 1987, Supernova 1987A is the closest exploding star to Earth to be detected since 1604 and it resides in the nearby Large Magellanic Cloud, a dwarf galaxy adjacent to our own Milky Way Galaxy. Credit: NASA, ESA, K. France (University of Colorado, Boulder), and P. Challis and R. Kirshner (Harvard-Smithsonian Center for Astrophysics) NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe. Follow us on Twitter Join us on Facebook

  6. ASCA Observations of W44

    NASA Technical Reports Server (NTRS)

    Hughes, John P.

    1999-01-01

    We report the detection, using data from the Advanced Satellite for Cosmology and Astrophysics (ASCA), of a hard X-ray source in the vicinity of the radio pulsar PSR B1853+01, which is located within the supernova remnant (SNR) W44. PSR B1853+01, a 267 ms pulsar, has to date been detected only in the radio band. Previous observations at soft X-ray energies (e.g., with ROSAT HRI) have failed to detect any significant X-ray emission (pulsed or unpulsed) from the pulsar. In addition, no high-energy emission (approx. > 4 keV) has been detected previously from W44. Over the 0.5-4.0 keV band, the ASCA data show soft thermal emission from W44, with a morphology very similar to that observed earlier by Einstein and ROSAT. In the high-energy band (4.0-9.5 keV), the SNR is, for the most part, invisible, although a source coincident with the position of PSR B1853+01 is evident. The observed ASCA spectra are consistent with a power-law origin (photon index approx. 2.3) for the X-ray emission from this source at a flux level (flux density approx. 0.5 micro Jy at I keV) consistent with previous upper limits. The maximum allowed size for the source is determined directiv from the ASCA data (<5 min.), while the minimum size is derived from the nondetection of a point source in the ROSAT HRI data (approx. > 30 sec.). Timing analysis of the hard X-ray source failed to detect pulsations at the pulsar's period. Based on these lines of evidence, we conclude that the new hard source in W44 represents an X-ray synchrotron nebula associated with PSR B1853+01, rather than the beamed output of the pulsar itself. This discoverv adds W44 to the small group of previously known plerionic SNRs This nebula lies at the low end of, but is consistent with, the correlation between X-ray luminosity and pulsar spin-down energy loss found for such objects, lending further support to our interpretation.

  7. 3D Simulations of Supernova Remnants from Type Ia Supernova Models

    NASA Astrophysics Data System (ADS)

    Johnson, Heather; Reynolds, S. P.; Frohlich, C.; Blondin, J. M.

    2014-01-01

    Type Ia supernovae (SNe) originate from thermonuclear explosions of white dwarfs. A great deal is still unknown about the explosion mechanisms, particularly the degree of asymmetry. However, Type Ia supernova remnants (SNRs) can bear the imprint of asymmetry long after the explosion. A SNR of interest is G1.9+0.3, the youngest Galactic SNR, which demonstrates an unusual spatial distribution of elements in the ejecta. While its X-ray spectrum is dominated by synchrotron emission, spectral lines of highly ionized Si, S, and Fe are seen in a few locations, with Fe near the edge of the remnant and with strongly varying Fe/Si ratios. An asymmetric explosion within the white dwarf progenitor may be necessary to explain these unusual features of G1.9+0.3, in particular the shocked Fe at large radii. We use the VH-1 hydrodynamics code to evolve initial Type Ia explosion models in 1, 2, and 3 dimensions at an age of 100 seconds provided by other researchers to study asymmetry, the ignition properties, and the nucleosynthesis resulting from these explosions. We follow the evolution of these models interacting with a uniform external medium to a few hundred years in age. We find the abundance and location of ejecta elements from our models to be inconsistent with the observations of G1.9+0.3; while our models show asymmetric element distributions, we find no tendency for iron-group elements to be found beyond intermediate-mass elements, or for significant iron to be reverse-shocked at all at the age of G1.9+0.3. We compare the amounts of shocked iron-group and intermediate-mass elements as a function of time in the different models. Some new kind of explosion asymmetry may be required to explain G1.9+0.3. This work was performed as part of NC State University's Undergraduate Research in Computational Astrophysics (URCA) program, an REU program supported by the National Science Foundation through award AST-1032736.

  8. The surviving companions in type Ia supernova remnants

    NASA Astrophysics Data System (ADS)

    Chen, Li-Qing; Meng, Xiang-Cun; Han, Zhan-Wen

    2017-08-01

    The single-degenerate (SD) model is one of the most popular progenitor models of type Ia supernovae (SNe Ia), in which the companion star can survive after an SN Ia explosion and show peculiar properties. Therefore, searching for the surviving companion in type Ia supernova remnants (SNRs) is a potential method to verify the SD model. In the SN 1604 remnant (Kepler’s SNR), although Chandra X-ray observation suggests that the progenitor is most likely a WD+AGB system, a the surviving companion has not been found. One possible reason is rapid rotation of the white dwarf (WD), causing explosion of the WD to be delayed for a spin-down timescale, and then the companion evolved into a WD before the supernova explosion, so the companion is too dim to be detected. We aim to verify this possible explanation by carrying out binary evolution calculations. In this paper, we use Eggleton’s stellar evolution code to calculate the evolution of binaries consisting of a WD+red giant (RG). We assume that the rapidly rotating WD can continuously increase its mass when its mass exceeds the Chandrasekhar mass limit ({M}{{Ch}}=1.378 {M}⊙ ) until the mass-transfer rate decreases to be lower than a critical value. Eventually, we obtain the final masses of a WD in the range 1.378 M ⊙ to 2.707 M ⊙. We also show that if the spin-down time is less than 106 yr, the companion star will be very bright and easily observed; but if the spin-down time is as long as ˜ 107 yr, the luminosities of the surviving companion would be lower than the detection limit. Our simulation provides guidance in hunting for the surviving companion stars in SNRs, and the fact that no surviving companion has been found in Kepler’s SNR may not be definite evidence disfavoring the SD origin of Kepler’s SN.

  9. Molecular environment and an X-ray study of the double-shell supernova remnant Kes 79

    NASA Astrophysics Data System (ADS)

    Zhou, Ping; Chen, Yang; Safi-Harb, Samar; Ming, Sun

    Kes 79 is a remarkable middle-age supernova remnant (SNR) with double shells in radio band and many structures in X-rays, harbouring a CCO and with a transient magnetar to the south. We have performed new 12CO J=1-0, 13CO J=1-0, 12CO J=2-1 observations towards this remnant to investigate its molecular environment. SNR Kes 79 is found to be associated with the molecular cloud in LSR velocity 100-115 km/s, which deformed the SNR's shell in the east. The inner radio shell appears to be well confined by a molecular shell at V_{LSR}˜113 km/s. We also revisited the 380 ks XMM-Newton data of Kes 79, which reveal many bright filamentary structures well coincident with infrared features and an X-ray faint halo confined by the outer radio shell. We performed a spatially resolved spectroscopic analysis for the X-ray filaments and the halo emission. We also studied the spatial distribution of the overabundant metal species that may be related to the asymmetric ejecta. Finally, we will discuss the evolution of Kes 79 combining the molecular line and X-ray properties.

  10. Combining MeV-GeV γ-ray and X-ray Observations: A Broadband View of Supernova Remnant Kes 41

    NASA Astrophysics Data System (ADS)

    Castro, Daniel; Joubert, Timothy; Slane, Patrick O.; Figueroa-Feliciano, Enectali

    2015-01-01

    We report the detection of γ-ray emission coincident with the supernova remnant (SNR) Kes 41, using data from the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. Kes 41 is believed to be interacting with molecular clouds, as evidenced by observations of hydroxyl (OH) maser emission at 1720 MHz in its direction and other observational information. SNR shocks are expected to be sites of cosmic ray acceleration, and clouds of dense material can provide effective targets for production of γ-rays from π0-decay. We model its broadband nonthermal emission (from radio to γ-ray) using a simple one-zone model, and after considering scenarios where the MeV-GeV source originate in either π0-decay or leptonic emission, we conclude that the γ-rays must be produced through the hadronic channel and derive a lower limit to the density with which the SNR is interacting. Additionally, we analyze the XMM-Newton X-ray observation of this remnant and derive an approximate density of the emmitting material. The discrepancy between the densities derived from the X-ray and γ-ray is discussed.

  11. Fermi-LAT and WMAP Observations of the Puppis A Supernova Remnant

    DOE PAGES

    Hewitt, J. W.; Grondin, M. -H.; Lemoine-Goumard, M.; ...

    2012-10-22

    In this paper, we report the detection of GeV γ-ray emission from the supernova remnant (SNR) Puppis A with the Fermi Gamma-Ray Space Telescope. Puppis A is among the faintest SNRs yet detected at GeV energies, with a luminosity of only 2.7 × 10 34 (D/2.2 kpc) 2 erg s -1 between 1 and 100 GeV. The γ-ray emission from the remnant is spatially extended, with a morphology matching that of the radio and X-ray emission, and is well described by a simple power law with an index of 2.1. We attempt to model the broadband spectral energy distribution (SED),more » from radio to γ-rays, using standard nonthermal emission mechanisms. To constrain the relativistic electron population we use 7 years of Wilkinson Microwave Anisotropy Probe data to extend the radio spectrum up to 93 GHz. Finally, both leptonic- and hadronic-dominated models can reproduce the nonthermal SED, requiring a total content of cosmic-ray electrons and protons accelerated in Puppis A of at least W CR ≈ (1-5) × 10 49 erg.« less

  12. The impact of different interstellar medium structures on the dynamical evolution of supernova remnants

    NASA Astrophysics Data System (ADS)

    Wang, Yueyang; Bao, Biwen; Yang, Chuyuan; Zhang, Li

    2018-05-01

    The dynamical properties of supernova remnants (SNRs) evolving with different interstellar medium structures are investigated through performing extensive two-dimensional magnetohydrodynamic (MHD) simulations in the cylindrical symmetry. Three cases of different interstellar medium structures are considered: the uniform medium, the turbulent medium and the cloudy medium. Large-scale density and magnetic fluctuations are calculated and mapped into the computational domain before simulations. The clouds are set by random distribution in advance. The above configuration allows us to study the time-dependent dynamical properties and morphological evolution of the SNR evolving with different ambient structures, along with the development of the instabilities at the contact discontinuity. Our simulation results indicate that remnant morphology deviates from symmetry if the interstellar medium contains clouds or turbulent density fluctuations. In the cloudy medium case, interactions between the shock wave and clouds lead to clouds' fragmentation. The magnetic field can be greatly enhanced by stretching field lines with a combination of instabilities while the width of amplification region is quite different among the three cases. Moreover, both the width of amplification region and the maximum magnetic-field strength are closely related to the clouds' density.

  13. SEARCHING FOR OVERIONIZED PLASMA IN THE GAMMA-RAY-EMITTING SUPERNOVA REMNANT G349.7+0.2

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

    Ergin, T.; Sezer, A.; Saha, L.

    2015-05-10

    G349.7+0.2 is a supernova remnant (SNR) expanding in a dense medium of molecular clouds and interacting with clumps of molecular material emitting gamma-rays. We analyzed the gamma-ray data of the Large Area Telescope on board the Fermi Gamma-Ray Space Telescope and detected G349.7+0.2 in the energy range of 0.2–300 GeV with a significance of ∼13σ, showing no extended morphology. Modeling of the gamma-ray spectrum revealed that the GeV gamma-ray emission dominantly originates from the decay of neutral pions, where the protons follow a broken power-law distribution with a spectral break at ∼12 GeV. To search for features of radiative recombinationmore » continua in the eastern and western regions of the remnant, we analyzed the Suzaku data of G349.7+0.2 and found no evidence for overionized plasma. In this paper, we discuss possible scenarios to explain the hadronic gamma-ray emission in G349.7+0.2 and the mixed morphology nature of this SNR.« less

  14. An XMM-Newton Study of the Mixed-morphology Supernova Remnant G346.6-0.2

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

    Auchettl, Katie; Lopez, Laura; Ng, C-Y.

    We present an X-ray imaging and spectroscopic study of the molecular cloud interacting mixed-morphology supernova remnant G346.6–0.2 using XMM-Newton . The X-ray spectrum of the remnant is well described by a recombining plasma that most likely arises from adiabatic cooling and has subsolar abundances of Mg, Si, and S. Our fits also suggest the presence of either an additional power-law component with a photon index of ∼2 or an additional thermal component with a temperature of ∼2.0 keV. We investigate the possible origin of this component and suggest that it could arise from either the Galactic ridge X-ray emission, anmore » unidentified pulsar wind nebula, or X-ray synchrotron emission from high-energy particles accelerated at the shock. However, deeper, high-resolution observations of this object are needed to shed light on the presence and origin of this feature. Based on its morphology, its Galactic latitude, the density of the surrounding environment, and its association with a dense molecular cloud, G346.6–0.2 most likely arises from a massive progenitor that underwent core collapse.« less

  15. Deep H.E.S.S. observations of the supernova remnant RX J0852.0-4622

    NASA Astrophysics Data System (ADS)

    Sushch, Iurii; Paz Arribas, Manuel; Komin, Nukri; Schwanke, Ullrich

    2016-06-01

    The largest TeV source, RX J0852.0-4622 (Vela Jr.), is one of the few supernova remnants (SNRs) with well resolved shell-like morphology at very-high-energy (VHE; E>100 GeV) gamma-rays. Strong non-thermal emission across the electromagnetic spectrum from radio to VHE gamma-rays, young age and proximity of the remnant makes it one of the prime objects for the study of particle acceleration aiming to test the paradigm of SNRs being sources of Galactic cosmic rays. Here we present deep H.E.S.S. observations of RX J0852.0-4622 with roughly doubled exposure comparing to previously published results. Improved statistics together with new analysis techniques result in a firm determination of the cut-off in the gamma-ray spectrum and allow the spatially resolved spectroscopy studies. A smooth connection of the H.E.S.S. spectrum to the spectrum at GeV energies as reported by Fermi/LAT provides an exciting opportunity to recover the present-time parent particle population in both leptonic and hadronic scenarios directly from the gamma-ray data alone. These new observations provide us a deeper insight and better understanding of the physical processes in SNRs.

  16. 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.

  17. Optimally setting up directed searches for continuous gravitational waves in Advanced LIGO O1 data

    NASA Astrophysics Data System (ADS)

    Ming, Jing; Papa, Maria Alessandra; Krishnan, Badri; Prix, Reinhard; Beer, Christian; Zhu, Sylvia J.; Eggenstein, Heinz-Bernd; Bock, Oliver; Machenschalk, Bernd

    2018-02-01

    In this paper we design a search for continuous gravitational waves from three supernova remnants: Vela Jr., Cassiopeia A (Cas A) and G347.3. These systems might harbor rapidly rotating neutron stars emitting quasiperiodic gravitational radiation detectable by the advanced LIGO detectors. Our search is designed to use the volunteer computing project Einstein@Home for a few months and assumes the sensitivity and duty cycles of the advanced LIGO detectors during their first science run. For all three supernova remnants, the sky positions of their central compact objects are well known but the frequency and spin-down rates of the neutron stars are unknown which makes the searches computationally limited. In a previous paper we have proposed a general framework for deciding on what target we should spend computational resources and in what proportion, what frequency and spin-down ranges we should search for every target, and with what search setup. Here we further expand this framework and apply it to design a search directed at detecting continuous gravitational wave signals from the most promising three supernova remnants identified as such in the previous work. Our optimization procedure yields broad frequency and spin-down searches for all three objects, at an unprecedented level of sensitivity: The smallest detectable gravitational wave strain h0 for Cas A is expected to be 2 times smaller than the most sensitive upper limits published to date, and our proposed search, which was set up and ran on the volunteer computing project Einstein@Home, covers a much larger frequency range.

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

    Montes, Gabriela; Ramirez-Ruiz, Enrico; Naiman, Jill

    The r -process nuclei are robustly synthesized in the material ejected during neutron star binary mergers (NSBMs). If NSBMs are indeed solely responsible for the solar system r -process abundances, a galaxy like our own would be required to host a few NSBMs per million years, with each event ejecting, on average, about 5 × 10{sup −2} M {sub ⊙} of r -process material. Because the ejecta velocities in the tidal tail are significantly larger than those in ordinary supernovae, NSBMs deposit a comparable amount of energy into the ISM. In contrast to extensive efforts studying spherical models for supernovamore » remnant evolution, calculations quantifying the impact of NSBM ejecta in the ISM have been lacking. To better understand their evolution, we perform a suite of three-dimensional hydrodynamic simulations of isolated NSBM ejecta expanding in environments with conditions adopted from Milky-Way-like galaxy simulations. Although the remnant morphology is highly complex at early times, the subsequent radiative evolution is remarkably similar to that of a standard supernova. This implies that sub-resolution supernova feedback models can be used in galaxy-scale simulations that are unable to resolve the key evolutionary phases of NSBMs. Among other quantities, we examine the radius, mass, and kinetic energy content of the remnant at shell formation. We find that the shell formation epoch is attained when the swept-up mass is about 10{sup 3}( n {sub H}/1 cm{sup −3}){sup −2/7} M {sub ⊙;} at this point, the mass fraction of r -process material is enhanced up to two orders of magnitude in relation to a solar metallicity ISM.« less

  19. LOFAR 150-MHz observations of SS 433 and W 50

    NASA Astrophysics Data System (ADS)

    Broderick, J. W.; Fender, R. P.; Miller-Jones, J. C. A.; Trushkin, S. A.; Stewart, A. J.; Anderson, G. E.; Staley, T. D.; Blundell, K. M.; Pietka, M.; Markoff, S.; Rowlinson, A.; Swinbank, J. D.; van der Horst, A. J.; Bell, M. E.; Breton, R. P.; Carbone, D.; Corbel, S.; Eislöffel, J.; Falcke, H.; Grießmeier, J.-M.; Hessels, J. W. T.; Kondratiev, V. I.; Law, C. J.; Molenaar, G. J.; Serylak, M.; Stappers, B. W.; van Leeuwen, J.; Wijers, R. A. M. J.; Wijnands, R.; Wise, M. W.; Zarka, P.

    2018-04-01

    We present Low-Frequency Array (LOFAR) high-band data over the frequency range 115-189 MHz for the X-ray binary SS 433, obtained in an observing campaign from 2013 February to 2014 May. Our results include a deep, wide-field map, allowing a detailed view of the surrounding supernova remnant W 50 at low radio frequencies, as well as a light curve for SS 433 determined from shorter monitoring runs. The complex morphology of W 50 is in excellent agreement with previously published higher frequency maps; we find additional evidence for a spectral turnover in the eastern wing, potentially due to foreground free-free absorption. Furthermore, SS 433 is tentatively variable at 150 MHz, with both a debiased modulation index of 11 per cent and a χ2 probability of a flat light curve of 8.2 × 10-3. By comparing the LOFAR flux densities with contemporaneous observations carried out at 4800 MHz with the RATAN-600 telescope, we suggest that an observed ˜0.5-1 Jy rise in the 150-MHz flux density may correspond to sustained flaring activity over a period of approximately 6 months at 4800 MHz. However, the increase is too large to be explained with a standard synchrotron bubble model. We also detect a wealth of structure along the nearby Galactic plane, including the most complete detection to date of the radio shell of the candidate supernova remnant G 38.7-1.4. This further demonstrates the potential of supernova remnant studies with the current generation of low-frequency radio telescopes.

  20. Recombining Plasma and Gamma-Ray Emission in the Mixed-morphology Supernova Remnant 3C 400.2

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

    Ergin, T.; Sezer, A.; Sano, H.

