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Sample records for pulsars supernova remnants

  1. Pulsar/Supernova Remnant Associations

    NASA Technical Reports Server (NTRS)

    Kaspi, Victoria M.

    1996-01-01

    We list and review proposed pulsar/supernova remnant associations, summarize recent highlights in the field, including searches for young pulsars, searches for remnants, recent studies of previously proposed associations, and attempts at pulsar/remnant association synthesis. we argue that most proposed pulsar/supernova remnant associations require additional investigation before they can be considered secure, and we suggest directions for future work.

  2. Pulsar-supernova remnant associations

    NASA Astrophysics Data System (ADS)

    Manchester, R. N.

    1994-04-01

    Pulsars and supernova remnants (SNRs) are both believed to be formed in the supernova explosions of massive stars. Therefore one might expect to see associations between the two classes of object. In fact, up until a couple of years ago, there was only a handful of believable associations and even now there are only nine or ten. It is relatively easy to explain why such a small fraction of the 600 or so known pulsars are associated with supernova remnants. The average pulsar lifetime is of the order of 106 years, whereas the average supernova remnant is detectable for about 104 years. Therefore, one would expect only about one percent of pulsars to be still associated, as is observed. It is somewhat more difficult to explain why so few of the 150 known supernova remnants have associated pulsars. The main factor is that supernova remnants are seen throughout the Galaxy whereas most pulsars are detectable only relatively close to the Sun, within a few kiloparsec. Another factor is that pulsar emission is beamed, so even if a pulsar exists in a relatively nearby supernova remnant, it may be undetectable. The most believable of the suggested associations are listed. Associations which are possible but by no means certain are indicated by question mark. For the more certain associations, the pulsar position is within the SNR boundaries (an exception is 'The Duck', where the pulsar is at the tip of the 'beak'), the distance estimates for the pulsar and SNR are compatible, and the age estimates are likewise compatible. References to most of these associations may be found in the pulsar catalog of Taylor, Manchester and Lyne (1993, Astrophys. J. Suppl., 88, 529). Recent references not included in the catalog are for PSR B1706-44 (McAdam, Osborne and Parkinson, 1993, Nature, 361, 516) and PSR B2334+61 (Kulkarni et al., 1993, Nature, 362, 135).

  3. Pulsar reenergization of old supernova remnant shells

    NASA Technical Reports Server (NTRS)

    Shull, J. Michael; Fesen, Robert A.; Saken, Jon M.

    1989-01-01

    The morphology of several unusual composite remnants are suggested to be affected by previously unrecognized interactions between high-velocity pulsars and old SNR shells, and the case of CTB 80 is pointed out as a likely example of such interactions. The interactions generate a new class of 'composite remnants' and furnish a novel method for the derivation of kinematic distances and SNR ages; this technique is noted to be especially useful when the pulsar has a measured spindown age or proper motion. It is predicted that a number of pulsars may interact with 80-100 pc radius 'superbubbles' produced by the combined action of winds and supernovae in OB associations.

  4. 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.

  5. Non-cosmological FRBs from young supernova remnant pulsars

    NASA Astrophysics Data System (ADS)

    Connor, Liam; Sievers, Jonathan; Pen, Ue-Li

    2016-05-01

    We propose a new extra but non-cosmological explanation for fast radio bursts (FRBs) based on very young pulsars in supernova remnants. Within a few hundred years of a core-collapse supernova, the ejecta is confined within ˜1 pc, providing a high enough column density of free electrons for the observed 375-1600 pc cm-3 of dispersion measure (DM). By extrapolating a Crab-like pulsar to its infancy in an environment like that of SN 1987A, we hypothesize such an object could emit supergiant pulses sporadically which would be bright enough to be seen at a few hundred megaparsecs. We hypothesize that such supergiant pulses would preferentially occur early in the pulsar's life when the free electron density is still high, which is why we do not see large numbers of moderate DM FRBs (≲300 pc cm-3). In this scenario, Faraday rotation at the source gives rotation measures (RMs) much larger than the expected cosmological contribution. If the emission were pulsar-like, then the polarization vector could swing over the duration of the burst, which is not expected from non-rotating objects. In this model, the scattering, large DM, and commensurate RM all come from one place which is not the case for the cosmological interpretation. The model also provides testable predictions of the flux distribution and repeat rate of FRBs, and could be furthermore verified by spatial coincidence with optical supernovae of the past several decades and cross-correlation with nearby galaxy maps.

  6. Radio-Quiet Pulsars and Point Sources in Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Helfand, David

    2002-04-01

    Since Baade and Zwicky made their prescient remark identifying the central blue star in the Crab Nebula as a neutron star, this pulsar's period has increased by 0.9 msec, turning 10^48 ergs of rotational kinetic energy into a relativistic wind that has been deposited in its surroundings. This makes the compact remnant of the supernova of 1054 AD highly conspicuous. It also makes this remnant highly anomalous. Nowhere else in the Galaxy does such a luminous young pulsar exists, despite the fact that at least half a dozen core-collapse supernovae have occurred since the Crab's birth. Indeed, the newly discovered central object in Cas A is four orders of magnitude less luminous in the X-ray band. While the Chandra and XMM-Newton Observatories are discovering an increasing number of Crab-like synchrotron nebulae (albeit, far less luminous than the prototype), they are also revealing X-ray point sources inside supernova remnants that lack detectable radio pulses and show no evidence of a relativistic outflow to power a surrounding nebula. I will provide an inventory of these objects, discuss whether or not truly radio-silent young neutron stars exist, and speculate on the emission mechanisms and power sources which make such objects shine. I will conclude with a commentary on the implications of this population for the distributions of pulsar birth parameters such as spin period, magnetic field strength, and space velocity, as well as offer a glimpse of what future observations might reveal about the demographics of core-collapse remnants.

  7. Future GLAST Observations of Supernova Remnants And Pulsar Wind Nebulae

    SciTech Connect

    Funk, S.; /KIPAC, Menlo Park

    2007-09-26

    Shell-type Supernova remnants (SNRs) have long been known to harbour a population of ultra-relativistic particles, accelerated in the Supernova shock wave by the mechanism of diffusive shock acceleration. Experimental evidence for the existence of electrons up to energies of 100 TeV was first provided by the detection of hard X-ray synchrotron emission as e.g. in the shell of the young SNR SN1006. Furthermore using theoretical arguments shell-type Supernova remnants have long been considered as the main accelerator of protons - Cosmic rays - in the Galaxy; definite proof of this process is however still missing. Pulsar Wind Nebulae (PWN) - diffuse structures surrounding young pulsars - are another class of objects known to be a site of particle acceleration in the Galaxy, again through the detection of hard synchrotron X-rays such as in the Crab Nebula. Gamma-rays above 100 MeV provide a direct access to acceleration processes. The GLAST Large Area telescope (LAT) will be operating in the energy range between 30 MeV and 300 GeV and will provide excellent sensitivity, angular and energy resolution in a previously rather poorly explored energy band. We will describe prospects for the investigation of these Galactic particle accelerators with GLAST.

  8. Supernovae and supernova remnants

    NASA Technical Reports Server (NTRS)

    Chevalier, Roger A.; Seward, Frederick D.

    1988-01-01

    The basic features and astrophysics of supernovae of types Ia, Ib, and II and of SNRs are discussed, summarizing the results of recent ground-based and space observations obtained at different wavelengths. Typical data are presented in graphs and sample images, and consideration is given to their implications for shock heating by the initial explosion, radioactive energy input, circumstellar interaction, and pulsar energy input. SNRs described include Tycho's remnant, Kepler's remnant, the Cyg loop, Pup A, the Crab Nebula, the Vela and Crab pulsars, and 0540-69.3 in the LMC. The need for high-spatial-resolution IR and X-ray spectra of these objects is indicated.

  9. Numerical simulations of composite supernova remnants for small σ pulsar wind nebulae

    NASA Astrophysics Data System (ADS)

    Vorster, M. J.; Ferreira, S. E. S.; de Jager, O. C.; Djannati-Ataï, A.

    2013-03-01

    Context. Composite supernova remnants consist of a pulsar wind nebula located inside a shell-type remnant. The presence of a shell has implications on the evolution of the nebula, although the converse is generally not true. Aims: The purpose of this paper is two-fold. The first aim is to determine the effect of the pulsar's initial luminosity and spin-down rate, the supernova ejecta mass, and density of the interstellar medium on the evolution of a spherically-symmetric, composite supernova remnant expanding into a homogeneous medium. The second aim is to investigate the evolution of the magnetic field in the pulsar wind nebula when the the composite remnant expands into a non-uniform interstellar medium. Methods: The Euler conservation equations for inviscid flow, together with the magnetohydrodynamic induction law in the kinematic limit, are solved numerically for a number of scenarios where the ratio of magnetic to particle energy is σ < 0.01. The simulations in the first part of the paper is solved in a one-dimensional configuration. In the second part of the paper, the effect of an inhomogeneous medium on the evolution is studied using a two-dimensional, axisymmetric configuration. Results: It is found that the initial spin-down luminosity and density of the interstellar medium has the largest influence on the evolution of the pulsar wind nebula. The spin-down time-scale of the pulsar only becomes important when this value is smaller than the time needed for the reverse shock of the shell remnant to reach the outer boundary of the nebula. For a remnant evolving in a non-uniform medium, the magnetic field along the boundary of the nebula will evolve to a value that is larger than the magnetic field in the interior. If the inhomogeneity of the interstellar medium is enhanced, while the spin-down luminosity is decreased, it is further found that a magnetic "cloud" is formed in a region that is spatially separated from the position of the pulsar.

  10. Observations of supernova remnants and pulsar wind nebulae at gamma-ray energies

    NASA Astrophysics Data System (ADS)

    Hewitt, John W.; Lemoine-Goumard, Marianne

    2015-08-01

    In the past few years, gamma-ray astronomy has entered a golden age thanks to two major breakthroughs: Cherenkov telescopes on the ground and the Large Area Telescope (LAT) onboard the Fermi satellite. The sample of supernova remnants (SNRs) detected at gamma-ray energies is now much larger: it goes from evolved supernova remnants interacting with molecular clouds up to young shell-type supernova remnants and historical supernova remnants. Studies of SNRs are of great interest, as these analyses are directly linked to the long standing issue of the origin of the Galactic cosmic rays. In this context, pulsar wind nebulae (PWNe) need also to be considered since they evolve in conjunction with SNRs. As a result, they frequently complicate interpretation of the gamma-ray emission seen from SNRs and they could also contribute directly to the local cosmic ray spectrum, particularly the leptonic component. This paper reviews the current results and thinking on SNRs and PWNe and their connection to cosmic ray production. xml:lang="fr"

  11. 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.

  12. Signatures of pulsars in the light curves of newly formed supernova remnants

    NASA Astrophysics Data System (ADS)

    Kotera, K.; Phinney, E. S.; Olinto, A. V.

    2013-07-01

    We explore the effect of pulsars, in particular those born with millisecond periods, on their surrounding supernova ejectas. While they spin down, fast-spinning pulsars release their tremendous rotational energy in the form of a relativistic magnetized wind that can affect the dynamics and luminosity of the supernova. We estimate the thermal and non-thermal radiations expected from these specific objects, concentrating at times a few years after the onset of the explosion. We find that the bolometric light curves present a high luminosity plateau (that can reach 1043-1044 erg s-1) over a few years. An equally bright TeV gamma-ray emission, and a milder X-ray peak (of the order of 1040-1042 erg s-1) could also appear a few months to a few years after the explosion, as the pulsar wind nebula emerges, depending on the injection parameters. The observations of these signatures by following the emission of a large number of supernovae could have important implications for the understanding of core-collapse supernovae and reveal the nature of the remnant compact object.

  13. Supernova remnant G292.2-0.5, its pulsar, and the Galactic magnetic field

    NASA Astrophysics Data System (ADS)

    Caswell, J. L.; McClure-Griffiths, N. M.; Cheung, M. C. M.

    2004-08-01

    The extended low-brightness Galactic radio source G292.2-0.5 is one of the few supernova remnants (SNRs) showing a likely association with a young pulsar. New observations of the remnant with the Australia Telescope Compact Array yield a distance of 8.4 kpc determined from HI absorption measurements, and the first detection of linear polarization. The polarization was studied at two frequencies near 5 GHz, revealing a high mean rotation measure, approximately +800 rad m-2, strikingly similar to that of the pulsar. This similarity, and the compatibility of the pulsar distance estimate with the new SNR distance, now provides overwhelming evidence that the pulsar is indeed embedded within the SNR, and that both were presumably born in the same supernova event. The ratio of rotation measure to pulsar dispersion measure yields a value of -1.4 μG (towards us) for the (density-weighted) average line-of-sight component of magnetic field for the 8.4-kpc path-length to the SNR and pulsar. The unusually high rotation measure, together with the large distance over which it has accumulated, argues that this field is a persistent feature on a large scale that outweighs smaller-scale fluctuations and reversals. The 8.4-kpc path-length lies almost wholly within the Carina spiral arm of our Galaxy and thus this portion of the arm possesses an average clockwise field of 1.4 μG. We interpret other evidence to suggest that the clockwise field extends for at least a further 8.5 kpc along the same arm, in the region where it is usually referred to as the Sagittarius arm. Observations such as these provide a powerful tool for exploring the large-scale structure of the Galactic magnetic field in relation to the spiral-arm structure.

  14. Proper-Motion Measurements of Pulsar B1951+32 in the Supernova Remnant CTB 80

    NASA Astrophysics Data System (ADS)

    Migliazzo, J. M.; Gaensler, B. M.; Backer, D. C.; Stappers, B. W.; van der Swaluw, E.; Strom, R. G.

    2002-03-01

    Using the Very Large Array and the Pie Town antenna, we have measured the position of the radio pulsar B1951+32 relative to nearby background radio sources at four epochs between 1989 and 2000. These data show a clear motion for the pulsar of 25+/-4 mas yr-1 at a position angle 252deg+/-7deg (north through east), corresponding to a transverse velocity 240+/-40 km s-1 for a distance to the source of 2 kpc. The measured direction of motion confirms that the pulsar is moving away from the center of its associated supernova remnant, the first time that such a result has been demonstrated. Independent of assumptions made about the pulsar birthplace, we show that the measured proper motion implies an age for the pulsar of 64+/-18 kyr, somewhat less than its characteristic age of 107 kyr. This discrepancy can be explained if the initial spin period of the pulsar was P0=27+/-6 ms.

  15. CONSTRAINING THE EVOLUTIONARY FATE OF CENTRAL COMPACT OBJECTS: ''OLD'' RADIO PULSARS IN SUPERNOVA REMNANTS

    SciTech Connect

    Bogdanov, Slavko; Ng, C.-Y.; Kaspi, Victoria M.

    2014-09-10

    Central compact objects (CCOs) constitute a population of radio-quiet, slowly spinning (≥100 ms) young neutron stars with anomalously high thermal X-ray luminosities. Their spin-down properties imply weak dipole magnetic fields (∼10{sup 10-11} G) and characteristic ages much greater than the ages of their host supernova remnants (SNRs). However, CCOs may posses strong ''hidden'' internal magnetic fields that may re-emerge on timescales of ≳10 kyr, with the neutron star possibly activating as a radio pulsar in the process. This suggests that the immediate descendants of CCOs may be masquerading as slowly spinning ''old'' radio pulsars. We present an X-ray survey of all ordinary radio pulsars within 6 kpc that are positionally coincident with Galactic SNRs in order to test the possible connection between the supposedly old but possibly very young pulsars and the SNRs. None of the targets exhibit anomalously high thermal X-ray luminosities, suggesting that they are genuine old ordinary pulsars unrelated to the superposed SNRs. This implies that CCOs are either latent radio pulsars that activate long after their SNRs dissipate or they remain permanently radio-quiet. The true descendants of CCOs remain at large.

  16. Pulsar Wind Nebulae, Space Velocities and Supernova Remnant Associations

    NASA Technical Reports Server (NTRS)

    2002-01-01

    I am pleased to be able to report significant progress in my research relevant to my LTSA grant. This progress I believe is demonstrated by a long list of publications in 2002, as detailed below. I summarize the research results my collaborators and I obtained in 2002. First, my group announced the major discovery of soft-gamma-repeater-like X-ray bursts from the anomalous X-ray pulsars lE-1048.1$-$5937 and lE-2259+586, using the Rossi X-ray Timing Explorer. This result provides an elegant and long-sought-after confirmation that this class of objects and the soft gamma repeaters share a common nature, namely that they are magnetars. Magnetars are a novel manifestation of young neutron stars, quite different from conventional Crab-like radio pulsars. This discovery was made as part of our regular monitoring program, among the goals of which was to detect such outbursts.

  17. 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. PMID:18927355

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

    SciTech Connect

    Abdo, Aous A.; Ackermann, M.; Atwood, W.B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Baring, M.G.; Bastieri, Denis; Baughman, B.M.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R.D.; Bloom, Elliott D.; Bogaert, G.; Bonamente, E.; Borgland, A.W.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.

    2009-05-15

    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 sources associated with star-forming regions and SNRs are such young pulsars.

  19. AN EXTREME PULSAR TAIL PROTRUDING FROM THE FRYING PAN SUPERNOVA REMNANT

    SciTech Connect

    Ng, C.-Y.; Bouchard, A.; Bucciantini, N.; Gaensler, B. M.; Camilo, F.; Chatterjee, S.

    2012-02-10

    The Frying Pan (G315.9-0.0) is a radio supernova remnant with a peculiar linear feature (G315.78-0.23) extending 10' radially outward from the rim of the shell. We present radio imaging and polarization observations obtained from the Molonglo Observatory Synthesis Telescope and the Australia Telescope Compact Array, confirming G315.78-0.23 as a bow-shock pulsar wind nebula (PWN) powered by the young pulsar J1437-5959. This is one of the longest pulsar tails observed in radio and it has a physical extent over 20 pc. We found a bow-shock standoff distance of 0.002 pc, smallest among similar systems, suggesting a large pulsar velocity over 1000 km s{sup -1} and a high Mach number {approx}200. The magnetic field geometry inferred from radio polarimetry shows a good alignment with the tail orientation, which could be a result of high flow speed. There are also hints that the postshock wind has a low magnetization and is dominated by electrons and positrons in energy. This study shows that PWNe can offer a powerful probe of their local environment, particularly for the case of a bow shock where the parent supernova shell is also detected.

  20. Non-thermal emission in astrophysical environments: From pulsars to supernova remnants

    NASA Astrophysics Data System (ADS)

    Lomiashvili, David

    The study of electromagnetic radiation from distant astrophysical objects provides essential data in understanding physics of these sources. In particular, non-thermal radiation provides great insight into the properties of local environments, particle populations, and emission mechanisms, knowledge which otherwise would remain untapped. Throughout the projects conducted for this dissertation, we modeled certain aspects of observed non-thermal emission from three classes of sources: radio pulsars, pulsar wind nebulae, and supernova remnants. Orbital variation in the double pulsar system PSR J0737-3039A/B can be used to probe the details of the magnetospheric structure of pulsar B. Strongly magnetized wind from pulsar A distorts the magnetosphere of pulsar B in a way similar to the solar wind's distortion of the Earth's magnetosphere. Using the two complimentary models of pulsar B's magnetosphere, adapted from the Earth's magnetosphere models by Dungey and Tsyganenko, we determine the precise location of the coherent radio emission generation region in pulsar B's magnetosphere. This analysis is complemented by modeling the observed evolution of the pulse profiles of B due to geodetic precession. The emission region is located at about 3750 stellar radii and has a horseshoe-like shape centered on the polar magnetic field lines. The best fit angular parameters of the emission region indicate that radio emission is generated on the field lines which, according to the theoretical models, originate close to the poles and carry the maximum current. When considered together, not only do the results of the two models converge, they can explain why the modulation of B's radio emission at A's period is observed only within a certain orbital phase region. We discuss the implications of these results for pulsar magnetospheric models and mechanisms of coherent radio emission generation. We also developed a spatially-resolved, analytic model for the high-energy non-thermal emission from pulsar wind nebulae (PWNe). Theoretically, synchrotron cooling should cause a gradual change in particle spectrum downstream. This effect is indeed observed in the X-ray spectra of The Crab Nebula , 3C 58, and G21.5.0.9. However, current theoretical models of PWNe that only account for the bulk motion in the pulsar outflow overestimate the steepening of the resulted emission spectrum. This implies that there is an additional mechanism of particle transport which would supply energetic particles to the outer layers of the PWN. Our model solves the lack of high-energy electrons in the outer regions of the nebula by taking the diffusion of particles into account. The resulting multi-wavelength spectra exhibits multiple breaks, which is in agreement with observations. Thin non-thermal X-ray filaments are often seen near shock fronts in young supernova remnants (SNRs), often spatially coincident with the high energy gamma-ray emission. The formation of such discrete features is likely influenced by the combined effects of radiative cooling, advection, and diffusion. Spatially-resolved spectral studies of the filaments may, therefore, provide significant insights into the relative importance of main physical processes involved in young SNRs. Using 1 Ms Chandra observation of Cassiopeia A, we perform advection-diffusion modeling of synchrotron emission of filaments to measure the magnetic field, shock obliquity, the diffusion strength and the plasma turbulence level.

  1. Mapping supernova remnants and pulsar wind nebulae across decades of energy

    NASA Astrophysics Data System (ADS)

    Hewitt, John W.

    2016-04-01

    Ground- and space-based gamma ray observatories of the past decade have given us a new understanding of particle accelerators in our galaxy. The improved spatial resolution and sensitivity of recent gamma-ray surveys of the Galactic plane have resolved confusion of sources identified numerous sources to study the physics of particle acceleration and the diffusion of energetic particles into the galaxy. Here I highlight some recent studies of Galactic accelerators from GeV to TeV energies, that allow us to disentangle hadronic from leptonic emission, constrain cosmic ray diffusion, and measure the conditions of particle acceleration. Supernova remnants and pulsar wind nebulae are found to be the two most common Galactic sources identified in very high energy gamma rays, and the future capabilities of CTA promise a dramatic increase in our knowledge of these classes which are currently limited to only a few of the most well-studied cases.

  2. Supernova remnant morphology

    NASA Astrophysics Data System (ADS)

    Manchester, R. N.

    1994-04-01

    The morphology of supernova remnants is principally determined by two components, a shell formed by interaction of the supernova ejecta with the surrounding medium, and a nebula which is powered directly by the associated pulsar. This nebula, often called a 'plerion', is usually located within the shell. These two components appear to evolve independently; in many cases there is no detectable plerion and in a few cases, the Crab Nebula being the most notable example, there is no detectable shell. A 'theoretician's supernova remnant' has spherical symmetry, but observers know that this is rarely the case. There are four main possible sources of non-sphericity, namely, the surrounding interstellar medium, the circumstellar medium, the surpernova explosion, and the associated pulsar. Supernovae often occured in active star formation regions and these regions often have complex networks of cavities blown by strong stellar winds. A supernova remnant expanding in this environment can consist of a several shell-like structure. IC443 is a good example (Braun and Strom, 1986, Astron. Astrophys., 1264, 193). The enhancement of Supernova remnant (SNR) shell brightness toward the Galactic plane (Caswell, 1977, Proc. Astron. Soc. Aust., 3, 130) is further evidence of the influence of the large-scale structure of the interstellar medium. One of the most common forms of non-sphericity is a bilateral symmetry attributed to a barrel-shaped enhancement of the shell (Kesteven and Caswell, 1987, Astron. Astrophys., 183, 118). There is good evidence that this and the associated bi-annular structure often obseved (Manchester, 1987, Astron. Astrophys., 171, 205) ar due to structure in the circumstellar material resulting from mass loss from the pre-supernova star (Storey et al., 1992, Astron. Astrophys., 265, 752). supernova remants (e.g., Tuohy, Clark and Burton, 1982, Astrophys. &J., 260, L65) are evidence that asymmetries can exist in the SN explosion itself. Finally, a central pulsar can introduce asymmetries. Pulsars receive a kick at birth giving them a velocity which may be as high as 100 km/s. *Plerions are therefore often offset from the centre of the shell and often have an asymmetric shape. -The most extreme case is G5.4-1.2 (The Duck) where the plerion is completely outside the shell and trails behind the pulsar (Frail and Kulkarni, 1991, Nature, 352, 785). It is also possible that the injection of relativistic particles into the nebula by a pulsar is non-spherical, resulting in corresponding non-spherical enhancements of the synchrotron emission. the synchrotron emission.

  3. Supernova remnants and pulsar wind nebulae with Imaging Atmospheric Cherenkov Telescopes (IACTs)

    NASA Astrophysics Data System (ADS)

    Eger, Peter

    2015-08-01

    The observation of very-high-energy (VHE, E > 100 GeV) gamma rays is an excellent tool to study the most energetic and violent environments in the Galaxy. This energy range is only accessible with ground-based instruments such as Imaging Atmospheric Cherenkov Telescopes (IACTs) that reconstruct the energy and direction of the primary gamma ray by observing the Cherenkov light from the induced extended air showers in Earths atmosphere. The main goals of Galactic VHE gamma-ray science are the identification of individual sources of cosmic rays (CRs), such as supernova remnants (SNRs), and the study of other extreme astrophysical objects at the highest energies, such as gamma-ray binaries and pulsar wind nebulae (PWNe). One of the main challenges is the discrimination between leptonic and hadronic gamma-ray production channels. To that end, the gamma-ray signal from each individual source needs to be brought into context with the multi-wavelength environment of the astrophysical object in question, particularly with observations tracing the density of the surrounding interstellar medium, or synchrotron radiation from relativistic electrons. In this review presented at the European Cosmic Ray Symposium 2014 (ECRS2014), the most recent developments in the field of Galactic VHE gamma-ray science are highlighted, with particular emphasis on SNRs and PWNe.