    3C 400.2 belongs to the mixed-morphology supernova remnant class, showing center-filled X-ray and shell-like radio morphology. We present a study of 3C 400.2 with archival Suzaku and Fermi -LAT observations. We find recombining plasma (RP) in the Suzaku spectra of north–east and south–east regions. The spectra of these regions are well described by two-component thermal plasma models: the hard component is in RP, while the soft component is in collisional ionization equilibrium (CIE) conditions. The RP has enhanced abundances, indicating that the X-ray emission has an ejecta origin, while the CIE has solar abundances associated with the interstellar material. Themore » X-ray spectra of north–west and south–west regions are best fitted by a two-component thermal plasma model: an ionizing and a CIE plasma. We have detected GeV gamma-ray emission from 3C 400.2 at the level of ∼5 σ , assuming a point-like source model with a power-law (PL) type spectrum. We have also detected a new GeV source at the level of ∼13 σ, assuming a Gaussian extension model with a PL-type spectrum in the neighborhood of the supernova remnant. We report the analysis results of 3C 400.2 and the new extended gamma-ray source, and discuss the nature of gamma-ray emission of 3C 400.2 in the context of existing NANTEN CO data, Dominion Radio Astrophysical Observatory H i data, and the Suzaku X-ray analysis results.« less

  1. X-ray study of the supernova remnant G337.2-0.7

    NASA Astrophysics Data System (ADS)

    Takata, Akihiro; Nobukawa, Masayoshi; Uchida, Hiroyuki; Tsuru, Takeshi Go; Tanaka, Takaaki; Koyama, Katsuji

    2016-06-01

    This paper reports on the Suzaku result of the Galactic supernova remnant (SNR) G337.2-0.7. The X-ray spectrum is well explained by three components in ionizing phase. One is a plasma with a low temperature kT = 0.70_{-0.03}^{+0.02}keV, solar abundances, and an ionization parameter n_et = 5.7^{+0.7}_{-0.4}× 10^{11}s cm-3. The second is a middle-temperature plasma with kT = 1.54^{+0.13}_{-0.02}keV and high metal abundances in a highly ionized state of n_et = 3.6^{+0.2}_{-0.5}× 10^{11}s cm-3, and the third is a high-temperature plasma with kT = 3.1^{+0.2}_{-0.1}keV and high metal abundances in a low-ionized state of n_et=2.1^{+0.4}_{-0.2}× 10^{10}s cm-3. The high metal-abundance plasmas are likely to be of an ejecta origin, while the solar abundance plasma would be of an interstellar-gas origin. The abundance pattern and mass of the ejecta confirm that G337.2-0.7 is a remnant of a Type Ia supernova (SN). The derived Fe mass of ejecta MFe = 0.025-0.039 M⊙ is far smaller than that expected from any Type Ia model, suggesting that most Fe has not yet been heated by the reverse shock. The ejecta has enhanced distribution in the northeastern region compared to the central region, and therefore the SN explosion or SNR evolution would be asymmetric.

  2. 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.

  3. Sizzling Remains of a Dead Star

    NASA Image and Video Library

    2013-01-07

    This new view of the historical supernova remnant Cassiopeia A, located 11,000 light-years away, was taken by NASA Nuclear Spectroscopic Telescope Array, or NuSTAR. While the star is long dead, its remains are still bursting with action.

  4. Discovery of a Young, Energetic Pulsar Near the Supernova Remnant G290.1-0.8 and the Gamma-Ray Source 2EG J1103-6106

    NASA Technical Reports Server (NTRS)

    Kaspi, V. M.; Bailes, M.; Manchester, R. N.; Stappers, B. W.; Sandhu, J.; Navarro, J.; D'Amico, N.

    1996-01-01

    We report on the discovery and follow-up timing observations of a 63-ms radio pulsar, PSR J1105-6107. We show that the pulsar is young, having a characteristic age of only 63kyr. We consider its possible association with the nearby remnant G290.1-0.8 (MSH 11-61A) but uncertainties in the distances and ages preclude a firm conclusion.

  5. Deep view of the Large Magellanic Cloud with six years of Fermi-LAT observations

    NASA Astrophysics Data System (ADS)

    Ackermann, M.; Albert, A.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Bloom, E. D.; Bonino, R.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buehler, R.; Caliandro, G. A.; Cameron, R. A.; Caragiulo, M.; Caraveo, P. A.; Cavazzuti, E.; Cecchi, C.; Charles, E.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Cohen-Tanugi, J.; Cutini, S.; D'Ammando, F.; de Angelis, A.; de Palma, F.; Desiante, R.; Digel, S. W.; Drell, P. S.; Favuzzi, C.; Ferrara, E. C.; Focke, W. B.; Franckowiak, A.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giordano, F.; Godfrey, G.; Grenier, I. A.; Grondin, M.-H.; Guillemot, L.; Guiriec, S.; Harding, A. K.; Hill, A. B.; Horan, D.; Jóhannesson, G.; Knödlseder, J.; Kuss, M.; Larsson, S.; Latronico, L.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lubrano, P.; Maldera, S.; Martin, P.; Mayer, M.; Mazziotta, M. N.; Michelson, P. F.; Mizuno, T.; Monzani, M. E.; Morselli, A.; Murgia, S.; Nuss, E.; Ohsugi, T.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Romani, R. W.; Sánchez-Conde, M.; Schulz, A.; Sgrò, C.; Siskind, E. J.; Smith, D. A.; Spada, F.; Spandre, G.; Spinelli, P.; Suson, D. J.; Takahashi, H.; Thayer, J. B.; Tibaldo, L.; Torres, D. F.; Tosti, G.; Troja, E.; Vianello, G.; Wood, M.; Zimmer, S.

    2016-02-01

    Context. The nearby Large Magellanic Cloud (LMC) provides a rare opportunity of a spatially resolved view of an external star-forming galaxy in γ-rays. The LMC was detected at 0.1-100 GeV as an extended source with CGRO/EGRET and using early observations with the Fermi-LAT. The emission was found to correlate with massive star-forming regions and to be particularly bright towards 30 Doradus. Aims: Studies of the origin and transport of cosmic rays (CRs) in the Milky Way are frequently hampered by line-of-sight confusion and poor distance determination. The LMC offers a complementary way to address these questions by revealing whether and how the γ-ray emission is connected to specific objects, populations of objects, and structures in the galaxy. Methods: We revisited the γ-ray emission from the LMC using about 73 months of Fermi-LAT P7REP data in the 0.2-100 GeV range. We developed a complete spatial and spectral model of the LMC emission, for which we tested several approaches: a simple geometrical description, template-fitting, and a physically driven model for CR-induced interstellar emission. Results: In addition to identifying PSR J0540-6919 through its pulsations, we find two hard sources positionally coincident with plerion N 157B and supernova remnant N 132D, which were also detected at TeV energies with H.E.S.S. We detect an additional soft source that is currently unidentified. Extended emission dominates the total flux from the LMC. It consists of an extended component of about the size of the galaxy and additional emission from three to four regions with degree-scale sizes. If it is interpreted as CRs interacting with interstellar gas, the large-scale emission implies a large-scale population of ~1-100 GeV CRs with a density of ~30% of the local Galactic value. On top of that, the three to four small-scale emission regions would correspond to enhancements of the CR density by factors 2 to 6 or higher, possibly more energetic and younger populations of CRs compared to the large-scale population. An alternative explanation is that this is emission from an unresolved population of at least two dozen objects, such as pulsars and their nebulae or supernova remnants. This small-scale extended emission has a spatial distribution that does not clearly correlate with known components of the LMC, except for a possible relation to cavities and supergiant shells. Conclusions: The Fermi-LAT GeV observations allowed us to detect individual sources in the LMC. Three of the newly discovered sources are associated with rare and extreme objects. The 30 Doradus region is prominent in GeV γ-rays because PSR J0540-6919 and N 157B are strong emitters. The extended emission from the galaxy has an unexpected spatial distribution, and observations at higher energies and in radio may help to clarify its origin. FITS file of Fig. 1 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/586/A71

  6. A Highly Ordered Magnetic Field in a Crushed Pulsar Wind Nebula in G327.1-1.1

    NASA Astrophysics Data System (ADS)

    Ma, Yik Ki; Ng, Chi-Yung; Bucciantini, Niccolò; Gaensler, Bryan M.; Slane, Patrick O.; Temim, Tea

    2015-01-01

    A significant fraction of a pulsar's spin-down luminosity is in the form of a relativistic magnetized particle outflow known as a pulsar wind. Confinement of the wind by the ambient medium creates a synchrotron-emitting bubble called a pulsar wind nebula (PWN). Studies of PWNe is important for understanding the physics of relativistic shocks and particle acceleration. Simulations suggest that a PWN will be crushed by the reverse shock of its surrounding supernova remnant at an age of ~10^4 yr, resulting in a turbulent environment. However, given the short timescale of the interaction stage, only a few such systems are observed.We present radio polarization observations of the PWN in supernova remnant G327.1-1.1, taken with the Australia Telescope Compact Array. Previous works suggest that this system has recently interacted with the supernova reverse shock, providing a rare example for the study of magnetic field in a crushed PWN. We found a highly ordered magnetic field in the PWN, which is unexpected given the presumed turbulent interior of the nebula. This suggests that the magnetic pressure in the PWN could play an important role in the interaction with supernova reverse shock.The Australia Telescope Compact Array is part of the Australia Telescope National Facility which is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO.YKM and CYN are supported by a ECS grant of the Hong Kong Government under HKU 709713P

  7. Columbia/Einstein observations of galactic X-ray sources

    NASA Technical Reports Server (NTRS)

    Long, K. S.

    1979-01-01

    The imaging observations of galactic clusters are presented. These fall into three categories: pre-main-sequence stars in the Orion nebulae, isolated-main-and-post main-sequence stars, and supernova remnants SNR. In addition to SNR, approximately 30 sources were detected.

  8. Hubble Sees Stars and a Stripe in Celestial Fireworks

    NASA Image and Video Library

    2008-07-01

    A delicate ribbon of gas floats eerily in our galaxy. This image, taken by NASA Hubble Space Telescope, is a very thin section of a supernova remnant caused by a stellar explosion that occurred more than 1,000 years ago.

  9. NASA Space Observatories Glimpse Faint Afterglow of Nearby Stellar Explosion

    NASA Astrophysics Data System (ADS)

    2005-10-01

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

  10. Stellar Forensics with Striking Image from Chandra

    NASA Astrophysics Data System (ADS)

    2007-10-01

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

  11. A progenitor binary and an ejected mass donor remnant of faint type Ia supernovae

    NASA Astrophysics Data System (ADS)

    Geier, S.; Marsh, T. R.; Wang, B.; Dunlap, B.; Barlow, B. N.; Schaffenroth, V.; Chen, X.; Irrgang, A.; Maxted, P. F. L.; Ziegerer, E.; Kupfer, T.; Miszalski, B.; Heber, U.; Han, Z.; Shporer, A.; Telting, J. H.; Gänsicke, B. T.; Østensen, R. H.; O'Toole, S. J.; Napiwotzki, R.

    2013-06-01

    Type Ia supernovae (SN Ia) are the most important standard candles for measuring the expansion history of the universe. The thermonuclear explosion of a white dwarf can explain their observed properties, but neither the progenitor systems nor any stellar remnants have been conclusively identified. Underluminous SN Ia have been proposed to originate from a so-called double-detonation of a white dwarf. After a critical amount of helium is deposited on the surface through accretion from a close companion, the helium is ignited causing a detonation wave that triggers the explosion of the white dwarf itself. We have discovered both shallow transits and eclipses in the tight binary system CD-30°11223 composed of a carbon/oxygen white dwarf and a hot helium star, allowing us to determine its component masses and fundamental parameters. In the future the system will transfer mass from the helium star to the white dwarf. Modelling this process we find that the detonation in the accreted helium layer is sufficiently strong to trigger the explosion of the core. The helium star will then be ejected at such high velocity that it will escape the Galaxy. The predicted properties of this remnant are an excellent match to the so-called hypervelocity star US 708, a hot, helium-rich star moving at more than 750 km s-1, sufficient for it to leave the Galaxy. The identification of both progenitor and remnant provides a consistent picture of the formation and evolution of underluminous SNIa.

  12. Molecular Environment and an X-Ray Spectroscopy of Supernova Remnant Kesteven 78

    NASA Astrophysics Data System (ADS)

    Zhou, Ping; Chen, Yang

    2011-12-01

    We investigate the molecular environment of the Galactic supernova remnant (SNR) Kesteven 78 and perform an XMM-Newton X-ray spectroscopic study for the northeastern edge of the remnant. SNR Kes 78 is found to interact with the molecular clouds (MCs) at a systemic local standard of rest velocity of 81 km s-1. At around this velocity, the SNR appears to contact a long molecular strip in the northeast and a large cloud in the east as revealed in the 13CO line, which may be responsible for the radio brightness peak and the OH maser, respectively. The 12CO-line bright region morphologically matches the eastern bright radio shell in general, and the SNR is consistent in extent with a CO cavity. Broadened 12CO-line profiles discerned in the eastern maser region and the western clumpy molecular arc and the elevated 12CO (J = 2-1)/(J = 1-0) ratios along the SNR boundary may be signatures of shock perturbation in the molecular gas. The SNR-MC association places the SNR at a kinematic distance of 4.8 kpc. The X-rays arising from the northeastern radio shell are emitted by underionized hot (~1.5 keV), low-density (~0.1 cm-3) plasma with solar abundance, and the plasma may be of intercloud origin. The age of the remnant is inferred to be about 6 kyr. The size of the molecular cavity in Kes 78 implies an initial mass around 22 M ⊙ for the progenitor.

  13. PROPER MOTIONS AND BRIGHTNESS VARIATIONS OF NONTHERMAL X-RAY FILAMENTS IN THE CASSIOPEIA A SUPERNOVA REMNANT

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

    Patnaude, Daniel J.; Fesen, Robert A.

    2009-05-20

    We present Chandra ACIS X-ray observations of the Galactic supernova remnant Cassiopeia A taken in 2007 December. Combining these data with previous archival Chandra observations taken in 2000, 2002, and 2004, we estimate the remnant's forward shock velocity at various points around the outermost shell to range between 4200 and 5200 {+-} 500 km s{sup -1}. Using these results together with previous analyses of Cas A's X-ray emission, we present a model for the evolution of Cas A and find that it's expansion is well fit by a {rho}{sub ej} {proportional_to} r {sup -(7-9)} ejecta profile running into a circumstellarmore » wind. We further find that while the position of the reverse shock in this model is consistent with that measured in the X-rays, in order to match the forward shock velocity and radius we had to assume that {approx} 30% of the explosion energy has gone into accelerating cosmic rays at the forward shock. The new X-ray images also show that brightness variations can occur for some forward shock filaments like that seen for several nonthermal filaments seen projected in the interior of the remnant. Spectral fits to exterior forward shock filaments and interior nonthermal filaments show that they exhibit similar spectra. This together with similar flux variations suggests that interior nonthermal filaments might be simply forward shock filaments seen in projection and not located at the reverse shock as has been recently proposed.« less

  14. Unveiling the spatial structure of the overionized plasma in the supernova remnant W49B

    NASA Astrophysics Data System (ADS)

    Zhou, Xin; Miceli, Marco; Bocchino, Fabrizio; Orlando, Salvatore; Chen, Yang

    2011-07-01

    W49B is a mixed-morphology supernova remnant with thermal X-ray emission dominated by the ejecta. In this remnant, the presence of overionized plasma has been directly established, with information about its spatial structure. However, the physical origin of the overionized plasma in W49B has not yet been understood. We investigate this intriguing issue through a 2D hydrodynamic model that takes into account, for the first time, the mixing of ejecta with the inhomogeneous circumstellar and interstellar medium, the thermal conduction, the radiative losses from optically thin plasma and the deviations from equilibrium of ionization induced by plasma dynamics. The model was set up on the basis of the observational results. We found that the thermal conduction plays an important role in the evolution of W49B, inducing the evaporation of the circumstellar ring-like cloud (whose presence has been deduced from previous observations) that mingles with the surrounding hot medium, cooling down the shocked plasma, and pushes the ejecta backwards to the centre of the remnant, forming there a jet-like structure. During the evolution, a large region of overionized plasma forms within the remnant. The overionized plasma originates from the rapid cooling of the hot plasma originally heated by the shock reflected from the dense ring-like cloud. In particular, we found two different ways for the rapid cooling of plasma to appear: (i) the mixing of relatively cold and dense material evaporated from the ring with the hot shocked plasma and (ii) the rapid adiabatic expansion of the ejecta. The spatial distribution of the radiative recombination continuum predicted by the numerical model is in good agreement with that observed.

  15. History of Chandra X-Ray Observatory

    NASA Image and Video Library

    2000-03-01

    The Chandra X-Ray Observatory has captured this spectacular image of G292.0+1.8, a young, oxygen-rich supernova remnant with a pulsar at its center surrounded by outflowing material. This image shows a rapidly expanding shell of gas that is 36 light-years across and contains large amounts of elements such as oxygen, neon, magnesium, silicon and sulfur. Embedded in this cloud of multimillion-degree gas is a key piece of evidence linking neutron stars and supernovae produced by the collapse of massive stars. With an age estimated at 1,600 years, G292.0+1.8 is one of three known oxygen-rich supernovae in our galaxy. These supernovae are of great interest to astronomers because they are one of the primary sources of the heavy elements necessary to form planets and people. Scattered through the image are bluish knots of emissions containing material that is highly enriched in newly created oxygen, neon, and magnesium produced deep within the original star and ejected by the supernova explosion.

  16. Molecular Diagnostics of Supernova Remnant Shocks

    NASA Astrophysics Data System (ADS)

    Lazendic, J. S.; Wardle, M.; Green, A. J.; Whiteoak, J. B.; Burton, M. G.

    We have undertaken a study of radio and infrared molecular-line emission towards several SNRs in order to investigate molecular signatures of SNR shocks, and to test models for OH maser production in SNRs. Here we present results on G349.7+0.2.

  17. The X-Ray Light Curve of the Very Luminous Supernova SN 1978K in NGC 1313

    NASA Astrophysics Data System (ADS)

    Schlegel, Eric M.; Petre, R.; Colbert, E. J. M.

    1996-01-01

    We present the 0.5-2.0 keV light curve of the X-ray luminous supernova SN 1978K in NGC 1313, based on six ROSAT observations spanning 1990 July to t994 July. SN 1978K is one of a few supernovae or supernova remnants that are very luminous (˜1039-1040 ergs s-1) in the X-ray, optical, and radio bands, and the first, at a supernova age of 10-20 yr, for which sufficient data exist to create an X-ray light curve. The X-ray flux is approximately constant over the 4 yr sampled by our observations, which were obtained 12-16 yr after the initial explosion. Three models exist to explain the large X-ray luminosity: pulsar input, a reverse shock running back into the expanding debris of the supernova, and the outgoing shock crushing of cloudlets in the debris field. Based upon calculations of Chevalier & Fransson, a pulsar cannot provide sufficient energy to produce the soft X-ray luminosity. Based upon the models and the light curve to date, it is not possible to discern the evolutionary phase of the supernova.

  18. HD271791: dynamical versus binary-supernova ejection scenario

    NASA Astrophysics Data System (ADS)

    Gvaramadze, V. V.

    2009-05-01

    The atmosphere of the extremely high-velocity (530-920kms-1) early B-type star HD271791 is enriched in α-process elements, which suggests that this star is a former secondary component of a massive tight binary system and that its surface was polluted by the nucleosynthetic products after the primary star exploded in a supernova. It was proposed that the (asymmetric) supernova explosion unbind the system and that the secondary star (HD271791) was released at its orbital velocity in the direction of Galactic rotation. In this Letter, we show that to explain the Galactic rest-frame velocity of HD271791 within the framework of the binary-supernova scenario, the stellar remnant of the supernova explosion (a <~10Msolar black hole) should receive an unrealistically large kick velocity of >=750-1200kms-1. We therefore consider the binary-supernova scenario as highly unlikely and instead propose that HD271791 attained its peculiar velocity in the course of a strong dynamical three- or four-body encounter in the dense core of the parent star cluster. Our proposal implies that by the moment of encounter HD271791 was a member of a massive post-supernova binary.

  19. X-Ray Illumination of the Ejecta of Supernova 1987A

    NASA Technical Reports Server (NTRS)

    Larsson, J.; Fransson, C.; Oestlin, G.; Groeningsson, P.; Jerkstrand, A.; Kozma, C.; Sollerman, J.; Challis, P.; Kirshner, R. P.; Chevalier, R. A.; hide

    2011-01-01

    When a massive star explodes as a supernova, substantial amounts of radioactive elements-primarily Ni-56, Ni-57 and Ti-44 are produced. After the initial from shock heating, the light emitted by the supernova is due to the decay of these elements. However, after decades, the energy powering a supernova remnant comes from the shock interaction between the ejecta and the surrounding medium. The transition to this phase has hitherto not been observed: supernovae occur too infrequently in the Milky Way to provide a young example, and extragalactic supernovae are generally too faint and too small. Here we report observations that show this transition in the supernova SN 1987A in the Large Magellan Cloud. From 1994 to 200l, the ejecta faded owing to radioactive decay of Ti-44 as predicted. Then the flux started to increase, more than doubling by the end of 2009. We show that this increase is the result of heat deposited by X-rays produced as the ejecta interacts with the surrounding material. In time, the X-rays will penetrate farther into the ejects, enabling us to analyse the structure and chemistry of the vanished star.

  20. The supernova remnant W49B as seen with H.E.S.S. and Fermi-LAT

    NASA Astrophysics Data System (ADS)

    H. E. S. S. Collaboration; Abdalla, H.; Abramowski, A.; Aharonian, F.; Benkhali, F. Ait; Akhperjanian, A. G.; Andersson, T.; Angüner, E. O.; Arrieta, M.; Aubert, P.; Backes, M.; Balzer, A.; Barnard, M.; Becherini, Y.; Tjus, J. Becker; Berge, D.; Bernhard, S.; Bernlöhr, K.; Blackwell, R.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Bregeon, J.; Brun, F.; Brun, P.; Bryan, M.; Bulik, T.; Capasso, M.; Carr, J.; Casanova, S.; Cerruti, M.; Chakraborty, N.; Chalme-Calvet, R.; Chaves, R. C. G.; Chen, A.; Chevalier, J.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Condon, B.; Conrad, J.; Cui, Y.; Davids, I. D.; Decock, J.; Degrange, B.; Deil, C.; Devin, J.; deWilt, P.; Dirson, L.; Djannati-Ataï, A.; Domainko, W.; Donath, A.; Drury, L. O.'C.; Dubus, G.; Dutson, K.; Dyks, J.; Edwards, T.; Egberts, K.; Eger, P.; Ernenwein, J.-P.; Eschbach, S.; Farnier, C.; Fegan, S.; Fernandes, M. V.; Fiasson, A.; Fontaine, G.; Förster, A.; Funk, S.; Füßling, M.; Gabici, S.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Gottschall, D.; Goyal, A.; Grondin, M.-H.; Hadasch, D.; Hahn, J.; Haupt, M.; Hawkes, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hinton, J. A.; Hofmann, W.; Hoischen, C.; Holler, M.; Horns, D.; Ivascenko, A.; Jacholkowska, A.; Jamrozy, M.; Janiak, M.; Jankowsky, D.; Jankowsky, F.; Jingo, M.; Jogler, T.; Jouvin, L.; Jung-Richardt, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kerszberg, D.; Khélifi, B.; Kieffer, M.; King, J.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Kraus, M.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lau, J.; Lees, J.-P.; Lefaucheur, J.; Lefranc, V.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Leser, E.; Lohse, T.; Lorentz, M.; Liu, R.; López-Coto, R.; Lypova, I.; Marandon, V.; Marcowith, A.; Mariaud, C.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; Meintjes, P. J.; Meyer, M.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Mohrmann, L.; Morå, K.; Moulin, E.; Murach, T.; Naurois, M. de; Niederwanger, F.; Niemiec, J.; Oakes, L.; O'Brien, P.; Odaka, H.; Öttl, S.; Ohm, S.; Ostrowski, M.; Oya, I.; Padovani, M.; Panter, M.; Parsons, R. D.; Pekeur, N. W.; Pelletier, G.; Perennes, C.; Petrucci, P.-O.; Peyaud, B.; Piel, Q.; Pita, S.; Poon, H.; Prokhorov, D.; Prokoph, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Reimer, A.; Reimer, O.; Renaud, M.; los Reyes, R. de; Rieger, F.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Salek, D.; Sanchez, D. A.; Santangelo, A.; Sasaki, M.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwemmer, S.; Settimo, M.; Seyffert, A. S.; Shafi, N.; Shilon, I.; Simoni, R.; Sol, H.; Spanier, F.; Spengler, G.; Spies, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tibaldo, L.; Tiziani, D.; Tluczykont, M.; Trichard, C.; Tuffs, R.; Uchiyama, Y.; van der Walt, D. J.; Eldik, C. van; Rensburg, C. van; Soelen, B. van; Vasileiadis, G.; Veh, J.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Voisin, F.; Völk, H. J.; Vuillaume, T.; Wadiasingh, Z.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Yang, R.; Zabalza, V.; Zaborov, D.; Zacharias, M.; Zdziarski, A. A.; Zech, A.; Zefi, F.; Ziegler, A.; Żywucka, N.; Fermi-LAT Collaboration; Katsuta, J.

    2018-04-01

    The supernova remnant (SNR) W49B originated from a core-collapse supernova that occurred between one and four thousand years ago, and subsequently evolved into a mixed-morphology remnant, which is interacting with molecular clouds (MC). Gamma-ray observations of SNR-MC associations are a powerful tool to constrain the origin of Galactic cosmic rays, as they can probe the acceleration of hadrons through their interaction with the surrounding medium and subsequent emission of non-thermal photons. We report the detection of a γ-ray source coincident with W49B at very high energies (VHE; E > 100 GeV) with the H.E.S.S. Cherenkov telescopes together with a study of the source with five years of Fermi-LAT high-energy γ-ray (0.06-300 GeV) data. The smoothly connected, combined source spectrum, measured from 60 MeV to multi-TeV energies, shows two significant spectral breaks at 304 ± 20 MeV and 8.4-2.5+2.2 GeV; the latter is constrained by the joint fit from the two instruments. The detected spectral features are similar to those observed in several other SNR-MC associations and are found to be indicative of γ-ray emission produced through neutral-pion decay. The H.E.S.S. gamma-ray excess map (see Fig. 1, in FITS format) of the W49 region is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/612/A5

  1. Late-Time Evolution of Composite Supernova Remnants: Deep Chandra Observations and Hydrodynamical Modeling of a Crushed Pulsar Wind Nebula in SNR G327.1-1.1

    NASA Technical Reports Server (NTRS)

    Temim, Tea; Slane, Patrick; Kolb, Christopher; Blondin, John; Hughes, John P.; Bucciantini, Niccolo

    2015-01-01

    In an effort to better understand the evolution of composite supernova remnants (SNRs) and the eventual fate of relativistic particles injected by their pulsars, we present a multifaceted investigation of the interaction between a pulsar wind nebula (PWN) and its host SNR G327.1-1.1. Our 350 ks Chandra X-ray observations of SNR G327.1-1.1 reveal a highly complex morphology; a cometary structure resembling a bow shock, prong-like features extending into large arcs in the SNR interior, and thermal emission from the SNR shell. Spectral analysis of the non-thermal emission offers clues about the origin of the PWN structures, while enhanced abundances in the PWN region provide evidence for mixing of supernova ejecta with PWN material. The overall morphology and spectral properties of the SNR suggest that the PWN has undergone an asymmetric interaction with the SNR reverse shock(RS) that can occur as a result of a density gradient in the ambient medium and or a moving pulsar that displaces the PWN from the center of the remnant. We present hydrodynamical simulations of G327.1-1.1 that show that its morphology and evolution can be described by a approx. 17,000 yr old composite SNR that expanded into a density gradient with an orientation perpendicular to the pulsar's motion. We also show that the RSPWN interaction scenario can reproduce the broadband spectrum of the PWN from radio to gamma-ray wavelengths. The analysis and modeling presented in this work have important implications for our general understanding of the structure and evolution of composite SNRs.

  2. FERMI LAT Discovery of Extended Gamma-Ray Emission in the Direction of Supernova Remnant W51C

    DOE PAGES

    Abdo, A. A.; Ackermann, M.; Ajello, M.; ...

    2009-10-27

    In this paper, the discovery of bright gamma-ray emission coincident with supernova remnant (SNR) W51C is reported using the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope. W51C is a middle-aged remnant (~10 4 yr) with intense radio synchrotron emission in its shell and known to be interacting with a molecular cloud. The gamma-ray emission is spatially extended, broadly consistent with the radio and X-ray extent of SNR W51C. The energy spectrum in the 0.2-50 GeV band exhibits steepening toward high energies. The luminosity is greater than 1 × 10 36 erg s –1 given the distance constraint of D > 5.5 kpc, which makes this object one of the most luminous gamma-ray sources in our Galaxy. The observed gamma-rays can be explained reasonably by a combination of efficient acceleration of nuclear cosmic rays at supernova shocks and shock-cloud interactions. The decay of neutral π mesons produced in hadronic collisions provides a plausible explanation for the gamma-ray emission. The product of the average gas density and the total energy content of the accelerated protons amounts tomore » $$\\bar{n}_{\\rm H}W_p \\simeq 5\\times 10^{51}\\ (D/6\\ {\\rm kpc})^2\\ \\rm erg\\ cm^{-3}$$. Electron density constraints from the radio and X-ray bands render it difficult to explain the LAT signal as due to inverse Compton scattering. Finally, the Fermi LAT source coincident with SNR W51C sheds new light on the origin of Galactic cosmic rays.« less

  3. Fermi-LAT Discovery of Extended Gamma-Ray Emission in the Direction of Supernova Remnant W51C

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

    Abdo, A.A.; /Naval Research Lab, Wash., D.C. /Federal City Coll.; Ackermann, M.

    The discovery of bright gamma-ray emission coincident with supernova remnant (SNR) W51C is reported using the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope. W51C is a middle-aged remnant ({approx}10{sup 4} yr) with intense radio synchrotron emission in its shell and known to be interacting with a molecular cloud. The gamma-ray emission is spatially extended, broadly consistent with the radio and X-ray extent of SNR W51C. The energy spectrum in the 0.2-50 GeV band exhibits steepening toward high energies. The luminosity is greater than 1 x 10{sup 36} erg s{sup -1} given the distance constraint of D >more » 5.5 kpc, which makes this object one of the most luminous gamma-ray sources in our Galaxy. The observed gamma-rays can be explained reasonably by a combination of efficient acceleration of nuclear cosmic rays at supernova shocks and shock-cloud interactions. The decay of neutral p mesons produced in hadronic collisions provides a plausible explanation for the gamma-ray emission. The product of the average gas density and the total energy content of the accelerated protons amounts to {bar n}{sub H} W{sub p} {approx_equal} 5 x 10{sup 51} (D/6 kpc){sup 2} erg cm{sup -3}. Electron density constraints from the radio and X-ray bands render it difficult to explain the LAT signal as due to inverse Compton scattering. The Fermi LAT source coincident with SNR W51C sheds new light on the origin of Galactic cosmic rays.« less

  4. POLYCYCLIC AROMATIC HYDROCARBON PROCESSING IN THE BLAST WAVE OF THE SUPERNOVA REMNANT N132D

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

    Tappe, A.; Rho, J.; Boersma, C.

    2012-08-01

    We present Spitzer Infrared Spectrograph 14-36 {mu}m mapping observations of the supernova remnant N132D in the Large Magellanic Cloud. This study focuses on the processing of polycyclic aromatic hydrocarbons (PAHs) that we previously identified in the southern blast wave. The mid-infrared spectra show strong continuum emission from shock-heated dust and a unique, nearly featureless plateau in the 15-20 {mu}m region, which we attribute to PAH molecules. The typical PAH emission bands observed in the surrounding interstellar medium ahead of the blast wave disappear, which indicates shock processing of PAH molecules. The PAH plateau appears most strongly at the outer edgemore » of the blast wave and coincides with diffuse X-ray emission that precedes the brightest X-ray and optical filaments. This suggests that PAH molecules in the surrounding medium are swept up and processed in the hot gas of the blast wave shock, where they survive the harsh conditions long enough to be detected. We also observe a broad emission feature at 20 {mu}m appearing with the PAH plateau. We speculate that this feature is either due to FeO dust grains or connected to the processing of PAHs in the supernova blast wave shock.« less

  5. The Origin of the Iron-rich Knot in Tycho’s Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Hiroya; Hughes, John P.; Badenes, Carles; Bravo, Eduardo; Seitenzahl, Ivo R.; Martínez-Rodríguez, Héctor; Park, Sangwook; Petre, Robert

    2017-01-01

    X-ray observations of supernova remnants (SNRs) allow us to investigate the chemical inhomogeneity of ejecta, offering unique insight into the nucleosynthesis in supernova explosions. Here we present detailed imaging and spectroscopic studies of the “Fe knot” located along the eastern rim of the Type Ia SNR Tycho (SN 1572) using Suzaku and Chandra long-exposure data. Surprisingly, the Suzaku spectrum of this knot shows no emission from Cr, Mn, or Ni, which is unusual for the Fe-rich regions in this SNR. Within the framework of the canonical delayed-detonation models for SN Ia, the observed mass ratios {M}{Cr}/{M}{Fe}< 0.023, {M}{Mn}/{M}{Fe}< 0.012, and {M}{Ni}/{M}{Fe}< 0.029 (at 90% confidence) can only be achieved for a peak temperature of (5.3-5.7) × {10}9 K and a neutron excess of ≲ 2.0× {10}-3. These constraints rule out the deep, dense core of a Chandrasekhar-mass white dwarf as the origin of the Fe knot and favor either incomplete Si burning or an α-rich freeze-out regime, probably close to the boundary. An explosive He burning regime is a possible alternative, although this hypothesis is in conflict with the main properties of this SNR.

  6. Hubble snap a beautiful supernova explosion some 160,000 light-years from Earth

    NASA Image and Video Library

    2017-12-08

    Of all the varieties of exploding stars, the ones called Type Ia are perhaps the most intriguing. Their predictable brightness lets astronomers measure the expansion of the universe, which led to the discovery of dark energy. Yet the cause of these supernovae remains a mystery. Do they happen when two white dwarf stars collide? Or does a single white dwarf gorge on gases stolen from a companion star until bursting? If the second theory is true, the normal star should survive. Astronomers used NASA's Hubble Space Telescope to search the gauzy remains of a Type Ia supernova in a neighboring galaxy called the Large Magellanic Cloud. They found a sun-like star that showed signs of being associated with the supernova. Further investigations will be needed to learn if this star is truly the culprit behind a white dwarf's fiery demise. This image, taken with NASA's Hubble Space Telescope, shows the supernova remnant SNR 0509-68.7, also known as N103B. It is located 160,000 light-years from Earth in a neighboring galaxy called the Large Magellanic Cloud. N103B resulted from a Type Ia supernova, whose cause remains a mystery. One possibility would leave behind a stellar survivor, and astronomers have identified a possible candidate. The actual supernova remnant is the irregular shaped dust cloud, at the upper center of the image. The gas in the lower half of the image and the dense concentration of stars in the lower left are the outskirts of the star cluster NGC 1850. The Hubble image combines visible and near-infrared light taken by the Wide Field Camera 3 in June 2014. Credit: NASA, ESA and H.-Y. Chu (Academia Sinica, Taipei) NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  7. A Search for High-Energy Gamma-Rays from Supernova SN1987A.

    NASA Astrophysics Data System (ADS)

    Waldron, Liam Edwin

    1992-01-01

    The Australian Defence Force Academy (ADFA) balloon -borne gamma-ray astronomy telescope was flown successfully from Alice Springs Australia twice during 1987 and 1988 (flights 87-2-19 and 88-1-5) with the aim of measuring the gamma-ray flux, in the energy range 50 to 500 MeV, from Supernova SN1987A in the Large Magellanic Cloud. The two flights corresponded to day 55 and day 407 respectively of remnant evolution. The instrument was complemented by a hard X-ray proportional counter, designed and constructed by the Istituto di Astrofisica Spaziale, CNR, Frascati Italy, and sensitive to the 10 to 250 KeV energy range. In this thesis, an account is given of the physical processes responsible for the production of gamma-rays astrophysical environments and their relation to supernovae and cosmic-rays. A description is then given of the main features of the gamma-ray telescope and its principle of operation, the most important part of the telescope being a spark-chamber used to determine the direction of arrival of incident gamma-rays. Data obtained during each flight was recorded as spark-chamber tacks on photographic film. A detailed account of the methods of subsequent data reduction and analysis, as carried out by the author, are given. The principal results of this work were that 3-sigma upper limits to the gamma-ray flux from Supernova SN1987A of 2.2 times 10^ {-5} photons cm^{ -2} s^{-1} and 3.4 times 10^{-5} photons cm^{-2} s^ {-1} were obtained for days 55 and 407 of remnant evolution respectively, these limits being somewhat lower than previously reported in the literature from a preliminary analysis of the data. The above two upper limits are consistent with Supernova SN1987A being an atypical Type-II supernova. That is, the progenitor was a blue, rather than a red, supergiant. The limits are compared with theoretical predictions related to current models of gamma-ray emission from young Type -II supernovae.

  8. Cassiopeia A: Supernova explosion and expansion simulations under strong asymmetry conditions

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

    Yakhin, R. A., E-mail: yakhin.rafael@gmail.com; Rozanov, V. B.; Zmitrenko, N. V.

    We propose a model for the explosion of a supernova and the expansion of its ejecta in the presence of a strong initial asymmetry (at the explosion time) in the central part of the star (core) and a possible smallscale asymmetry in the peripheral regions. The Chandra and NuSTAR observations of ejecta in the Cassiopeia A supernova remnant are analyzed. Based on our 1D and 2D numerical simulations performed using the DIANA and NUTCY codes, we propose a model for the explosion and expansion of ejecta that explains the observed experimental data where the materials initially located in the centralmore » region of the star end up on the periphery of the cloud of ejecta.« less

  9. Monsters in the sky. I mostri del cielo

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

    Maffei, P.

    1980-01-01

    The book treats astronomical objects and phenomena which remain unexplained or unproven by current investigators. Specific objects discussed include comets, satellite clouds surrounding the earth, tektites, the planet Vulcan (within the orbit of Mercury), Planet X (beyond Pluto), the Gum Nebula, planetary nebulae, supernovae, supernova remnants, transient X-ray sources, the possible extinction of the dinosaurs by an X-ray explosion and super-supernovae. Attention is also given to the star Eta Carinae, black holes, BL Lacertae objects, active galaxies, Markarian galaxies, N and compact galaxies, Seyfert galaxies, quasars, redshift anomalies, Stephan's quintet of galaxies, and intergalactic black holes or black dwarfs whichmore » may account for the mass necessary to bind together clusters of galaxies.« less

  10. Observaciones combinadas XMM-Newton/Chandra del remanente de supernova G306.3-0.9

    NASA Astrophysics Data System (ADS)

    Filócomo, A.; Combi, J. A.; García, F.; Suárez, A. E.; Luque-Escamilla, P. L.; Parón, S.

    2016-08-01

    In this paper we study the spatial and spectral distribution of the physical and chemical properties of the supernova remnant G306.3-0.9 by using data of the X-rays telescopes XMM-Newton and Chandra, which we complement with radio and infrared information in order to study the morphology of the source and the effect of the shock wave in the interestelar medium. The results show a non-uniform morphology of the emission, dominated by thermal radiation with high values of Ne, Mg, S, Ca, Ar and Fe in the central region, typical of ejecta material. Also, using an infrared flux distribution, we could restrict the type of the progenitor responsible of the supernova phenomena.

  11. A deep X-ray observation of the supernova remnant G304.6+0.1 (Kes 17) using Suzaku

    NASA Astrophysics Data System (ADS)

    Gök, F.; Sezer, A.