  4. 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. PMID:10534456

  5. A THOROUGH INVESTIGATION OF THE DISTANCE TO THE SUPERNOVA REMNANT CTB109 AND ITS PULSAR AXP J2301+5852

    SciTech Connect

    Kothes, R.; Foster, T. E-mail: fostert@brandonu.ca

    2012-02-10

    CTB109 is one of only three Galactic supernova remnants (SNRs) known to harbor an anomalous X-ray pulsar or magnetar. That makes this SNR an object of great importance and a prime target for high-energy astrophysics studies. Those studies rely heavily on the assumed distance to CTB109. There have been three major distance determinations over the last decade, all of which report completely different results. While chaotic distance determinations in the literature are not uncommon for SNRs as a class of object, the wild discrepancy in the distance to CTB109 makes it especially important to revisit and firmly resolve once and for all. In this Letter we bring to bear all available observational information and present a synthesis of evidence that consistently locates CTB109 within or close to the Perseus arm spiral shock, at a distance of 3.2 {+-} 0.2 kpc.

  6. Studies of Pulsar Wind Nebula in the Supernova Remnant IC443: Preliminary Observations from the Chandra Data

    NASA Astrophysics Data System (ADS)

    Ariyibi, E. A.

    2009-10-01

    Preliminary observations of the Chandra data were made in order to study the Pulsar Wind Nebula in the Supernova Remnant IC443. The Chandra X-ray observatory short observation on IC443 was centred on 13 chip ACIS. The CIAO analytical programme was used for the data analysis. The data were separated into point source, with an energy range of 2.1 to 10.0 keV, and diffuse source with energy less than 2.1 Kev. The resulting spectra were fitted to a power law. The observed density numbers and the normalised counts of both the point source and the diffuse source were used to describe the X-ray source. Afin d'étudier la "Pulsar wind Nebula" dans le reste de la Supernova IC 443, nous avons mené une exploitation préliminaire des observations provenant du satellite spatiale Chandra. L'observation brêve de IC 443, par Chandra fut centrée sur les composantes du spectromètre identifiées par la séquence 13. Le programme informatique CIAO fut utilisé pour l'analyse des données. Les données furent groupées en sources ponctuelles, chacune ayant des énergies allant de 2.1 a 10.0 kev ; et en sources diffuses chacune avec des énergies de moins de 2.1 kev. Les spectres obtenus furent interpolés à l'aide de fonction puissance. La densité de flux ainsi que le décompte des particules induites au détecteur par le rayonnement provenant des sources ponctuelles et diffuses furent utilisés pour décrire la source de rayon-X.

  7. Observation of Crab-Like Supernova Remnants

    NASA Technical Reports Server (NTRS)

    Seward, Frederick D.

    2001-01-01

    The purpose of this program was to observe the supernova remnants 3C58 and G21.5-0.9 and to search for pulsed emission. If a pulsar were to be found, the period derivative and inferred magnetic field would have extreme values if pulsar evolution had followed the standard model. If this is not the case, the standard model must be revised. We also sought to obtain very accurate measurement of the synchrotron emission spectrum of each remnant.

  8. An association between a long-period pulsar and an old supernova remnant

    NASA Technical Reports Server (NTRS)

    Kulkarni, S. R.; Predehl, P.; Hasinger, G.; Aschenbach, B.

    1993-01-01

    A possible association between pulsar 2334 + 61, with a relatively long period of 0.5 s, and G114.3 + 0.3, a fairly old SNR is reported. The flat spectral index of -0.36 +/- 0.03 and large fractional polariazation suggest that the radio emission is powered by the pulsar. If so, the pulsar must have been born with a relatively short period of less than 100 ms. As the SNR is not particularly unusual morphologically, there might be many more such SNRs containing pulsars that are not beamed towards us.

  9. Discovery of a Be/X-ray pulsar binary and associated supernova remnant in the Wing of the Small Magellanic Cloud

    NASA Astrophysics Data System (ADS)

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

    2012-02-01

    We report on a new Be/X-ray pulsar binary located in the Wing of the Small Magellanic Cloud (SMC). The strong pulsed X-ray source was discovered with the Chandra and XMM-Newton X-ray observatories. The X-ray pulse period of 1062 s is consistently determined from both Chandra and XMM-Newton observations, revealing one of the slowest rotating X-ray pulsars known in the SMC. The optical counterpart of the X-ray source is the emission-line star 2dFS 3831. Its B0-0.5(III)e+ spectral type is determined from VLT-FLAMES and 2dF optical spectroscopy, establishing the system as a Be/X-ray binary (Be-XRB). The hard X-ray spectrum is well fitted by a power law with additional thermal and blackbody components, the latter reminiscent of persistent Be-XRBs. This system is the first evidence of a recent supernova in the low-density surroundings of NGC 602. We detect a shell nebula around 2dFS 3831 in Hα and [O III] images and conclude that it is most likely a supernova remnant. If it is linked to the supernova explosion that created this new X-ray pulsar, its kinematic age of (2-4) × 104 yr provides a constraint on the age of the pulsar.

  10. Discovery of a young, 267 millisecond pulsar in the supernova remnant W44

    NASA Technical Reports Server (NTRS)

    Wolszczan, A.; Cordes, J. M.; Dewey, R. J.

    1991-01-01

    This paper reports the discovery of a 267 msec pulsar, PSR 1853 + 01, in the SNR W44 (G34.7 - 0.4), located south of the W44, well within its radio shell and at the outher edge of the X-ray emission region which fills the SNR interior. The PSR 1853 + 01 is separated only 20 arcmin from the PSR 1854 + 00 pulsar discovered by Mohanty (1983). Results of timing observatons of PSR 1853 + 01 are presented, and a possible relationship between the two objects is examined. It is suggested that the two pulsars may have a common origin in a binary system disrupted by the explosion that produced W44.

  11. Timing Behavior of the Magnetically Active Rotation-Powered Pulsar in the Supernova Remnant Kesteven 75

    NASA Technical Reports Server (NTRS)

    Livingstone, Margaret A.; Gavriil, Fotis P.; Kaspi, Victoria M.

    2009-01-01

    We report a large spin-up glitch in PSR J1846-0258 which coincided with the onset of magnetar-like behavior on 2006 May 31. We show that the pulsar experienced an unusually large glitch recovery, with a recovery fraction of Q = 5.9+/-0.3, resulting in a net decrease of the pulse frequency. Such a glitch recovery has never before been observed in a rotation-powered pulsar, however, similar but smaller glitch over-recovery has been recently reported in the magnetar AXP 4U 0142+61 and may have occurred in the SGR 1900+14. We discuss the implications of the unusual timing behavior in PSR J1846-0258 on its status as the first identified magnetically active rotation-powered pulsar.

  12. 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.

  13. Discovery of Radio Pulsations from the X-ray Pulsar JO205+6449 in Supernova Remnant 3C58 with the Green Bank Telescope

    NASA Technical Reports Server (NTRS)

    Camilo, F.; Stairs, I. H.; Lorimer, D. R.; Backer, D. C.; Ransom, S. M.; Klein, B.; Wielebinski, R.; Kramer, M.; McLaughlin, M. A.; Arzoumanian, Z.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    We report the discovery with the 100m Green Bank Telescope of 65 ms radio pulsations from the X-ray pulsar J0205+6449 at the center of supernova remnant 3C58, making this possibly the youngest radio pulsar known. From our observations at frequencies of 820 and 1375 MHz, the free electron column density to USSR J0205+6449 is found to be 140.7 +/- 0.3/cc pc. The barycentric pulsar period P and P(dot) determined from a phase-coherent timing solution are consistent with the values previously measured from X-ray observations. The averaged radio profile of USSR J0205+6449 consists of one sharp pulse of width = 3 ms = 0.05 P. The pulsar is an exceedingly weak radio source, with pulse-averaged flux density in the 1400 MHz band of approximately 45 micro-Jy and a spectral index of approximately -2.1. Its radio luminosity of approximately 0.5 may kpc(exp 2) at 1400 MHz is lower than that of approximately 99% of known pulsar and is the lowest among known young pulsars.

  14. DEEP X-RAY OBSERVATIONS OF THE YOUNG HIGH-MAGNETIC-FIELD RADIO PULSAR J1119-6127 AND SUPERNOVA REMNANT G292.2-0.5

    SciTech Connect

    Ng, C.-Y.; Kaspi, V. M.; Ho, W. C. G.; Weltevrede, P.; Bogdanov, S.; Shannon, R.; Gonzalez, M. E.

    2012-12-10

    High-magnetic-field radio pulsars are important transition objects for understanding the connection between magnetars and conventional radio pulsars. We present a detailed study of the young radio pulsar J1119-6127, which has a characteristic age of 1900 yr and a spin-down-inferred magnetic field of 4.1 Multiplication-Sign 10{sup 13} G, and its associated supernova remnant G292.2-0.5, using deep XMM-Newton and Chandra X-ray Observatory exposures of over 120 ks from each telescope. The pulsar emission shows strong modulation below 2.5 keV with a single-peaked profile and a large pulsed fraction of 0.48 {+-} 0.12. Employing a magnetic, partially ionized hydrogen atmosphere model, we find that the observed pulse profile can be produced by a single hot spot of temperature 0.13 keV covering about one-third of the stellar surface, and we place an upper limit of 0.08 keV for an antipodal hot spot with the same area. The non-uniform surface temperature distribution could be the result of anisotropic heat conduction under a strong magnetic field, and a single-peaked profile seems common among high-B radio pulsars. For the associated remnant G292.2-0.5, its large diameter could be attributed to fast expansion in a low-density wind cavity, likely formed by a Wolf-Rayet progenitor, similar to two other high-B radio pulsars.

  15. High resolution radio study of the pulsar wind nebula within the supernova remnant G0.9+0.1

    NASA Astrophysics Data System (ADS)

    Dubner, G.; Giacani, E.; Decourchelle, A.

    2008-09-01

    Aims: We have conducted a study in radio wavelengths and in X-rays of the pulsar wind nebula (PWN) in the supernova remnant (SNR) G0.9+0.1 with the goal of investigating in detail its morphology and to accurately determine its characteristic parameters. Methods: To carry out this research we have observed the PWN at λ3.6 and 6 cm using the Australia Telescope Compact Array (ATCA) and combined these data with existing multiconfiguration VLA data and single dish observations in order to recover information at all spatial scales. We have also reprocessed VLA archival data at λ20 cm. From all these observational data we have produced high-fidelity images at the three radio frequencies with angular resolution better than 3''. The radio data were compared to X-ray data obtained with Chandra and in two different observing runs with XMM-Newton. Results: The new observations revealed that the morphology and symmetry suggested by Chandra observations (torus and jet-like features) are basically preserved in the radio range in spite of the rich structure observed in the radio emission of this PWN, including several arcs, bright knots, extensions and filaments. The reprocessed X-ray images show for the first time that the X-ray plasma fills almost the same volume as the radio PWN. Notably the X-ray maximum does not coincide with the radio maximum and the neutron star candidate CXOU J174722.8-280915 lies within a small depression in the radio emission. From the new radio data we have refined the flux density estimates, obtaining S_PWN˜ 1.57 Jy, almost constant between λ3.6 and λ20 cm. For the whole SNR (compact core and shell), a flux density S20~ cm= 11.5 Jy was estimated. Based on the new and the existing λ90 cm flux density estimates, we derived a spectral index α_PWN=-0.18± 0.04 and α_shell=-0.68± 0.07. From the combination of the radio data with X-ray data, a spectral break is found near ν˜ 2.4 × 1012 Hz. The total radio PWN luminosity is L_radio=1.2×1035 erg s-1 when a distance of 8.5 kpc is adopted. By assuming equipartition between particle and magnetic energies, we estimate a nebular magnetic field B = 56~ μG. The associated particle energy turns out to be U_part=5 × 1047 erg and the magnetic energy U_mag=2 × 1047 erg. The high ratio between magnetic and particles flux energy density suggests that the pulsar wind just started to become particle dominated. Based on an empirical relation between X-ray luminosity and pulsar energy loss rate, and the comparison with the calculated total energy, a lower limit of 1100 yr is derived for the age of this PWN.

  16. PROGENITORS OF RECOMBINING SUPERNOVA REMNANTS

    SciTech Connect

    Moriya, Takashi J.

    2012-05-01

    Usual supernova remnants have either ionizing plasma or plasma in collisional ionization equilibrium, i.e., the ionization temperature is lower than or equal to the electron temperature. However, the existence of recombining supernova remnants, i.e., supernova remnants with ionization temperature higher than the electron temperature, has been recently confirmed. One suggested way to have recombining plasma in a supernova remnant is to have a dense circumstellar medium at the time of the supernova explosion. If the circumstellar medium is dense enough, collisional ionization equilibrium can be established in the early stage of the evolution of the supernova remnant and subsequent adiabatic cooling, which occurs after the shock wave gets out of the dense circumstellar medium, makes the electron temperature lower than the ionization temperature. We study the circumstellar medium around several supernova progenitors and show which supernova progenitors can have a circumstellar medium dense enough to establish collisional ionization equilibrium soon after the explosion. We find that the circumstellar medium around red supergiants (especially massive ones) and the circumstellar medium dense enough to make Type IIn supernovae can establish collisional ionization equilibrium soon after the explosion and can evolve to become recombining supernova remnants. Wolf-Rayet stars and white dwarfs have the possibility to be recombining supernova remnants but the fraction is expected to be very small. As the occurrence rate of the explosions of red supergiants is much higher than that of Type IIn supernovae, the major progenitors of recombining supernova remnants are likely to be red supergiants.

  17. What Shapes Supernova Remnants?

    NASA Astrophysics Data System (ADS)

    Lopez, Laura A.

    2014-01-01

    Evidence has mounted that Type Ia and core-collapse (CC) supernovae (SNe) can have substantial deviations from spherical symmetry; one such piece of evidence is the complex morphologies of supernova remnants (SNRs). However, the relative role of the explosion geometry and the environment in shaping SNRs remains an outstanding question. Recently, we have developed techniques to quantify the morphologies of SNRs, and we have applied these methods to the extensive X-ray and infrared archival images available of Milky Way and Magellanic Cloud SNRs. In this proceeding, we highlight some results from these studies, with particular emphasis on SNR asymmetries and whether they arise from ``nature'' or ``nurture''.

  18. 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.

  19. The Size of the Extragalactic Source J1801-231 and the Association of Pulsar PSR B1758-23 with the Supernova Remnant W28

    NASA Astrophysics Data System (ADS)

    Claussen, M. J.; Goss, W. M.; Desai, K. M.; Brogan, C. L.

    2002-12-01

    We have used the NRAO Very Large Array (VLA) in conjunction with the Very Long Baseline Array (VLBA), Pie Town, New Mexico, antenna as a real-time interferometer system to measure the size of the extragalactic source J1801-231 as a function of frequency from 1285 to 4885 MHz. These observations were made in an attempt to determine the effect interstellar scattering has on the observed sizes of OH (1720 MHz) masers in the nearby (d=2.5 kpc) supernova remnant W28. The observations clearly show that J1801-231 displays angular broadening due to turbulence in the Galaxy's interstellar medium. The minimum distance of the nearby (2' from J1801-231) pulsar PSR B1758-23 is constrained to be 9.4+/-2.4 kpc. This value is based on both the measured size of 220 mas for J1801-231 at 1715 MHz and the temporal broadening of the pulsar. A single thin scattering screen along the line of sight to the W28 OH (1720 MHz) masers must be at 4.7+/-1.2 kpc for this minimum pulsar distance. The screen may be placed closer to the Earth, but for reasonable values of the pulsar distance (i.e., the pulsar is within the Galaxy), this choice leads to a negligible scattering contribution to the sizes of the masers. Thus, the OH (1720 MHz) masers, at a distance of 2.5+/-0.7 kpc, are unaffected by interstellar scattering, and the measured maser sizes must be intrinsic. Our measured upper limits to the size of the pulsar itself are consistent with the distance estimates to the pulsar and the scattering screen.

  20. 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.

  1. A search for stellar remnants of supernovae

    NASA Technical Reports Server (NTRS)

    Fesen, R. A.; Kirshner, R. P.; Winkler, P. F., Jr.

    1979-01-01

    The slitless spectra of the stars in the central regions of six galactic supernova remnants Cas A, Kepler, Tycho, SN 1006, RCW 86, and the Cygnus Loop were obtained with the prime focus transmission gratings at the 4M telescopes on Kitt Peak and Cerro Tololo. It was found that no stellar remnant with an unusually blue or peculiar spectrum is present in any of the remnants down to the limit of m sub pg of 18.5. Except for the Cygnus Loop, the area searched in each remnant is large enough that objects with transverse velocities of 1000 km/s would be well within the field. The results are also compared with a computation of emission from gas near a neutron star and with the unpulsed emission from the Crab pulsar; in both cases upper limits were set which place constraints on a possible condensed stellar remnant.

  2. Supernova Remnants And GLAST

    SciTech Connect

    Slane, Patrick; /Harvard-Smithsonian Ctr. Astrophys.

    2011-11-29

    It has long been speculated that supernova remnants represent a major source of cosmic rays in the Galaxy. Observations over the past decade have ceremoniously unveiled direct evidence of particle acceleration in SNRs to energies approaching the knee of the cosmic ray spectrum. Nonthermal X-ray emission from shell-type SNRs reveals multi-TeV electrons, and the dynamical properties of several SNRs point to efficient acceleration of ions. Observations of TeV gamma-ray emission have confirmed the presence of energetic particles in several remnants as well, but there remains considerable debate as to whether this emission originates with high energy electrons or ions. Equally uncertain are the exact conditions that lead to efficient particle acceleration. Based on the catalog of EGRET sources, we know that there is a large population of Galactic gamma-ray sources whose distribution is similar to that of SNRs.With the increased resolution and sensitivity of GLAST, the gamma-ray SNRs from this population will be identified. Their detailed emission structure, along with their spectra, will provide the link between their environments and their spectra in other wavebands to constrain emission models and to potentially identify direct evidence of ion acceleration in SNRs. Here I summarize recent observational and theoretical work in the area of cosmic ray acceleration by SNRs, and discuss the contributions GLAST will bring to our understanding of this problem.

  3. CHANDRA AND XMM-NEWTON STUDIES OF THE SUPERNOVA REMNANT G292.2-0.5 ASSOCIATED WITH THE PULSAR J1119-6127

    SciTech Connect

    Kumar, Harsha S.; Safi-Harb, Samar; Gonzalez, Marjorie E. E-mail: samar@physics.umanitoba.ca

    2012-08-01

    We present the first detailed imaging and spatially resolved spectroscopic study of the Galactic supernova remnant (SNR) G292.2-0.5, associated with the high-magnetic field radio pulsar (PSR) J1119-6127, using Chandra and XMM-Newton. The high-resolution X-ray images reveal a partially limb-brightened morphology in the west, with diffuse emission concentrated toward the interior of the remnant unlike the complete shell-like morphology observed at radio wavelengths. The spectra of most of the diffuse emission regions within the remnant are best described by a two-component thermal+non-thermal model. The thermal component is described by a plane-parallel, non-equilibrium ionization plasma model with a temperature kT ranging from 1.3{sup +0.3}{sub -0.2} keV in the western side of the remnant to 2.3{sup +2.9}{sub -0.5} keV in the east, a column density increasing from 1.0{sup +0.1}{sub -0.6} Multiplication-Sign 10{sup 22} cm{sup -2} in the west to 1.8{sup +0.2}{sub -0.4} Multiplication-Sign 10{sup 22} cm{sup -2} in the east, and a low ionization timescale ranging from (5.7{sup +0.8}{sub -0.7}) Multiplication-Sign 10{sup 9} cm{sup -3} s in the SNR interior to (3.6{sup +0.7}{sub -0.6}) Multiplication-Sign 10{sup 10} cm{sup -3} s in the western side-suggestive of expansion of a young remnant in a low-density medium. The spatial and spectral differences across the SNR are consistent with the presence of a dark cloud in the eastern part of the SNR, absorbing the soft X-ray emission, as also revealed by the optical image of that region. The spectra from some of the regions also show slightly enhanced metal abundances from Ne, Mg, and Si, hinting at the first evidence for ejecta heated by the reverse shock. Comparing our inferred metal abundances to core-collapse nucleosynthesis models yields, we estimate a high progenitor mass of {approx}30 M{sub Sun} suggesting a Type Ib/c supernova. We confirm the presence of non-thermal X-ray emission from regions close to the pulsar, with the emission characterized by a power-law model with a hard photon index similar to that seen in the compact pulsar wind nebula. We estimate an SNR age range between 4.2 kyr (free expansion phase) and 7.1 kyr (Sedov phase) at an assumed distance of 8.4 kpc, a factor of a few higher than the measured pulsar's age upper limit of 1.9 kyr.

  4. Multi-frequency observations of SNR J0453-6829 in the LMC. A composite supernova remnant with a pulsar wind nebula

    NASA Astrophysics Data System (ADS)

    Haberl, F.; Filipović, M. D.; Bozzetto, L. M.; Crawford, E. J.; Points, S. D.; Pietsch, W.; De Horta, A. Y.; Tothill, N.; Payne, J. L.; Sasaki, M.

    2012-07-01

    Context. The Large Magellanic Cloud (LMC) is rich in supernova remnants (SNRs), which can be investigated in detail with radio, optical, and X-ray observations. SNR J0453-6829 is an X-ray and radio-bright remnant in the LMC, within which previous studies revealed the presence of a pulsar wind nebula (PWN), making it one of the most interesting SNRs in the Local Group of galaxies. Aims: We study the emission of SNR J0453-6829 to improve our understanding of its morphology, spectrum, and thus the emission mechanisms in the shell and the PWN of the remnant. Methods: We obtained new radio data with the Australia Telescope Compact Array and analysed archival XMM-Newton observations of SNR J0453-6829. We studied the morphology of SNR J0453-6829 from radio, optical, and X-ray images and investigated the energy spectra in the different parts of the remnant. Results: Our radio results confirm that this LMC SNR hosts a typical PWN. The prominent central core of the PWN exhibits a radio spectral index αCore of -0.04 ± 0.04, while in the rest of the SNR shell the spectral slope is somewhat steeper with αShell = -0.43 ± 0.01. We detect regions with a mean polarisation of P ≅ (12 ± 4)% at 6 cm and (9 ± 2)% at 3 cm. The full remnant is of roughly circular shape with dimensions of (31 ± 1) pc × (29 ± 1) pc. The spectral analysis of the XMM-Newton EPIC and RGS spectra allowed us to derive physical parameters for the SNR. Somewhat depending on the spectral model, we obtain for the remnant a shock temperature of around 0.2 keV and estimate the dynamical age to 12 000-15 000 years. Using a Sedov model we further derive an electron density in the X-ray emitting material of 1.56 cm-3, typical for LMC remnants, a large swept-up mass of 830 M⊙, and an explosion energy of 7.6 × 1050 erg. These parameters indicate a well evolved SNR with an X-ray spectrum dominated by emission from the swept-up material.

  5. Discovery of a 105-ms X-ray Pulsar in Kesteven-79: On the Nature of Compact Central Objects in Supernova Remnants

    NASA Technical Reports Server (NTRS)

    Gotthelf, E. V.; Halpern, J. P.; Seward, F. D.

    2005-01-01

    We report the discovery of 105-ms X-ray pulsations from the compact central object (CCO) in the supernova remnant \\snr\\ using data acquired with the {\\it Newton X-Ray Multi-Mirror Mission). Using two observations of the pulsar taken 6-days apart we derive an upper limit on its spin-down rate of $\\dot P < 9 \\times 10"{-14}$-s-${-l)$,a nd find no evidence for binary orbital motion. The implied energy loss rate is $\\dot E < 3 \\times 10A{36)$-ergs-s$A{-1)$, polar magnetic field strength is $B-{\\rm p) < 3 \\times 10A{12)$-G, and spin-down age is $\\tau > 18.5$-kyr. The latter exceeds the remnant's estimated age, suggesting that the pulsar was born spinning near its current period. The X-ray spectrum of \\psr\\ is best characterized as a blackbody of temperature $kT {BB) =, 0.43\\pm0.02$ keV, radius $R-{BB) \\approx 1.3$-km, and $I{\\rm bol) = 5.2 \\times 10A{33)$ ergs-sSA{-1)$ at $d = 7.1$-kpc. The sinusoidal light curve is modulated with a pulsed fraction of $>45\\%$, suggestive of a small hot spot on the surface of the rotating neutron star. The lack of a discernible pulsar wind nebula is consistent with an interpretation of \\psr\\ as a rotation-powered pulsar whose spin-down luminosity falls below the empirical threshold for generating bright wind nebulae, $\\dot E-{\\rm c) = 4 \\times 10A{36)$-ergs-sSA{-I)$. The age discrepancy suggests that its $\\dot E$ has always been below $\\dot E c$, perhaps a distinguishing property of the CCOs. Alternatively, the X-ray spectrum of \\psr\\ suggests a low-luminosity AXP, but the weak inferred $B-{\\rm p)$ field is incompatible with a magnetar theory of its X-ray luminosity. The ordinary spin parameters discovered from \\psr\\ highlight the inability of existing theories to explain the high luminosities and temperatures of CCO thermal X-ray spectra.