    2012-06-01

    In this paper, we present the analysis of a deep (99.6 ks) observation of G304.6+0.1 with the X-ray Imaging Spectrometer on board the Suzaku satellite. The X-ray spectral data are well fitted with a plasma model consisting of a thermal component, in collisional ionization equilibrium, and a non-thermal component. The thermal emission is well fitted with the VMEKAL model with an electron temperature of kTe˜ 0.75 keV, a high absorbing column density of NH˜ 3.9 × 1022 cm-2 and near/lower solar abundances, which indicate that the X-ray emitting plasma of G304.6+0.1 is dominated by a swept-up ambient medium. The non-thermal component is well fitted with a power-law model with a photon index of Γ˜ 1.4. We have found a relatively high electron density ne˜ 2.3f-1/2 cm-3, an age t˜ 1.4 × 104f1/2 yr and an X-ray emitting mass Mx˜ 380f1/2 M⊙ at an adopted distance of d= 10 kpc. Using the morphological and spectral X-ray data, we confirm that the remnant is a new member of the mixed-morphology supernova remnants.

  12. Observations of the Non-Thermal X-ray Emission from the Galactic Supernova Remnant G347.3-0.5

    NASA Technical Reports Server (NTRS)

    Pannuti, Thomas G.; Allen, Glenn E.

    2002-01-01

    G347.3-0.5 (ALEX J1713.7-3946) is a member of the new class of shell-type Galactic supernova remnants (SNRs) that feature non-thermal components to their X-ray emission. We have analyzed the X-ray spectrum of this SNR over a broad energy range (0.5 to 30 key) using archived data from observations made with two satellites, the R6ntgensatellit (ROSA I) and the Advanced Satellite for Cosmology and Astrophysics (ASCA), along with data from our own observations made with the Rossi X-ray Timing Explorer (RXTE) Using a combination of the models EQUIL and SRCUT to fit thermal and non-thermal emission, respectively, from this SNR, we find evidence for a modest thermal component to G347.30.5's diffuse emission with a corresponding energy of kT approx. = 1.4 key. We also obtain an estimate of 70 Texas for the maximum energy of the cosmic-ray electrons that, have been accelerated by this SNR.

  13. A neutron star with a carbon atmosphere in the Cassiopeia A supernova remnant.

    PubMed

    Ho, Wynn C G; Heinke, Craig O

    2009-11-05

    The surface of hot neutron stars is covered by a thin atmosphere. If there is accretion after neutron-star formation, the atmosphere could be composed of light elements (H or He); if no accretion takes place or if thermonuclear reactions occur after accretion, heavy elements (for example, Fe) are expected. Despite detailed searches, observations have been unable to confirm the atmospheric composition of isolated neutron stars. Here we report an analysis of archival observations of the compact X-ray source in the centre of the Cassiopeia A supernova remnant. We show that a carbon atmosphere neutron star (with low magnetic field) produces a good fit to the spectrum. Our emission model, in contrast with others, implies an emission size consistent with theoretical predictions for the radius of neutron stars. This result suggests that there is nuclear burning in the surface layers and also identifies the compact source as a very young ( approximately 330-year-old) neutron star.

  14. Magnetic Field Amplification in Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Xu, Siyao; Lazarian, Alex

    2017-12-01

    Based on the new findings on the turbulent dynamo in Xu & Lazarian, we examine the magnetic field amplification in the context of supernova remnants. Due to the strong ion-neutral collisional damping in the weakly ionized interstellar medium, the dynamo in the preshock turbulence remains in the damping kinematic regime, which leads to a linear-in-time growth of the magnetic field strength. The resultant magnetic field structure enables effective diffusion upstream and shock acceleration of cosmic rays to energies above the “knee.” Differently, the nonlinear dynamo in the postshock turbulence leads to a linear-in-time growth of the magnetic energy due to the turbulent magnetic diffusion. Given a weak initial field strength in the postshock region, the magnetic field saturates at a significant distance from the shock front as a result of the inefficiency of the nonlinear dynamo. This result is in a good agreement with existing numerical simulations and well explains the X-ray spots detected far behind the shock front.

  15. The TeV supernova remnant shell HESS J1731-347 and its surroundings

    NASA Astrophysics Data System (ADS)

    Capasso, M.; Condon, B.; Coffaro, M.; Cui, Y.; Gottschall, D.; Klochkov, D.; Marandon, V.; Maxted, N.; Pühlhofer, G.; Rowell, G.; H.E.S.S. Collaboration

    2017-01-01

    HESS J1731-347 is a shell-type supernova remnant emitting both TeV gamma rays and non-thermal X-ray photons, spatially coincident with the radio SNR G353.6-0.7. Hadronic and leptonic scenarios (or a blend of both) are discussed in the literature to explain the TeV emission from the object. In 2011, a γ-ray excess was also found in the neighborhood of the source (HESS J1729-345). Here we present results of an updated analysis obtained with the meanwhile available additional H.E.S.S. data. Beyond HESS J1731-347, the analysis reveals the morphology of the emission of the adjacent TeV source HESS J1729-345 and the emission in between the two sources in greater detail. The results permit us to correlate the TeV emission outside of the SNR with molecular gas tracers, and to confront the data with scenarios in which the TeV emission outside the SNR is produced by escaping cosmic rays.

  16. Evidence for a Neutral Iron Line Generated by MeV Protons from Supernova Remnants Interacting with Molecular Clouds

    NASA Astrophysics Data System (ADS)

    Nobukawa, Kumiko K.; Nobukawa, Masayoshi; Koyama, Katsuji; Yamauchi, Shigeo; Uchiyama, Hideki; Okon, Hiromichi; Tanaka, Takaaki; Uchida, Hiroyuki; Tsuru, Takeshi G.

    2018-02-01

    Supernova remnants (SNRs) have been prime candidates for Galactic cosmic-ray accelerators. When low-energy cosmic-ray protons (LECRp) collide with interstellar gas, they ionize neutral iron atoms and emit the neutral iron line (Fe I Kα) at 6.40 keV. We search for the iron K-shell line in seven SNRs from the Suzaku archive data of the Galactic plane in the 6^\\circ ≲ l≲ 40^\\circ ,| b| < 1^\\circ region. All of these SNRs interact with molecular clouds. We discover Fe I Kα line emissions from five SNRs (W28, Kes 67, Kes 69, Kes 78, and W44). The spectra and morphologies suggest that the Fe I Kα line is produced by interactions between LECRp and the adjacent cold gas. The proton energy density is estimated to be ≳10–100 eV cm‑3, which is more than 10 times higher than that in the ambient interstellar medium.

  17. FERMI LAT discovery of extended gamma-ray emissions in the vicinity of the HB 3 supernova remnant

    DOE PAGES

    Katagiri, H.; Yoshida, K.; Ballet, J.; ...

    2016-02-11

    We report the discovery of extended gamma-ray emission measured by the Large Area Tele- scope (LAT) onboard the Fermi Gamma-ray Space Telescope in the region of the supernova rem- nant (SNR) HB 3 (G132.7+1.3) and the W3 HII complex adjacent to the southeast of the remnant. W3 is spatially associated with bright 12CO (J=1-0) emission. The gamma-ray emission is spatially correlated with this gas and the SNR. We discuss the possibility that gamma rays originate in inter- actions between particles accelerated in the SNR and interstellar gas or radiation fields. The decay of neutral pions produced in nucleon-nucleon interactions betweenmore » accelerated hadrons and interstellar gas provides a reasonable explanation for the gamma-ray emission. The emission fromW3 is consistent with irradiation of the CO clouds by the cosmic rays accelerated in HB 3.« less

  18. An interstellar cloud density from Copernicus observations of CO in the spectrum of Zeta Ophiuchi

    NASA Technical Reports Server (NTRS)

    Smith, A. M.; Stecher, T. P.; Krishna Swamy, K. S.

    1978-01-01

    Interstellar CO absorption bands in Copernicus spectra of Zeta Oph have been studied. Absorption profiles, computed under the assumption that excitation is due to collisions with H2 molecules and interaction with the 3-K background radiation field, were fitted to the reduced data of nine bands. When a gas kinetic temperature of 56 K is assumed, the best-fit condition implies a hydrogen-nucleus density of 120 per cu cm, a CO column density of 1.2 by 10 to the 15th power per sq cm, and a radial-velocity dispersion of 0.9 km/s. The relevance of these results to existing ideas concerning the Zeta Oph interstellar clouds is discussed. It is suggested that the strongest interstellar component is not circumstellar in origin but is instead part of a supernova remnant. Simple calculations are made to establish the plausibility of the supernova-remnant identification. This suggestion is also supported by Heiles's (1976) 21-cm pictures.

  19. The Lighthouse nebula: a run-away pulsar, its PWN, jets and parent SNR

    NASA Astrophysics Data System (ADS)

    Pavan, L.; Bordas, P.; Puhlhofer, G.; et al.

    2016-06-01

    Some 10-20 kyr ago a pulsar was born from a core collapse event, receiving right away a strong kick. Nowadays this pulsar is powering the Lighthouse Nebula (IGR J11014-6103): a complex system of outflows comprising the bow-shock PWN, and two well collimated jets extending perpendicularly to the pulsar's direction of motion. Whereas sharing some clear commonalities with the well known Guitar Nebula, the Lighthouse nebula is the only such system where the parent supernova remnant is well visible and bright in X-rays. I will describe the results from our recent Chandra X-ray campaign, and follow-up optical and radio observations, analyse the properties of the PWN, and possible interpretations on the nature of the long helicoidal jets and of the other outflows that we identified. I will also discuss the link between this system and its parent supernova remnant MSH 11-61A, which could help shedding a light on the processes that give birth to such peculiar systems.

  20. The Distribution of Cosmic-Ray Sources in the Galaxy, Gamma-Rays and the Gradient in the CO-to-H2 Relation

    NASA Technical Reports Server (NTRS)

    Strong, A. W.; Moskalenko, I. V.; Reimer, O.; Diehl, S.; Diehl, R.

    2004-01-01

    We present a solution to the apparent discrepancy between the radial gradient in the diffuse Galactic gamma-ray emissivity and the distribution of supernova remnants, believed to be the sources of cosmic rays. Recent determinations of the pulsar distribution have made the discrepancy even more apparent. The problem is shown to be plausibly solved by a variation in the Wco-to-N(H2) scaling factor. If this factor increases by a factor of 5-10 from the inner to the outer Galaxy, as expected from the Galactic metallicity gradient and supported by other evidence, we show that the source distribution required to match the radial gradient of gamma-rays can be reconciled with the distribution of supernova remnants as traced by current studies of pulsars. The resulting model fits the EGRET gamma-ray profiles extremely well in longitude, and reproduces the mid-latitude inner Galaxy intensities better than previous models.

  1. SOFT X-RAY SPECTROSCOPY OF THE CYGNUS LOOP SUPERNOVA REMNANT

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

    Oakley, Phil; McEntaffer, Randall; Cash, Webster, E-mail: Oakley@mit.edu

    2013-03-20

    We present the results of a suborbital rocket flight whose scientific target was the Cygnus Loop Supernova Remnant. The payload consists of wire grid collimators, off-plane grating arrays, and gaseous electron multiplier (GEM) detectors. The system is designed for spectral measurements in the 17-107 A bandpass with a resolution up to {approx}60 ({lambda}/{Delta}{lambda}). The Extended X-ray Off-plane Spectrometer (EXOS) was launched on a Terrier-Black Brant rocket on 2009 November 13 from White Sands Missile Range and obtained 340 s of useable scientific data. The X-ray emission is dominated by O VII and O VIII, including the He-like O VII tripletmore » at {approx}22 A. Another emission feature at {approx}45 A is composed primarily of Si XI and Si XII. The best-fit model to this spectrum is an equilibrium plasma model at a temperature of log(T) = 6.4 (0.23 keV).« less

  2. Kinematics of Ultra-high-velocity Gas in the Expanding Molecular Shell Adjacent to the W44 Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Yamada, Masaya; Oka, Tomoharu; Takekawa, Shunya; Iwata, Yuhei; Tsujimoto, Shiho; Tokuyama, Sekito; Furusawa, Maiko; Tanabe, Keisuke; Nomura, Mariko

    2017-01-01

    We mapped the ultra-high-velocity feature (the “Bullet”) detected in the expanding molecular shell associated with the W44 supernova remnant using the Nobeyama Radio Observatory 45 m telescope and the Atacama Submillimeter Telescope Experiment 10 m telescope. The Bullet clearly appears in the CO J = 1-0, CO J = 3-2, CO J = 4-3, and HCO+ J = 1-0 maps with a compact appearance (0.5 × 0.8 pc2) and an extremely broad-velocity width (ΔV ≃ 100 km s-1). The line intensities indicate that the Bullet has a higher density and temperature than those in the expanding molecular shell. The kinetic energy of the Bullet amounts to 1048.0 erg, which is approximately 1.5 orders of magnitude greater than the kinetic energy shared to the small solid angle of it. Two possible formation scenarios with an inactive isolated black hole are presented.

  3. The Origin of Radially Aligned Magnetic Fields in Young Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Inoue, Tsuyoshi; Shimoda, Jiro; Ohira, Yutaka; Yamazaki, Ryo

    2013-08-01

    It has been suggested by radio observations of polarized synchrotron emissions that downstream magnetic fields in some young supernova remnants (SNRs) are oriented radially. We study the magnetic field distribution of turbulent SNRs driven by the Richtmyer-Meshkov instability (RMI)—in other words, the effect of rippled shock—by using three-dimensional magnetohydrodynamics simulations. We find that the induced turbulence has radially biased anisotropic velocity dispersion that leads to a selective amplification of the radial component of the magnetic field. The RMI is induced by the interaction between the shock and upstream density fluctuations. Future high-resolution polarization observations can distinguish the following candidates responsible for the upstream density fluctuations: (1) inhomogeneity caused by the cascade of large-scale turbulence in the interstellar medium, the so-called big power-law in the sky; (2) structures generated by the Drury instability in the cosmic-ray modified shock; and (3) fluctuations induced by the nonlinear feedback of the cosmic-ray streaming instability.

  4. The Spin-down of PSR B1509-58

    NASA Astrophysics Data System (ADS)

    Gvaramadze, V. V.

    It is generally accepted that the PSR B1509-58 is associated with the supernova remnant (SNR) MSH 15-52 . The spin-down age of the pulsar is years, while the size and the general appearance of the SNR suggest that this system is much older. A few possible explanations of this discrepancy have been put forward. We offer an alternative one and suggest that the high spin-down rate of the pulsar characterizes only a relatively short period of its (present) spin history, and that the enhanced braking torque is connected with the interaction between the pulsar's magnetosphere and the dense matter of a circumstellar clump (created during the late evolutionary stages of the supernova (SN) progenitor star). Our suggestion implies that the "true" age of PSR B1509-58 could be much larger than the spin-down age, and therefore the SNR MSH 15-52 is a middle-aged remnant similar to the Vela SNR. Some possible consequences of our suggestion are discussed.

  5. Pulsar Wind Nebulae, Space Velocities and Supernova Remnant

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The original proposal for this LTSA grant was for X-ray studies of pulsars, and especially pulsar wind nebulae and what they could tell us about pulsar properties, especially their space velocities. By any metric, this program has been very successful. No fewer than 14 papers on directly related topics (and several dozen more on related topics) have been published in refereed journals with the PI as lead or co-author, all observational results that have had significant impact on the field. These include the first X-ray detection of the "Duck" pulsar, a clear demonstration that estimated pulsar ages can be off by over an order of magnitude (via observations of the young supernova remnant G11.2-0.3) and the detection of the first pulsar wind nebula around a millisecond pulsar. These publications have also resulted in 4 press releases. Moreover, they also represent the thesis work of two PhD students at MIT (Froney Crawford and Mike Pivovaroff) and one postdoctoral fellow, Bryan Gaensler, now Assistant Professor at Harvard.

  6. Disentangling X-Ray Emission Processes In Vela-Like Pulsars

    NASA Technical Reports Server (NTRS)

    Gaensler, Bryan; Mushotzky, Richard (Technical Monitor)

    2002-01-01

    This grant is to support analysis of data from the X-ray Multi-mirror Mission (XMM). Specifically, we have been awarded time to observe two young neutron stars, B1823-13 and B1046-58, whose X-ray emission is expected to be a complicated combination of emission from an associated supernova remnant, from a wind-powered synchrotron nebula, from magnetospheric pulsations, and from the surface of the neutron star itself. It is only with XMM's unique combination of spectral, temporal and angular resolution that all these different processes can be separated and studied. Observations of B1823-13 have been conducted and analyzed. We interpret the data as follows: The unpulsed extended non-thermal nature of the central core argues that the extended source of emission corresponds to synchrotron emission from a nebula powered by the pulsar. The temperature of the diffuse component is too high to be interpreted as thermal emission; we rather argue that this extended component is non-thermal emission from a surrounding supernova remnant shell.

  7. 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.

  8. Probing the Reverse Shock in an Oxygen-Rich Supernova Remnant

    NASA Technical Reports Server (NTRS)

    Sonneborn, George (Technical Monitor); Gaetz, Terrance J.

    2003-01-01

    The aim of this proposal was to examine the O VI emission at three positions around the X-ray bright ring of the remnant in order to investigate the relation between the O VI emission, the X-ray O VII and O VIII emission, and the optical [O III] emission, and how these vary around the rim of the remnant. So far, only one Far Ultraviolet Spectroscopic Explorer (FUSE) pointing at the remnant has been performed, together with the background pointing needed to subtract the diffuse scattered light from nearby O stars. The data were recalibrated using the CalFUSE calibration pipeline, but the emission is faint enough that hand processing will be needed for this pointing to optimize the extraction. Rereduction of the data is underway. A postdoctoral fellow has also been hired, and in part she will assist with the analysis.

  9. A Central Source in the Supernova Remnant Kes 79

    NASA Astrophysics Data System (ADS)

    Seward, F.; Slane, P.; Smith, R.; Sun, M.

    2002-04-01

    Kes 79 (G33.6+0.1) was observed 31 July 2001 for 30 ks with the Chandra ACIS-I instrument. This remnant, in the constellation Aquila, lies in the galactic plane at a distance of ~10 kpc. The 11^' angular diameter implies an age of a few thousand years. The morphology shows faint outer and bright inner shells. The Chandra image reveals, for the first time, a point-like source at the center of the remnant. This source has a black body spectrum with kT = 0.5 keV. No regular pulsations were found at periods greater than 6.4 s (the ACIS integration time is 3.2 s). No surrounding synchrotron emission wass detected. The X-ray luminosity is 7 × 10^33 erg/s, about 1% the luminosity of the entire remnant. The source may be similar to the one at the center of Cas A.

  10. Observational Evidence for High Neutronization in Supernova Remnants: Implications for Type Ia Supernova Progenitors

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

    Martínez-Rodríguez, Héctor; Badenes, Carles; Andrews, Brett

    The physical process whereby a carbon–oxygen white dwarf explodes as a Type Ia supernova (SN Ia) remains highly uncertain. The degree of neutronization in SN Ia ejecta holds clues to this process because it depends on the mass and the metallicity of the stellar progenitor, and on the thermodynamic history prior to the explosion. We report on a new method to determine ejecta neutronization using Ca and S lines in the X-ray spectra of Type Ia supernova remnants (SNRs). Applying this method to Suzaku data of Tycho, Kepler , 3C 397, and G337.2−0.7 in the Milky Way, and N103B inmore » the Large Magellanic Cloud, we find that the neutronization of the ejecta in N103B is comparable to that of Tycho and Kepler , which suggests that progenitor metallicity is not the only source of neutronization in SNe Ia. We then use a grid of SN Ia explosion models to infer the metallicities of the stellar progenitors of our SNRs. The implied metallicities of 3C 397, G337.2−0.7, and N103B are major outliers compared to the local stellar metallicity distribution functions, indicating that progenitor metallicity can be ruled out as the origin of neutronization for these SNRs. Although the relationship between ejecta neutronization and equivalent progenitor metallicity is subject to uncertainties stemming from the {sup 12}C + {sup 16}O reaction rate, which affects the Ca/S mass ratio, our main results are not sensitive to these details.« less

  11. Cosmic Ornament of Gas and Dust

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] 4-Panel Version Figure 1 [figure removed for brevity, see original site] [figure removed for brevity, see original site] [figure removed for brevity, see original site] Silicon Gas Figure 2 Argon Figure 3 Dust Collection Figure 4

    This beautiful bulb might look like a Christmas ornament but it is the blown-out remains of a stellar explosion, or supernova. Called Cassiopeia A, this supernova remnant is located about 10,000 light-years away in our own Milky Way galaxy. The remains are shown here in an infrared composite from NASA's Spitzer Space Telescope. Silicon gas is blue and argon gas is green, while red represents about 10,000 Earth masses worth of dust. Yellow shows areas where red and green overlap.

    The fact that these two features line up (as seen in yellow in the combined view) tells astronomers that the dust, together with the gas, was created in the explosion. This is the best evidence yet that supernovae are a significant source of dust in the early universe something that was postulated before, but not proven. Dust in our young universe is important because it eventually made its way into future stars, planets and even people.

    In figure 1, the upper left panel is a composite made up of three infrared views shown in the remaining panels. The bottom left view (figure 3) shows argon gas (green) that was synthesized as it was ejected from the star. The upper right panel (figure 2) shows silicon gas (blue) deep in the interior of the remnant. This cooler gas, called the unshocked ejecta, was also synthesized in the supernova blast. The bottom right view (figure 4) shows a collection of dust (red), including proto-silicates, silicate dioxide and iron oxide.

    The data for these images were taken by Spitzer's infrared spectrograph, which splits light apart to reveal the fingerprints of molecules and elements. In total, Spitzer collected separate 'spectra' at more than 1,700 positions across Cassiopeia A. Astronomers then created maps from this massive grid of data, showing the remnant in a multitude of infrared colors.

  12. Supernova Remnant Science with AXIS

    NASA Astrophysics Data System (ADS)

    Williams, Brian J.; Yamaguchi, Hiroya; AXIS Science Team

    2018-01-01

    We present an overview of the supernova remnant (SNR) science that will be achieved with the Advanced X-ray Imaging Satellite (AXIS). AXIS follows in the footsteps of the spectacularly successful Chandra X-ray Observatory with similar or higher angular resolution and an order of magnitude more collecting area in the 0.3-10 keV band. These capabilities enable major advances in several areas of SNR science. These include, but are not limited to: 1) a more thorough spatial mapping of the ejecta products of both intermediate-mass and iron-group elements in core-collapse and Type Ia SNRs, particularly in remnants with a small diameter. The iron-group elements, specifically Cr, Mn, and Ni, are extremely important for constraining the explosion mechanism for SNe, but are generally weak and difficult to detect with Chandra, XMM-Newton, and Suzaku. 2) Studying the interface of a shock wave with the ambient ISM/CSM to constrain the degree of particle heating and acceleration at shock fronts. Chandra has only provided upper limits on shock precursor emission, and a detailed study of the thermal and nonthermal emission at the shock with greatly increased photon count rates will constrain the properties of the immediate post-shock plasma. 3) A high spatial resolution X-ray observatory will continue to build on the legacy begun by Chandra of studying the proper motion of young remnants. Directly measuring the dynamics of an SNR's evolution is crucial for understanding the explosion mechanism, and with the order of magnitude increase collecting area, we can measure the expansion of individual elemental species in the ejecta. 4) We will greatly increase the statistics of SNRs in nearby galaxies, going much faster and deeper than Chandra's observations. The increased depth of coverage would allow us to do spectroscopy in places where it was previously possible only to do rudimentary statistics. We can compare the local SNR population with the local star-formation rates for galaxies, important for supernova progenitor models. Finally, there is significant ancillary science that can be achieved by surveying nearby galaxies.

  13. Constraints on Cosmic-ray Acceleration Efficiency in Balmer Shocks of Two Young Type Ia Supernova Remnants in the Large Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Hovey, Luke; Hughes, John P.; McCully, Curtis; Pandya, Viraj; Eriksen, Kristoffer

    2018-01-01

    We present results from an optical study of two young Balmer-dominated remnants of SNIa in the Large Magellanic Cloud, 0509-67.5 and 0519-69.0, in an attempt to search for signatures of efficient cosmic-ray (CR) acceleration. We combine proper motion measurements from HST with corresponding optical spectroscopic measurements of the Hα line at multiple rim positions from VLT/FORS2 and SALT/RSS and compare our results to published Balmer shock models. Analysis of the optical spectra result in broad Hα widths in the range of 1800-4000 km s-1 for twelve separate Balmer-dominated filaments that show no evidence for forbidden line emission, the corresponding shock speeds from proper motion measurements span a range of 1600-8500 km s-1. Our measured values of shock speeds and broad Hα widths in 0509-67.5 and 0519-69.0 are fit well with a Balmer shock model that does not include effects of efficient CR acceleration. We determine an upper limit of 7%/Χ (95% confidence) on the CR acceleration efficiency for our ensemble of data points, where Χ is the ionization fraction of the pre-shock gas. The upper limits on the individual remnants are 6%/Χ (0509-67.5) and 11%/Χ (0519-69.0). These upper limits are below the integrated CR acceleration efficiency in the Tycho supernova remnant, where the shocks predominantly show little Hα emission, indicating that Balmer-dominated shocks are not efficient CR accelerators.

  14. Supernova kicks and dynamics of compact remnants in the Galactic Centre

    NASA Astrophysics Data System (ADS)

    Bortolas, Elisa; Mapelli, Michela; Spera, Mario

    2017-08-01

    The Galactic Centre (GC) is a unique place to study the extreme dynamical processes occurring near a supermassive black hole (SMBH). Here, we investigate the role of supernova (SN) explosions occurring in massive binary systems lying in a disc-like structure within the innermost parsec. We use a regularized algorithm to simulate 3 × 104 isolated three-body systems composed of a stellar binary orbiting the SMBH. We start the integration when the primary member undergoes an SN explosion and analyse the impact of SN kicks on the orbits of stars and compact remnants. We find that SN explosions scatter the lighter stars in the pair on completely different orbits, with higher eccentricity and inclination. In contrast, stellar-mass black holes (BHs) and massive stars retain memory of the orbit of their progenitor star. Our results suggest that SN kicks are not sufficient to eject BHs from the GC. We thus predict that all BHs that form in situ in the central parsec of our Galaxy remain in the GC, building up a cluster of dark remnants. In addition, the change of neutron star (NS) orbits induced by SNe may partially account for the observed dearth of NSs in the GC. About 40 per cent of remnants stay bound to the stellar companion after the kick; we expect up to 70 per cent of them might become X-ray binaries through Roche lobe filling. Finally, the eccentricity of some light stars becomes >0.7 as an effect of the SN kick, producing orbits similar to those of the G1 and G2 dusty objects.

  15. An XMM-Newton Study of the Mixed-morphology Supernova Remnant W28 (G6.4-0.1)

    NASA Astrophysics Data System (ADS)

    Zhou, Ping; Safi-Harb, Samar; Chen, Yang; Zhang, Xiao; Jiang, Bing; Ferrand, Gilles

    2014-08-01

    We have performed an XMM-Newton imaging and spectroscopic study of supernova remnant (SNR) W28, a prototype mixed-morphology or thermal composite SNR believed to be interacting with a molecular cloud. The observed hot X-ray emitting plasma is characterized by low metal abundances, showing no evidence of ejecta. The X-rays arising from the deformed northeastern shell consist of a thermal component with a temperature of ~0.3 keV plus a hard component of either thermal (temperature ~0.6 keV) or non-thermal (photon index = 0.9-2.4) origin. The X-ray emission in the SNR interior is blobby and the corresponding spectra are best described as the emission from a cold (~0.4 keV) plasma in non-equilibrium ionization with an ionization timescale of ~4.3 × 1011 cm-3 s plus a hot (~0.8 keV) gas in collisional ionization equilibrium. Applying the two-temperature model to the smaller central regions, we find non-uniform interstellar absorption, temperature, and density distribution, which indicates that the remnant is evolving in a non-uniform environment with denser material in the east and north. The cloudlet evaporation mechanism can essentially explain the properties of the X-ray emission in the center, and thermal conduction may also play a role for length scales comparable to the remnant radius. A recombining plasma model with an electron temperature of ~0.6 keV is also feasible for describing the hot central gas with the recombination age of the gas estimated at ~2.9 × 104 yr.

  16. Predicting the next local supernova

    NASA Astrophysics Data System (ADS)

    Middleditch, John

    2018-06-01

    It has been over 31 years since Supernova 1987A, and we have learned many things from the neutrinos, light curve, evolving spectrum including the “Bochum Event” at day 19.2, the associated “Bright Spot” or “Mystery Spot,” and its motion away from the position of the progenitor, Sk -69o202, the mixing, rings, X- and gamma-rays, polarization, and the 467.5 Hz pulsation and its associated ~1,000 s precession (or the lack of any strongly magnetized remnant). Finally, our understanding of this event has progressed to the point where we have a time interval of a few months during which we can predict which supergiant star in our local neighborhood out to 5 Megaparsecs will be the next to die in a supernova explosion.

  17. Flamsteed's Supernova of 1680

    NASA Astrophysics Data System (ADS)

    Fesen, R. A.

    2001-12-01

    A recent proper motion study of 40 knots in the Cas A supernova remnant indicated a knot convergent date of A.D. 1671.3 +/-0.9 assuming no deceleration (Thorstensen, Fesen, & van den Bergh 2001, AJ, 122, 297). However, because these optical knots are made visible by their shock passage through the local ISM/CSM, some deceleration is expected. A deceleration of just ~ 1.6 km s-1 yr-1 over a 300 yr time span would yield an explosion date around A.D. 1680, consistent with a suspected sighting of the Cas A supernova by J. Flamsteed in August 1680 (Ashworth, 1980, J. Hist. Astron., 11, 1). We discuss Flamsteed's likely observations of SN 1680 in terms of their constrains on the light curve and peak brightness and possible implications regarding the Cas A SN subtype.

  18. Supernova research with VLBI

    NASA Astrophysics Data System (ADS)

    Bartel, Norbert; Bietenholz, Michael F.

    2016-06-01

    Core-collapse supernovae have been monitored with VLBI from shortly after the explosion to many years thereafter. Radio emission is produced as the ejecta hit the stellar wind left over from the dyingstar. Images show the details of the interaction as the shock front expands into the circumstellar medium. Measurements of the velocity and deceleration of the expansion provide information on both the ejecta and the circumstellar medium. VLBI observations can also search for the stellar remnant of the explosion, a neutron star or a black hole. Combining the transverse expansion rate with the radial expansion rate from optical spectra allows a geometric determination of the distance to the host galaxy. We will present results from recent VLBI observations, focus on their interpretations, and show updated movies of supernovae from soon after their explosion to the present.

  19. Found: A Galaxy's Missing Gamma Rays

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-04-01

    Recent reanalysis of data from the Fermi Gamma-ray Space Telescope has resulted in the first detection of high-energy gamma rays emitted from a nearby galaxy. This discovery reveals more about how supernovae interact with their environments.Colliding Supernova RemnantAfter a stellar explosion, the supernovas ejecta expand, eventually encountering the ambient interstellar medium. According to models, this generates a strong shock, and a fraction of the kinetic energy of the ejecta is transferred into cosmic rays high-energy radiation composed primarily of protons and atomic nuclei. Much is still unknown about this process, however. One open question is: what fraction of the supernovas explosion power goes into accelerating these cosmic rays?In theory, one way to answer this is by looking for gamma rays. In a starburst galaxy, the collision of the supernova-accelerated cosmic rays with the dense interstellar medium is predicted to produce high-energy gamma rays. That radiation should then escape the galaxy and be visible to us.Pass 8 to the RescueObservational tests of this model, however, have beenstumped by Arp 220. This nearby ultraluminous infrared galaxy is the product of a galaxy merger ~700 million years ago that fueled a frenzy of starbirth. Due to its dusty interior and extreme levels of star formation, Arp 220 has long been predicted to emit the gamma rays produced by supernova-accelerated cosmic rays. But though weve looked, gamma-ray emission has never been detected from this galaxy until now.In a recent study, a team of scientists led by Fang-Kun Peng (Nanjing University) reprocessed 7.5 years of Fermi observations using the new Pass 8 analysis software. The resulting increase in resolution revealed the first detection of GeV emission from Arp 220!Acceleration EfficiencyGamma-ray luminosity vs. total infrared luminosity for LAT-detected star-forming galaxies and Seyferts. Arp 220s luminosities are consistent with the scaling relation. [Peng et al. 2016]Peng and collaborators argue that this emission is due solely to cosmic-ray interactions with interstellar gas. This picture is supported by the lack of variability in the emission, and the fact that Arp 220s gamma-ray luminosity is consistent with the scaling relation between gamma-ray and infrared luminosity for star-forming galaxies. The authors also argue that, due to Arp 220s high gas density, all cosmic rays will interact with the gas before escaping.Under these two assumptions, Peng and collaborators use the gamma-ray luminosity and the known supernova rate in Arp 220 to estimate how efficiently cosmic rays are acceleratedby supernova remnants in the galaxy. They determine that 4.2 2.6% of the supernova remnants kinetic energy is used to accelerate cosmic rays above 1 GeV.This is the first time such a rate has been measured directly from gamma-ray emission, but its consistent with estimates of 3-10% efficiency in the Milky Way. Future analysis of other ultraluminous infrared galaxies like Arp 220 with Fermi (and Pass 8!) will hopefully reveal more about these recent-merger, starburst environments.CitationFang-Kun Peng et al 2016 ApJ 821 L20. doi:10.3847/2041-8205/821/2/L20

  20. MAGNETAR-POWERED SUPERNOVAE IN TWO DIMENSIONS. I. SUPERLUMINOUS SUPERNOVAE

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

    Chen, Ke-Jung; Woosley, S. E.; Sukhbold, Tuguldur, E-mail: ken.chen@nao.ac.jp

    2016-11-20

    Previous studies have shown that the radiation emitted by a rapidly rotating magnetar embedded in a young supernova can greatly amplify its luminosity. These one-dimensional studies have also revealed the existence of an instability arising from the piling up of radiatively accelerated matter in a thin dense shell deep inside the supernova. Here, we examine the problem in two dimensions and find that, while instabilities cause mixing and fracture this shell into filamentary structures that reduce the density contrast, the concentration of matter in a hollow shell persists. The extent of the mixing depends upon the relative energy input bymore » the magnetar and the kinetic energy of the inner ejecta. The light curve and spectrum of the resulting supernova will be appreciably altered, as will the appearance of the supernova remnant, which will be shellular and filamentary. A similar pile up and mixing might characterize other events where energy is input over an extended period by a centrally concentrated source, e.g., a pulsar, radioactive decay, a neutrino-powered wind, or colliding shells. The relevance of our models to the recent luminous transient ASASSN-15lh is briefly discussed.« less

  1. The binary progenitor of Tycho Brahe's 1572 supernova.

    PubMed

    Ruiz-Lapuente, Pilar; Comeron, Fernando; Méndez, Javier; Canal, Ramon; Smartt, Stephen J; Filippenko, Alexei V; Kurucz, Robert L; Chornock, Ryan; Foley, Ryan J; Stanishev, Vallery; Ibata, Rodrigo

    2004-10-28

    The brightness of type Ia supernovae, and their homogeneity as a class, makes them powerful tools in cosmology, yet little is known about the progenitor systems of these explosions. They are thought to arise when a white dwarf accretes matter from a companion star, is compressed and undergoes a thermonuclear explosion. Unless the companion star is another white dwarf (in which case it should be destroyed by the mass-transfer process itself), it should survive and show distinguishing properties. Tycho's supernova is one of only two type Ia supernovae observed in our Galaxy, and so provides an opportunity to address observationally the identification of the surviving companion. Here we report a survey of the central region of its remnant, around the position of the explosion, which excludes red giants as the mass donor of the exploding white dwarf. We found a type G0-G2 star, similar to our Sun in surface temperature and luminosity (but lower surface gravity), moving at more than three times the mean velocity of the stars at that distance, which appears to be the surviving companion of the supernova.

  2. CSI in Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Chu, You-Hua

    2017-02-01

    Supernovae (SNe) explode in environments that have been significantly modified by the SN progenitors. For core-collapse SNe, the massive progenitors ionize the ambient interstellar medium (ISM) via UV radiation and sweep the ambient ISM via fast stellar winds during the main sequence phase, replenish the surroundings with stellar material via slow winds during the luminous blue variable (LBV) or red supergiant (RSG) phase, and sweep up the circumstellar medium (CSM) via fast winds during the Wolf-Rayet (WR) phase. If a massive progenitor was in a close binary system, the binary interaction could have caused mass ejection in certain preferred directions, such as the orbital plane, and even bipolar outflow/jet. As a massive star finally explodes, the SN ejecta interacts first with the CSM that was ejected and shaped by the star itself. As the newly formed supernova remnant (SNR) expands further, it encounters interstellar structures that were shaped by the progenitor from earlier times. Therefore, the structure and evolution of a SNR is largely dependent on the initial mass and close binarity of the SN progenitor. The Large Magellanic Cloud (LMC) has an excellent sample of over 50 confirmed SNRs that are well resolved by Hubble Space Telescope, Chandra X-ray Observatory, and Spitzer Space Telescope. These multi-wavelength observations allow us to conduct stellar forensics in SNRs and understand the wide variety of morphologies and physical properties of SNRs observed.

  3. The Origin of the Iron-Rich Knot in Tycho's Supernova Remnant

    NASA Technical Reports Server (NTRS)

    Yamaguchi, Hiroya; Hughes, John P.; Badenes, Carles; Bravo, Eduardo; Seitenzahl, Ivo R.; Martinez-Rodriguez, Hector; Park, Sangwook; Petre, Robert

    2017-01-01

    X-ray observations of supernova remnants (SNRs) allow us to investigate the chemical inhomogeneity of ejecta, offering unique insight into the nucleosynthesis in supernova explosions. Here we present detailed imaging and spectroscopic studies of the Fe knot located along the eastern rim of the Type Ia SNR Tycho ( SN 1572) using Suzaku and Chandra long-exposure data. Surprisingly, the Suzaku spectrum of this knot shows no emission from Cr, Mn, or Ni, which is unusual for the Fe-rich regions in this SNR. Within the framework of the canonical delayed-detonation models for SN Ia, the observed mass ratios M(sub Cr)/M(sub Fe) is less than 0.023, M(sub Mn)/M(sub Fe) is less than 0.012, and M(sub Ni)/M(sub Fe) is less than 0.029 (at 90% confidence) can only be achieved for a peak temperature of (5.3 - 5.7) x 10(exp. 9) K and a neutron excess of approximately less than 2.0 x 10(exp. -3). These constraints rule out the deep, dense core of a Chandrasekhar-mass white dwarf as the origin of the Fe knot and favor either incomplete Si burning or an Alpha-rich freeze-out regime, probably close to the boundary. An explosive He burning regime is a possible alternative, although this hypothesis is in conflict with the main properties of this SNR.