  6. 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

  7. 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.

  8. Young Pulsar Reveals Clues to Supernova

    NASA Astrophysics Data System (ADS)

    2001-09-01

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

  9. X-RAY OBSERVATIONS OF THE SUPERNOVA REMNANT CTB 87 (G74.9+1.2): AN EVOLVED PULSAR WIND NEBULA

    SciTech Connect

    Matheson, H.; Safi-Harb, S.; Kothes, R. E-mail: samar@physics.umanitoba.ca

    2013-09-01

    Pulsar wind nebulae (PWNe) studies with the Chandra X-Ray Observatory have opened a new window to address the physics of pulsar winds, zoom on their interaction with their hosting supernova remnant (SNR) and interstellar medium, and identify their powering engines. We here present a new 70 ks, plus an archived 18 ks, Chandra ACIS observation of the SNR CTB 87 (G74.9+1.2), classified as a PWN with unusual radio properties and poorly studied in X-rays. We find that the peak of the X-ray emission is clearly offset from the peak of the radio emission by {approx}100'' and located at the southeastern edge of the radio nebula. We detect a point source-the putative pulsar-at the peak of the X-ray emission and study its spectrum separately from the PWN. This new point source, CXOU J201609.2+371110, is surrounded by a compact nebula displaying a torus-like structure and possibly a jet. A more extended diffuse nebula is offset from the radio nebula, extending from the point source to the northwest for {approx}250''. The spectra of the point source, compact nebula, and extended diffuse nebula are all well described by a power-law model with a photon index of 1.1 (0.7-1.6), 1.2 (0.9-1.4), and 1.7 (1.5-1.8), respectively, for a column density N{sub H} = 1.38 (1.21-1.57) Multiplication-Sign 10{sup 22} cm{sup -2} (90% confidence). The total X-ray luminosity of the source is {approx}1.6 Multiplication-Sign 10{sup 34} erg s{sup -1} at an assumed distance of 6.1 kpc, with {approx}2% and 6% contribution from the point source and compact nebula, respectively. The observed properties suggest that CTB 87 is an evolved ({approx}5-28 kyr) PWN, with the extended radio emission likely a ''relic'' PWN, as in Vela-X and G327.1-1.1. To date, however, there is no evidence for thermal X-ray emission from this SNR, and the SNR shell is still missing, suggesting expansion into a low-density medium (n{sub 0} < 0.2 D{sup -1/2}{sub 6.1} cm{sup -3}), likely caused by a stellar wind bubble blown by the progenitor star.

  10. Neutrinos from Supernovas and Supernova Remnants

    SciTech Connect

    Costantini, M.L.; Vissani, F.

    2005-10-12

    Supernovae (SN) and supernova remnants (SNR) have key roles in galaxies, but their physical descriptions is still incomplete. Thus, it is of interest to study neutrino radiation to understand SN and SNR better. We will discuss: (1) The {approx}10 MeV thermal neutrinos that arise from core collapse SN, that were observed for SN1987A, and can be seen with several existing or planned experiments. (2) The 10-100 TeV neutrinos expected from galactic SNRs (in particular from RX J1713.7-3946) targets of future underwater neutrino telescopes.

  11. Observing Supernovae and Supernova Remnants with JWST

    NASA Astrophysics Data System (ADS)

    Sonneborn, George; Temim, Tea; Williams, Brian J.; Blair, William P.

    2015-01-01

    The James Webb Space Telescope (JWST) will enable near- and mid-infrared studies of supernovae (SN) and supernova remnants (SNR) in the Milky Way and galaxies throughout the local universe and to high redshift. JWST's instrumentation provides imaging, coronography, and spectroscopy (R<3000) over the wavelength range 1-29 microns. The unprecedented sensitivity and angular resolution will enable spectroscopic study of new and recent supernovae, including molecule and dust formation, in galaxies at least out to 30 Mpc, and imaging to much greater distances. The Target of Opportunity response time can be as short as 48 hours, enabling quick follow-up observations of important SN events. JWST will be ideal for the study of Galactic and Magellanic Clouds supernova remnants, particularly young remnants with hot dust. Its high angular resolution (0.07" at 2 microns, 0.7" at 20 microns) will allow direct comparison between the IR, optical, and X-ray morphologies, identifying sites of dust emission in both the ejecta and the shocked ISM unresolved by previous IR telescopes. There is a rich spectrum of atomic lines (H, He I, [Si I], [Fe II], [Ni I-III], [Co II-III], [S III-IV], [Ar II-III], [Ne II, III, V], [O IV]) and molecules (CO, SiO, H2) of importance for SN and SNR studies. JWST is a large aperture (6.5m), cryogenic, infrared-optimized space observatory under construction by NASA, ESA, and CSA for launch in 2018. The JWST observatory will be placed in an Earth-Sun L2 orbit by an Ariane 5 launch vehicle provided by ESA. The observatory is designed for a 5-year prime science mission, with consumables for 10 years of science operations. The first call for proposals for JWST observations will be released in 2017.

  12. Featured Image: Modeling Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-05-01

    This image shows a computer simulation of the hydrodynamics within a supernova remnant. The mixing between the outer layers (where color represents the log of density) is caused by turbulence from the Rayleigh-Taylor instability, an effect that arises when the expanding core gas of the supernova is accelerated into denser shell gas. The past standard for supernova-evolution simulations was to perform them in one dimension and then, in post-processing, manually smooth out regions that undergo Rayleigh-Taylor turbulence (an intrinsically multidimensional effect). But in a recent study, Paul Duffell (University of California, Berkeley) has explored how a 1D model could be used to reproduce the multidimensional dynamics that occur in turbulence from this instability. For more information, check out the paper below!CitationPaul C. Duffell 2016 ApJ 821 76. doi:10.3847/0004-637X/821/2/76

  13. When will a pulsar in supernova 1987a be seen?

    NASA Technical Reports Server (NTRS)

    Michel, F. Curtis; Kennel, C. F.; Fowler, William A.

    1987-01-01

    The means by which a pulsar might be detected in the remnant of supernova 1987a in the Large Magellanic Cloud is examined. One possibility is that the slower-than-radioactive decay typically seen in the type II light curves is itself the sign of powering by the underlying pulsar, with the decline representing not the spinning down of the pulsar but rather the declining nebular opacity that would allow increasing amounts of the energy to escape as gamma rays. The test of this hypothesis (if the supernova conforms to type II expectations) would be to look for the 'missing' energy in the form of those gamma rays that escape from the remnant instead of powering it.

  14. When will a pulsar in supernova 1987a be seen?

    PubMed

    Michel, F C; Kennel, C F; Fowler, W A

    1987-11-13

    The means by which a pulsar might be detected in the remnant of supernova 1987a in the Large Magelanic Cloud is examined. One possibility is that the slower-than-radioactive decay typically seen in the type II light curves is itself the sign of powering by the underlying pulsar, with the decline representing not the spinning down of the pulsar but rather the declining nebular opacity that would allow increasing amounts of the energy to escape as gamma rays. The test of this hypothesis (if the supernova conforms to type II expectations) would be to look for the "missing" energy in the form of those gamma rays that escape from the remnant instead of powering it. PMID:17829358

  15. Chandra Supernova Remnant Catalog Update

    NASA Astrophysics Data System (ADS)

    Seward, Frederick

    2009-09-01

    We seek funds to hire a person to repair and update our web-based catalog of Chandra supernova remnant observations. We have found this quite useful for general-knowledge browsing and for proposal preparation. It is also used by a number of organizations. Eliminating the PI's computer, search engines, and selecting one remnant (so a catalog visit counts as 1) we record about 50-100 hits/month. But after 5 years of use, environment updates and other improvements have broken some of the scripts. Some information is hard to retrieve and catalog updates are now done by hand. There are also research possibilities which could be enhanced. We need someone to concentrate on this for 3-6 months, fix the scripts, and incorporate new material.

  16. The MOST supernova remnant catalogue (MSC)

    NASA Astrophysics Data System (ADS)

    Whiteoak, J. B. Z.; Green, A. J.

    1998-11-01

    The MOST Supernova Remnant Catalogue (MSC) is a catalogue of supernova remnants (SNRs) in the southern Galaxy within the area 245 deg <= l <= 355 deg , |b| < 1.5 deg. It was produced from observations made at 0.843 GHz with a resolution of 43" using the Molonglo Observatory Synthesis Telescope (MOST).

  17. Supernova Remnants in High Definition

    NASA Astrophysics Data System (ADS)

    Slane, Patrick; Badenes, Carles; Freyer, Chris; Hughes, Jack; Lee, Herman Shiu-Hang; Lopez, Laura; Patnaude, Daniel; Reynolds, Steve; Temim, Tea; Williams, Brian; Wongwathanarat, Annop; Yamaguchi, Hiroya

    2015-10-01

    As the observable products of explosive stellar death, supernova remnants reveal some of the most direct information on the physics of the explosions, the properties of the progenitor systems, and the demographics of compact objects formed in the supernova events. High sensitivity X-ray observations have allowed us to probe the properties of the shocked plasma, providing constraints on abundances and ionization states that connect directly progenitor masses and metallicities, the nature of the explosions (core-collapse vs. thermonuclear), and the physics of shock heating and particle acceleration in fast shocks. Studies of SNRs in the Magellanic Clouds have provided information on source demographics in a low metallicity environment, and deep searches for point sources in Galactic SNRs imply that many remnants contain rapidly cooling neutron stars or black holes. Based on Chandra observations, we know that crucial measurements required to advance our knowledge in these areas are possible only with much more sensitive observations at high angular resolution. From identifying the effects of particle acceleration on the post-shock gas in young SNRs like Tycho to obtaining spatially resolved spectra - and identifying compact objects - for young SNRs in the Magellanic Clouds, the capabilities of a facility like the X-ray Surveyor are required. Here I present a summary of recent advances brought about by spectral investigations of SNRs, and discuss particular examples of new advances that will be enabled by X-ray Surveyor capabilities.

  18. Cosmic Ray Acceleration in Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Blasi, P.

    2011-06-01

    We review the main observational and theoretical facts about acceleration of Galactic cosmic rays in supernova remnants, discussing the arguments in favor and against a connection between cosmic rays and supernova remnants, the so-called supernova remnant paradigm for the origin of Galactic cosmic rays. Recent developments in the modeling of the mechanism of diffusive shock acceleration are discussed, with emphasis on the role of 1) magnetic field amplification, 2) acceleration of nuclei heavier than hydrogen, 3) presence of neutrals in the circumstellar environment. The status of the supernova-cosmic ray connection in the time of Fermi-LAT and Cherenkov telescopes is also discussed.

  19. Radio emission from supernova remnants

    NASA Astrophysics Data System (ADS)

    Dubner, Gloria; Giacani, Elsa

    2015-09-01

    The explosion of a supernova releases almost instantaneously about 10^{51} ergs of mechanic energy, changing irreversibly the physical and chemical properties of large regions in the galaxies. The stellar ejecta, the nebula resulting from the powerful shock waves, and sometimes a compact stellar remnant, constitute a supernova remnant (SNR). They can radiate their energy across the whole electromagnetic spectrum, but the great majority are radio sources. Almost 70 years after the first detection of radio emission coming from an SNR, great progress has been achieved in the comprehension of their physical characteristics and evolution. We review the present knowledge of different aspects of radio remnants, focusing on sources of the Milky Way and the Magellanic Clouds, where the SNRs can be spatially resolved. We present a brief overview of theoretical background, analyze morphology and polarization properties, and review and critically discuss different methods applied to determine the radio spectrum and distances. The consequences of the interaction between the SNR shocks and the surrounding medium are examined, including the question of whether SNRs can trigger the formation of new stars. Cases of multispectral comparison are presented. A section is devoted to reviewing recent results of radio SNRs in the Magellanic Clouds, with particular emphasis on the radio properties of SN 1987A, an ideal laboratory to investigate dynamical evolution of an SNR in near real time. The review concludes with a summary of issues on radio SNRs that deserve further study, and analysis of the prospects for future research with the latest-generation radio telescopes.

  20. 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.

  1. ANTIPROTONS PRODUCED IN SUPERNOVA REMNANTS

    SciTech Connect

    Berezhko, E. G.; Ksenofontov, L. T.

    2014-08-20

    We present the energy spectrum of an antiproton cosmic ray (CR) component calculated on the basis of the nonlinear kinetic model of CR production in supernova remnants (SNRs). The model includes the reacceleration of antiprotons already existing in the interstellar medium as well as the creation of antiprotons in nuclear collisions of accelerated protons with gas nuclei and their subsequent acceleration by SNR shocks. It is shown that the production of antiprotons in SNRs produces a considerable effect in their resultant energy spectrum, making it essentially flatter above 10 GeV so that the spectrum at TeV energies increases by a factor of 5. The calculated antiproton spectrum is consistent with the PAMELA data, which correspond to energies below 100 GeV. As a consistency check, we have also calculated within the same model the energy spectra of secondary nuclei and show that the measured boron-to-carbon ratio is consistent with the significant SNR contribution.

  2. ANTIMATTER PRODUCTION IN SUPERNOVA REMNANTS

    SciTech Connect

    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{sup -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.

  3. Cosmic rays and the Monogem supernova remnant

    NASA Astrophysics Data System (ADS)

    Erlykin, A. D.; Wolfendale, A. W.

    2004-10-01

    Recent findings indicate that the Monogem Ring and the associated pulsar PSR B0656 + 14 may be the `Single Source' responsible for the formation of the sharp knee in the cosmic ray energy spectrum at 3 PeV. The energy spectrum of cosmic rays expected for the Monogem Ring supernova remnant (SNR) from our SNR acceleration model [J. Phys. G: Nucl. Part. Phys. 27 (2001) 941] has been published by us elsewhere [J. Phys. G: Nucl. Part. Phys. 29 (2003) 709] . In this paper we go on to estimate the contribution of the pulsar B0656 + 14 to the cosmic rays in the PeV region. We conclude that although the pulsar can contribute to the formation of the knee, it cannot be the dominant source of it and an SNR is still needed. We also examine the possibility of the pulsar giving the peak of the extensive air shower (EAS) intensity observed from the region inside the Monogem Ring [ApJ Lett. 597 (2003) L129]. The estimates of the gamma-ray flux produced by cosmic ray particles from this pulsar indicate that it can be the source of the observed peak, if the particles were confined within the SNR during a considerable fraction of its total age. The flux of gamma quanta at PeV energies has a high sensitivity to the duration of the confinement. The estimates of this time and of the following diffusion of cosmic rays from the confinement volume turn out to be in remarkable agreement with the time needed for these cosmic rays to propagate to the solar system and to form the observed knee in the cosmic ray energy spectrum. Other possible mechanisms for the production of particles which could give rise to the observed narrow peak in the EAS intensity were also examined. Electrons scattered on the microwave background or on X-rays, emitted by SNR, cannot be responsible for the gamma-quanta in the peak. Neutrons produced in PP-collisions or released from the disintegration of accelerated nuclei seem to be also unable to create the peak since they cannot give the observed flux. If the experimental EAS results concerning a point-like source are confirmed, they can be important, since they will give evidence for the acceleration of protons or heavier nuclei by the pulsar; they will give evidence for the existence of a confinement mechanism in SNR; they will confirm that cosmic rays produced by the Monogem Ring SNR and associated pulsar B0656 + 14 were released recently giving rise to the formation of the sharp knee and the observed narrow peak in the EAS intensity; they will give strong support for the Monogem Ring SNR and the associated pulsar B0656 + 14 being identified as the Single Source proposed in our Single Source Model of the knee. examined mechanism are made.

  4. Observations of young core collapse supernova remnants

    NASA Astrophysics Data System (ADS)

    Tziamtzis, Anestis

    Studies of young remnants offer an opportunity to test theoretical models of stellar evolution, explosion models and nucleosynthesis, as well as our understanding of the compact objects in the centre of the exploded stars. The first part of the thesis involves observations of the Crab nebula. We have used photometric and spectroscopic observations to search for a faint halo around the visible nebula, that could carry the missing mass and kinetic energy of the nebula. No halo was found. In the photometric data due to psf contamination, and in the spectroscopic no fast velocity components were present. We have also used optical and IR photometry to check for variation in the emissivity and dynamic structure of the Crab pulsar wind nebula (PWN), to try to understand the nature of plerionic PWNe. There, we measured flux variations up to 20% in the IR and also shifting of the wisps with velocities up to 0.2c. We also showed that the nearby red knot moves in tandem with the Crab pulsar. The second part of the thesis, deals with photometric & spectroscopic observations of SN 1987A in the LMC. The aim of the project was to monitor the evolution of the outer rings (ORs) of SN 1987A. The fading of the ORs is consistent with recombination and cooling after the initial flash ionization by the supernova. From the spectroscopic data we measured the density and temperature in the ORs where we found temperatures of ~ 12,000 K for the [N II] gas, and ~ 25,000 K for the [O III]. Finally, from the [O II], and [S II] ratios we estimated electron densities of ~ 1,000 cm-3 and ~ 2,500 cm-3, respectively. From the evolution of Hα, we argue that the highest density in the ORs could be 5,000 cm-3.

  5. The MOST supernova remnant catalogue (MSC).

    NASA Astrophysics Data System (ADS)

    Whiteoak, J. B. Z.; Green, A. J.

    1996-08-01

    A catalogue of supernova remnants in the southern Galaxy within the area 245 <=l <=355deg , |b|<~ 1.5deg has been produced from observations made at 0.843 GHz with a resolution of 43" using the Molonglo Observatory Synthesis Telescope (MOST). The catalogue, presented here, provides greyscale images and contour maps of known and newly-discovered remnants. The increased resolution and sensitivity of these observations has resulted in better statistics for southern remnants.

  6. Core-collapse supernova remnants and interactions with their surroundings

    NASA Astrophysics Data System (ADS)

    Brantseg, Thomas Felton

    This thesis examines three core-collapse supernova remnants (SNR)---the Cygnus Loop in the Milky Way and 0453-68.5 and 0540-69.3 in the Large Magellanic Cloud---of varying ages and in varying states of interaction with the surrounding interstellar medium (ISM), using X-ray imaging spectroscopy with Chandra and supplemental data from other wavelengths. We use results from our analysis to address three main questions. First, we examine the applicability of the common Sedov-Taylor adiabatic blast wave model to core-collapse supernovae. Second, we determine the elemental abundances around the shell of these supernova remnants to determine if the use of SNRs as a gauge of abundances in the ISM is justified. Finally, we examine the pulsar wind nebulae (PWNe) in 0453-68.5 and 0540-69.3 and search for evidence of interaction between these PWNe and their immediate surroundings. We see highly inhomogeneous ISM surrounding all three surveyed SNRs, contrary to the key assumption in the Sedov-Taylor model of a uniform surrounding medium. In all three studied SNRs, we find that shock speeds are dependent on the density of the surrounding material. As subsidiary results, we also find depleted elemental abundances of oxygen, magnesium, and silicon, relative to typical ISM, around all three studied supernova remnants. Although this subsidiary result is not conclusive, we believe that it merits a followup study. In 0540-69.3 and 0453-68.5, which contain central pulsars, we find that the explosion directionality, which can be inferred from the pulsar's proper motion relative to the SNR, is not related to the morphology of the SNR itself. We conclude from this that the asymmetric shapes common in core-collapse supernova remnants can be more a function of the complex environments surrounding the progenitors of core-collapse supernovae than of the supernova explosions themselves. Finally, we see that the PWN in 0453-68.5 shows signs of having mixed with the surrounding thermal- emitting material, while the PWN in 0540-69.3 appears to have not mixed with or interacted with the surrounding SNR material to any substantial degree. We believe that this result may indicate that the degree of interaction between a PWN and its surroundings is dependent on age and possibly shell morphology, although further study is needed.

  7. Progenitor's Signatures in Type Ia Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Chiotellis, A.; Kosenko, D.; Schure, K. M.; Vink, J.

    2013-01-01

    The remnants of Type Ia supernovae (SNe Ia) can provide important clues about their progenitor histories. We discuss two well-observed supernova remnants (SNRs) that are believed to have resulted from SNe Ia, and use various tools to shed light on the possible progenitor histories. We find that Kepler's SNR is consistent with a symbiotic binary progenitor consisting of a white dwarf and an AGB star. Our hydrosimulations can reproduce the observed kinematic and morphological properties. For Tycho's remnant we use the characteristics of the X-ray spectrum and kinematics to show that the ejecta has likely interacted with dense circumstellar gas.

  8. Supernova Remnant in 3-D

    NASA Technical Reports Server (NTRS)

    2009-01-01

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

    For the first time, a multiwavelength three-dimensional reconstruction of a supernova remnant has been created. This stunning visualization of Cassiopeia A, or Cas A, the result of an explosion approximately 330 years ago, uses data from several telescopes: X-ray data from NASA's Chandra X-ray Observatory, infrared data from NASA's Spitzer Space Telescope and optical data from the National Optical Astronomy Observatory 4-meter telescope at Kitt Peak, Ariz., and the Michigan-Dartmouth-MIT 2.4-meter telescope, also at Kitt Peak. In this visualization, the green region is mostly iron observed in X-rays. The yellow region is a combination of argon and silicon seen in X-rays, optical, and infrared including jets of silicon plus outer debris seen in the optical. The red region is cold debris seen in the infrared. Finally, the blue reveals the outer blast wave, most prominently detected in X-rays.

    Most of the material shown in this visualization is debris from the explosion that has been heated by a shock moving inwards. The red material interior to the yellow/orange ring has not yet encountered the inward moving shock and so has not yet been heated. These unshocked debris were known to exist because they absorb background radio light, but they were only recently discovered in infrared emission with Spitzer. The blue region is composed of gas surrounding the explosion that was heated when it was struck by the outgoing blast wave, as clearly seen in Chandra images.

    To create this visualization, scientists took advantage of both a previously known phenomenon the Doppler effect and a new technology that bridges astronomy and medicine. When elements created inside a supernova, such as iron, silicon and argon, are heated they emit light at certain wavelengths. Material moving towards the observer will have shorter wavelengths and material moving away will have longer wavelengths. Since the amount of the wavelength shift is related to the speed of motion, one can determine how fast the debris are moving in either direction. Because Cas A is the result of an explosion, the stellar debris is expanding radially outwards from the explosion center. Using simple geometry, the scientists were able to construct a 3-D model using all of this information. A program called 3-D Slicer modified for astronomical use by the Astronomical Medicine Project at Harvard University in Cambridge, Mass. was used to display and manipulate the 3-D model. Commercial software was then used to create the 3-D fly-through.

    The blue filaments defining the blast wave were not mapped using the Doppler effect because they emit a different kind of light synchrotron radiation that does not emit light at discrete wavelengths, but rather in a broad continuum. The blue filaments are only a representation of the actual filaments observed at the blast wave.

    This visualization shows that there are two main components to this supernova remnant: a spherical component in the outer parts of the remnant and a flattened (disk-like) component in the inner region. The spherical component consists of the outer layer of the star that exploded, probably made of helium and carbon. These layers drove a spherical blast wave into the diffuse gas surrounding the star. The flattened component that astronomers were unable to map into 3-D prior to these Spitzer observations consists of the inner layers of the star. It is made from various heavier elements, not all shown in the visualization, such as oxygen, neon, silicon, sulphur, argon and iron.

    High-velocity plumes, or jets, of this material are shooting out from the explosion in the plane of the disk-like component mentioned above. Plumes of silicon appear in the northeast and southwest, while those of iron are seen in the southeast and north. These jets were already known and Doppler velocity measurements have been made for these structures, but their orientation and position with respect to the rest of the debris field had never been mapped before now.

    This new insight into the structure of Cas A gained from this 3-D visualization is important for astronomers who build models of supernova explosions. Now, they must 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.

  9. An IRAS survey of Galactic supernova remnants

    NASA Technical Reports Server (NTRS)

    Saken, Jon M.; Fesen, Robert A.; Shull, J. M.

    1992-01-01

    A new independent survey of the IR emission for 161 Galactic supernova remnants are presented on the basis of Skyflux image data from the Infrared Astronomical Satellite. A new Galactic rotation curve with current IAU constants, R0 = 8.5 kpc and V0 = 220 km/s, is used to derive new kinematic distances for 11 of the 44 positively or possibly identified remnants. Temperature-sensitive flux ratio images are employed to help identify and define remnant emission structures and fluxes, particularly in complex regions. Of the 161 remnants examined, clear IR emission from 35 was found, with nine additional possible detections. Almost all young remnants (Tycho, Kepler, Cas A, Crab) were found to have a significant 12- and 25-micron flux, while older remnants are brightest at 60 and 100 microns. Correlations with mass and temperature indicate that older remnants are both colder and more massive, as expected from decreasing velocity. No radius-luminosity correlation was seen.

  10. Optical supernova remnant observations from Skinakas Observatory

    NASA Astrophysics Data System (ADS)

    Mavromatakis, F.; Papamastorakis, J.; Ventura, J.; Boumis, P.

    High energy studies of supernova remnants provide direct insight into major properties of these objects. Morphological and spectral studies of remnants in X-rays allow us to estimate parameters like the age of the remnant, the explosion energy and the ambient interstellar density. Optical studies of supernova remnants focus on the interaction of the primary blast wave with dense "clouds" found in the insterstellar medium. Optical observations of individual remnants performed at Skinakas Observatory in Crete, Greece consist of flux calibrated wide field CCD images taken with the 0.3 m telescope and absolute flux calibrated long-slit spectra obtained with the 1.3 m telescope. The site conditions and the unique capabilities of a small telescope equipped with a CCD camera allowed us to perform high quality deep observations leading to the discovery of optical emission from several remnants for the first time. We present results on the known supernova remnants G65.3+5.7, G82.2+5.3, G114.3+0.3 as well as current results on previously unknown filamentary structures and probable candidate remnants. Typical densities of the interstellar "clouds" are of the order of a few atoms per cm3 , and the shock velocities are found in the range of 90-140 km s-1 . The optical spectra further suggest the presence of moderate magnetic fields of several μG.

  11. High-energy antiprotons from old supernova remnants.

    PubMed

    Blasi, Pasquale; Serpico, Pasquale D

    2009-08-21

    A recently proposed model explains the rise in energy of the positron fraction measured by the PAMELA satellite in terms of hadronic production of positrons in aged supernova remnants, and acceleration therein. Here we present a preliminary calculation of the antiproton flux produced by the same mechanism. While the model is consistent with present data, a rise of the antiproton to proton ratio is predicted at high energy, which strikingly distinguishes this scenario from other astrophysical explanations of the positron fraction (such as pulsars). We briefly discuss important implications for dark matter searches via antimatter. PMID:19792708

  12. Optical supernova remnant observations from Skinakas Observatory

    NASA Astrophysics Data System (ADS)

    Mavromatakis, F.; Papamastorakis, J.; Ventura, J.; Boumis, P.

    High energy studies of supernova remnants provide direct insight into major properties of these objects. Morphological and spectral studies of remnants in X-rays allow us to estimate parameters like the age of the remnant, the explosion energy and the ambient interstellar density. Optical studies of supernova remnants focus on the interaction of the primary blast wave with dense "clouds" found in the interstellar medium. Optical observations of individual remnants performed at Skinakas Observatory in Crete, Greece consist of flux calibrated wide field CCD images taken with the 0.3 m telescope and absolute flux calibrated long-slit spectra obtained with the 1.3 m telescope. The site conditions and the unique capabilities of a small telescope equipped with a CCD camera allowed us to perform high quality deep observations leading to the discovery of optical emission from several remnants for the first time. We present results on the known supernova remnants G73.9+0.9, G82.2+5.3 as well as current results on previously unknown filamentary structures. Typical densities of the interstellar "clouds" are of the order of a few atoms per cm 3, and the shock velocities are found in the range of 90-140 km s -1. The optical spectra further suggest the presence of moderate magnetic fields.

  13. Evolution of multiple supernova remnants

    NASA Astrophysics Data System (ADS)

    Vasiliev, Evgenii O.; Nath, Biman B.; Shchekinov, Yuri

    2015-01-01

    Heating of the interstellar medium (ISM) by multiple supernova (SN) explosions is at the heart of producing galaxy-scale outflows in starburst galaxies. Standard models of outflows assume a high efficiency of SNe in heating the gas to X-ray emitting temperatures and filling the central region of starburst with hot gas, in order to launch vigorous outflows. We use hydrodynamical simulations to study the efficiency of multiple SNe in heating the ISM and filling the volume with gas of high temperatures. We argue that it is important for SN remnants to have a large filling factor and a large heating efficiency. For this, they have to be clustered in space and time, and keep exploding until the hot gas percolates through the whole region, in order to compensate for the radiative loss. In the case of a limited number of SNe, we find that although the filling factor can be large, the heating efficiency declines after reaching a large value. In the case of a continuous series of SNe, the hot gas (T ≥ 3 × 106 K) can percolate through the whole region after the total volume filling factor reaches a threshold of ˜0.3. The efficiency of heating the gas to X-ray temperatures can be ≥0.1 after this percolation epoch, which occurs after a period of ≈10 Myr for a typical starburst SN rate density of νSN ≈ 10-9 pc-3 yr-1 and gas density of n ≈ 10 cm-3 in starburst nuclei regions. This matches the recent observations of a time delay of similar order between the onset of star formation and galactic outflows. The efficiency to heat gas up to X-ray temperatures (≥106.5 K) roughly scales as ν _SN^{0.2} n^{-0.6}. For a typical SN rate density and gas density in starburst nuclei, the heating efficiency is ˜0.15, also consistent with previous interpretations from X-ray observations. We discuss the implications of our results with regard to observational diagnostics of ionic ratios and emission measures in starburst nuclei regions.

  14. 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.

  15. 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.

  16. 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)

  17. Dynamics of Kepler's supernova remnant

    NASA Technical Reports Server (NTRS)

    Borkowski, Kazimierz J.; Blondin, John M.; Sarazin, Craig L.

    1992-01-01

    Observations of Kepler's SNR have revealed a strong interaction with the ambient medium, far in excess of that expected at a distance of about 600 pc away from the Galactic plane where Kepler's SNR is located. This has been interpreted as a result of the interaction of supernova ejecta with the dense circumstellar medium (CSM). Based on the bow-shock model of Bandiera (1985), we study the dynamics of this interaction. The CSM distribution consists of an undisturbed stellar wind of a moving supernova progenitor and a dense shell formed in its interaction with a tenuous interstellar medium. Supernova ejecta drive a blast wave through the stellar wind which splits into the transmitted and reflected shocks upon hitting this bow-shock shell. We identify the transmitted shock with the nonradiative, Balmer-dominated shocks found recently in Kepler's SNR. The transmitted shock most probably penetrated the shell in the vicinity of the stagnation point.

  18. "Suzaku Highlight Results on Supernova Remnants"

    NASA Technical Reports Server (NTRS)

    Petre, Robert

    2006-01-01

    Highlights of the early Suzaku (formerly Astro-E2) observations of supernova remnants are presented. Suzaku offers unique capabilities for the study of supernova remnants. The unprecedented combination of imaging and spectral resolution below 1 keV in the X-ray Imaging Spectrometer (XIS) makes possible mapping of C, N and O abundances in Galactic remnants of all ages. The first detection of carbon lines in the Cygnus Loop and mapping of the O VII to O VIII ratio in SN 1006 demonstrate this capability. The XIS sensitivity to soft, low surface brightness emission is exemplified by spectroscopy in the 0.3-1.0 keV band of the North Polar Spur and other Galactic ISM structures. Such observations make possible inferences about plasma conditions and abundances. The sensitivity above 6 keV via a combination of the XIS (below 10 keV) and the Hard X-ray Detector (above 10 keV) allows broad band (2-40 keV) spectroscopy and mapping of extended remnants with hard emission components. These components are generally associated with sites of particle acceleration, and measuring their spectral shape potentially provides information about the TeV electron population and its acceleration and energy loss mechanisms. Examples of such remnants observed by Suzaku are the non-thermal emission dominated remnants RX J1713.7-3946 and RX J0852.0-4622, for which flux beyond 30 keV has been detected. The status of the mission and prospects for future groundbreaking observations of supernova remnants will be discussed.

  19. A Multiwavelength Study of Tycho's Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Petre, Robert

    The remnant of the supernova of 1572 A.D., now known as Tycho's Supernova Remnant (SNR), is one of the most well studied SNRs in existence, having been observed with telescopes from radio waves to gamma-rays. We propose a multi-wavelength study of this remnant, with particular focus on archival data in the infrared from Spitzer, WISE, and Herschel, and in gamma-rays from Fermi. The IR data is of extremely high-quality, and will allow us to answer or further constrain several mysteries regarding Tycho, known to be the remnant of a Type Ia supernova. Is the remnant a source of particle acceleration producing cosmic-rays in excess of 10^15 ev? What is the source of the gamma-ray emission seen at both GeV and TeV energies? What is the nature of the medium surrounding the remnant, into which it is currently expanding at over 4000 km/s? Has any dust formed in the iron-rich ejected material from the supernova? The answers to all of these questions will require a multi-wavelength approach, and we will supplement the IR and gamma-ray data here with archival X-ray data from both Chandra and XMM- Newton. In young SNRs like Tycho, IR and X-ray emission is inherently connected, since the hot ions and electrons that give rise to the thermal X-ray emission also heat (and destroy) dust grains in the post-shock gas. Infrared spectroscopy is a highly sensitive function of gas density, and provides a more powerful diagnostic tool for this parameter than X-rays alone do. This post-shock density is a crucial parameter for both particle acceleration and gamma-ray emission models, and the IR data will allow us to measure this density at any point in the remnant. We will explore the relationship between dust and gas in the immediate post-shock region. Because the blast wave is encountering the ambient Galactic ISM, this will provide strong constraints on the dust composition and dust-to-gas mass ratio in the general ISM. At all wavelengths, Tycho is a wealth of information, and by combining multiple wavelengths into a single analysis, we can learn a great deal about supernovae, the environments into which they explode, and they shock interaction with the ISM.

  20. Observation of stellar remnants from recent supernovae

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    The current observational situation regarding the presence or absence of collapsed stellar objects associated with supernova remnants is reviewed. The theoretical expectations and observational evidence for the various possible classes of stellar remnants are discussed. The results of searches for these objects in the radio, optical, X-ray and gamma-ray regions of the spectrum are outlined with the conclusion that nine bona fide candidates are currently known. The implications of these results for the origin and evolution of compact objects are summarized.

  1. Shock enhancement of HCO/+/. [in supernova remnants

    NASA Technical Reports Server (NTRS)

    Dickinson, D. F.; Dinger, A. S. C.; Kuiper, T. B. H.; Rodriguez Kuiper, E. N.

    1980-01-01

    In the shocked gas associated with the supernova remnant IC 443, it is found that the HCO(+)/CO abundance is approximately 0.004. This is about 100 times greater than in the unshocked gas in this source where the ratio is typical of molecular clouds. This increase contradicts some current models for shock chemistry which predict a decrease of HCO(+) behind shock fronts.

  2. X-rays from Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Aschenbach, B.

    A summary of X-ray observations of supernova remnants is presented including the explosion fragment A of the Vela SNR, Tycho, N132D, RX J0852-4622, the Crab Nebula and the 'bulls eye', and SN 1987A, high-lighting the progress made with Chandra and XMM-Newton and touching upon the questions which arise from these observations and which might inspire future research.

  3. Supernova--remnant origin of cosmic rays?

    PubMed

    Butt, Yousaf M; Torres, Diego F; Romero, Gustavo E; Dame, Thomas M; Combi, Jorge A

    2002-08-01

    It is thought that Galactic cosmic-ray nuclei are gradually accelerated to high energies (up to about 300 TeV per nucleon, where 1 TeV is 10(12) eV) in the expanding shock waves connected with the remnants of powerful supernova explosions. However, this conjecture has eluded direct observational confirmation since it was first proposed in 1953 (ref. 3). Enomoto et al. claim to have finally found definitive evidence that corroborates this model, proposing that very-high-energy, TeV-range, gamma-rays from the supernova remnant (SNR) RX J1713.7-3946 are due to the interactions of energetic nuclei in this region. Here we argue that their claim is not supported by the existing multiwavelength spectrum of this source. The search for the origin(s) of Galactic cosmic-ray nuclei may be closing in on the long-suspected supernova-remnant sources, but it is not yet over. PMID:12152068

  4. Spectral Mapping of Kepler's Supernova Remnant

    NASA Astrophysics Data System (ADS)

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

    2008-03-01

    We propose to leverage our extensive previous multi-wavelength investigations of Kepler's supernova remnant (SN 1604) by obtaining IRS spectral maps of this premier example of a 'massive Type Ia' remnant. Of particular interest is the dense circumstellar medium (CSM) evidently surrounding Kepler. This material is best investigated in infrared, where shock-heated dust reveals the thermal-gas density and possible composition clues such as the 10-micron silicate feature. Full LL coverage (14-38 um) will permit detailed mapping of continuum shape changes with spatial position that are only hinted at from our previous MIPS 24 and 70 um imaging. SL mapping of selected regions will permit detailed studies of changes in the silicate feature with position, suggested by two slit positions in earlier observations. Combined with our deep Chandra observation (750 ks), these data will permit a detailed study of dust destruction in fast shocks. Kepler also shows regions near the remnant edge dominated by synchrotron X-ray emission, indicating electron acceleration to energies of order 100 TeV. However, the dominance of synchrotron continuum means that properties of the thermal medium, important for understanding shock-acceleration physics, cannot be diagnosed with X-rays. Our IRS spectra should allow such diagnosis. Kepler's unique position among Type Ia supernova remnants makes it a critical target for the understanding of the Type Ia phenomenon.

  5. Discovery of an X-ray Jet Associated with Supernova Remnant G54.1+0.3

    NASA Astrophysics Data System (ADS)

    Lu, F. J.; Aschenbach, B.; Song, L. M.; Durouchoux, Ph.

    We present in this paper the discovery of an X-ray jet associated with the Crab-like supernova remnant G54.1+0.3. It points to the northeast with a length about 4'' from the center of the nebula and has a flux ~ 1/6 of the whole remnant. The X-ray jet is consistent with the radio extension to the northeast, suggesting that it is connected with the pulsar embedded in the remnant.

  6. Pulsar recoil by large-scale anisotropies in supernova explosions.

    PubMed

    Scheck, L; Plewa, T; Janka, H-Th; Kifonidis, K; Müller, E

    2004-01-01

    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. PMID:14753979

  7. Are Supershells Powered by Multiple Supernovae? Modeling the Radio Pulsar Population Produced by OB Associations

    NASA Astrophysics Data System (ADS)

    Perna, Rosalba; Gaensler, Bryan M.

    2004-05-01

    Traditional searches for radio pulsars have targeted individual small regions such as supernova remnants or globular clusters or have covered large contiguous regions of the sky. None of these searches have been specifically directed toward giant supershells, some of which are likely to have been produced by multiple supernova (SN) explosions from an OB association. Here we perform a Monte Carlo simulation of the pulsar population associated with supershells powered by multiple SNe. We predict that several tens of radio pulsars associated with the largest Galactic supershells (with kinetic energies >~1053 ergs) could be detected with current instruments and a few pulsars associated with the smaller supershells. We test these predictions for some of the supershells that lie in regions covered by past pulsar surveys. For the smaller supershells, our results are consistent with the few detected pulsars per bubble. For the giant supershell GSH 242-03+37, we find the multiple SN hypothesis inconsistent with current data at the ~95% level. We stress the importance of undertaking deep pulsar surveys in correlation with supershells. Failure to detect any pulsar enhancement in the largest of them would put serious constraints on the multiple SN origin for them. Conversely, the discovery of the pulsar population associated with a supershell would allow a different, independent approach to the study of pulsar properties.

  8. SN 1054: A pulsar-powered supernova?

    NASA Astrophysics Data System (ADS)

    Li, Shao-Ze; Yu, Yun-Wei; Huang, Yan

    2015-11-01

    The famous ancient supernova SN 1054 could have been too bright to be explained in the “standard” radioactive-powered supernova scenario. As an alternative attempt, we demonstrate that the spin-down of the newly born Crab pulsar could provide a sufficient energy supply to make SN 1054 visible at daytime for 23 days and at night for 653 days, where a one-zone semi-analytical model is employed. Our results indicate that SN 1054 could be a “normal” cousin of magnetar-powered superluminous supernovae. Therefore, SN 1054-like supernovae could be a probe to uncover the properties of newly born neutron stars, which provide initial conditions for studies on neutron star evolutions.

  9. 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.

  10. The Hubble Heritage Image of the Crab Nebula Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Blair, W. P.; English, J.; Bond, H. E.; Christian, C. A.; Frattare, L.; Hamilton, F.; Levay, Z.; Noll, K. S.

    2000-05-01

    The Hubble Heritage Project has the aim of providing the public with pictorially striking images of celestial objects obtained with NASA's Hubble Space Telescope. Here we present a 5-color Wide Field Planetary Camera 2 (WFPC2) image of the Crab Nebula, a ~950 year old supernova remnant located 6500 light-years distant in the constellation Taurus. The images were obtained in 1995 January and April, and the science investigation reporting results was published by Blair, W. P., et al. (1997, ApJS, 109, 473--480). Over 10 hours of exposure time through 5 separate optical continuum band and emission-line filters were used to study size scales and ionization structures of the filaments and newly synthesized dust within the expanding ejecta. The Heritage version of these data shows several important aspects of the Crab Nebula all in one spectacular image. The continuum image shows stars, including the enigmatic pulsar (the collapsed core of the original star) and the ghostly diffuse synchrotron nebula energized by the pulsar. The synchrotron nebula in turn heats and ionizes the surrounding clumpy filaments of gas and dust visible in the emission line images. These filaments are the supernova ejecta that were expelled during the explosion and are now expanding outward from the pulsar at high speed. The different colors in the picture show optical emission lines of hydrogen (orange), nitrogen (red), sulfur (pink) and oxygen (bluish-green). The subtle changes in color from one filament to the next arise because of varying temperatures and densities of the gas, and variable chemical abundances of the ``star stuff," or the doppler shifting of emission into or out of the various narrow filter bandpasses. Support for this work was provided by NASA through grant numbers GO-07632.01-96A and GO-5354.04-93A from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

  11. Vivid View of Tycho's Supernova Remnant

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This composite image of the Tycho supernova remnant combines infrared and X-ray observations obtained with NASA's Spitzer and Chandra space observatories, respectively, and the Calar Alto observatory, Spain. It shows the scene more than four centuries after the brilliant star explosion witnessed by Tycho Brahe and other astronomers of that era.

    The explosion has left a blazing hot cloud of expanding debris (green and yellow). The location of the blast's outer shock wave can be seen as a blue sphere of ultra-energetic electrons. Newly synthesized dust in the ejected material and heated pre-existing dust from the area around the supernova radiate at infrared wavelengths of 24 microns (red). Foreground and background stars in the image are white.

  12. Multi-Wavelength Observations of Supernova Remnants

    NASA Technical Reports Server (NTRS)

    Williams, B.

    2012-01-01

    Supernova remnants (SNRs) provide a laboratory for studying various astrophysical processes, including particle acceleration, thermal and non thermal emission processes across the spectrum, distribution of heavy elements, the physics of strong shock waves, and the progenitor systems and environments of supernovae. Long studied in radio and X-rays, the past decade has seen a dramatic increase in the detection and subsequent study of SNRs in the infrared and gamma-ray regimes. Understanding the evolution of SNRs and their interaction with the interstellar medium requires a multi-wavelength approach. I will review the various physical processes observed in SNRs and how these processes are intertwined. In particular, I will focus on X-ray and infrared observations, which probe two very different but intrinsically connected phases of the ISM: gas and dust. I will discuss results from multi-wavelength studies of several SNRs at various stages of evolution, including Kepler, RCW 86, and the Cygnus Loop.

  13. VHE Gamma-ray Supernova Remnants

    SciTech Connect

    Funk, Stefan; /KIPAC, Menlo Park

    2007-01-22

    Increasing observational evidence gathered especially in X-rays and {gamma}-rays during the course of the last few years support the notion that Supernova remnants (SNRs) are Galactic particle accelerators up to energies close to the ''knee'' in the energy spectrum of Cosmic rays. This review summarizes the current status of {gamma}-ray observations of SNRs. Shell-type as well as plerionic type SNRs are addressed and prospect for observations of these two source classes with the upcoming GLAST satellite in the energy regime above 100 MeV are given.

  14. The Origin of Kepler's Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Patnaude, Daniel J.; Badenes, Carles; Park, Sangwook; Laming, J. Martin

    2012-09-01

    It is now well established that Kepler's supernova remnant (SNR) is the result of a Type Ia explosion. With an age of 407 yr and an angular diameter of ~4', Kepler is estimated to be between 3.0 and 7.0 kpc distant. Unlike other Galactic Type Ia SNRs such as Tycho and SN 1006, and SNR 0509-67.5 in the Large Magellanic Cloud, Kepler shows evidence for a strong circumstellar interaction. A bowshock structure in the north is thought to originate from the motion of a mass-losing system through the interstellar medium prior to the supernova. We present results of hydrodynamical and spectral modeling aimed at constraining the circumstellar environment of the system and the amount of 56Ni produced in the explosion. Using models that contain either 0.3 M ⊙ (subenergetic) or 1.0 M ⊙ (energetic) of 56Ni, we simulate the interaction between supernova Ia ejecta and various circumstellar density models. Based on dynamical considerations alone, we find that the subenergetic models favor a distance to the SNR of <6.4 kpc, while the model that produces 1 M ⊙ of 56Ni requires a distance to the SNR of >7 kpc. The X-ray spectrum is consistent with an explosion that produced ~1 M ⊙ of 56Ni, ruling out the subenergetic models, and suggesting that Kepler's SNR was an SN 1991T-like event. Additionally, the X-ray spectrum rules out a pure r -2 wind profile expected from isotropic mass loss up to the time of the supernova. Introducing a small cavity around the progenitor system results in modeled X-ray spectra that are consistent with the observed spectrum. If a wind-shaped circumstellar environment is necessary to explain the dynamics and X-ray emission from the shocked ejecta in Kepler's SNR, then we require that the distance to the remnant be greater than 7 kpc.

  15. An optical and near infrared search for a pulsar in Supernova 1987A

    SciTech Connect

    Sasseen, T.P.

    1990-12-01

    We describe a search for an optical pulsar in the remnant of Supernova 1987A. We have performed over one hundred separate observations of the supernova, covering wavelengths from 3500 angstroms to 1.8 microns, with sensitivity to pulsations as faint as magnitude 22.7. As of September 26, 1990, we have not seen evidence for pulsations due to a pulsar in the supernova. We discuss the implications of this result on predictions of pulsar optical luminosity. We have constructed for the search two photodiode detectors and a data system. We describe their design, calibration and performance. These detectors have allowed us to increase our sensitivity as much as a factor of 5 over standard photomultiplier tubes, and extend this search to near infrared wavelengths. 59 refs., 10 figs., 1 tab.

  16. Chandra Observations of Supernova Remnants and Neutron Stars: An Overview

    NASA Technical Reports Server (NTRS)

    Weisskopf, Martin C.

    2002-01-01

    We present a brief overview of Chandra observations of supernova remnants and neutron stars, with emphasis on neutron stars in supernova remnants. The Chandra images demonstrate the importance of angular resolution in separating the neutron star emission from the surrounding nebulosity.

  17. Tachyonic Cherenkov radiation from supernova remnants

    NASA Astrophysics Data System (ADS)

    Tomaschitz, Roman

    2015-12-01

    The subexponential decay observed in the γ-ray spectral maps of supernova remnants is explained in terms of tachyonic Cherenkov emission from a relativistic electron population. The tachyonic radiation densities of an electronic spinor current are derived, the total density as well as the transversal and longitudinal polarization components, taking account of electron recoil. Tachyonic flux quantization subject to dispersive and dissipative permeabilities is discussed, the matrix elements of the transversal and longitudinal Poynting vectors of the Maxwell-Proca field are obtained, Cherenkov emission angles and radiation conditions are derived. The spectral energy flux of an ultra-relativistic electron plasma is calculated, a tachyonic Cherenkov fit to the high-energy (1 GeV to 30 TeV) γ-ray spectrum of the Crab Nebula is performed, and estimates of the linear polarization degree are given. The spectral tail shows subexponential Weibull decay, which can be modeled with a frequency-dependent tachyon mass in the dispersion relations. Tachyonic flux densities interpolate between exponential and power-law spectral decay, which is further illustrated by Cherenkov fits to the γ-ray spectra of the supernova remnants IC 443 and W44. Subexponential spectral decay is manifested in double-logarithmic spectral maps as curved Weibull or straight power-law slope.

  18. The Blast Wave of Tycho's Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Cassam-Chenaï, Gamil; Hughes, John P.; Ballet, Jean; Decourchelle, Anne

    2007-08-01

    We use the Chandra X-Ray Observatory to study the region in the Tycho supernova remnant between the blast wave and the shocked ejecta interface or contact discontinuity. This zone contains all the history of the shock-heated gas and cosmic-ray acceleration in the remnant. We present for the first time evidence for significant spatial variations of the X-ray synchrotron emission in the form of spectral steepening from a photon index of ~2.6 right at the blast wave to a value of ~3.0 several arcseconds behind. We interpret this result along with the profiles of radio and X-ray intensity using a self-similar hydrodynamical model including cosmic-ray back-reaction that accounts for the observed ratio of radii between the blast wave and contact discontinuity. Two different assumptions were made about the postshock magnetic field evolution: one where the magnetic field (amplified at the shock) is simply carried by the plasma flow and remains relatively high in the postshock region (synchrotron losses limited rim case), and another where the amplified magnetic field is rapidly damped behind the blast wave (magnetic damping case). Both cases fairly well describe the X-ray data; however, both fail to explain the observed radio profile. The projected synchrotron emission leaves little room for the presence of thermal emission from the shocked ambient medium. This can only be explained if the preshock ambient medium density in the vicinity of the Tycho supernova remnant is below 0.6 cm-3.