  4. A Search for High-Energy Gamma Rays from Supernova 1987A

    NASA Astrophysics Data System (ADS)

    Waldron, Liam Edwin

    1993-01-01

    The Australian Defense Force Academy (ADFA) balloon-borne gamma-ray astronomy telescope was flown successfully from Alice Springs, Australia, twice during 1987 and 1988 (Flights 87-2-19 and 88-1-5) with the aim of measuring the gamma-ray flux, in the energy range 50-500 MeV, from Supernova 1987A in the Large Magellanic Cloud. The two flights correspond to day 55 and 407, respectively, of remnant evolution. The instrument was complemented by a hard X-ray proportional counter, designed and constructed by the Istituto di Astrofisica Spaziale, CNR, Frascati, Italy, and sensitive to the 10-250 keV energy range. In this thesis, an account is given of the physical processes responsible for the production of gamma rays in astrophysical environments and their relation to supernovae and cosmic rays. A description is then given of main features of the gamma-ray telescope and its principles of operation, the most important part of the telescope being a spark chamber used to determine the direction of arrival of incident gamma rays. Data obtained during each flight were recorded as spark-chamber tracks on the photographic film. A detailed account of the methods of subsequent data reduction and analysis, as carried out by the author, is given. The principal results of this work were that 3-sigma upper limits to the gamma-ray flux from SN 1987A of 2.2 and 3.4 X 10^-5 photons cm^-2s^-1 were obtained for days 55 and 407 of remnant evolution, respectively, these limits being somewhat lower than previously reported in the literature from a preliminary analysis of the data. The above two upper limits are consistent with SN 1987A being an atypical Type II supernova. That is, the progenitor was a blue, rather than a red, supergiant. The limits are compared with theoretical predictions related to current models of gamma-ray emission from young Type II supernovae. (SECTION: Dissertation Abstracts)

  5. Core collapse supernovae from blue supergiant progenitors : The evolutionary history of SN 1987A

    NASA Astrophysics Data System (ADS)

    Menon, Athira

    2015-08-01

    SN 1987A is historically one of the most remarkable supernova explosions to be seen from Earth. Due to the proximity of its location in the LMC, it remains the most well-studied object outside the solar system. It was also the only supernova whose progenitor was observed prior to its explosion.SN 1987A however, was a unique and enigmatic core collapse supernova. It was the first Type II supernova to have been observed to have exploded while its progenitor was a blue supergiant (BSG). Until then Type II supernovae were expected to originate from explosions of red supergiants (RSGs). A spectacular triple-ring nebula structure, rich in helium and nitrogen, was observed around the remnant, indicating a recent RSG phase before becoming a BSG. Even today it is not entirely understood what the evolutionary history may have been to cause a BSG to explode. The most commonly accepted hypothesis for its origin is the merger of a massive binary star system.An evolutionary scenario for such a binary system, was proposed by Podsiadlowski (1992) (P92). Through SPH simulations of the merger and the stellar evolution of the post-merger remnant, Ivanova & Podsiadlowski (2002) and (2003) (I&M) could successfully obtain the RSG to BSG transition of the progenitor.The aim of the present work is to produce the evolutionary history of the progenitor of SN 1987A and its explosion. We construct our models based on the results of P92 and I&M. Here, the secondary (less massive) star is accreted on the primary, while being simultaneously mixed in its envelope over a period of 100 years. The merged star is evolved until the onset of core collapse. For this work we use the 1-dimensional, implicit, hydrodynamical stellar evolution code, KEPLER. A large parameter space is explored, consisting of primary (16-20 Ms) and secondary masses (5-8 Ms), mixing boundaries, and accreting timescales. Those models whose end states match the observed properties of the progenitor of SN 1987A are exploded. The nuclear yields and light curve of the explosion are then compared with the observed data of SN 1987A.

  6. The Interstellar 7Li/6Li Ratio in the Diffuse Gas Near IC 443

    NASA Astrophysics Data System (ADS)

    Ritchey, A. M.; Taylor, C. J.; Federman, S. R.; Lambert, D. L.

    2010-11-01

    Supernova remnants are believed to be the primary acceleration sites of Galactic cosmic rays (GCR), which are essential to gas-phase interstellar chemistry since they are a major source of ionization in both diffuse and dense environments. The interaction of accelerated particles with interstellar gas will also synthesize isotopes of the light elements Li, Be, and B through the spallation of CNO nuclei (producing all stable LiBeB isotopes) and through α+α fusion (yielding 6Li and 7Li, only). Type II supernovae may provide an additional source of 7Li and 11B during core collapse through neutrino-induced spallation in the He and C shells of the progenitor star (the ν-process). However, direct observational evidence for light element synthesis resulting from cosmic-ray or neutrino-induced spallation is rare. Here, we examine 7Li/6Li isotope ratios along four lines of sight through the supernova remnant IC 443 using observations of the Li I λ6707 doublet made with the Hobby-Eberly Telescope (HET) at McDonald Observatory. The 7Li/6Li ratio in the general interstellar medium is expected to be similar to the ratio of ~12 that characterizes solar system material. A local enhancement in the cosmic-ray flux will act to lower 7Li/6Li, yielding a ratio of ~2 when cosmic rays dominate Li synthesis. Gamma-ray emission from IC 443 provides strong evidence for the interaction of cosmic rays accelerated by the remnant with the ambient atomic and molecular gas. Yet this material has also been contaminated by the ejecta of a Type II supernova, which should be enriched in 7Li. We are seeking 7Li/6Li ratios that are either higher than the solar system ratio as a result of the ν-process or lower due to cosmic-ray spallation. Since the fine structure separation of the Li I doublet is comparable to the isotope shift (~7 km s-1) and each fine structure line is further split into hyperfine components, the velocity structure along the line of sight must be carefully constrained if meaningful 7Li/6Li ratios are to be determined. In our analysis, the strongest components seen in K I and CH are used to synthesize the complex Li I profiles. We will discuss the implications of our results on 7Li/6Li (and Li/K) ratios in the context of Li production by Type II supernovae.

  7. Supernova Ejecta in the Youngest Galactic Supernova Remnant G1.9+0.3

    NASA Technical Reports Server (NTRS)

    Borkowski, Kazimierz J.; Reynolds, Stephen P.; Hwang, Una; Green, David A.; Petre, Robert; Krishnamurthy, Kalyani; Willett, Rebecca

    2013-01-01

    G1.9+0.3 is the youngest known Galactic supernova remnant (SNR), with an estimated supernova (SN) explosion date of approximately 1900, and most likely located near the Galactic Center. Only the outermost ejecta layers with free-expansion velocities (is) approximately greater than 18,000 km s-1 have been shocked so far in this dynamically young, likely Type Ia SNR. A long (980 ks) Chandra observation in 2011 allowed spatially-resolved spectroscopy of heavy-element ejecta. We denoised Chandra data with the spatio-spectral method of Krishnamurthy et al., and used a wavelet based technique to spatially localize thermal emission produced by intermediate-mass elements (IMEs: Si and S) and iron. The spatial distribution of both IMEs and Fe is extremely asymmetric, with the strongest ejecta emission in the northern rim. Fe K alpha emission is particularly prominent there, and fits with thermal models indicate strongly oversolar Fe abundances. In a localized, outlying region in the northern rim, IMEs are less abundant than Fe, indicating that undiluted Fe-group elements (including 56Ni) with velocities greater than 18,000 km s-1 were ejected by this SN. But in the inner west rim, we find Si- and S-rich ejecta without any traces of Fe, so high-velocity products of O-burning were also ejected. G1.9+0.3 appears similar to energetic Type Ia SNe such as SN 2010jn where iron-group elements at such high free-expansion velocities have been recently detected. The pronounced asymmetry in the ejecta distribution and abundance inhomogeneities are best explained by a strongly asymmetric SN explosion, similar to those produced in some recent 3D delayed-detonation Type Ia models.

  8. Fermi Large Area Telescope observations of the supernova remnant HESS J1731-347

    NASA Astrophysics Data System (ADS)

    Yang, Rui-zhi; Zhang, Xiao; Yuan, Qiang; Liu, Siming

    2014-07-01

    Context. HESS J1731-347 has been identified as one of the few TeV-bright shell-type supernova remnants (SNRs). These remnants are dominated by nonthermal emission, and the nature of TeV emission has been continuously debated for nearly a decade. Aims: We carry out the detailed modeling of the radio to γ-ray spectrum of HESS J1731-347 to constrain the magnetic field and energetic particles sources, which we compare with those of the other TeV-bright shell-type SNRs explored before. Methods: Four years of data from Fermi Large Area Telescope (LAT) observations for regions around this remnant are analyzed, leading to no detection correlated with the source discovered in the TeV band. The Markov chain Monte Carlo method is used to constrain parameters of one-zone models for the overall emission spectrum. Results: Based on the 99.9% upper limits of fluxes in the GeV range, one-zone hadronic models with an energetic proton spectral slope greater than 1.8 can be ruled out, which favors a leptonic origin for the γ-ray emission, making this remnant a sibling of the brightest TeV SNR RX J1713.7-3946, the Vela Junior SNR RX J0852.0-4622, and RCW 86. The best-fit leptonic model has an electron spectral slope of 1.8 and a magnetic field of ~30 μG, which is at least a factor of 2 higher than those of RX J1713.7-3946 and RX J0852.0-4622, posing a challenge to the distance estimate and/or the energy equipartition between energetic electrons and the magnetic field of this source. A measurement of the shock speed will address this challenge and has implications on the magnetic field evolution and electron acceleration driven by shocks of SNRs.

  9. Identification of PSR1758-23 as a runaway pulsar from the supernova remnant W28

    NASA Technical Reports Server (NTRS)

    Frall, D. A.; Kulkarni, S. R.; Vasisht, G.

    1993-01-01

    New observations are presented which indicate that the large dispersion and scattering of the pulses from PSR1758-23 are caused by a dense screen of ionized material located along the line of sight. This reconciles the distances to the pulsar with that to SNR W28.

  10. X-ray line emission from the Puppis A supernova remnant - Oxygen lines

    NASA Technical Reports Server (NTRS)

    Winkler, P. F.; Clark, G. W.; Markert, T. H.; Petre, R.; Canizares, C. R.

    1981-01-01

    Six prominent X-ray emission lines of O VII and O VIII have been detected from a portion of the Puppis A supernova remnant in observations with the Einstein Observatory Focal Plane Crystal Spectrometer. The lines are sufficiently well resolved to serve as diagnostics of the emitting plasma. From the relative intensities of the lines, it is inferred that the population of O VIII is about 1.5 times that of O VII, and that electron collisions are the dominant excitation mechanism in the plasma. A locus of allowed electron temperatures and interstellar-absorption column densities is derived: 1.5 x 10 to the 6th K, and (2-6) x 10 to the 21st per sq cm. The data are consistent with either a thin plasma source in equilibrium at a temperature of 2.2 x 10 to the 6th K with a column density of 4 x 10 to the 21st per sq cm, or with a nonequilibrium source in which the electrons have been shock-heated to a higher temperature and oxygen is underionized.

  11. High Spatial Resolution X-Ray Spectroscopy of the IC443 Pulsar Wind Nebula

    NASA Astrophysics Data System (ADS)

    Swartz, Douglas A.; Weisskopf, Martin C.; Bucciantini, Niccolo; Clarke, Tracy E.; Karovska, Margarita; Pavlov, George G.; van der Horst, Alexander; Yukita, Mihoko; Zavlin, Vyacheslav

    2014-08-01

    Deep Chandra ACIS observations of the region around the putative pulsar CXOU J061705.3+222127, in the supernova remnant IC443, reveal a ~5" radius ring-like morphology surrounding the pulsar and a jet-like structure oriented roughly north-south across the ring and through the pulsar's location. The observations further confirm that (1) the spectrum and flux of the central object are consistent with a rotation-powered pulsar, (2) the non-thermal spectrum and morphology of the surrounding nebula are consistent with a pulsar wind, and (3) the spectrum at greater distances is consistent with thermal emission from the supernova remnant. The cometary shape of the nebula, suggesting motion towards the southwest, appears to be subsonic: There is no evidence for a strong bow shock; and the ring is not distorted by motion through the ambient medium. Comparing this observation with historical observations of the same target we set a 99-% confidence upper limit to the proper motion of CXOU J061705.3+222127 to be less than 310 km/s, with the best-fit (but not statistically significant) direction toward the west.

  12. Suzaku Observation of Diffuse X-ray Emission from the Carina Nebula

    NASA Technical Reports Server (NTRS)

    Hamaguchi, Kenji; Petre, Robert; Matsumoti, Hironori; Tsujimoto, Masahiro; Holt, Stephan S.; Ezoe, Yuichiro; Ozawa, Hideki; Tsuboi, Yohko; Soong, Yang; Kitamoto, Shunji; hide

    2007-01-01

    We studied extended X-ray emission from the Carina Nebula taken with the Suzaku CCD camera XIS on 2005 Aug. 29. The X-ray morphology, plasma temperature and absorption to the plasma are consistent with the earlier Einstein results. The Suzaku spectra newly revealed emission lines from various spices including oxygen, but not from nitrogen. This result restricts the N/O ratio significantly low, compared with evolved massive stellar winds, suggesting that the diffuse emission is originated in an old supernova remnant or a super shell produced by multiple supernova remnants. The X-ray spectra from the north and south of eta Car showed distinct differences between 0.3-2 keV. The south spectrum shows strong L-shell lines of iron ions and K-shell lines of silicon ions, while the north spectrum shows them weak in intensity. This means that silicon and iron abundances are a factor of 2-4 higher in the south region than in the north region. The abundance variation may be produced by an SNR ejecta, or relate to the dust formation around the star forming core.

  13. Intermediate-mass Elements in Young Supernova Remnants Reveal Neutron Star Kicks by Asymmetric Explosions

    NASA Astrophysics Data System (ADS)

    Katsuda, Satoru; Morii, Mikio; Janka, Hans-Thomas; Wongwathanarat, Annop; Nakamura, Ko; Kotake, Kei; Mori, Koji; Müller, Ewald; Takiwaki, Tomoya; Tanaka, Masaomi; Tominaga, Nozomu; Tsunemi, Hiroshi

    2018-03-01

    The birth properties of neutron stars (NSs) yield important information about the still-debated physical processes that trigger the explosion as well as on intrinsic neutron-star physics. These properties include the high space velocities of young neutron stars with average values of several 100 km s‑1, with an underlying “kick” mechanism that is not fully clarified. There are two competing possibilities that could accelerate NSs during their birth: anisotropic ejection of either stellar debris or neutrinos. Here we present new evidence from X-ray measurements that chemical elements between silicon and calcium in six young gaseous supernova remnants are preferentially expelled opposite to the direction of neutron star motion. There is no correlation between the kick velocities and magnetic field strengths of these neutron stars. Our results support a hydrodynamic origin of neutron-star kicks connected to asymmetric explosive mass ejection, and they conflict with neutron-star acceleration scenarios that invoke anisotropic neutrino emission caused by particle and nuclear physics in combination with very strong neutron-star magnetic fields.

  14. A search for new supernova remnant shells in the Galactic plane with H.E.S.S.

    NASA Astrophysics Data System (ADS)

    H. E. S. S. Collaboration; Abdalla, H.; Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Akhperjanian, A. G.; Andersson, T.; Angüner, E. O.; Arakawa, M.; Arrieta, M.; Aubert, P.; Backes, M.; Balzer, A.; Barnard, M.; Becherini, Y.; Becker Tjus, J.; Berge, D.; Bernhard, S.; Bernlöhr, K.; Blackwell, R.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bonnefoy, S.; Bordas, P.; Bregeon, J.; Brun, F.; Brun, P.; Bryan, M.; Büchele, M.; Bulik, T.; Capasso, M.; Carr, J.; Casanova, S.; Cerruti, M.; Chakraborty, N.; Chaves, R. C. G.; Chen, A.; Chevalier, J.; Coffaro, M.; Colafrancesco, S.; Cologna, G.; Condon, B.; Conrad, J.; Cui, Y.; Davids, I. D.; Decock, J.; Degrange, B.; Deil, C.; Devin, J.; deWilt, P.; Dirson, L.; Djannati-Ataï, A.; Domainko, W.; Donath, A.; Drury, L. O.'C.; Dutson, K.; Dyks, J.; Edwards, T.; Egberts, K.; Eger, P.; Ernenwein, J.-P.; Eschbach, S.; Farnier, C.; Fegan, S.; Fernandes, M. V.; Fiasson, A.; Fontaine, G.; Förster, A.; Funk, S.; Füßling, M.; Gabici, S.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Gottschall, D.; Goyal, A.; Grondin, M.-H.; Hahn, J.; Haupt, M.; Hawkes, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hinton, J. A.; Hofmann, W.; Hoischen, C.; Holch, T. L.; Holler, M.; Horns, D.; Ivascenko, A.; Iwasaki, H.; Jacholkowska, A.; Jamrozy, M.; Janiak, M.; Jankowsky, D.; Jankowsky, F.; Jingo, M.; Jogler, T.; Jouvin, L.; Jung-Richardt, I.; Kastendieck, M. A.; Katarzyński, K.; Katsuragawa, M.; Katz, U.; Kerszberg, D.; Khangulyan, D.; Khélifi, B.; King, J.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Kraus, M.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lau, J.; Lees, J.-P.; Lefaucheur, J.; Lefranc, V.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Leser, E.; Lohse, T.; Lorentz, M.; Liu, R.; López-Coto, R.; Lypova, I.; Marandon, V.; Marcowith, A.; Mariaud, C.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; Meintjes, P. J.; Meyer, M.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Mohrmann, L.; Morå, K.; Moulin, E.; Murach, T.; Nakashima, S.; de Naurois, M.; Niederwanger, F.; Niemiec, J.; Oakes, L.; O'Brien, P.; Odaka, H.; Öttl, S.; Ohm, S.; Ostrowski, M.; Oya, I.; Padovani, M.; Panter, M.; Parsons, R. D.; Pekeur, N. W.; Pelletier, G.; Perennes, C.; Petrucci, P.-O.; Peyaud, B.; Piel, Q.; Pita, S.; Poon, H.; Prokhorov, D.; Prokoph, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Richter, S.; Rieger, F.; Romoli, C.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Saito, S.; Salek, D.; Sanchez, D. A.; Santangelo, A.; Sasaki, M.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwemmer, S.; Seglar-Arroyo, M.; Settimo, M.; Seyffert, A. S.; Shafi, N.; Shilon, I.; Simoni, R.; Sol, H.; Spanier, F.; Spengler, G.; Spies, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stycz, K.; Sushch, I.; Takahashi, T.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tibaldo, L.; Tiziani, D.; Tluczykont, M.; Trichard, C.; Tsuji, N.; Tuffs, R.; Uchiyama, Y.; van der Walt, D. J.; van Eldik, C.; van Rensburg, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Voisin, F.; Völk, H. J.; Vuillaume, T.; Wadiasingh, Z.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Yang, R.; Zabalza, V.; Zaborov, D.; Zacharias, M.; Zanin, R.; Zdziarski, A. A.; Zech, A.; Zefi, F.; Ziegler, A.; Żywucka, N.; Bamba, A.; Fukui, Y.; Sano, H.; Yoshiike, S.

    2018-04-01

    A search for new supernova remnants (SNRs) has been conducted using TeV γ-ray data from the H.E.S.S. Galactic plane survey. As an identification criterion, shell morphologies that are characteristic for known resolved TeV SNRs have been used. Three new SNR candidates were identified in the H.E.S.S. data set with this method. Extensive multiwavelength searches for counterparts were conducted. A radio SNR candidate has been identified to be a counterpart to HESS J1534-571. The TeV source is therefore classified as a SNR. For the other two sources, HESS J1614-518 and HESS J1912+101, no identifying counterparts have been found, thus they remain SNR candidates for the time being. TeV-emitting SNRs are key objects in the context of identifying the accelerators of Galactic cosmic rays. The TeV emission of the relativistic particles in the new sources is examined in view of possible leptonic and hadronic emission scenarios, taking the current multiwavelength knowledge into account.

  15. Accreting Compact Object at the Center of the Supernova Remnant RCW 103.

    NASA Astrophysics Data System (ADS)

    Sanwal, D.; Garmire, G. P.; Garmire, A.; Pavlov, G. G.; Mignani, R.

    2002-05-01

    We observed the radio-quiet central compact object of the supernova remnant RCW 103 with the Chandra ACIS during 13.8 hours on 2002 March 3, when the source was in high state, with a time-averaged flux of 8*E-12 erg cm-2 s-1 in the 0.5--8.0 keV band. The complex light curve of the source shows a period of about 6.4 hours and two partial eclipses or dips per period, separated by 180o in phase. The variability of the source proves that it is powered by accretion, likely from a low-mass companion in a binary system. Deep near-IR observations of the source with VLT suggest a potential counterpart of the compact object about 2'' from the nominal Chandra position. The magnitudes of the potential counterpart are J ≈ 22.3, H ≈ 19.6, and Ks ≈ 18.5, with an uncertainty of about 0.5 mag. We will discuss possible interpretations of the observational results. This work was partially supported by NASA grants NAS8-01128 and NAG5-10865.