  19. 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.

  20. The First Fermi LAT Supernova Remnant Catalog

    NASA Astrophysics Data System (ADS)

    Acero, F.; Ackermann, M.; Ajello, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Bloom, E. D.; Bonino, R.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caputo, R.; Caragiulo, M.; Caraveo, P. A.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cohen, J. M.; Cohen-Tanugi, J.; Cominsky, L. R.; Condon, B.; Conrad, J.; Cutini, S.; D’Ammando, F.; de Angelis, A.; de Palma, F.; Desiante, R.; Digel, S. W.; Di Venere, L.; Drell, P. S.; Drlica-Wagner, A.; Favuzzi, C.; Ferrara, E. C.; Franckowiak, A.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Gomez-Vargas, G. A.; Grenier, I. A.; Grondin, M.-H.; Guillemot, L.; Guiriec, S.; Gustafsson, M.; Hadasch, D.; Harding, A. K.; Hayashida, M.; Hays, E.; Hewitt, J. W.; Hill, A. B.; Horan, D.; Hou, X.; Iafrate, G.; Jogler, T.; Jóhannesson, G.; Johnson, A. S.; Kamae, T.; Katagiri, H.; Kataoka, J.; Katsuta, J.; Kerr, M.; Knödlseder, J.; Kocevski, D.; Kuss, M.; Laffon, H.; Lande, J.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Magill, J.; Maldera, S.; Marelli, M.; Mayer, M.; Mazziotta, M. N.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Moretti, E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nemmen, R.; Nuss, E.; Ohsugi, T.; Omodei, N.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Perkins, J. S.; Pesce-Rollins, M.; Petrosian, V.; Piron, F.; Pivato, G.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Renaud, M.; Reposeur, T.; Rousseau, R.; Saz Parkinson, P. M.; Schmid, J.; Schulz, A.; Sgrò, C.; Siskind, E. J.; Spada, F.; Spandre, G.; Spinelli, P.; Strong, A. W.; Suson, D. J.; Tajima, H.; Takahashi, H.; Tanaka, T.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Tibolla, O.; Torres, D. F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Vianello, G.; Wells, B.; Wood, K. S.; Wood, M.; Yassine, M.; den Hartog, P. R.; Zimmer, S.

    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 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, 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.

  1. HESS upper limits for Kepler's supernova remnant

    NASA Astrophysics Data System (ADS)

    Aharonian, F.; Akhperjanian, A. G.; Barres de Almeida, U.; Bazer-Bachi, A. R.; Behera, B.; Beilicke, M.; Benbow, W.; Berge, D.; Bernlöhr, K.; Boisson, C.; Bolz, O.; Borrel, V.; Braun, I.; Brion, E.; Brucker, J.; Bühler, R.; Bulik, T.; Büsching, I.; Boutelier, T.; Carrigan, S.; Chadwick, P. M.; Chounet, L.-M.; Clapson, A. C.; Coignet, G.; Cornils, R.; Costamante, L.; Dalton, M.; Degrange, B.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; O'C. Drury, L.; Dubois, F.; Dubus, G.; Dyks, J.; Egberts, K.; Emmanoulopoulos, D.; Espigat, P.; Farnier, C.; Feinstein, F.; Fiasson, A.; Förster, A.; Fontaine, G.; Füßling, M.; Gallant, Y. A.; Giebels, B.; Glicenstein, J. F.; Glück, B.; Goret, P.; Hadjichristidis, C.; Hauser, D.; Hauser, M.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hinton, J. A.; Hoffmann, A.; Hofmann, W.; Holleran, M.; Hoppe, S.; Horns, D.; Jacholkowska, A.; de Jager, O. C.; Jung, I.; Katarzyński, K.; Kendziorra, E.; Kerschhaggl, M.; Khélifi, B.; Keogh, D.; Komin, Nu.; Kosack, K.; Lamanna, G.; Latham, I. J.; Lemoine-Goumard, M.; Lenain, J.-P.; Lohse, T.; Martin, J. M.; Martineau-Huynh, O.; Marcowith, A.; Masterson, C.; Maurin, D.; McComb, T. J. L.; Moderski, R.; Moulin, E.; Naumann-Godo, M.; de Naurois, M.; Nedbal, D.; Nekrassov, D.; Nolan, S. J.; Ohm, S.; Olive, J.-P.; de Oña Wilhelmi, E.; Orford, K. J.; Osborne, J. L.; Ostrowski, M.; Panter, M.; Pedaletti, G.; Pelletier, G.; Petrucci, P.-O.; Pita, S.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raubenheimer, B. C.; Raue, M.; Rayner, S. M.; Renaud, M.; Ripken, J.; Rob, L.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Ruppel, J.; Sahakian, V.; Santangelo, A.; Schlickeiser, R.; Schöck, F. M.; Schröder, R.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Shalchi, A.; Sol, H.; Spangler, D.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Superina, G.; Tam, P. H.; Tavernet, J.-P.; Terrier, R.; van Eldik, C.; Vasileiadis, G.; Venter, C.; Vialle, J. P.; Vincent, P.; Vivier, M.; Völk, H. J.; Volpe, F.; Wagner, S. J.; Ward, M.; Zdziarski, A. A.; Zech, A.

    2008-09-01

    Aims: Observations of Kepler's supernova remnant (G4.5+6.8) with the HESS telescope array in 2004 and 2005 with a total live time of 13 h are presented. Methods: Stereoscopic imaging of Cherenkov radiation from extensive air showers is used to reconstruct the energy and direction of the incident gamma rays. Results: No evidence for a very high energy (VHE: >100 GeV) gamma-ray signal from the direction of the remnant is found. An upper limit (99% confidence level) on the energy flux in the range 230 GeV{-}12.8 TeV of 8.6 × 10-13 erg cm-2 s-1 is obtained. Conclusions: In the context of an existing theoretical model for the remnant, the lack of a detectable gamma-ray flux implies a distance of at least 6.4 kpc. A corresponding upper limit for the density of the ambient matter of 0.7 cm-3 is derived. With this distance limit, and assuming a spectral index Γ = 2, the total energy in accelerated protons is limited to Ep < 8.6 × 1049 erg. In the synchrotron/inverse Compton framework, extrapolating the power law measured by RXTE between 10 and 20 keV down in energy, the predicted gamma-ray flux from inverse Compton scattering is below the measured upper limit for magnetic field values greater than 52 μ G.

  2. 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.

  3. FERMI LARGE AREA TELESCOPE OBSERVATION OF SUPERNOVA REMNANT S147

    SciTech Connect

    Katsuta, J.; Uchiyama, Y.; Tanaka, T.; Tajima, H.; Bechtol, K.; Funk, S.; Lande, J.; Ballet, J.; Lemoine-Goumard, M.

    2012-06-20

    We present an analysis of gamma-ray data obtained with the Large Area Telescope on board the Fermi Gamma-ray Space Telescope in the region around supernova remnant (SNR) S147 (G180.0-1.7). A spatially extended gamma-ray source detected in an energy range of 0.2-10 GeV is found to coincide with SNR S147. We confirm its spatial extension at >5{sigma} confidence level. The gamma-ray flux is (3.8 {+-} 0.6) Multiplication-Sign 10{sup -8} photons cm{sup -2} s{sup -1}, corresponding to a luminosity of 1.3 Multiplication-Sign 10{sup 34} (d/1.3 kpc){sup 2} erg s{sup -1} in this energy range. The gamma-ray emission exhibits a possible spatial correlation with the prominent H{alpha} filaments of SNR S147. There is no indication that the gamma-ray emission comes from the associated pulsar PSR J0538+2817. The gamma-ray spectrum integrated over the remnant is likely dominated by the decay of neutral {pi} mesons produced through the proton-proton collisions in the filaments. The reacceleration of the pre-existing cosmic rays and subsequent adiabatic compression in the filaments is sufficient to provide the energy density required of high-energy protons.

  4. 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.; Ros´ska, 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.

  5. 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.

  6. 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.

  7. Radio flux variation of young supernova remnants

    SciTech Connect

    Ivanov, V.P.; Bubukin, I.T.; Stankevich, K.S.

    1982-01-01

    The 31.5-cm radio flux density of Cas A, the Crab Nebula, and the remnant of the 1572 supernova relative to that of the radio galaxies Cyg A and Vir A was measured in 1981. Comparison with similar observations in 1964 and 1972 shows that over the past decade the decline of the Cas A flux has slowed by a factor 2.2 and now amounts to (0.413 +- 0.08)%/yr. The Crab flux was (3.5 +- 1.0)% weaker in 1981 than in 1964 and 1972; it probably dropped abruptly between 1972 and 1977. For the 1572 SNR the annual mean decline over the 17-yr period is (0.5 +- 0.15)%/yr.

  8. An infrared survey of Galactic supernova remnants

    NASA Technical Reports Server (NTRS)

    Arendt, Richard G.

    1989-01-01

    A survey of Galactic supernova remnants (SNRs) in the infrared has been completed. Flux densities or upper limits on the flux densities have been measured for 157 objects in each of the four broad bands surveyed by the Infrared Astronomical Satellite (IRAS). Nearly one-third of the known SNRs exhibit some evidence of infrared emission. Confusion with other Galactic sources is a serious problem. Contour maps and halftone images are presented for 51 SNRs which are probable infrared sources. Initial analysis indicates that both the infrared spectra or colors and the ratio of infrared to radio brightnesses can discriminate between the youngest SNRs and older SNRs. In general, however, SNRs cannot be distinguished from other Galactic sources solely on the basis of their infrared colors. No apparent relation is found between the infrared surface brightnesses and the diameters of SNRs.

  9. Interstellar scattering of compact radio sources near supernova remnants

    NASA Technical Reports Server (NTRS)

    Spangler, S. R.; Mutel, R. L.; Benson, J. M.; Cordes, J. M.

    1986-01-01

    A multifrequency VLBI search for interstellar scattering of extragalactic radio sources near supernova remnants is reported. VLBI observations at 610, 1663, and 4991 MHz were made of compact sources near the supernova remnants CTA 1, G33.6 + 0.1, G74.9 + 1.2, and HB 21, and 610 MHz observations were also made of a source near HB 9. These observations were motivated by the possibility of enhanced cosmic ray-induced turbulence in front of supernova remnants, as expected in 'diffusive' theories of shock wave acceleration. Angular broadening is definitely seen in the case of the source 2013 + 370, which lies within 4 arcmin of the supernova remnant G74.9 + 1.2. Present observations cannot unambiguously attribute the scattering material to the supernova remnant, as the line of sight also passes through the Cygnus OB1 association. The source 1849 + 005 appears to be highly scattered, as fringes were not detected even on short baselines at 5 GHz. This result may be due to the low galactic longitude of this source rather than its proximity to the supernova remnant G 33.6 + 0.1. Broadening was not detected for sources whose lines of sight pass close to the supernova remnants HB 9, HB 21, and CTA 1.

  10. Cosmic ray acceleration in young supernova remnants

    NASA Astrophysics Data System (ADS)

    Schure, K. M.; Bell, A. R.

    2013-10-01

    We investigate the appearance of magnetic field amplification resulting from a cosmic ray escape current in the context of supernova remnant shock waves. The current is inversely proportional to the maximum energy of cosmic rays, and is a strong function of the shock velocity. Depending on the evolution of the shock wave, which is drastically different for different circumstellar environments, the maximum energy of cosmic rays as required to generate enough current to trigger the non-resonant hybrid instability that confines the cosmic rays follows a different evolution and reaches different values. We find that the best candidates to accelerate cosmic rays to few PeV energies are young remnants in a dense environment, such as a red supergiant wind, as may be applicable to Cassiopeia A. We also find that for a typical background magnetic field strength of 5 ?G the instability is quenched in about 1000 years, making SN1006 just at the border of candidates for cosmic ray acceleration to high energies.

  11. Synthetic Observation of Turbulent Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Shimoda, Jiro; Inoue, Tsuyoshi; Ohira, Yutaka; Yamazaki, Ryo

    It is known that observations of polarized radio synchrotron emissions from young supernova remnants show radially oriented distributions of magnetic field. By using synthetic polarization observations of the results of three-dimensional magnetohydrodynamics simulations, we find that the radially oriented distribution of magnetic field can be reproduced by turbulent dynamo mechanism induced by the Richtmyer-Meshkov instability. In the simulation, we consider propagation of a supernova blast wave shock in realistic inhomogeneous interstellar medium. Interaction between the density inhomogeneity and the shock wave induces the so-called Richtmyer-Meshkov instability that generates shear of radial-component velocity in the downstream of the blast wave. In such medium, magnetic field lines are stretched by the shear motion that leads to amplification of radial-component magnetic field. Thus, the downstream magnetic field is oriented parallel to the shock normal. We conclude that the observed polarized synchrotron emission is successfully explained by the dynamo effect induced by the Richtmyer-Meshkov instability.

  12. 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.

  13. Supernova remnants and the origin of cosmic rays

    NASA Astrophysics Data System (ADS)

    Vink, Jacco

    2014-01-01

    Supernova remnants have long been considered to be the dominant sources of Galactic cosmic rays. For a long time the prime evidence consisted of radio synchrotron radiation from supernova remnants, indicating the presence of electrons with energies of several GeV. However, in order to explain the cosmic ray energy density and spectrum in the Galaxy supernova remnant should use 10% of the explosion energy to accelerate particles, and about 99% of the accelerated particles should be protons and other atomic nuclei. Over the last decade a lot of progress has been made in providing evidence that supernova remnant can accelerate protons to very high energies. The evidence consists of, among others, X-ray synchrotron radiation from narrow regions close to supernova remnant shock fronts, indicating the presence of 10-100 TeV electrons, and providing evidence for amplified magnetic fields, gamma-ray emission from both young and mature supernova remnants. The high magnetic fields indicate that the condition for accelerating protons to >1015 eV are there, whereas the gamma-ray emission from some mature remnants indicate that protons have been accelerated.

  14. An X-ray View of the Zoo of Compact Objects and Associated Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Safi-Harb, Samar

    2015-08-01

    Core-collapse explosions of massive stars leave behind some of the most exotic compact objects in the Universe. These include: rotation-powered pulsars like the Crab, powering pulsar wind nebulae (PWNe) observed across the electromagnetic spectrum; highly magnetized neutron stars ("magnetars") shining or bursting at high-energies; and X-ray emitting “Central Compact Objects” (CCOs) with intrinsic properties and emission mechanism that remain largely unknown. I will highlight this observed diversity of compact stellar remnants from an X-ray perspective, and address the connection between their properties and those of their hosting supernova remnants (SNRs). In particular I will highlight topics related to their formation and evolution, including: 1) which supernovae make magnetars and the shell-less PWNe?, 2) what can we learn from the apparent age discrepancy between SNRs and their associated pulsars? I will conclude with prospects for observations of SNRs with the upcoming ASTRO-H X-ray mission. The unprecedented spectral resolution on board of ASTRO-H’s micro-calorimeter will particularly open a new discovery window for supernova progenitors' science.

  15. Modelling the interaction of thermonuclear supernova remnants with circumstellar structures: the case of Tycho's supernova remnant

    NASA Astrophysics Data System (ADS)

    Chiotellis, A.; Kosenko, D.; Schure, K. M.; Vink, J.; Kaastra, J. S.

    2013-10-01

    The well-established Type Ia remnant of Tycho's supernova (SN 1572) reveals discrepant ambient medium-density estimates based on either the measured dynamics or the X-ray emission properties. This discrepancy can potentially be solved by assuming that the supernova remnant (SNR) shock initially moved through a stellar wind bubble, but is currently evolving in the uniform interstellar medium with a relatively low density. We investigate this scenario by combining hydrodynamical simulations of the wind-loss phase and the SNR evolution with a coupled X-ray emission model, which includes non-equilibrium ionization. For the explosion models we use the well-known W7 deflagration model and the delayed detonation model that was previously shown to provide good fits to the X-ray emission of Tycho's SNR. Our simulations confirm that a uniform ambient density cannot simultaneously reproduce the dynamical and X-ray emission properties of Tycho. In contrast, models that considered that the remnant was evolving in a dense, but small, wind bubble reproduce reasonably well both the measured X-ray emission spectrum and the expansion parameter of Tycho's SNR. Finally, we discuss possible mass-loss scenarios in the context of single- and double-degenerate models which possibly could form such a small dense wind bubble.

  16. Locating the Periodic Transient GRO J1849-03; Gamma-Ray Luminous Supernovae Remnants

    NASA Technical Reports Server (NTRS)

    Kaaret, P.; White, Nicholas (Technical Monitor)

    2000-01-01

    We obtained one 50 ks observation of the Monoceros supernova remnant under this proposal. This supernova remnant was selected because it overlaps the error box of a gamma-ray source. Much to our surprise, we discovered a hard x-ray point source instead of the diffuse hard x-ray emission we expected from the supernova remnant. A paper on the discovery of the hard x-ray source and on follow-up optical observations identifying a likely Bestar companion was published in the Astrophysical Journal. Subsequently, a reanalysis of the same data yielded the detection of pulsations from the x-ray source. These results were also published in the Astrophysical Journal. Subsequent x-ray observations, which we performed under later proposals, have shown that the x-ray pulsar has a characteristic spin-down age of less than 1400 years in a binary system. The system is likely the first discovered very young, highly-energetic, rotation-powered pulsar in a binary system and offers an exciting opportunity to study the infancy and early evolution of neutron-star binaries.

  17. XMM-NEWTON OBSERVATIONS OF TWO CANDIDATE SUPERNOVA REMNANTS

    SciTech Connect

    Kargaltsev, O.; Schmitt, B. M.; Pavlov, G. G.; Misanovic, Z.

    2012-01-20

    Candidate supernova remnants (SNRs) G23.5+0.1 and G25.5+0.0 were observed by XMM-Newton in the course of a snapshot survey of plerionic and composite SNRs in the Galactic plane. In the field of G23.5+0.1, we detected an extended source, {approx}3' in diameter, which we tentatively interpret as a pulsar wind nebula (PWN) of the middle-aged radio pulsar B1830-08 (J1833-0827; P = 85.3 ms, {tau} = 147 kyr, E-dot = 5.8 Multiplication-Sign 10{sup 35} erg s{sup -1}, d = 5.7 kpc), with the PWN luminosity L{sub 0.2-10keV} Almost-Equal-To 5 Multiplication-Sign 10{sup 33} erg s{sup -1} Almost-Equal-To 8 Multiplication-Sign 10{sup -3} E-dot . The pulsar is not resolved in the EPIC images. Our analysis suggests an association between PSR B1830-08 and the surrounding diffuse radio emission. If the radio emission is due to the SNR, then the pulsar must be significantly younger than its characteristic age. Alternatively, the radio emission may come from a relic PWN. The field also contains SGR 1833-0832 and another middle-aged pulsar B1829-08 (J1832-0827; P = 647 ms, {tau} = 161 kyr, E-dot = 9.3 Multiplication-Sign 10{sup 33} erg s{sup -1}, d = 4.7 kpc), none of which are detected in our observation. In the field of G25.5+0.0, which contains the extended TeV source HESS J1837-069, we detected the recently discovered young high-energy pulsar J1838-0655 (P = 70.5 ms, {tau} = 23 kyr, E-dot = 5.5 Multiplication-Sign 10{sup 36} erg s{sup -1}) embedded in a PWN with extent of 1.'3. The unabsorbed pulsar + PWN luminosity is L{sub 2-11keV} Almost-Equal-To 2 Multiplication-Sign 10{sup 34} erg s{sup -1} Almost-Equal-To 4 Multiplication-Sign 10{sup -3} E-dot at an assumed distance of 7 kpc. We also detected another PWN candidate (AX J1837.3-0652) with an extent of 2' and unabsorbed luminosity L{sub 2-10keV} Almost-Equal-To 4 Multiplication-Sign 10{sup 33} erg s{sup -1} at d = 7 kpc. The third X-ray source, located within the extent of the HESS J1837-069, has a peculiar extended radio counterpart, possibly a radio galaxy with a double nucleus or a microquasar. We did not find any evidence of the SNR emission in the G25.5+0.0 field. We provide detailed multiwavelength analysis and identifications of other field sources and discuss robustness of the G25.5+0.0 and G23.5+0.1 classifications as SNRs.

  18. Nonspherical supernova remnants. IV - Sequential explosions in OB associations

    NASA Technical Reports Server (NTRS)

    Tenorio-Tagle, G.; Bodenheimer, P.; Rozyczka, M.

    1987-01-01

    Multisupernova remnants, driven by sequential supernova explosions in OB associations, are modelled by means of two-dimensional hydrodynamical calculations. It is shown that due to the Rayleigh-Taylor instability the remnants quickly evolve into highly irregular structures. A critical evaluation of the multisupernova model as an explanation for supershells is given.

  19. MODIFIED EQUIPARTITION CALCULATION FOR SUPERNOVA REMNANTS

    SciTech Connect

    Arbutina, B.; Urosevic, D.; Andjelic, M. M.; Pavlovic, M. Z.; Vukotic, B.

    2012-02-10

    Determination of the magnetic field strength in the interstellar medium is one of the more complex tasks of contemporary astrophysics. We can only estimate the order of magnitude of the magnetic field strength by using a few very limited methods. Besides the Zeeman effect and Faraday rotation, the equipartition or minimum-energy calculation is a widespread method for estimating magnetic field strength and energy contained in the magnetic field and cosmic-ray particles by using only the radio synchrotron emission. Despite its approximate character, it remains a useful tool, especially when there are no other data about the magnetic field in a source. In this paper, we give a modified calculation that we think is more appropriate for estimating magnetic field strengths and energetics in supernova remnants (SNRs). We present calculated estimates of the magnetic field strengths for all Galactic SNRs for which the necessary observational data are available. The Web application for calculation of the magnetic field strengths of SNRs is available at http://poincare.matf.bg.ac.rs/{approx}arbo/eqp/.

  20. Supernova remnants in star forming regions.

    NASA Astrophysics Data System (ADS)

    Asvarov, Abdul; Mammadkhanova, Gunel

    2015-08-01

    Understanding the star formation processes is one of the fundamental problems of modern astrophysics. Star formation takes place on very large range of the temporal and spatial scales and at the different physical conditions. Star formation is an inherently complex phenomenon that involves many physical processes from hydrodynamics to high energy particle acceleration and radiation. Despite this, the star forming regions show clear observational relationships between some observational parameters. Among them it is important to note the well-known tight radio-continuum/far-infrared correlation for star forming regions, which holds both within galaxies (down to 100 pc or less) and from galaxy to galaxy, and over several orders of magnitude in luminosity. The supernova (SN) explosions and the remnants of SNe are the most plausible contributors for an origin of this correlation. In this presentation we consider the evolution of SNRs in star formations regions with very different physical conditions taking into account in simple way the diffusive shock acceleration of particles in SNRs, the effects of ambient pressure and gravitational field. From our analysis it follows the formation of compact regions filled with relativistic gas, which may manifest themselves through X-ray and gamma-ray emissions.

  1. Nonthermal Radiation from Supernova Remnant Shocks

    NASA Astrophysics Data System (ADS)

    Kang, Hyesung

    2013-09-01

    Most of high energy cosmic rays (CRs) are thought to be produced by diffusive shock acceleration (DSA) at supernova remnants (SNRs) within the Galaxy. Fortunately, nonthermal emissions from CR protons and electrons can provide direct observational evidence for such a model and place strong constraints on the complex nonlinear plasma processes in DSA theory. In this study we calculate the energy spectra of CR protons and electrons in Type Ia SNRs, using time-dependent DSA simulations that incorporate phenomenological models for some wave-particle interactions. We demonstrate that the timedependent evolution of the self-amplified magnetic fields, Alfvnic drift, and escape of the highest energy particles affect the energy spectra of accelerated protons and electrons, and so resulting nonthermal radiation spectrum. Especially, the spectral cutoffs in X-ray and γ-ray emission spectra are regulated by the evolution of the highest energy particles, which are injected at the early phase of SNRs. Thus detailed understandings of nonlinear wave-particle interactions and time-dependent DSA simulations of SNRs are crucial in testing the SNR hypothesis for the origin of Galactic cosmic rays.

  2. Gamma ray emission from radiative supernova remnants

    NASA Astrophysics Data System (ADS)

    Asvarov, Abdul

    In this presentation we have considered Gamma-ray emission from supernova remnants (SNRs) evolving in high density environments, for which the radiative phase of evolution is more typical. Gamma-rays from such objects are believed to have hadronic origin, i.e. as a result of decay of neutral pi-mesons, created in the p-p collisions of relativistic hadrons (protons, etc.) with interstellar medium protons. DSA mechanism is considered as the main mechanism of acceleration of relativistic particles. We assume that SNR evolves in more or less homogeneous interstellar medium. This is contrary to two main models of origin of Gamma-rays from shell type SNRs, which are: 1) Runaway CR model which considers Gamma-ray emission from molecular clouds illuminated by runaway CRs that have escaped from the SNRs; 2) Crushed Cloud model, which considers the shocked interstellar clouds being responsible for the gamma-ray emission of the SNR. The considered model gives the largest conversion rate of SN energy to gamma-rays. It has been found that under certain (close to real) conditions considered here type of SNRs can easily provide the flux of gamma-rays with energies > 100 MeV, typical for the large number of unidentified sources listed in the recent Fermi LAT source catalog. We have obtained conditions under which SNRs are better observable in gamma-rays than in other bands of the electromagnetic spectrum.

  3. Discovery of optical candidate supernova remnants in Sagittarius

    NASA Astrophysics Data System (ADS)

    Alikakos, J.; Boumis, P.; Christopoulou, P. E.; Goudis, C. D.

    2012-08-01

    During an [O III] survey of planetary nebulae, we identified a region in Sagittarius containing several candidate supernova remants (SNRs) and obtained deep optical narrow-band images and spectra to explore their nature. We obtained images of the area of interest by acquiring observations in the emission lines of Hα + [N II], [S II] and [O III]. The resulting mosaic covers an area of 1.4° × 1.0°, where both filamentary and diffuse emission was discovered, suggesting that there is more than one SNR in the area. Deep long-slit spectra were also taken of eight different regions. Both the flux-calibrated images and the spectra show that the emission from the filamentary structures originates from shock-heated gas, while the photo-ionization mechanism is responsible for the diffuse emission. Part of the optical emission is found to be correlated with the radio at 4850 MHz suggesting that they are related, while the infrared emission found in the area at 12 μm and 22 μm marginally correlates with the optical. The presence of the [O III] emission line in one of the candidate SNRs implies that the shock velocities in the interstellar "clouds" are between 120 km s-1 and 200 km s-1, while its absence in the other candidate SNRs indicates that the shock velocities there are slower. For all candidate remnants, the [S II] λλ 6716/6731 ratio indicates that the electron densities are below 240 cm-3, while the Hα emission is measured to be between 0.6 and 41 × 10-17 erg s-1 cm-2 arcsec-2. The existence of eight pulsars within 1.5° of the center of the candidate SNRs also implies that there are many SNRs in the area as well as that the detected optical emission could be part of a number of supernovae explosions.

  4. High energy survey of supernova remnants with BATSE

    NASA Technical Reports Server (NTRS)

    McCollough, M. L.; Wilson, C. A.; Zhang, S. N.; Harmon, B. A.

    1997-01-01

    The burst and transient source experiment (BATSE) survey of the high energy emission from supernova remnants is reported on. The ability of BATSE to continuously monitor the entire sky in the 20 keV to 2 MeV energy range enables a large group of remnants to by studied at high energies. Preliminary analysis indicates the likely detection of several supernova remnants other than the Crab nebula. Among these are MSH 15-52, Vela, Cas A and possibly HB 9. The techniques employed are discussed together with the status of the survey and its limitations.

  5. The X-ray spectrum and jet of supernova remnant G54.1+0.3

    NASA Astrophysics Data System (ADS)

    Lu, F. J.; Aschenbach, B.; Song, L. M.; Durouchoux, Ph.

    2001-09-01

    We present in this paper the X-ray spectrum and the discovery of an X-ray jet associated with supernova remnant (SNR) G54.1+0.3, by using the ASCA and ROSAT data. Its X-ray spectrum can be best fitted with a power law model with photon index -1.9 (+0.1/-0.2), absorbed energy flux in 0.7 - 10.0 keV 6.8×10-12 erg cm-2 s-1, and column density 17.9 (+2.8/-2.5)×1021 cm-2. The X-ray jet points to the northeast with a length about 40" from the center of the remnant and coincides with the radio extension in this direction well. We propose that the X-ray jet is connected with the pulsar embedded in the remnant.

  6. X-ray evidence for electron-ion equilibrium and ionization nonequilibrium in Young supernova remnants

    NASA Technical Reports Server (NTRS)

    Pravdo, S. H.; Smith, B. W.

    1979-01-01

    X-ray emission up to 25 keV from the supernova remnants Cas A and Tycho has been detected with the A-2 spectroscopy experiment on HEAO 1. The spectra must include continuum components with effective temperature of about 10 to the 8th K which could arise from optically thin plasmas in the collisionless shock fronts. This is the first indication of electron-ion temperature equilibrium in the expanding shell of young remnants. The equivalent widths of the K-alpha and K-beta iron line blends in Cas A have also been measured and it is found that their ratio is not compatible with the measured X-ray temperature in the collisional ionization equilibrium model. Finally, an unsuccessful search has been conducted for hard X-ray pulsars in both remnants.

  7. X-ray evidence for electron-ion equilibrium and ionization nonequilibrium in young supernova remnants

    NASA Technical Reports Server (NTRS)

    Pravdo, S. H.; Smith, B. W.

    1979-01-01

    The A-2 spectroscopy experiment on HEAO 1 detected X-ray emission up to 25 keV from the supernova remnants Cas A and Tycho. The spectra must include continuum components with effective temperature equivalent or 10 to the 8th power K which could arise from optically thin plasmas in the collisionless shock fronts. This is the first indication of electron-ion temperature equilibrium in the expanding shell of young remnants. Measurements of the equivalent widths of the K alpha and K beta iron line blends in Cas A, show that their ratio is not compatible with the measured X-ray temperature in the collisional ionization equilibrium model. The search for hard X-ray pulsars in both remnants was unsuccessful.

  8. RXTE Observation of the TYCHO Supernova Remnant

    NASA Astrophysics Data System (ADS)

    The, Lih-Sin

    1998-01-01

    SN1006 [4] and Cas A [1, 9] supernova remnants have been shown convincingly to have a hard X-ray power-law continuum. This continuum is thought to be the synchrotron radiation from accelerated electrons of approx. 100 TeV at the shock fronts. Our goal of AO2 RXTE observation is to detect the hard X-ray continuum and to determine the nature of the continuum from Tycho SNR. A detection of a power-law continuum from Tycho SNR can strongly argue for SNRs are the source of cosmic rays with the first order Fermi acceleration as the energizing process. We report the results of our AO2 RXTE 1 x 105 sec observation of Tycho SNR. We detect two components of the X-ray spectrum from Tycho SNR both at better than 3 omega confidence. The best two component models are: bremsstrahlung (kT=2.67 +/- 0.13 keV) + bremsstrahlung (kT=7.07 +/- 2.21/1.72 keV) or bremsstrahlung (kT=2.36 +/- 0.21/0.57 keV) + power-law (gamma=2.58 +/- 0.12/0.09 ). This result is an improvement compaxed with the previous most sensitive X-ray measurements by Ginga which shows Tycho's observed X-ray continuum requires a two-component model to yield acceptable fits with the hard component parameters being highly uncertain. Our RXTE measurements constrain all parameter within 3o, ranges. However, we cannot yet distinguish between thermal and nonthermal models for the hard component. In the followings, we describe what we accomplished in the period covered by the grant proposal.

  9. Supernova Remnants, Cosmic Rays, and GLAST

    SciTech Connect

    Reynolds, Steve

    2006-02-13

    The shock waves of supernova remnants (SNRs) are the traditional sources of Galactic cosmic rays, at least up to about 3000 TeV (the 'knee' energy in the cosmic-ray spectrum). In the last decade or so, X-ray observations have confirmed in a few SNRs the presence of synchrotron-X-ray-emitting electrons with energies of order 100 TeV. TeV photons from SNRs have been observed with ground-based air Cerenkov telescopes as well, but it is still unclear whether they are due to hadronic processes (inelastic p-p scattering of cosmic-ray protons from thermal gas, with secondary neutral pions decaying to gamma rays), or to leptonic processes (inverse-Compton upscattering of cosmic microwave background photons, or bremsstrahlung). The spatial structure of synchrotron X-rays as observed with the Chandra X-ray Observatory suggests the remarkable possibility that magnetic fields are amplified by orders of magnitude in strong shock waves. The electron spectra inferred from X-rays reach 100 TeV, but at that energy are cutting off steeply, well below the 'knee' energy. Are the cutoff processes due only to radiative losses so that ion spectra might continue unsteepened? Can we confirm the presence of energetic ions in SNRs at all? Are typical SNRs capable of supplying the pool of Galactic cosmic rays? Is strong magnetic-field amplification a property of strong astrophysical shocks in general? These major questions require the next generation of observational tools. I shall outline the theoretical and observational framework of particle acceleration to high energies in SNRs, and shall describe how GLAST will advance this field.

  10. Supernova Remnants, Cosmic Rays, and GLAST

    SciTech Connect

    Reynolds, Steve

    2006-02-13

    The shock waves of supernova remnants (SNRs) are the traditional sources of Galactic cosmic rays, at least up to about 3000 TeV (the "knee" energy in the cosmic-ray spectrum). In the last decade or so, X-ray observations have confirmed in a few SNRs the presence of synchrotron-X-ray-emitting electrons with energies of order 100 TeV. TeV photons from SNRs have been observed with ground-based air Cerenkov telescopes as well, but it is still unclear whether they are due to hadronic processes (inelastic p-p scattering of cosmic-ray protons from thermal gas, with secondary neutral pions decaying to gamma rays), or to leptonic processes (inverse-Compton upscattering of cosmic microwave background photons, or bremsstrahlung). The spatial structure of synchrotron X-rays as observed with the Chandra X-ray Observatory suggests the remarkable possibility that magnetic fields are amplified by orders of magnitude in strong shock waves. The electron spectra inferred from X-rays reach 100 TeV, but at that energy are cutting off steeply, well below the "knee" energy. Are the cutoff processes due only to radiative losses so that ion spectra might continue unsteepened? Can we confirm the presence of energetic ions in SNRs at all? Are typical SNRs capable of supplying the pool of Galactic cosmic rays? Is strong magnetic-field amplification a property of strong astrophysical shocks in general? These major questions require the next generation of observational tools. I shall outline the theoretical and observational framework of particle acceleration to high energies in SNRs, and shall describe how GLAST will advance this field.

  11. Supernova Remnant Observations with Micro-X

    NASA Astrophysics Data System (ADS)

    Figueroa, Enectali

    Micro-X is a sounding rocket payload that combines an X-ray microcalorimeter with an imaging mirror to offer breakthrough science from high spectral resolution observations of extended X-ray sources. This payload has been in design and development for the last five years and is now completely built and undergoing integration; its first flight will be in November, 2012, as part of our current NASA award. This four-year follow-on proposal seeks funding for: (1) analysis of the first flight data, (2) the second flight and its data analysis, (3) development of payload upgrades and launch of the third flight, and (4) third flight data analysis. The scientific payload consists of a Transition Edge Sensor (TES) microcalorimeter array at the focus of a flight-proven conical imaging mirror. Micro-X capitalizes on three decades of NASA investment in the development of microcalorimeters and X-ray imaging optics. Micro-X offers a unique combination of bandpass, collecting area, and spectral and angular resolution. The spectral resolution goal across the 0.2 - 3.0 keV band is 2 - 4 eV Full-Width at Half Maximum (FWHM). The measured angular resolution of the mirror is 2.4 arcminute Half-Power Diameter (HPD). The effective area of the mirror, 300 square centimeters at 1 keV, is sufficient to provide observations of unprecedented quality of several astrophysical X-ray sources, even in a brief sounding rocket exposure of 300 sec. Our scientific program for this proposal will focus on supernova remnants (SNRs), whose spatial extent has made high-energy resolution observations with grating instruments extremely challenging. X-ray observations of SNRs with microcalorimeters will enable the study of the detailed atomic physics of the plasma; the determination of temperature, turbulence, and elemental abundances; and in conjunction with historical data, full three dimensional mapping of the kinematics of the remnant. These capabilities will open new avenues towards understanding the explosion mechanisms of supernovae and their roles in energy and heavy-element injection into galaxies, their evolution into SNRs, their interactions with their environments, and finally their roles as particle accelerators. For the first flight, we will observe an ejecta region in the Puppis A SNR. The Puppis A bright eastern knot (BEK), is the target of second flight in 2014. The third flight, in late 2015 or early 2016, will make an observation of the Cas A SNR. We will continue to advance the technology readiness of TES microcalorimeters while enhancing the science capability of the payload by implementing a series of improvements for the third flight. For the observation of Cas A in the third flight, we will upgrade from the 128-pixel array with 1 arcminute pixels used in the first two flights to a higher-energy resolution (1 eV FWHM) 256-pixel array with 20 arcsecond pixels and a new 30 arcsecond HPD mirror to enable improved imaging spectroscopy with our payload. The Micro-X team includes leaders in the development of microcalorimeters, SQUID readout systems, and segmented and full-shell grazing incidence X-ray optics, as well as highly experienced sounding rocket instrument developers, and scientific experts on supernova remnants. These investigators are located at institutions with strong space instrumentation traditions with the infrastructure to ensure a successful flight program. With Micro-X, we have designed a versatile payload capable of providing high-resolution science and a testbed for new technology. The first flight this year will make significant scientific contributions well ahead of the Astro-H mission. The program will also aid in the understanding and development of future flight-qualified microcalorimeter systems for larger orbiting missions. Finally, it will continue to attract talented young scientists to X-ray astrophysics and thus serve as a direct pipeline of future leaders of NASA missions.

  12. The radio remnant of Supernova 1987A at high frequencies and high resolution

    NASA Astrophysics Data System (ADS)

    Zanardo, G.; Staveley-Smith, L.; Ng, C.-Y.; Gaensler, B. M.; Potter, T. M.; Manchester, R. N.; Tzioumis, A. K.

    2014-01-01

    As the remnant of Supernova (SN) 1987A has been getting brighter over time, new observations at high frequencies have allowed imaging of the radio emission at unprecedented detail. We present a new radio image at 44 GHz of the supernova remnant (SNR), derived from observations performed with the Australia Telescope Compact Array (ATCA) in 2011. The diffraction-limited image has a resolution of 349225 mas, which is the highest achieved to date in high-dynamic range images of the SNR. We also present a new image at 18 GHz, also derived from ATCA observations performed in 2011, which is super-resolved to 0''.25. The new 44 and 18 GHz images yield the first high-resolution spectral index map of the remnant. The comparison of the 44 GHz image with contemporaneous X-ray and H? observations allows further investigations of the nature of the remnant asymmetry and sheds more light into the progenitor hypotheses and SN explosion. In light of simple free-free absorption models, we discuss the likelihood of detecting at 44 GHz the possible emission originating from a pulsar wind nebula (PWN) or a compact source in the centre of the remnant.

  13. A BROADBAND STUDY OF THE EMISSION FROM THE COMPOSITE SUPERNOVA REMNANT MSH 11-62

    SciTech Connect

    Slane, Patrick; Castro, Daniel; Foight, Dillon; and others

    2012-04-20

    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. The observations suggest a relatively young system expanding into a low-density region. Here, 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 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.

  14. 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.; Moffett, David A.

    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.

  15. 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.

  16. Multiwavelength Signatures of Cosmic Ray Acceleration by Young Supernova Remnants

    SciTech Connect

    Vink, Jacco

    2008-12-24

    An overview is given of multiwavelength observations of young supernova remnants, with a focus on the observational signatures of efficient cosmic ray acceleration. Some of the effects that may be attributed to efficient cosmic ray acceleration are the radial magnetic fields in young supernova remnants, magnetic field amplification as determined with X-ray imaging spectroscopy, evidence for large post-shock compression factors, and low plasma temperatures, as measured with high resolution optical/UV/X-ray spectroscopy. Special emphasis is given to spectroscopy of post-shock plasma's, which offers an opportunity to directly measure the post-shock temperature. In the presence of efficient cosmic ray acceleration the post-shock temperatures are expected to be lower than according to standard equations for a strong shock. For a number of supernova remnants this seems indeed to be the case.

  17. Chandra Observation of Supernova Remnant G54.1+0.3: A Close Cousin of the Crab Nebula

    NASA Astrophysics Data System (ADS)

    Lu, F. J.; Wang, Q. D.; Aschenbach, B.; Durouchoux, P.; Song, L. M.

    2002-03-01

    We present a Chandra Advanced CCD Imaging Spectrometer observation of supernova remnant G54.1+0.3. This supernova remnant is resolved into several distinct X-ray-emitting components: a central bright pointlike source (CXOU J193030.13+185214.1), a surrounding ring, bipolar elongations, plus low surface brightness diffuse emission. The spectra of these components are all well described by power-law models; the spectral index steepens with increasing distance from the pointlike source. We find no evidence for any thermal plasma emission that would correspond to shocked interstellar medium or ejecta. The observed morphological and spectral characteristics suggest that G54.1+0.3 is the closest ``cousin'' of the Crab Nebula-a pulsar wind nebula driven by a combination of equatorial and polar outflows from the putative pulsar represented by the pointlike X-ray source.

  18. SUPERNOVA REMNANT PROGENITOR MASSES IN M31

    SciTech Connect

    Jennings, Zachary G.; Williams, Benjamin F.; Dalcanton, Julianne J.; Gilbert, Karoline M.; Fouesneau, Morgan; Weisz, Daniel R.; Murphy, Jeremiah W.; Dolphin, Andrew E. E-mail: adolphin@raytheon.com

    2012-12-10

    Using Hubble Space Telescope photometry, we age-date 59 supernova remnants (SNRs) in the spiral galaxy M31 and use these ages to estimate zero-age main-sequence masses (M{sub ZAMS}) for their progenitors. To accomplish this, we create color-magnitude diagrams (CMDs) and employ CMD fitting to measure the recent star formation history of the regions surrounding cataloged SNR sites. We identify any young coeval population that likely produced the progenitor star, then assign an age and uncertainty to that population. Application of stellar evolution models allows us to infer the M{sub ZAMS} from this age. Because our technique is not contingent on identification or precise location of the progenitor star, it can be applied to the location of any known SNRs. We identify significant young star formation around 53 of the 59 SNRs and assign progenitor masses to these, representing a factor of {approx}2 increase over currently measured progenitor masses. We consider the remaining six SNRs as either probable Type Ia candidates or the result of core-collapse progenitors that have escaped their birth sites. In general, the distribution of recovered progenitor masses is bottom-heavy, showing a paucity of the most massive stars. If we assume a single power-law distribution, dN/dM{proportional_to}M{sup {alpha}}, then we find a distribution that is steeper than a Salpeter initial mass function (IMF) ({alpha} = -2.35). In particular, we find values of {alpha} outside the range -2.7 {>=} {alpha} {>=} -4.4 to be inconsistent with our measured distribution at 95% confidence. If instead we assume a distribution that follows a Salpeter IMF up to some maximum mass, then we find that values of M{sub Max} > 26 are inconsistent with the measured distribution at 95% confidence. In either scenario, the data suggest that some fraction of massive stars may not explode. The result is preliminary and requires more SNRs and further analysis. In addition, we use our distribution to estimate a minimum mass for core collapse between 7.0 and 7.8 M{sub Sun }.

  19. Historical Supernova Explosions in Our Galaxy and Their Remnants

    NASA Astrophysics Data System (ADS)

    Green, David A.

    Supernova explosions mark the end points of stellar evolution, releasing large amounts of material and energy into the interstellar medium. In our Galaxy the expected rate of supernovae is about 1 in every 50 years or so, although it is only the relatively nearby ones that are expected to be visible optically, due to obscuration. Over the last two thousand years or so there are historical records of nine Galactic supernovae. The majority of these records are from East Asia (i.e. China, Japan and Korea), although the most recent historical supernovae have European records, and there are a variety of Arabic records also available for some events. Here I review these records of the historical supernovae, and the modern observations of the supernova remnants that they have produced.

  20. X-ray Observations of the Tycho Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Hughes, John P.

    2006-06-01

    In this presentation I summarize some key new findings from recent Chandra and XMM-Newton data on the remnant of the supernova (SN) observed by Tycho Brahe in 1572, which is widely believed to have been of Type Ia origin. Studies of the Tycho supernova remnant (SNR) at the current epoch address aspects of SN Ia physics, the evolution of young SNRs, and cosmic ray acceleration at high Mach-number shocks.Research on the Tycho SNR at Rutgers has been supported by Chandra grants GO3-4066X and AR5-6010X.

  1. Nonthermal X-ray Emission in Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Dyer, K. K.; Reynolds, S. P.; Borkowski, K. J.; Petre, R.

    2000-12-01

    While synchrotron emission in supernova remnants has been observed and analyzed to great effect at radio wavelengths, there is a growing number of both galactic and extragalactic supernova remnants with nonthermal (non-plerionic) emission in the X-ray band. In the past the only tool available to describe X-ray synchrotron emission was the generic powerlaw model. Powerlaw models are inadequate for several reasons: simple comparison of radio and X-ray fluxes show that synchrotron must drop significantly below the radio-measured powerlaw somewhere before X-ray energies. Powerlaw models are also very poorly constrained. Coupled with a complex thermal model there is often no unique solution for the thermal-nonthermal separation. I will present synchrotron models, which use the radio spectral index and flux as inputs and include the full single-particle emissivity. Our models of synchrotron emission can account for the spectra of dominantly nonthermal supernova remnants with interesting consequences for residual thermal abundances and acceleration of particles. In addition, these models, which use the radio spectral index and flux as inputs, deliver a much better-constrained separation between the thermal and nonthermal components. These models make both spectral and spatial predictions, describing how the nonthermal emission varies across the remnant. We have demonstrated that the integrated spectrum of SN1006, a remnant dominated by nonthermal emission, is well described by synchrotron models. As an example of the use of thermal and nonthermal models I will present spatially resolved observations of this remnant, analyzed with versions of the synchrotron model designed to describe the remnant subregions. Armed with spatially resolved nonthermal models and new thermal models we now have the tools to separate thermal and nonthermal X-rays in supernova remnants. The ability to separate thermal and nonthermal emission is essential to understanding the thermal component, as well as having implications for nonthermal emission. This work is supported by the Graduate Student Researchers Program through NASA's GSFC.

  2. Energy of Tycho's Supernova Remnant is increasing with time

    PubMed Central

    Barenblatt, Grigory Isaakovich

    2008-01-01

    It is shown, using the Zeldovich integral relations, that the energy of Tycho's Supernova Remnant is strongly growing with time, approximately as t1/3. This growth can be attributed to the exothermic reactions going inside the remnant. The use of the assumption of the adiabaticity of the motion inside of the shock front, and no losses or gain of energy at the front, seems therefore unjustified. PMID:18202174

  3. 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.

  4. A Survey For Broadened CO Lines Toward Galactic Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Kilpatrick, Charles; Bieging, John H.; Rieke, George

    2016-01-01

    We performed molecular spectroscopy in 12CO J=2-1 with the Heinrich Hertz Submillimeter Telescope toward 50 Galactic supernova remnants as part of a systematic survey for broad molecular line regions indicative of interactions with molecular clouds. These observations revealed broad molecular lines toward nineteen remnants, including nine newly identified associations between molecular clouds and remnants. Morphology of the molecular emission suggests molecular shocks can arise at large separations from the remnants, consistent with a scenario where high-velocity ejecta from bipolar outflows or fast-moving knots shocks nearby molecular clouds. Also, broadened 12CO J=2-1 line emission should be detectable toward virtually all supernova remnant/molecular cloud interactions and, therefore, the total number of observed interactions is low. This result favors predictions that SN feedback plays little or no role in star formation over short timescales. In addition, we find no significant association between TeV gamma-ray sources and molecular cloud interactions, contrary to predictions that supernova remnant/molecular cloud interfaces are the primary venues for cosmic ray acceleration.

  5. Young supernova remnants and the knee in the cosmic ray spectrum

    NASA Astrophysics Data System (ADS)

    Erlykin, A.; Wibig, T.; Wolfendale, A. W.

    2011-05-01

    It has recently been suggested that neutron stars inside the shells of young supernova remnants (SNR) are the sources of PeV cosmic rays and that the interaction of the particles with the radiation field in the SNR causes electron pair production, which has relevance to recent observations of "high" positron fluxes. Furthermore, the character of the interaction is such that the well-known knee in the cosmic ray energy spectrum can be explained. Our examination of the mechanism leads us to believe that the required parameters of SN and pulsars are so uncommon that the knee and positron fraction can only be explained if a single, local and recent SN - and associated pulsar - are concerned. In this case the mechanism can be valid.

  6. The Crab Nebula and related supernova remnants; Proceedings of the Workshop, George Mason University, Fairfax, VA, October 11, 12, 1984

    NASA Technical Reports Server (NTRS)

    Kafatos, M. C. (Editor); Henry, R. B. C. (Editor)

    1985-01-01

    Papers are presented on the Crab Nebula's composition, helium distribution, outer structure and jet, and evolution. Attention is given to line emission from supernova remnants and charge transfer reactions, a magnetohydrodynamic model of the Crab Nebula and its radiation, inferences made using data on the pulsed flux from the crab pulsar, a new interpretation of the crab pulsar X-ray interpulse radiation, and evolutionary models of the Crab Nebula's progenitor. Other topics include the evolution of the centimeter flux of 3C58 and the Crab Nebula, a search for a shock wave around the Crab Nebula, high resolution radio studies of the Crab Nebula, supernova shell structure, and the nature of the remnant 0540-693 and its implications for the study of crablike remnants. Papers are also presented on X-ray observations of: Crab-like remnants, the Crab Nebula, the Vela X region, W28, and 3C400.2. Other papers include the 50 millisecond pulsar in the Large Magellanic Cloud and the X-ray pulse emission mechanism, optical emission from the plerionic core of CTB 80, and one-arcminute resolution observations of W50.