  16. Suzaku Observations of the Non-thermal Supernova Remnant HESS J1731-347

    NASA Astrophysics Data System (ADS)

    Bamba, Aya; Pühlhofer, Gerd; Acero, Fabio; Klochkov, Dmitry; Tian, Wenwu; Yamazaki, Ryo; Li, Zhiyuan; Horns, Dieter; Kosack, Karl; Komin, Nukri

    2012-09-01

    A detailed analysis of the non-thermal X-ray emission from the northwestern and southern parts of the supernova remnant (SNR) HESS J1731-347 with Suzaku is presented. The shell portions covered by the observations emit hard and lineless X-rays. The spectrum can be reproduced by a simple absorbed power-law model with a photon index Γ of 1.8-2.7 and an absorption column density N H of (1.0-2.1) × 1022 cm-2. These quantities change significantly from region to region; the northwestern part of the SNR has the hardest and most absorbed spectrum. The western part of the X-ray shell has a smaller curvature than the northwestern and southern shell segments. A comparison of the X-ray morphology to the very high energy gamma-ray and radio images was performed. The efficiency of the electron acceleration and the emission mechanism in each portion of the shell are discussed. Thermal X-ray emission from the SNR was searched for but could not be detected at a significant level.

  17. Impacts of the Detection of Cassiopeia A Point Source.

    PubMed

    Umeda; Nomoto; Tsuruta; Mineshige

    2000-05-10

    Very recently the Chandra first light observation discovered a point-like source in the Cassiopeia A supernova remnant. This detection was subsequently confirmed by the analyses of the archival data from both ROSAT and Einstein observations. Here we compare the results from these observations with the scenarios involving both black holes (BHs) and neutron stars (NSs). If this point source is a BH, we offer as a promising model a disk-corona type model with a low accretion rate in which a soft photon source at approximately 0.1 keV is Comptonized by higher energy electrons in the corona. If it is an NS, the dominant radiation observed by Chandra most likely originates from smaller, hotter regions of the stellar surface, but we argue that it is still worthwhile to compare the cooler component from the rest of the surface with cooling theories. We emphasize that the detection of this point source itself should potentially provide enormous impacts on the theories of supernova explosion, progenitor scenario, compact remnant formation, accretion to compact objects, and NS thermal evolution.

  18. Degeneracy breakdown as a source of supernovae Ia

    NASA Astrophysics Data System (ADS)

    Clavelli, L.

    2018-01-01

    In a confined system of multiple Fermions, the particles are forced into high energy levels by the Pauli Exclusion Principle. We refer to this system as a Pauli tower. We pursue the investigation of a model for sub-Chandrasekhar supernovae Ia explosions (SNIa) in which the energy stored in the Pauli tower is released to trigger a nuclear deflagration. The simplest physical model for such a degeneracy breakdown and collapse of the Pauli tower is a phase transition to an exactly supersymmetric state in which the scalar partners of protons, neutrons, and leptons become degenerate with the familiar fermions of our world as in the supersymmetric standard model with susy breaking parameters relaxed to zero. We focus on the ability of the susy phase transition model to fit the total SNIa rate as well as the delay time distribution of SNIa after the birth of a progenitor white dwarf. We also study the ejected mass distribution and its correlation with delay time. Finally, we discuss the expected SNIa remnant in the form of a black hole of roughly Jupiter mass and the prospects for detecting such remnants.

  19. HESS J1640-465 - an exceptionally luminous TeV γ-ray supernova remnant

    NASA Astrophysics Data System (ADS)

    Abramowski, A.; Aharonian, F.; Benkhali, F. Ait; Akhperjanian, A. G.; Angüner, E.; Anton, G.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker Tjus, J.; Bernlöhr, K.; Birsin, E.; Bissaldi, E.; Biteau, J.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P. M.; Chalme-Calvet, R.; Chaves, R. C. G.; Cheesebrough, A.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Conrad, J.; Couturier, C.; Cui, Y.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; Drury, L. O'C.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, K.; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Grondin, M.-H.; Grudzińska, M.; Häffner, S.; Hahn, J.; Harris, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Khélifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Kluźniak, W.; Kneiske, T.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Méhault, J.; Meintjes, P. J.; Menzler, U.; Meyer, M.; Moderski, R.; Mohamed, M.; Moulin, E.; Murach, T.; Naumann, C. L.; de Naurois, M.; Niemiec, J.; Nolan, S. J.; Oakes, L.; Ohm, S.; Wilhelmi, E. de Oña; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Arribas, M. Paz; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Poon, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Raue, M.; Reimer, A.; Reimer, O.; Renaud, M.; Reyes, R. de los; Rieger, F.; Rob, L.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sol, H.; Spengler, G.; Spies, F.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Szostek, A.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; van Soelen, B.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Völk, H. J.; Volpe, F.; Vorster, M.; Vuillaume, T.; Wagner, S. J.; Wagner, P.; Ward, M.; Weidinger, M.; Weitzel, Q.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Zabalza, V.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.

    2014-04-01

    The results of follow-up observations of the TeV γ-ray source HESS J1640-465 from 2004 to 2011 with the High Energy Stereoscopic System (HESS) are reported in this work. The spectrum is well described by an exponential cut-off power law with photon index Γ = 2.11 ± 0.09stat ± 0.10sys, and a cut-off energy of E_c = 6.0^{+2.0}_{-1.2} TeV. The TeV emission is significantly extended and overlaps with the northwestern part of the shell of the SNR G338.3-0.0. The new HESS results, a re-analysis of archival XMM-Newton data and multiwavelength observations suggest that a significant part of the γ-ray emission from HESS J1640-465 originates in the supernova remnant shell. In a hadronic scenario, as suggested by the smooth connection of the GeV and TeV spectra, the product of total proton energy and mean target density could be as high as WpnH ˜ 4 × 1052(d/10kpc)2 erg cm-3.

  20. Diffuse gamma-ray emission from self-confined cosmic rays around Galactic sources

    NASA Astrophysics Data System (ADS)

    D'Angelo, Marta; Morlino, Giovanni; Amato, Elena; Blasi, Pasquale

    2018-02-01

    The propagation of particles accelerated at supernova remnant shocks and escaping the parent remnants is likely to proceed in a strongly non-linear regime, due to the efficient self-generation of Alfvén waves excited through streaming instability near the sources. Depending on the amount of neutral hydrogen present in the regions around the sites of supernova explosions, cosmic rays may accumulate an appreciable grammage in the same regions and get self-confined for non-negligible times, which in turn results in an enhanced rate of production of secondaries. Here we calculate the contribution to the diffuse gamma-ray background due to the overlap along lines of sight of several of these extended haloes as due to pion production induced by self-confined cosmic rays. We find that if the density of neutrals is low, the haloes can account for a substantial fraction of the diffuse emission observed by Fermi-Large Area Telescope (LAT), depending on the orientation of the line of sight with respect to the direction of the Galactic Centre.

  1. Mapping the three-dimensional dust extinction towards the supernova remnant S147 - the S147 dust cloud

    NASA Astrophysics Data System (ADS)

    Chen, B.-Q.; Liu, X.-W.; Ren, J.-J.; Yuan, H.-B.; Huang, Y.; Yu, B.; Xiang, M.-S.; Wang, C.; Tian, Z.-J.; Zhang, H.-W.

    2017-12-01

    We present a three-dimensional (3D) extinction analysis in the region towards the supernova remnant (SNR) S147 (G180.0-1.7) using multiband photometric data from the Xuyi Schmidt Telescope Photometric Survey of the Galactic Anticentre (XSTPS-GAC), 2MASS and WISE. We isolate a previously unrecognized dust structure likely to be associated with SNR S147. The structure, which we term as 'S147 dust cloud', is estimated to have a distance d = 1.22 ± 0.21 kpc, consistent with the conjecture that S147 is associated with pulsar PSR J0538 + 2817. The cloud includes several dense clumps of relatively high extinction that locate on the radio shell of S147 and coincide spatially with the CO and gamma-ray emission features. We conclude that the usage of CO measurements to trace the SNR associated MCs is unavoidably limited by the detection threshold, dust depletion and the difficulty of distance estimates in the outer Galaxy. 3D dust extinction mapping may provide a better way to identify and study SNR-MC interactions.

  2. When Disorder Looks Like Order: A New Model to Explain Radial Magnetic Fields in Young Supernova Remnants

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

    West, J. L.; Gaensler, B. M.; Jaffe, T.

    Radial magnetic fields are observed in all known young, shell-type supernova remnants in our Galaxy, including Cas A, Tycho, Kepler, and SN1006, and yet the nature of these radial fields has not been thoroughly explored. Using a 3D model, we consider the existence and observational implications of an intrinsically radial field. We also present a new explanation of the origin of the radial pattern observed from polarization data as resulting from a selection effect due to the distribution of cosmic-ray electrons (CREs). We show that quasi-parallel acceleration can concentrate CREs at regions where the magnetic field is radial, making amore » completely turbulent field appear ordered, when it is in fact disordered. We discuss observational properties that may help distinguish between an intrinsically radial magnetic field and the case where it only appears radial due to the CRE distribution. We also show that the case of an intrinsically radial field with a quasi-perpendicular CRE acceleration mechanism has intriguing similarities to the observed polarization properties of SN1006.« less

  3. Polarized Balmer line emission from supernova remnant shock waves efficiently accelerating cosmic rays

    NASA Astrophysics Data System (ADS)

    Shimoda, Jiro; Ohira, Yutaka; Yamazaki, Ryo; Laming, J. Martin; Katsuda, Satoru

    2018-01-01

    Linearly polarized Balmer line emissions from supernova remnant shocks are studied taking into account the energy loss of the shock owing to the production of non-thermal particles. The polarization degree depends on the downstream temperature and the velocity difference between upstream and downstream regions. The former is derived once the line width of the broad component of the H α emission is observed. Then, the observation of the polarization degree tells us the latter. At the same time, the estimated value of the velocity difference independently predicts adiabatic downstream temperature that is derived from Rankine Hugoniot relations for adiabatic shocks. If the actually observed downstream temperature is lower than the adiabatic temperature, there is a missing thermal energy which is consumed for particle acceleration. It is shown that a larger energy-loss rate leads to more highly polarized H α emission. Furthermore, we find that polarized intensity ratio of H β to H α also depends on the energy-loss rate and that it is independent of uncertain quantities such as electron temperature, the effect of Lyman line trapping and our line of sight.

  4. Revised Distances to 21 Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Ranasinghe, S.; Leahy, D. A.

    2018-05-01

    We carry out a comprehensive study of H I 21 cm line observations and 13CO line observations of 21 supernova remnants (SNRs). The aim of the study is to search for H I absorption features to obtain kinematic distances in a consistent manner. The 21 SNRs are in the region of sky covered by the Very Large Array Galactic Plane Survey (H I 21 cm observations) and Galactic Ring Survey (13CO line observations). We obtain revised distances for 10 SNRs based on new evidence in the H I and 13CO observations. We revise distances for the other 11 SNRs based on an updated rotation curve and new error analysis. The mean change in distance for the 21 SNRs is ≃25%, i.e., a change of 1.5 kpc compared to a mean distance for the sample of 6.4 kpc. This has a significant impact on interpretation of the physical state of these SNRs. For example, using a Sedov model, age and explosion energy scale as the square of distance, and inferred ISM density scales as distance.

  5. KINEMATICS OF ULTRA-HIGH-VELOCITY GAS IN THE EXPANDING MOLECULAR SHELL ADJACENT TO THE W44 SUPERNOVA REMNANT

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

    Yamada, Masaya; Oka, Tomoharu; Takekawa, Shunya

    We mapped the ultra-high-velocity feature (the “Bullet”) detected in the expanding molecular shell associated with the W44 supernova remnant using the Nobeyama Radio Observatory 45 m telescope and the Atacama Submillimeter Telescope Experiment 10 m telescope. The Bullet clearly appears in the CO J = 1–0, CO J = 3–2, CO J = 4–3, and HCO{sup +} J = 1–0 maps with a compact appearance (0.5 × 0.8 pc{sup 2}) and an extremely broad-velocity width (Δ V ≃ 100 km s{sup −1}). The line intensities indicate that the Bullet has a higher density and temperature than those in the expandingmore » molecular shell. The kinetic energy of the Bullet amounts to 10{sup 48.0} erg, which is approximately 1.5 orders of magnitude greater than the kinetic energy shared to the small solid angle of it. Two possible formation scenarios with an inactive isolated black hole are presented.« less

  6. 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.

  7. The Chinese "Jing Xing" of 1006: Its Identity and Astrological Meaning

    NASA Astrophysics Data System (ADS)

    Sun, Xiaochun

    2006-08-01

    The outburst of supernovae 1006 was one of most spectacular astronomical events in history. This event was observed in almost all civilizations. In the Song China, it was known as the appearance of a jing xing , one type of "guest stars". Based on a the descriptions given by various observers from China, Japan and Arabic world, this paper reconstructs the light curve of this supernovae. A close examination of the Chinese descriptions of its location also suggests that the remnant of this supernova might be identified with another radio source other than widely recognized "SN1006". Furthermore, this paper examines the astrological interpretations of this event given by the Chinese astronomers. It shows that such astronomical events had tremendous political implications and their astrological interpretations were shaped by political situation of the time.

  8. Detection of a noble gas molecular ion, 36ArH+, in the Crab Nebula.

    PubMed

    Barlow, M J; Swinyard, B M; Owen, P J; Cernicharo, J; Gomez, H L; Ivison, R J; Krause, O; Lim, T L; Matsuura, M; Miller, S; Olofsson, G; Polehampton, E T

    2013-12-13

    Noble gas molecules have not hitherto been detected in space. From spectra obtained with the Herschel Space Observatory, we report the detection of emission in the 617.5- and 1234.6-gigahertz J = 1-0 and 2-1 rotational lines of (36)ArH(+) at several positions in the Crab Nebula, a supernova remnant known to contain both molecular hydrogen and regions of enhanced ionized argon emission. Argon-36 is believed to have originated from explosive nucleosynthesis in massive stars during core-collapse supernova events. Its detection in the Crab Nebula, the product of such a supernova event, confirms this expectation. The likely excitation mechanism for the observed (36)ArH(+) emission lines is electron collisions in partially ionized regions with electron densities of a few hundred per centimeter cubed.

  9. EVOLUTION OF HIGH-ENERGY PARTICLE DISTRIBUTION IN MATURE SHELL-TYPE SUPERNOVA REMNANTS

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

    Zeng, Houdun; Xin, Yuliang; Liu, Siming

    Multi-wavelength observations of mature supernova remnants (SNRs), especially with recent advances in γ -ray astronomy, make it possible to constrain energy distribution of energetic particles within these remnants. In consideration of the SNR origin of Galactic cosmic rays and physics related to particle acceleration and radiative processes, we use a simple one-zone model to fit the nonthermal emission spectra of three shell-type SNRs located within 2° on the sky: RX J1713.7−3946, CTB 37B, and CTB 37A. Although radio images of these three sources all show a shell (or half-shell) structure, their radio, X-ray, and γ -ray spectra are quite different,more » offering an ideal case to explore evolution of energetic particle distribution in SNRs. Our spectral fitting shows that (1) the particle distribution becomes harder with aging of these SNRs, implying a continuous acceleration process, and the particle distributions of CTB 37A and CTB 37B in the GeV range are harder than the hardest distribution that can be produced at a shock via the linear diffusive shock particle acceleration process, so spatial transport may play a role; (2) the energy loss timescale of electrons at the high-energy cutoff due to synchrotron radiation appears to be always a bit (within a factor of a few) shorter than the age of the corresponding remnant, which also requires continuous particle acceleration; (3) double power-law distributions are needed to fit the spectra of CTB 37B and CTB 37A, which may be attributed to shock interaction with molecular clouds.« less

  10. XMM-Newton studies of the supernova remnant G350.0-2.0

    NASA Astrophysics Data System (ADS)

    Karpova, A.; Shternin, P.; Zyuzin, D.; Danilenko, A.; Shibanov, Yu.

    2016-11-01

    We report the results of XMM-Newton observations of the Galactic mixed-morphology supernova remnant G350.0-2.0. Diffuse thermal X-ray emission fills the north-western part of the remnant surrounded by radio shell-like structures. We did not detect any X-ray counterpart of the latter structures, but found several bright blobs within the diffuse emission. The X-ray spectrum of the most part of the remnant can be described by a collisionally ionized plasma model VAPEC with solar abundances and a temperature of ≈0.8 keV. The solar abundances of plasma indicate that the X-ray emission comes from the shocked interstellar material. The overabundance of Fe was found in some of the bright blobs. We also analysed the brightest point-like X-ray source 1RXS J172653.4-382157 projected on the extended emission. Its spectrum is well described by the two-temperature optically thin thermal plasma model MEKAL typical for cataclysmic variable stars. The cataclysmic variable source nature is supported by the presence of a faint (g ≈ 21) optical source with non-stellar spectral energy distribution at the X-ray position of 1RXS J172653.4-382157. It was detected with the XMM-Newton optical/UV monitor in the U filter and was also found in the archival Hα and optical/near-infrared broad-band sky survey images. On the other hand, the X-ray spectrum is also described by the power law plus thermal component model typical for a rotation powered pulsar. Therefore, the pulsar interpretation of the source cannot be excluded. For this source, we derived the upper limit for the pulsed fraction of 27 per cent.

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

    Pan, Kuo-Chuan; Ricker, Paul M.; Taam, Ronald E., E-mail: kpan2@illinois.edu, E-mail: pmricker@illinois.edu, E-mail: r-taam@northwestern.edu

    The progenitor systems of Type Ia supernovae (SNe Ia) are still under debate. Based on recent hydrodynamics simulations, non-degenerate companions in the single-degenerate scenario (SDS) should survive the supernova (SN) impact. One way to distinguish between the SDS and the double-degenerate scenario is to search for the post-impact remnant stars (PIRSs) in SN Ia remnants. Using a technique that combines multi-dimensional hydrodynamics simulations with one-dimensional stellar evolution simulations, we have examined the post-impact evolution of helium-rich binary companions in the SDS. It is found that these helium-rich PIRSs (He PIRSs) dramatically expand and evolve to a luminous phase (L {approx}more » 10{sup 4} L{sub Sun }) about 10 yr after an SN explosion. Subsequently, they contract and evolve to become hot blue-subdwarf-like (sdO-like) stars by releasing gravitational energy, persisting as sdO-like stars for several million years before evolving to the helium red-giant phase. We therefore predict that a luminous OB-like star should be detectable within {approx}30 yr after the SN explosion. Thereafter, it will shrink and become an sdO-like star in the central regions of SN Ia remnants within star-forming regions for SN Ia progenitors evolved via the helium-star channel in the SDS. These He PIRSs are predicted to be rapidly rotating (v{sub rot} {approx}> 50 km s{sup -1}) and to have high spatial velocities (v{sub linear} {approx}> 500 km s{sup -1}). Furthermore, if SN remnants have diffused away and are not recognizable at a later stage, He PIRSs could be an additional source of single sdO stars and/or hypervelocity stars.« less

  12. H-alpha images of the Cygnus Loop - A new look at shock-wave dynamics in an old supernova remnant

    NASA Technical Reports Server (NTRS)

    Fesen, Robert A.; Kwitter, Karen B.; Downes, Ronald A.