  7. TYPING SUPERNOVA REMNANTS USING X-RAY LINE EMISSION MORPHOLOGIES

    SciTech Connect

    Lopez, L. A.; Ramirez-Ruiz, E.; Badenes, C.; Huppenkothen, D.; Jeltema, T. E.

    2009-11-20

    We present a new observational method to type the explosions of young supernova remnants (SNRs). By measuring the morphology of the Chandra X-ray line emission in 17 Galactic and Large Magellanic Cloud SNRs with a multipole expansion analysis (using power ratios), we find that the core-collapse SNRs are statistically more asymmetric than the Type Ia SNRs. We show that the two classes of supernovae can be separated naturally using this technique because X-ray line morphologies reflect the distinct explosion mechanisms and structure of the circumstellar material. These findings are consistent with recent spectropolarimetry results showing that core-collapse supernovae explosions are intrinsically more asymmetric.

  8. Exploring the supernova remnant G308.4-1.4

    NASA Astrophysics Data System (ADS)

    Prinz, T.; Becker, W.

    2012-08-01

    Aims: We present a detailed X-ray and radio wavelength study of G308.4-1.4, a candidate supernova remnant (SNR) in the ROSAT All Sky Survey and the MOST supernova remnant catalog to identify it as a SNR. Methods: The SNR candidate and its central sources were studied using observations from the Chandra X-ray Observatory, Swift, the Australian Telescope Compact Array (ATCA) at 1.4 and 2.5 GHz and WISE infrared observation at 24 μm. Results: We conclude that G308.4-1.4 is indeed a supernova remnant because its morphology matches at X-ray, radio- and infrared wavelengths, its spectral energy distribution in the X-ray band, and its emission characteristics in the radio band. G308.4-1.4 is a shell-type SNR. X-ray, radio- and infrared emission is seen only in the eastern part of the remnant. The X-ray emission can best be described by an absorbed non-equilibrium collisional plasma with a hydrogen density of nH = (1.02 ± 0.04) × 1022 cm-2, a plasma temperature of 6.3-0.7+1.2 million Kelvin, and an under-abundance of iron, neon and magnesium, as well as an overabundance in sulfur with respect to the solar values. The SNR has a spectral index in the radio band of α = -0.7 ± 0.2. A detailed analysis revealed that the remnant is at a distance of 6 to 12 kpc and the progenitor star exploded ~ 5000 to 7500 years ago. Two faint X-ray point sources located near to the remnant's geometrical center are detected. Both sources have no counterpart at other wavelengths, leaving them as candidates for the compact remnant of the supernova explosion.

  9. X-ray Emission from the Galactic Supernova Remnant G272.2-3.2

    NASA Astrophysics Data System (ADS)

    McEntaffer, Randall L.; Grieves, N.; Brantseg, T.

    2013-04-01

    We present analysis of Chandra X-ray Observatory data detailing a galactic supernova remnant, G272.2-3.2. A clear shell of emission has been resolved for the first time as a series of filaments and knots around the entire rim of the remnant. Spectral analysis of these features show that they are consistent with shock heating of interstellar material in a clumpy medium. Spatially separated from this shell we see a central diffuse region dominated by harder, hotter emission. Spatial spectroscopy shows a clear enhancement of metals consistent with a Type Ia explosion, namely S, Si, and Fe. We find no clear evidence for a compact object or pulsar wind nebula and argue for a Type Ia origin. Consideration of the ionization timescales suggest an age of 8700 years for G272.2-3.2.

  10. HIGH-ENERGY EMISSION FROM THE COMPOSITE SUPERNOVA REMNANT MSH 15-56

    SciTech Connect

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

    2013-05-01

    MSH 15-56 (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.

  11. 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.

  12. 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.

  13. 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

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

    NASA Astrophysics Data System (ADS)

    Badenes, Carles

    2010-04-01

    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.

  15. Supernova Remnants in the Magellanic Clouds. VI. The DEM L316 Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Williams, R. M.; Chu, Y.-H.

    2005-12-01

    The DEM L316 system contains two shells, both with the characteristic signatures of supernova remnants (SNRs). We analyze Chandra and XMM-Newton data for DEM L316, investigating its spatial and spectral X-ray features. Our Chandra observations resolve the structure of the northeastern SNR (shell A) as a bright inner ring and a set of ``arcs'' surrounded by fainter diffuse emission. The spectrum is well fit by a thermal plasma model with a temperature of ~1.4 keV; we do not find significant spectral differences for different regions of this SNR. The southwestern SNR (shell B) exhibits an irregular X-ray outline, with a brighter interior ring of emission including a bright knot of emission. Overall, the emission of the SNR is well described by a thermal plasma of temperature ~0.6 keV. The bright knot, however, is spectrally distinct from the rest of the SNR, requiring the addition of a high-energy spectral component consistent with a power-law spectrum of photon index 1.6-1.8. We confirm the findings of Nishiuchi and coworkers that the spectra of these shells are notably different, with shell A requiring a high iron abundance for a good spectral fit, implying a Type Ia origin. We further explicitly compare abundance ratios to model predictions for Type Ia and Type II supernovae. The low ratios for shell A (O/Fe of 1.5 and Ne/Fe of 0.2) and the high ratios for shell B (O/Fe of 30-130 and Ne/Fe of 8-16) are consistent with Type Ia and Type II origins, respectively. The difference between the SNR progenitor types casts some doubt on the suggestion that these SNRs are interacting with one another.

  16. Hydrodynamic instabilities in supernova remnants - Self-similar driven waves

    NASA Technical Reports Server (NTRS)

    Chevalier, Roger A.; Blondin, John M.; Emmering, Robert T.

    1992-01-01

    An initial study aimed at elucidating the multidimensional aspects of the hydrodynamic instabilities in supernova remnants is presented. Self-similar solutions are found to exist for the interaction of a steep power-law density profile expanding into a relatively flat stationary power-law density profile. Consideration of the pressure and entropy profiles in the shocked 1D flows shows that the flows are subject to convective instability, by a local criterion. The growth rate for the instability becomes very large near the contact discontinuity between the two shocked regions. A linear analysis of the complete self-similar solutions shows that the solutions are unstable above a critical wavenumber and that the growth rate is greatest at the position of the contact discontinuity. The X-ray image of the remnant of SN 1572 (Tycho) shows emission from clumps of supernova ejecta, which is good evidence for instabilities in this remnant.

  17. High Resolution Images of Young Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Dyer, K. K.; Reynolds, S. P.

    1999-05-01

    3C 396 provides a morphological middle ground between young remnants whose morphology is obviously shaped by density variations in the circumstellar material, such as 3C 397 and remnants expanding into a relatively empty or smoothly varying regions such as 3C 391 or SN 1006 AD. The small scale "arcs" superimposed upon nearly perfect spherical morphology of 3C 396 can be seen in new high resolution VLA images at 20 and 6 cm. We discuss polarization and its spatial distribution across the remnant. We will examine archival X-ray observations and address the correlations between radio and X-ray images in terms of the dynamical evolution of the remnant and its interaction with the circumstellar medium. We also discuss radio images of 3C 397 and SN 1006 AD in comparison with 3C 396. We will examine possible spectral index variations across the remnant. This research is supported by NASA grant NAG5-7153 and NGT5-65 through the Graduate Student Researchers Program.

  18. Properties of Optically Selected Supernova Remnant Candidates in M33

    NASA Astrophysics Data System (ADS)

    Lee, Jong Hwan; Lee, Myung Gyoon

    2014-10-01

    Narrowband images covering strong emission lines are efficient for surveying supernova remnants (SNRs) in nearby galaxies. Using the narrowband images provided by the Local Group Galaxy Survey, we searched for SNRs in M33. Culling the objects with enhanced [S II]/Hα and round morphology in the continuum-subtracted Hα and [S II] images, we produced a list of 199 sources. Among them, 79 are previously unknown. Their progenitor and morphology types were classified. A majority of the sample (170 objects) are likely remnants of core-collapse supernovae (SNe), and 29 are remnants of Type Ia SNe. The cumulative size distribution of these objects is found to be similar to that of the M31 remnants derived in a similar way. We obtain a power-law slope, α = 2.38 ± 0.05. Thus, a majority of the sources are considered to be in the Sedov-Taylor phase, consistent with previous findings. The histogram of the emission-line ratio ([S II]/Hα) of the remnants has two concentrations at [S II]/Hα ~ 0.55 and ~0.8, as in M31. Interestingly, L X (and L 20 cm) of the compact center-bright objects are correlated with their optical luminosity. The remnants with X-ray emission have brighter optical surface brightnesses and smaller diameters than those without X-ray emission.

  19. Properties of optically selected supernova remnant candidates in M33

    SciTech Connect

    Lee, Jong Hwan; Lee, Myung Gyoon E-mail: mglee@astro.snu.ac.kr

    2014-10-01

    Narrowband images covering strong emission lines are efficient for surveying supernova remnants (SNRs) in nearby galaxies. Using the narrowband images provided by the Local Group Galaxy Survey, we searched for SNRs in M33. Culling the objects with enhanced [S II]/Hα and round morphology in the continuum-subtracted Hα and [S II] images, we produced a list of 199 sources. Among them, 79 are previously unknown. Their progenitor and morphology types were classified. A majority of the sample (170 objects) are likely remnants of core-collapse supernovae (SNe), and 29 are remnants of Type Ia SNe. The cumulative size distribution of these objects is found to be similar to that of the M31 remnants derived in a similar way. We obtain a power-law slope, α = 2.38 ± 0.05. Thus, a majority of the sources are considered to be in the Sedov-Taylor phase, consistent with previous findings. The histogram of the emission-line ratio ([S II]/Hα) of the remnants has two concentrations at [S II]/Hα ∼ 0.55 and ∼0.8, as in M31. Interestingly, L {sub X} (and L {sub 20cm}) of the compact center-bright objects are correlated with their optical luminosity. The remnants with X-ray emission have brighter optical surface brightnesses and smaller diameters than those without X-ray emission.

  20. Complex structure of the supernova remnant HB 3

    NASA Technical Reports Server (NTRS)

    Leahy, D. A.; Venkatesan, D.; Long, K. S.; Naranan, S.

    1985-01-01

    HB 3 is an old, large (84 pc diameter) supernova remnant associated with the W3 H II region/molecular cloud complex. Observations of the imaging proportional counter (IPC) onboard the Einstein X-ray astronomy satellite have been reprocessed to yield a contour map of X-ray brightness and spectra of various regions of this remnant. The measured IPC flux is 2.4 x 10 to the -11th ergs per sq cm per s, giving a 0.2-4 keV luminosity of 1.6 x 10 to the 35th ergs/s for a column densityof 6 x 10 to the 21st per sq cm. The measured X-ray temperatures reveal a decrease from center to limb of the remnant of 1-0.3 keV. HB 3 is in the late adiabatic blast-wave phase of evolution, 30,000 to 50,000 yr old and with an initial blast energy of 3 x 10 to the 50th ergs. The X-ray map is compared with available radio and optical images. In X-rays, HB 3 has two components - a diffuse emission inside the 84 pc radio remnant and a ring of emission at the center of 30 pc in diameter. The diffuse emission is similar to that from other supernova remnants which are moderately obscured (column density, nH approximately 10 to the 22nd per sq cm). Three possibilities for the origin of the ring are explored: (1) a second supernova remnant, (2) a shocked shell in the interstellar medium surrounding HB 3, and (3) reverse-shock heated ejecta. There is no hot neutron star within the remnant.

  1. A Newly Recognized Very Young Supernova Remnant in M83

    NASA Astrophysics Data System (ADS)

    Blair, William P.; Winkler, P. Frank; Long, Knox S.; Whitmore, Bradley C.; Kim, Hwihyun; Soria, Roberto; Kuntz, K. D.; Plucinsky, Paul P.; Dopita, Michael A.; Stockdale, Christopher

    2015-02-01

    As part of a spectroscopic survey of supernova remnant candidates in M83 using the Gemini-South telescope and Gemini Multi-Object Spectrograph, we have discovered one object whose spectrum shows very broad lines at H?, [O I] ??6300, 6363, and [O III] ??4959, 5007, similar to those from other objects classified as "late time supernovae". Although six historical supernovae have been observed in M83 since 1923, none were seen at the location of this object. Hubble Space Telescope (HST) Wide Field Camera 3 images show a nearly unresolved emission source, while Chandra and ATCA data reveal a bright X-ray source and nonthermal radio source at the position. Objects in other galaxies showing similar spectra are only decades post-supernova, which raises the possibility that the supernova that created this object occurred during the last century but was missed. Using photometry of nearby stars from the HST data, we suggest the precursor was at least 17 M ?, and the presence of broad H? in the spectrum makes a type II supernova likely. The supernova must predate the 1983 Very Large Array radio detection of the object. We suggest examination of archival images of M83 to search for evidence of the supernova event that gave rise to this object, and thus provide a precise age. Based on observations made with NASA's Chandra X-Ray Observatory, which is operated by the Smithsonian Astrophysical Observatory under contract # NAS83060, with data obtained through program GO1-12115.

  2. A Newly Recognized Very Young Supernova Remnant in M83

    NASA Astrophysics Data System (ADS)

    Blair, William P.; Winkler, P. Frank; Long, Knox S.; Whitmore, Bradley C.; Kim, Hwihyun; Soria, Roberto; Kuntz, K. D.; Plucinsky, Paul P.; Dopita, Michael A.; Stockdale, Christopher

    2015-01-01

    As part of a spectroscopic survey of supernova remnant candidates in M83 using the Gemini-South telescope and GMOS, we have discovered one object whose spectrum shows very broad lines at Halpha, [O I] 6300, and [O III] 5007, similar to those from other objects classified as `late time supernovae.' Although six historical supernovae have been observed in M83 since 1923, none were seen at the location of this object. Hubble Space Telescope Wide Field Camera 3 images show a nearly unresolved emission source, while Chandra and ATCA data reveal a bright X-ray source and nonthermal radio source at the position. Objects in other galaxies showing similar spectra are only decades post-supernova, which raises the possibility that the supernova that created this object occurred during the last century but was not observed. Using photometry of nearby stars from the HST data, we suggest the precursor was at least 17 M(sun), and the presence of broad Halpha in the spectrum makes a type II supernova likely. The supernova must predate the 1983 VLA radio detection of the object. We suggest examination of archival images of M83 to search for evidence of the supernova event that gave rise to this object, and thus provide a precise time since the explosion.We acknowledge STScI grants under the umbrella program ID GO-12513 to Johns Hopkins University, STScI, and Middlebury College. PFW acknowledges additional support from the National Science Foundation through grant AST-0908566.

  3. Circumstellar Dust in the Remnant of Kepler's Type Ia Supernova

    NASA Astrophysics Data System (ADS)

    Williams, Brian J.; Blair, W. P.; Borkowski, K. J.; Ghavamian, P.; Long, K. S.; Reynolds, S. P.; Sankrit, R.

    2012-01-01

    Kepler's Supernova Remnant, the remains of the supernova of 1604, is widely believed to be the result of a Type Ia supernova, and shows IR, optical, and X-ray evidence for an interaction of the blast wave with a dense circumstellar medium (CSM). We present low-resolution 7.5-38 μm IR spectra of selected regions within the remnant, obtained with the Spitzer Space Telescope. Spectra of those regions where the blast wave is encountering circumstellar material show strong features at 10 and 18 μm. These spectral features are most consistent with various silicate particles, likely formed in the stellar outflow from the progenitor system during the AGB stage of evolution. While it is possible that some features may arise from freshly formed ejecta dust, morphological evidence suggests that it is more likely that they originate from dust in the CSM. We isolate the dust grain absorption efficiencies for several regions in Kepler and compare them to laboratory data for dust particles of various compositions. The hottest dust in the remnant originates in the regions of dense, radiatively shocked clumps of gas, identified in optical images. Models of collisionally heated dust show that such shocks are capable of heating grains to temperatures of > 150 K. We confirm the finding that Kepler's SNR is still interacting with CSM in at least part of the remnant after 400 years. The significant quantities of silicate dust are consistent with a relatively massive progenitor.

  4. 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.

  5. 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.

  6. Are young supernova remnants interacting with circumstellar gas

    SciTech Connect

    Chevalier, R.A.

    1982-08-15

    The young remnants of galactic Type I supernovae (SN 1006, SN 1572, and SN 1604) appear to be interacting with moderately dense gas (n/sub O/> or =0.1 cm/sup -3/). If the gas in the ambient interstellar medium, the observations suggest that gas of this density is fairly pervasive. If the gas is circumstellar, there are important implications for the progenitors of Type I supernovae. A plausible density distribution for circumstellar gas is rhoinfinityr/sup -2/. The expansion of a supernova into such a medium is examined and is compared with expansion into a uniform medium. The two cases can be distinguished on the basis of their density profiles and their rates of expansion. Currently available data factor the hypothesis of expansion in a uniform medium for all three Type I remnants; the evidence is the strongest for SN 1572 and the weakest for SN 1604. Further X-ray and radio observations of the galactic remnants and of extragalactic Type I supernovae should serve to test this hypothesis.

  7. A 3D numerical model for Kepler's supernova remnant

    NASA Astrophysics Data System (ADS)

    Toledo-Roy, J. C.; Esquivel, A.; Velázquez, P. F.; Reynoso, E. M.

    2014-07-01

    We present new 3D numerical simulations for Kepler's supernova remnant. In this work we revisit the possibility that the asymmetric shape of the remnant in X-rays is the product of a Type Ia supernova explosion which occurs inside the wind bubble previously created by an AGB companion star. Due to the large peculiar velocity of the system, the interaction of the strong AGB wind with the interstellar medium results in a bow shock structure. In this new model we propose that the AGB wind is anisotropic, with properties such as mass-loss rate and density having a latitude dependence, and that the orientation of the polar axis of the AGB star is not aligned with the direction of motion. The ejecta from the Type Ia supernova explosion is modelled using a power-law density profile, and we let the remnant evolve for 400 yr. We computed synthetic X-ray maps from the numerical results. We find that the estimated size and peculiar X-ray morphology of Kepler's supernova remnant are well reproduced by considering an AGB mass-loss rate of 10-5 M⊙ yr-1, a wind terminal velocity of 10 km s-1, an ambient medium density of 10-3 cm-3 and an explosion energy of 7 × 1050 erg. The obtained total X-ray luminosity of the remnant in this model reaches 6 × 1050 erg, which is within a factor of 2 of the observed value, and the time evolution of the luminosity shows a rate of decrease in recent decades of ˜2.4 per cent yr-1 that is consistent with the observations.

  8. Featured Image: A Supernova Remnant in X-Rays

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2015-09-01

    This is a three-color X-ray image taken by Chandra of the supernova remnant RCW 103. This supernova remnant is an unusual system: its young, but unlike other remnants of its age, metal-rich ejecta hadnt previously been discovered in it. In this paper, Kari Frank (Pennsylvania State University) and collaborators analyze the three deepest Chandra observations of RCW 103 and find the first evidence for metal-rich ejecta emission scattered throughout the remnant. Their analyses also help to constrain the identity of the mysterious compact stellar object powering the remnant. In this image, red = 0.30.85 keV, green = 0.851.70 keV, and blue = 1.73.0 keV; click on the image for the full view. For more information and the original image, see the paper here:Kari A. Frank et al 2015 ApJ 810 113 doi:10.1088/0004-637X/810/2/113.

  9. Infrared echoes near the supernova remnant Cassiopeia A.

    PubMed

    Krause, Oliver; Rieke, George H; Birkmann, Stephan M; Le Floc'h, Emeric; Gordon, Karl D; Egami, Eiichi; Bieging, John; Hughes, John P; Young, Erick T; Hinz, Joannah L; Quanz, Sascha P; Hines, Dean C

    2005-06-10

    Two images of Cassiopeia A obtained at 24 micrometers with the Spitzer Space Telescope over a 1-year time interval show moving structures outside the shell of the supernova remnant to a distance of more than 20 arc minutes. Individual features exhibit apparent motions of 10 to 20 arc seconds per year, independently confirmed by near-infrared observations. The observed tangential velocities are at roughly the speed of light. It is likely that the moving structures are infrared echoes, in which interstellar dust is heated by the explosion and by flares from the compact object near the center of the remnant. PMID:15947181

  10. A mechanism for strong shock electron heating in supernova remnants

    NASA Technical Reports Server (NTRS)

    Cargill, P. J.; Papadopoulos, K.

    1988-01-01

    It is shown that collisionless shock waves propagating away from a supernova may be directly responsible for the 10 keV X-ray emission seen in supernova remnants. A sequence of plasma instabilities (Buneman and ion acoustic) between the reflected and/or transmitted ions and the background electrons at the foot of the shock front can give rise to rapid anomalous heating of electrons. Hybrid simulations of a perpendicular collisionless shock are presented to demonstrate that this heating can arise within a self-consistently computed shock structure.

  11. Carbon Monoxide in the Cassiopeia a Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Rho, J.; Jarrett, T. H.; Reach, W. T.; Gomez, H.; Andersen, M.

    2009-03-01

    We report the likely detection of near-infrared 2.29 μm first overtone carbon monoxide (CO) emission from the young supernova (SN) remnant Cassiopeia A (Cas A). The continuum-subtracted CO filter map reveals CO knots within the ejecta-rich reverse shock. We compare the first overtone CO emission with that found in the well studied supernova SN 1987A and find ~30 times less CO in Cas A. The presence of CO suggests that molecule mixing is small in the SN ejecta and that astrochemical processes and molecule formation may continue at least ~300 yr after the initial explosion.

  12. Energetic particles in supernova remnants: Results from VHE Observations

    NASA Astrophysics Data System (ADS)

    Slane, Patrick O.

    2016-01-01

    The rapidly-expanding ejecta in supernova remnants drive fast shocks in the surrounding medium. These shocks heat the ambient gas and create conditions suitable for the acceleration of charged particles to energies exceeding hundreds of TeV. These particles are believedto form the primary component of Galactic cosmic rays. The details of the acceleration process, including the need for amplified magnetic fields, the evidence for the presence of energetic hadrons, the process of particle escape, and the contributions from compressed and re-accelerated ambient cosmic rays are complex. Measurements across the electromagnetic spectrum are required to fully constrain the process, and observations of VHE gamma-rays from supernova remnants are particularly crucial. Here I will summarize current results from studies of particle acceleration in SNRs, with particular emphasis on the crucial constraints provided by the VHE observations.

  13. Galactic Propagation of Cosmic Rays from Individual Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Nierstenhöfer, Nils; Graeser, Philipp; Schuppan, Florian; Tjus, Julia

    2015-08-01

    It is widely believed that supernova remnants are the best candidate sources for the observed cosmic ray flux up to the knee, i.e. up to ∼PeV energies. Indeed, the gamma-ray spectra of some supernova remnants can be well explained by assuming the decay of neutral pions which are created in hadronic interactions. Therefore, fitting the corresponding gamma spectra allows us to derive the spectra of cosmic rays at the source which are locally injected into our Galaxy. Using these spectra as a starting point, we propagate the cosmic rays through the Galaxy using the publicly available GALPROP code. Here, we will present first results on the contribution of those SNRs to the total cosmic ray flux and discuss implications.

  14. Are supernovae radio sources - A search for radio emission from young supernova remnants

    NASA Technical Reports Server (NTRS)

    Brown, R. L.; Marscher, A. P.

    1978-01-01

    A search has been conducted for radio emission at 11 and 3.7 cm from 46 recent supernovae having accurately determined positions and ages of a few months to 79 years. None of these supernovae was detected at a flux density greater than 5-10 mJy. These negative results cannot be explained by internal absorption and are thus due to intrinsically weak synchrotron emission in young supernova remnants. There are two possibilities: either (1) relativistic particles are accelerated not by the supernova outburst but by processes occurring much later (at least about 75 years) in the remnant or (2) the magnetic field in the young remnants evolves very slowly, in proportion to the inverse square root of time, so that its value in the remnants observed was no more than about 0.002 gauss. The constraints the observations place on these possibilities and on the energy in cosmic rays in young remnants are discussed. Gamma-ray observations at times of no more than about 1 year following an outburst will allow one to discriminate between the two alternative explanations of the radio results.

  15. FERMI LARGE AREA TELESCOPE DETECTION OF SUPERNOVA REMNANT RCW 86

    SciTech Connect

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

    2014-04-20

    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.

  16. Chandra's View of Tycho's Supernova Remnant

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This Chandra image reveals, in detail, the turbulent debris created by a supernova explosion that was observed by the Danish Astronomer Tycho Brahe in the year 1572. The colors show different x-ray energies, with red, green, and blue representing low, medium, and high energies, respectively. Most likely caused by the destruction of a white dwarf star, a shock wave produced by the expanding debris is outlined by the sharp blue circular arcs of 20 million degree Celsius gas seen on the outer rim. The stellar debris, visible only by x-ray, has a temperature of about 10 million degrees, and shows up as mottled yellow, green, and red fingers of gas.

  17. 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.