    1992-01-01

    Attention is given to deep H-alpha images of portions of the east, west, and southwest limbs of the Cygnus Loop which illustrate several aspects of shock dynamics in a multiphase interstellar medium. An H-alpha image of the isolated eastern shocked cloud reveals cloud deformation and gas stripping along the cloud's edges, shock front diffraction and reflection around the rear of the cloud, and interior remnant emission due to upstream shock reflection. A faint Balmer-dominated filament is identified 30 arcmin further west of the remnant's bright line of western radiative filaments. This detection indicates a far more westerly intercloud shock front position than previously realized, and resolves the nature of the weak X-ray, optical, and nonthermal radio emission observed west of NGC 6960. Strongly curved Balmer-dominated filaments along the remnant's west and southwest edge may indicate shock diffraction caused by shock wave passage in between clouds.

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

    NASA Astrophysics Data System (ADS)

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

    2005-12-01

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

  14. MODELING SNR CASSIOPEIA A FROM THE SUPERNOVA EXPLOSION TO ITS CURRENT AGE: THE ROLE OF POST-EXPLOSION ANISOTROPIES OF EJECTA

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

    Orlando, S.; Miceli, M.; Pumo, M. L.

    The remnants of core-collapse supernovae (SNe) have complex morphologies that may reflect asymmetries and structures developed during the progenitor SN explosion. Here we investigate how the morphology of the supernova remnant Cassiopeia A (Cas A) reflects the characteristics of the progenitor SN with the aim of deriving the energies and masses of the post-explosion anisotropies responsible for the observed spatial distribution of Fe and Si/S. We model the evolution of Cas A from the immediate aftermath of the progenitor SN to the three-dimensional interaction of the remnant with the surrounding medium. The post-explosion structure of the ejecta is described bymore » small-scale clumping of material and larger-scale anisotropies. The hydrodynamic multi-species simulations consider an appropriate post-explosion isotopic composition of the ejecta. The observed average expansion rate and shock velocities can be well reproduced by models with ejecta mass M {sub ej} ≈ 4 M {sub ⊙} and explosion energy E {sub SN} ≈ 2.3 × 10{sup 51} erg. The post-explosion anisotropies (pistons) reproduce the observed distributions of Fe and Si/S if they had a total mass of ≈0.25 M {sub ⊙} and a total kinetic energy of ≈1.5 × 10{sup 50} erg. The pistons produce a spatial inversion of ejecta layers at the epoch of Cas A, leading to the Si/S-rich ejecta physically interior to the Fe-rich ejecta. The pistons are also responsible for the development of the bright rings of Si/S-rich material which form at the intersection between the reverse shock and the material accumulated around the pistons during their propagation. Our result supports the idea that the bulk of asymmetries observed in Cas A are intrinsic to the explosion.« less

  15. Hitomi observations of the LMC SNR N 132 D: Highly redshifted X-ray emission from iron ejecta

    NASA Astrophysics Data System (ADS)

    Hitomi Collaboration; Aharonian, Felix; Akamatsu, Hiroki; Akimoto, Fumie; Allen, Steven W.; Angelini, Lorella; Audard, Marc; Awaki, Hisamitsu; Axelsson, Magnus; Bamba, Aya; Bautz, Marshall W.; Blandford, Roger; Brenneman, Laura W.; Brown, Gregory V.; Bulbul, Esra; Cackett, Edward M.; Chernyakova, Maria; Chiao, Meng P.; Coppi, Paolo S.; Costantini, Elisa; de Plaa, Jelle; de Vries, Cor P.; den Herder, Jan-Willem; Done, Chris; Dotani, Tadayasu; Ebisawa, Ken; Eckart, Megan E.; Enoto, Teruaki; Ezoe, Yuichiro; Fabian, Andrew C.; Ferrigno, Carlo; Foster, Adam R.; Fujimoto, Ryuichi; Fukazawa, Yasushi; Furuzawa, Akihiro; Galeazzi, Massimiliano; Gallo, Luigi C.; Gandhi, Poshak; Giustini, Margherita; Goldwurm, Andrea; Gu, Liyi; Guainazzi, Matteo; Haba, Yoshito; Hagino, Kouichi; Hamaguchi, Kenji; Harrus, Ilana M.; Hatsukade, Isamu; Hayashi, Katsuhiro; Hayashi, Takayuki; Hayashida, Kiyoshi; Hiraga, Junko S.; Hornschemeier, Ann; Hoshino, Akio; Hughes, John P.; Ichinohe, Yuto; Iizuka, Ryo; Inoue, Hajime; Inoue, Yoshiyuki; Ishida, Manabu; Ishikawa, Kumi; Ishisaki, Yoshitaka; Iwai, Masachika; Kaastra, Jelle; Kallman, Tim; Kamae, Tsuneyoshi; Kataoka, Jun; Katsuda, Satoru; Kawai, Nobuyuki; Kelley, Richard L.; Kilbourne, Caroline A.; Kitaguchi, Takao; Kitamoto, Shunji; Kitayama, Tetsu; Kohmura, Takayoshi; Kokubun, Motohide; Koyama, Katsuji; Koyama, Shu; Kretschmar, Peter; Krimm, Hans A.; Kubota, Aya; Kunieda, Hideyo; Laurent, Philippe; Lee, Shiu-Hang; Leutenegger, Maurice A.; Limousin, Olivier; Loewenstein, Michael; Long, Knox S.; Lumb, David; Madejski, Greg; Maeda, Yoshitomo; Maier, Daniel; Makishima, Kazuo; Markevitch, Maxim; Matsumoto, Hironori; Matsushita, Kyoko; McCammon, Dan; McNamara, Brian R.; Mehdipour, Missagh; Miller, Eric D.; Miller, Jon M.; Mineshige, Shin; Mitsuda, Kazuhisa; Mitsuishi, Ikuyuki; Miyazawa, Takuya; Mizuno, Tsunefumi; Mori, Hideyuki; Mori, Koji; Mukai, Koji; Murakami, Hiroshi; Mushotzky, Richard F.; Nakagawa, Takao; Nakajima, Hiroshi; Nakamori, Takeshi; Nakashima, Shinya; Nakazawa, Kazuhiro; Nobukawa, Kumiko K.; Nobukawa, Masayoshi; Noda, Hirofumi; Odaka, Hirokazu; Ohashi, Takaya; Ohno, Masanori; Okajima, Takashi; Ota, Naomi; Ozaki, Masanobu; Paerels, Frits; Paltani, Stéphane; Petre, Robert; Pinto, Ciro; Porter, Frederick S.; Pottschmidt, Katja; Reynolds, Christopher S.; Safi-Harb, Samar; Saito, Shinya; Sakai, Kazuhiro; Sasaki, Toru; Sato, Goro; Sato, Kosuke; Sato, Rie; Sato, Toshiki; Sawada, Makoto; Schartel, Norbert; Serlemtsos, Peter J.; Seta, Hiromi; Shidatsu, Megumi; Simionescu, Aurora; Smith, Randall K.; Soong, Yang; Stawarz, Łukasz; Sugawara, Yasuharu; Sugita, Satoshi; Szymkowiak, Andrew; Tajima, Hiroyasu; Takahashi, Hiromitsu; Takahashi, Tadayuki; Takeda, Shin'ichiro; Takei, Yoh; Tamagawa, Toru; Tamura, Takayuki; Tanaka, Takaaki; Tanaka, Yasuo; Tanaka, Yasuyuki T.; Tashiro, Makoto S.; Tawara, Yuzuru; Terada, Yukikatsu; Terashima, Yuichi; Tombesi, Francesco; Tomida, Hiroshi; Tsuboi, Yohko; Tsujimoto, Masahiro; Tsunemi, Hiroshi; Tsuru, Takeshi Go; Uchida, Hiroyuki; Uchiyama, Hideki; Uchiyama, Yasunobu; Ueda, Shutaro; Ueda, Yoshihiro; Uno, Shin'ichiro; Urry, C. Megan; Ursino, Eugenio; Watanabe, Shin; Werner, Norbert; Wilkins, Dan R.; Williams, Brian J.; Yamada, Shinya; Yamaguchi, Hiroya; Yamaoka, Kazutaka; Yamasaki, Noriko Y.; Yamauchi, Makoto; Yamauchi, Shigeo; Yaqoob, Tahir; Yatsu, Yoichi; Yonetoku, Daisuke; Zhuravleva, Irina; Zoghbi, Abderahmen

    2018-03-01

    We present Hitomi observations of N 132 D, a young, X-ray bright, O-rich core-collapse supernova remnant in the Large Magellanic Cloud (LMC). Despite a very short observation of only 3.7 ks, the Soft X-ray Spectrometer (SXS) easily detects the line complexes of highly ionized S K and Fe K with 16-17 counts in each. The Fe feature is measured for the first time at high spectral resolution. Based on the plausible assumption that the Fe K emission is dominated by He-like ions, we find that the material responsible for this Fe emission is highly redshifted at ˜ 800 km s-1 compared to the local LMC interstellar medium (ISM), with a 90% credible interval of 50-1500 km s-1 if a weakly informative prior is placed on possible line broadening. This indicates (1) that the Fe emission arises from the supernova ejecta, and (2) that these ejecta are highly asymmetric, since no blueshifted component is found. The S K velocity is consistent with the local LMC ISM, and is likely from swept-up ISM material. These results are consistent with spatial mapping that shows the He-like Fe concentrated in the interior of the remnant and the S tracing the outer shell. The results also show that even with a very small number of counts, direct velocity measurements from Doppler-shifted lines detected in extended objects like supernova remnants are now possible. Thanks to the very low SXS background of ˜ 1 event per spectral resolution element per 100 ks, such results are obtainable during short pointed or slew observations with similar instruments. This highlights the power of high-spectral-resolution imaging observations, and demonstrates the new window that has been opened with Hitomi and will be greatly widened with future missions such as the X-ray Astronomy Recovery Mission (XARM) and Athena.

  16. The imprint of Gould's belt on the local cosmic ray electron spectrum

    NASA Astrophysics Data System (ADS)

    Pohl, M.; Perrot, C.; Grenier, I.

    2001-08-01

    In a recent paper Pohl and Esposito (1998) demonstrated that if the sources of cosmic-rays are discrete, as are Supernova Remnants (SNR), then the spectra of cosmic-ray electrons largely vary with location and time and the locally measured electron spectrum may not be representative of the electron spectra elsewhere in the Galaxy, which could be substantially harder than the local one. They have shown that the observed excess of γ-ray emission above 1 GeV can in fact be partially explained as a correspondingly hard inverse Compton component, provided the bulk of cosmic-ray electrons is produced in SNR. As part of a program to model the Galactic γ-ray foreground we have continued the earlier studies by investigating the impact of the star forming region Gould's Belt on the local electron spectrum. If the electron sources in Gould's Belt were continous, the local electron spectrum would be slightly hardened. If the electron sources are discrete, which is the more probable case, the variation in the local electron spectrum found by Pohl & Esposito persists. 1 The local cosmic-ray electron spectrum The recent detections of non-thermal X-ray synchrotron radiation from the supernova remnants SN1006 (Koyama et al., 1995), RX J1713.7-3946 (Koyama et al., 1997), IC443 (Keohane et al., 1997; Slane et al., 1999), Cas A (Allen et al., 1997), and RCW86 (Borkowski et al., 2001) and the subsequent detections of SN1006 (Tanimori et al., 1998), RX J1713.7-3946 (Muraishi et al., 2000), and Cas A (Aharonian et al., 2001) at TeV energies support the hypothesis that at least Galactic cosmic-ray electrons are accelerated predominantly in SNR. The Galactic distribution and spectrum of cosmic-ray electrons are intimately linked to the distribution and nature of their sources. Supernovae and hence their remnants are tran-

  17. A Renewed Look at the Planetary Nebula Luminosity Function: Circumstellar Extinction and Contamination From Compact Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Davis, Brian; Ciardullo, Robin; Feldmeier, John; Jacoby, George H.; McCarron, Adam; Herrmann, Kimberly

    2018-01-01

    The planetary nebula luminosity function (PNLF) has been used as an extragalactic distance indicator since 1988, but there are still unsolved problems associated with its use. The two most serious involve PNLF distances beyond ~ 10 Mpc, which tend to be slightly smaller than those of other methods, and the lack of a theoretical explanation for the technique. We investigate these questions using a combination of narrow-band imaging data from the KPNO 4-m telescope, and recent LRS2 spectroscopy from the Hobby-Eberly Telescope.For the first project, we consider the implications of spectroscopic investigations by Kreckel et al. (2017), who found that in M74, several of the brightest planetary nebula (PN) candidates found by Herrmann et al. (2008) are actually compact supernova remnants (SNRs). First, we measure the [O III] and H-alpha fluxes of all the known SNRs in M31 and M33, and test whether those objects could be misidentified as bright PNe at distances beyond ~ 8 Mpc. We also obtain spectroscopy of bright PN candidates in the Fireworks Galaxy, NGC 6946, to test for PN/SNR confusion via the strengths of the [N II] and [S II] emission lines. Both experiments suggest that compact supernova remnants are not an important source of contamination in photometric surveys for extragalactic PNe.For the second project, we, for the first time, determine the de-reddened PNLF of an old stellar population. By performing spectroscopy of the brightest PN in M31’s bulge and measuring the objects’ Balmer decrements, we remove the effects of circumstellar extinction and derive the true location of the PNLF’s bright-end cutoff. In future studies, these data can be used to directly test the latest PNLF models, which combine modern post-AGB stellar evolutionary tracks with the physics of expanding nebulae.

  18. CTIO, ROSAT HRI, and Chandra ACIS Observations of the Archetypical Mixed-morphology Supernova Remnant W28 (G6.4–0.1)

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

    Pannuti, Thomas G.; Kosakowski, Alekzander R.; Ernst, Sonny

    We present a joint analysis of optical emission-line and X-ray observations of the archetypical Galactic mixed-morphology supernova remnant (MMSNR) W28 (G6.4–0.1). MMSNRs comprise a class of sources whose shell-like radio morphology contrasts with a filled center in X-rays; the origin of these contrasting morphologies remains uncertain. Our CTIO images reveal enhanced [S ii] emission relative to H α along the northern and eastern rims of W28. Hydroxyl (OH) masers are detected along these same rims, supporting prior studies suggesting that W28 is interacting with molecular clouds at these locations, as observed for several other MMSNRs. Our ROSAT HRI mosaic ofmore » W28 provides almost complete coverage of the supernova remnant (SNR). The X-ray and radio emission is generally anti-correlated, except for the luminous northeastern rim, which is prominent in both bands. Our Chandra observation sampled the X-ray-luminous central diffuse emission. Spectra extracted from the bright central peak and from nearby annular regions are best fit with two overionized recombining plasma models. We also find that while the X-ray emission from the central peak is dominated by swept-up material, that from the surrounding regions shows evidence for oxygen-rich ejecta, suggesting that W28 was produced by a massive progenitor. We also analyze the X-ray properties of two X-ray sources (CXOU J175857.55−233400.3 and 3XMM J180058.5–232735) projected into the interior of W28 and conclude that neither is a neutron star associated with the SNR. The former is likely to be a foreground cataclysmic variable or a quiescent low-mass X-ray-binary, while the latter is likely to be a coronally active main-sequence star.« less

  19. Chandra Maps Vital Elements From Supernova

    NASA Astrophysics Data System (ADS)

    1999-12-01

    A team of astronomers led by Dr. John Hughes of Rutgers University in Piscataway, NJ has used observations from NASA's orbital Chandra X-ray Observatory to make an important new discovery that sheds light on how silicon, iron, and other elements were produced in supernova explosions. An X-ray image of Cassiopeia A (Cas A), the remnant of an exploded star, reveals gaseous clumps of silicon, sulfur, and iron expelled from deep in the interior of the star. The findings appear online in the Astrophysical Journal Letters at http://www.journals.uchicago.edu/ and are slated for print publication on Jan. 10, 2000. Authors of the paper, "Nucleosynthesis and Mixing in Cassiopeia A", are Hughes, Rutgers graduate student Cara Rakowski, Dr. David Burrows of the Pennsylvania State University, University Park, PA and Dr. Patrick Slane of the Harvard-Smithsonian Center for Astrophysics, Cambridge, MA. According to Hughes, one of the most profound accomplishments of twentieth century astronomy is the realization that nearly all of the elements other than hydrogen and helium were created in the interiors of stars. "During their lives, stars are factories that take the simplest element, hydrogen, and convert it into heavier ones," he said. "After consuming all the hydrogen in their cores, stars begin to evolve rapidly, until they finally run out of fuel and begin to collapse. In stars ten times or so more massive than our Sun, the central parts of the collapsing star may form a neutron star or a black hole, while the rest of the star is blown apart in a tremendous supernova explosion." Supernovae are rare, occurring only once every 50 years or so in a galaxy like our own. "When I first looked at the Chandra image of Cas A, I was amazed by the clarity and definition," said Hughes. "The image was much sharper than any previous one and I could immediately see lots of new details." Equal in significance to the image clarity is the potential the Chandra data held for measuring the composition of the various knots and filaments of stellar material visible in Cas A. Not only could the astronomers determine the composition of many knots in the remnant from the Chandra data, they were also able to infer where in the exploding star the knots had originated. For example, the most compact and brightest knots were composed mostly of silicon and sulfur, with little or no iron. This pointed to an origin deep in the star's interior where the temperatures had reached three billion degrees during the collapse and resulting supernova. Elsewhere, they found fainter features that contained significant amounts of iron as well as some silicon and sulfur. This material was produced even deeper in the star, where the temperatures during the explosion had reached higher values of four to five billion degrees. When Hughes and his collaborators compared where the compact silicon-rich knots and fainter iron-rich features were located in Cas A, they discovered that the iron-rich features from deepest in the star were near the outer edge of the remnant. This meant that they had been flung the furthest by the explosion that created Cas A. Even now this material appears to be streaming away from the site of the explosion with greater speed than the rest of the remnant. By studying the Cas A Chandra data further, astronomers hope to identify which of the several processes proposed by theoretical studies is likely to be the correct mechanism for explaining supernova explosions, both in terms of the dynamics and elements they produce. "In addition to understanding how iron and the other elements are produced in stars, we also want to learn how it gets out of stars and into the interstellar medium. This is why the study of supernovas and supernova remnants is so important," said Hughes. "Once released from stars, newly-created elements can then participate in the formation of new stars and planets in a great cycle that has gone on numerous times already. It is remarkable to realize that our planet Earth and indeed even humanity itself is part of this vast cosmic cycle." The Chandra observation was taken with the Advanced CCD Imaging Spectrometer (ACIS) on August 19, 1999. ACIS was built by Pennsylvania State University, and the Massachusetts Institute of Technology, Cambridge, MA. Press: Fact Sheet (08/99) To follow Chandra's progress, visit the Chandra site at: http://chandra.harvard.edu AND http://chandra.nasa.gov NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program. TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass.

  20. A fast-evolving luminous transient discovered by K2/Kepler

    NASA Astrophysics Data System (ADS)

    Rest, A.; Garnavich, P. M.; Khatami, D.; Kasen, D.; Tucker, B. E.; Shaya, E. J.; Olling, R. P.; Mushotzky, R.; Zenteno, A.; Margheim, S.; Strampelli, G.; James, D.; Smith, R. C.; Förster, F.; Villar, V. A.

    2018-04-01

    For decades, optical time-domain searches have been tuned to find ordinary supernovae, which rise and fall in brightness over a period of weeks. Recently, supernova searches have improved their cadences and a handful of fast-evolving luminous transients have been identified1-5. These have peak luminosities comparable to type Ia supernovae, but rise to maximum in less than ten days and fade from view in less than one month. Here we present the most extreme example of this class of object thus far: KSN 2015K, with a rise time of only 2.2 days and a time above half-maximum of only 6.8 days. We show that, unlike type Ia supernovae, the light curve of KSN 2015K was not powered by the decay of radioactive elements. We further argue that it is unlikely that it was powered by continuing energy deposition from a central remnant (a magnetar or black hole). Using numerical radiation hydrodynamical models, we show that the light curve of KSN 2015K is well fitted by a model where the supernova runs into external material presumably expelled in a pre-supernova mass-loss episode. The rapid rise of KSN 2015K therefore probes the venting of photons when a hypersonic shock wave breaks out of a dense extended medium.

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