  18. The Kinematics of Kepler's Supernova Remnant as Revealed by Chandra

    NASA Astrophysics Data System (ADS)

    Vink, Jacco

    2008-12-01

    I have determined the expansion of the supernova remnant of SN 1604 (Kepler's supernova) based on archival Chandra ACIS-S observations made in 2000 and 2006. The measurements were done in several distinct energy bands, and were made for the remnant as a whole, and for six individual sectors. The average expansion parameter indicates that the remnant expands on average as r propto t0.5, but there are significant differences in different parts of the remnant: the bright northwestern part expands as r propto t0.35, whereas the rest of the remnant's expansion shows an expansion r propto t0.6. The latter is consistent with an explosion in which the outer part of the ejecta has a negative power law slope for density (ρ propto v-n) of n = 7, or with an exponential density profile [ρ propto exp (- v/ve) ]. The expansion parameter in the southern region, in conjunction with the shock radius, indicates a rather low value (<5 × 1050 erg) for the explosion energy of SN 1604 for a distance of 4 kpc. A higher explosion energy is consistent with the results if the distance is larger. The filament in the eastern part of the remnant, which is dominated by X-ray synchrotron radiation, seems to mark a region with a fast shock speed r propto t0.7, corresponding to a shock velocity of v = 4200 km s-1, for a distance to SN 1604 of 4 kpc. This is consistent with the idea that X-ray synchrotron emission requires shock velocities in excess of ~2000 km s-1. The X-ray-based expansion measurements reported are consistent with results based on optical and radio measurements but disagree with previous X-ray measurements based on ROSAT and Einstein observations.

  19. DA 530: A Supernova Remnant in a Stellar Wind Bubble

    NASA Astrophysics Data System (ADS)

    Landecker, T. L.; Routledge, D.; Reynolds, S. P.; Smegal, R. J.; Borkowski, K. J.; Seward, F. D.

    1999-12-01

    The high-latitude supernova remnant (SNR) DA 530 (G93.3+6.9), apparently a typical shell remnant, has highly polarized radio continuum emission and a very uniform circumferential magnetic field. We present new radio continuum (408 and 1420 MHz) and H I line observations, made with the Dominion Radio Astrophysical Observatory Synthesis Telescope, and we have made the first detection of X-ray emission from the SNR, using the ROSAT Position-Sensitive Proportional Counter. The SNR lies within a shell of H I, possibly created by an earlier stellar wind, whose kinematic distance is nominally 2.5 kpc but whose actual distance may be larger. The X-ray emission is extremely faint. A Raymond-Smith ionization-equilibrium model fits the data and suggests a very low density, ~0.05 cm-3, consistent with the occurrence of the supernova in a stellar wind cavity, but this model yields an explosion energy 100 times lower than the accepted value. A nonequilibrium shock model, incorporating a range of ionization timescales, is able to give more realistic physical parameters for the supernova remnant. On the balance of the evidence, we place DA 530 at a distance of 3.5 kpc, the largest distance permitted by the H I observations, where it lies 420 pc above the Galactic plane. The explosion, probably a Type Ia supernova, in a low-density cavity has resulted in weak X-ray emission and slow evolution. The explosion energy was 3.9×1050 ergs and the age is ~5000 years. The remnant, having swept up 3.9 Msolar in an ambient density of ~0.01 cm-3, is only now in the adiabatic phase, and this explains the absence of detected optical emission. Despite the low ambient density the efficiency of generation of synchrotron radio emission is ~0.4%, higher than in some historical SNRs. The ratio of radio to X-ray flux is about 100 times that for the remnant of SN 1006, which has comparable radio continuum properties. The very uniform magnetic field is not explained. DA 530 joins a small group of remnants at high Galactic latitude with unusual features, perhaps resulting from low ambient densities. Inhomogeneous nonequilibrium ionization models may be required for the interpretation of the X-ray emission from many other older SNRs.

  20. A high sensitivity search for X-rays from supernova remnants in Aquila

    NASA Technical Reports Server (NTRS)

    Schwartz, D. A.; Bleach, D. A.; Boldt, E. A.; Holt, S. S.; Serlemitsos, P. J.

    1972-01-01

    A high sensitivity scan of the galactic plane was performed to search for 2-20 keV X-rays from supernova remnants. The spectra of five X-ray sources detected between 44 deg and 31 deg longitude, of which only two might be associated with suggested supernova remnants, are reported on. Upper limits are presented for the 19 possible supernova remnants scanned in this survey.

  1. A high-sensitivity search for X-rays from supernova remnants in Aquila.

    NASA Technical Reports Server (NTRS)

    Schwartz, D. A.; Boldt, E. A.; Holt, S. S.; Serlemitsos, P. J.; Bleach, R. D.

    1972-01-01

    A high-sensitivity scan of the galactic plane from 70 to 30 deg was performed to search for 2-20-keV X rays from supernova remnants. The spectra of five X-ray sources detected between 44 and 31 deg longitude are presented, of which only two might be associated with suggested supernova remnants. Upper limits are given for the 19 possible supernova remnants scanned.

  2. 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.

  3. A multi-wavelength look at the young plerionic supernova remnant 0540-69.3

    SciTech Connect

    Brantseg, T.; McEntaffer, R. L.; Grieves, N.; Bozzetto, L. M.; Filipovic, M.

    2014-01-01

    We present a study of the plerionic supernova remnant 0540-69.3 in the LMC in X-ray, radio, optical, and infrared. We find that the shell of 0540-69.3 is characterized in the X-ray by thermal nonequilibrium plasma with depleted Mg and Si abundances and a temperature of kT ∼ 0.7 keV. This thermal emission is superimposed with synchrotron emission in several regions. Based on X-ray spectra and on morphological considerations in all surveyed wavebands, we conclude that the shell is expanding into a clumpy and highly inhomogeneous medium. In one region of the shell we find an overabundance of Ne, suggesting the presence of ejecta near the edge of the remnant. We also see evidence for reheating of material via a reverse shock originating from the interaction of the supernova blast wave with a particularly dense cloud in the surrounding medium. Finally, we perform the first detailed study of the 'halo' region extending 1.2-2.2 pc from the central pulsar. We detect the presence of thermal and nonthermal spectral components but do not find evidence for mixing or ejecta. We conclude that the thermal component is not a counterpart to similar optical and infrared halos and that it is most likely due to the projection of shell material along the line of sight.

  4. Spectroscopic studies of iron emissions from supernova remnants with Suzaku

    NASA Astrophysics Data System (ADS)

    Yamaguchi, H.

    We present X-ray spectroscopy of iron (Fe) emission from supernova remnants (SNRs) with Suzaku. Although young SNRs retain crucial information about their explosion and nucleosynthesis mechanisms, interactions with the surrounding material can conceal these data. Therefore, it is not unusual that even the basic progenitor type (i.e., Ia or core-collapse) of a remnant remains controversial. Our proposed method, solely using the Fe K-shell X-ray spectrum, successfully discriminates the progenitors of young ejecta-dominated SNRs. We find that the Fe ejecta in Type Ia SNRs are commonly less ionized than those in core-collapse SNRs. It is found, moreover, that luminosity and centroid of the Fe-K emission are well correlated among each group of Type Ia or core-collapse remnants, and that the more luminous remnants tend to be more highly ionized. These results may reflect the pre-explosion density of the remnants as well as the amount of the synthesized Fe. We also mention historical development of the X-ray studies of SNRs.

  5. Fermi-LAT observations of supernova remnants Kesteven 79

    SciTech Connect

    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 {sup 12}CO J = 1 → 0 and HCO{sup +} 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 π{sup 0} 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.

  6. The Fascinating High-Energy World of Neutron Stars and Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Safi-Harb, Samar

    2006-06-01

    The past few years have witnessed a fast growth in the high-energy astrophysics community in Canada, thanks to new opportunities including the University Faculty Award (UFA) program introduced by the Natural Sciences and Engineering Research Council of Canada (NSERC) to appoint promising female researchers to faculty positions in science and engineering. As a UFA fellow at the University of Manitoba, I have had the unique opportunity to contribute to the launch of a new astronomy program in the department of Physics (renamed to Physics and Astronomy). My research focuses on observational studies of neutron stars, pulsar wind nebulae, and supernova remnants. The study of these exotic objects helps address the physics of the extreme and probe some of the most energetic events in the Universe. I will highlight exciting discoveries in this field and some of the questions to be addressed with current and future high-energy missions.

  7. 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.

  8. R-Process Ejecta in the VELA Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Wallerstein, George

    1990-12-01

    Groundbased, X-ray and radio studies reveal many properties of supernovae but none except for the neutrinos from SN1987A have been able to tell us anything about the mechanism of the explosion. By looking for r-process and heavy iron-peak isotopes we can estimate the amount of neutronized material ejected and hence get a grip on what actually happened during the explosion. We will search for interstellar absorption lines of KrI, HgII, Os II, W II, and Pt II in stars within and behind the Vela supernova remnant. Substantial quantities of these elements are expected to be ejected in supernova explosions. However, recent competing theories of the supernova explosion mechanism predict differing amounts of r-process ejecta and in this way our observation will provide important constraints on these models. This will be a direct observational input on the supernova mechanism, a theoretical problem on which much time, effort, and manpower have been expended.

  9. Uncovering The Properties of Young Neutron Stars and Their Surrounding Supernova A Remnants

    NASA Technical Reports Server (NTRS)

    Slane, Patrick O.; Oliversen, Ronald J. (Technical Monitor)

    2003-01-01

    In the third year of this program, the following studies have been undertaken in support of this effort: G292.0+1.8: In our previous work on this SNR, we discovered a young neutron star and its associated pulsar wind nebula. Radio observations by Camilo et al. (2002) have identified a young 136 ms pulsar in the direction of G292.0+1.8. We have used Chandra HRC observations of the central source to identify X-ray pulsations at the same period, thus establishing the neutron star as the radio pulsar counterpart. We have also set limits on the cooling of this young neutron star based on the unpulsed component of the X-ray emission. We find that the limit falls slightly below standard cooling models in which the modified Urca process is responsible for the bulk of the interior neutrino emission. A paper summarizing these results is currently being circulated amongst co-authors for review prior to publication. 3c 58: Our Chandra observations of this Crab-like SNR revealed the presence of a young, rapidly rotating pulsar as well as a central compact nebula which we interpret as a toroidal structure associated with the pulsar wind termination shock. Our modeling of this structure has allowed us to establish a temperature upper limit for the neutron star which falls well below predictions from standard cooling models, and implies the presence of exotic particles (such as pion condensates) or other processes that increase the neutrino production rate in the interior. A paper summarizing this work has been published in the Astrophysical Journal (Slane, Helfand, & Murray 2002, ApJ, 571, L45), and the results were the subject of a NASA Space Science Update (4/10/2002) which led to extensive media coverage. Based upon our initial observations, we submitted a successful Chandra Large Project proposal for a 350 ks observation of this young neutron star and its wind nebula. Kes 79: Our Chandra observations of this SNR reveal a compact central source which appears to be the neutron star formed in the explosion that produced the remnant. There is no evidence for a surrounding pulsar wind nebula. The source properties are similar to the central source in Cas A even though the Kes 79 remnant is considerably older. The results have been published in the Astrophysical Journal (Seward, Slane, Smith, and Sun 2003, ApJ, 584,414). Chandra Survey for Compact Objects in Supernova Remnants: We have formed a collaboration to carry out an extensive search for young neutron stars in nearby supernova remnants. Using X-ray observations from an approved Chandra Large Project, as well as from additional approved XMM observations, we are investigating a volume-limited sample of SNRs for which there is currently no evidence of associated neutron stars. We have obtained extensive optical and 1R data to complement the project, and analysis of these data is currently underway.

  10. Molecular environment of the supernova remnant IC 443: Discovery of the molecular shells surrounding the remnant

    SciTech Connect

    Su, Yang; Fang, Min; Yang, Ji; Zhou, Ping; Chen, Yang

    2014-06-20

    We have carried out {sup 12}CO, {sup 13}CO, and C{sup 18}O observations toward the mixed morphology supernova remnant (SNR) IC 443. The observations cover a 1.°5 × 1.°5 area and allow us to investigate the overall molecular environment of the remnant. Some northern and northeastern partial shell structure of CO gas is around the remnant. One of the partial shells, about 5' extending beyond the northeastern border of the remnant's bright radio shell, seems to just confine the faint radio halo. On the other hand, some faint CO clumps can be discerned along the eastern boundary of the faint remnant's radio halo. Connecting the eastern CO clumps, the northeastern partial shell structures, and the northern CO partial shell, we can see that a half molecular ring structure appears to surround the remnant. The LSR velocity of the half-ring structure is in the range of –5 km s{sup –1} to –2 km s{sup –1}, which is consistent with that of the –4 km s{sup –1} molecular clouds. We suggest that the half-ring structure of the CO emission at V {sub LSR} ∼ –4 km s{sup –1} is associated with the SNR. The structures are possibly swept up by the stellar winds of SNR IC 443's massive progenitor. Based on the Wide-field Infrared Survey Explorer and the Two Micron All Sky Survey near-IR database, 62 young stellar object (YSO) candidates are selected within the radio halo of the remnant. These YSO candidates concentrated along the boundary of the remnant's bright radio shell are likely to be triggered by the stellar winds from the massive progenitor of SNR IC 443.

  11. What We Can Learn From Supernova Remnant Size Distributions

    NASA Astrophysics Data System (ADS)

    Elwood, Benjamin; Murphy, Jeremiah; Diaz, Mariangelly

    2016-01-01

    Previous literature regarding size distributions of supernova remnants generally discuss a uniform distribution for the radius, occasionally considering a Gaussian alternative. We indeed show that these distributions are consistent with log-normal, which can be considered a natural consequence of the Central Limit Theorem and Sedov expansion. Modeling explosion energy, remnant age, and ambient density as independent, random distributions, we show, using simple Monte Carlo simulations, that the size distribution is indistinguishable from log-normal when the SNR sample size is of order three hundred. This implies that these SNR distributions provide only information on the mean and variance, yielding additional information only when the sample size grows large. We then proceed to Bayesian statistical inference to characterize the information provided by the size distributions. In particular, we use the mean and variance of sizes and explosion energies to subsequently estimate the mean and variance of the ambient medium surrounding SNR progenitors. This in turn allows us to characterize potential bias in studies involving samples of supernova remnants.

  12. 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.

  13. Constraining the Progenitor Masses of Core Collapse Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Díaz Rodríguez, Mariangelly; Murphy, Jeremiah Wayne; Elwood, Benjamin; Williams, Benjamin F.; Rubin, David

    2016-01-01

    Understanding the progenitor mass distribution of supernova explosions is an important observational constraint of stellar evolution theory. Recently, a novel approach was proposed to significantly increase the number of progenitor masses: characterize the progenitor mass of supernova remnants (SNRs) by age-dating the local stellar population. Preliminary statistical analyses suggested that there is a lack of SNRs around the most massive of massive stars. This suggested that there is a maximum mass for core collapse supernova explosions, or there is a bias against finding SNRs associated with the most massive stars. We test for a bias by considering the distribution of SNRs sizes using a Monte Carlo simulation. We find that the distribution of remnants sizes is the same for low mass progenitors and high mass progenitors. This implies that there is no bias against finding SNRs around the most massive progenitors. Our next step is to apply Bayesian statistical inference and obtain the joint probability for all the parameters involved in the statistical distribution model: the minimum mass, maximum mass, and slope of the mass distribution.

  14. Extremely fast acceleration of cosmic rays in a supernova remnant.

    PubMed

    Uchiyama, Yasunobu; Aharonian, Felix A; Tanaka, Takaaki; Takahashi, Tadayuki; Maeda, Yoshitomo

    2007-10-01

    Galactic cosmic rays (CRs) are widely believed to be accelerated by shock waves associated with the expansion of supernova ejecta into the interstellar medium. A key issue in this long-standing conjecture is a theoretical prediction that the interstellar magnetic field can be substantially amplified at the shock of a young supernova remnant (SNR) through magnetohydrodynamic waves generated by cosmic rays. Here we report a discovery of the brightening and decay of X-ray hot spots in the shell of the SNR RX J1713.7-3946 on a one-year timescale. This rapid variability shows that the X-rays are produced by ultrarelativistic electrons through a synchrotron process and that electron acceleration does indeed take place in a strongly magnetized environment, indicating amplification of the magnetic field by a factor of more than 100. The X-ray variability also implies that we have witnessed the ongoing shock-acceleration of electrons in real time. Independently, broadband X-ray spectrometric measurements of RX J1713.7-3946 indicate that electron acceleration proceeds in the most effective ('Bohm-diffusion') regime. Taken together, these two results provide a strong argument for acceleration of protons and nuclei to energies of 1 PeV (10(15) eV) and beyond in young supernova remnants. PMID:17914390

  15. No cold dust within the supernova remnant Cassiopeia A.

    PubMed

    Krause, Oliver; Birkmann, Stephan M; Rieke, George H; Lemke, Dietrich; Klaas, Ulrich; Hines, Dean C; Gordon, Karl D

    2004-12-01

    A large amount (about three solar masses) of cold (18 K) dust in the prototypical type II supernova remnant Cassiopeia A was recently reported. It was concluded that dust production in type II supernovae can explain how the large quantities (approximately 10(8) solar masses) of dust observed in the most distant quasars could have been produced within only 700 million years after the Big Bang. Foreground clouds of interstellar material, however, complicate the interpretation of the earlier submillimetre observations of Cas A. Here we report far-infrared and molecular line observations that demonstrate that most of the detected submillimetre emission originates from interstellar dust in a molecular cloud complex located in the line of sight between the Earth and Cas A, and is therefore not associated with the remnant. The argument that type II supernovae produce copious amounts of dust is not supported by the case of Cas A, which previously appeared to provide the best evidence for this possibility. PMID:15577902

  16. 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.

  17. G11.2-0.3: The Young Remnant of a Stripped-envelope Supernova

    NASA Astrophysics Data System (ADS)

    Borkowski, Kazimierz J.; Reynolds, Stephen P.; Roberts, Mallory S. E.

    2016-03-01

    We present results of a 400 ks Chandra observation of the young shell supernova remnant (SNR) G11.2-0.3, containing a pulsar and pulsar-wind nebula (PWN). We measure a mean expansion rate for the shell since 2000 of 0.0277 ± 0.0018% yr-1, implying an age between 1400 and 2400 yr, and making G11.2-0.3 one of the youngest core-collapse SNRs in the Galaxy. However, we find very high absorption (AV ˜ 16m ± 2m), confirming near-IR determinations and ruling out a claimed association with the possible historical SN of 386 CE. The PWN shows strong jets and a faint torus within a larger, more diffuse region of radio emission and nonthermal X-rays. Central soft thermal X-ray emission is anticorrelated with the PWN; that, and more detailed morphological evidence, indicates that the reverse shock has already reheated all ejecta and compressed the PWN. The pulsar characteristic energy-loss timescale is well in excess of the remnant age, and we suggest that the bright jets have been produced since the recompression. The relatively pronounced shell and diffuse hard X-ray emission in the interior, enhanced at the inner edge of the shell, indicate that the immediate circumstellar medium into which G11.2-0.3 is expanding was quite anisotropic. We propose a possible origin for G11.2-0.3 in a stripped-envelope progenitor that had lost almost all its envelope mass, in an anisotropic wind or due to binary interaction, leaving a compact core whose fast winds swept previously lost mass into a dense irregular shell, and which exploded as a SN cIIb or Ibc.

  18. Supernova 1987A: a Template to Link Supernovae to Their Remnants

    NASA Astrophysics Data System (ADS)

    Orlando, S.; Miceli, M.; Pumo, M. L.; Bocchino, F.

    2015-09-01

    The emission of supernova remnants (SNRs) reflects the properties of both the progenitor supernovae (SNe) and the surrounding environment. The complex morphology of the remnants, however, hampers the disentanglement of the two contributions. Here, we aim at identifying the imprint of SN 1987A on the X-ray emission of its remnant and at constraining the structure of the environment surrounding the SN. We performed high-resolution hydrodynamic simulations describing SN 1987A soon after the core-collapse and the following three-dimensional expansion of its remnant between days 1 and 15,000 after the SN. We demonstrated that the physical model reproducing the main observables of SN 1987A during the first 250 days of evolution also reproduces the X-ray emission of the subsequent expanding remnant, thus bridging the gap between SNe and SNRs. By comparing model results with observations, we constrained the explosion energy in the range 1.2-1.4 × 1051 erg and the envelope mass in the range 15-17 M⊙. We found that the shape of X-ray lightcurves and spectra at early epochs (<15 years) reflects the structure of outer ejecta: our model reproduces the observations if the outermost ejecta have a post-explosion radial profile of density approximated by a power law with index α = -8. At later epochs, the shapes of X-ray lightcurves and spectra reflect the density structure of the nebula around SN 1987A. This enabled us to ascertain the origin of the multi-thermal X-ray emission, disentangle the imprint of the SN on the remnant emission from the effects of the remnant interaction with the environment, and constrain the pre-supernova structure of the nebula.

  19. Radio structure of the remnant of Tycho's supernova (SN 1572)

    NASA Technical Reports Server (NTRS)

    Dickel, J. R.; Van Breugel, W. J. M.; Strom, R. G.

    1991-01-01

    The radio emission from the remnant of Tycho's supernova of 1572 arises in a nearly circular, clumpy shell. A very distinct, thin bright rim just outside the main shell can be seen around most of the periphery of the remnant. The outer edge of radio emission, usually defined by this bright rim, coincides perfectly with the outer X-ray boundary. Most of the emission is polarized by a modest amount, with the outer rim particularly prominent. Observations at several wavelengths are used to map out the rotation measure at high angular resolution, and determine the intrinsic magnetic field direction. The magnetic field shows a somewhat cellular pattern but with a net radial orientation and a generally fairly low degree of polarization.

  20. Radio structure of the remnant of Tycho's supernova (SN 1572)

    SciTech Connect

    Dickel, J.R.; Van breugel, W.J.M.; Strom, R.G. Lawrence Livermore National Laboratory, Livermore, CA Netherlands Foundation for Research in Astronomy, Dwingeloo )

    1991-06-01

    The radio emission from the remnant of Tycho's supernova of 1572 arises in a nearly circular, clumpy shell. A very distinct, thin bright rim just outside the main shell can be seen around most of the periphery of the remnant. The outer edge of radio emission, usually defined by this bright rim, coincides perfectly with the outer X-ray boundary. Most of the emission is polarized by a modest amount, with the outer rim particularly prominent. Observations at several wavelengths are used to map out the rotation measure at high angular resolution, and determine the intrinsic magnetic field direction. The magnetic field shows a somewhat cellular pattern but with a net radial orientation and a generally fairly low degree of polarization. 44 refs.

  1. 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.

  2. Gamma-Ray Emission From Crushed Clouds in Supernova Remnants

    SciTech Connect

    Uchiyama, Yasunobu; Blandford, Roger D.; Funk, Stefan; Tajima, Hiroyasu; Tanaka, Takaaki; ,

    2010-10-27

    It is shown that the radio and gamma-ray emission observed from newly-found 'GeV-bright' supernova remnants (SNRs) can be explained by a model, in which a shocked cloud and shock-accelerated cosmic rays (CRs) frozen in it are simultaneously compressed by the supernova blastwave as a result of formation of a radiative cloud shock. Simple reacceleration of pre-existing CRs is generally sufficient to power the observed gamma-ray emission through the decays of {pi}{sup 0}-mesons produced in hadronic interactions between high-energy protons (nuclei) and gas in the compressed-cloud layer. This model provides a natural account of the observed synchrotron radiation in SNRs W51C, W44 and IC 443 with flat radio spectral index, which can be ascribed to a combination of secondary and reaccelerated electrons and positrons.

  3. Reverse-Shock in Tycho’s Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Lu, F. J.; Ge, M. Y.; Zheng, S. J.; Zhang, S. N.; Long, X.; Aschenbach, B.

    2015-06-01

    Thermal X-ray emission from young supernova remnants (SNRs) is usually dominated by the emission lines of the supernova ejecta, which are widely believed to be crossed and thus heated by the inward-propagating reverse shock (RS). Previous works using X-ray imaging data have shown that the ejecta are heated by the RS by locating the peak emission region of the most recently ionized matter, which is found to be well separated toward the inside from the outermost boundary. Here we report the discovery of a systematic increase of the Sulfur (S) to Silicon (Si) Kα line flux ratio with radius in Tycho’s SNR. This allows us, for the first time, to present continuous radial profiles of the ionization age and, furthermore, the elapsed ionization time since the onset of the ionization, which gives the history of the propagation of the ionization front into the SNR ejecta.

  4. X-ray line emission from the Tycho supernova remnant

    NASA Technical Reports Server (NTRS)

    Pravdo, S. H.; Smith, B. W.; Charles, P. A.; Tuohy, I. R.

    1979-01-01

    The observation of the X-ray spectrum of the Tycho supernova remnant in the energy range 0.5 to 20 keV is discussed. Four significant line features in the spectrum: The K alpha lines of silicon, sulphur, and iron; and the L lines of iron are examined. Comparisons between the silicon and sulphur equivalent widths and K alpha iron line energies of Tycho and Cas A are discussed. Suggest that the X-ray emitting plasma in Tycho is further from collisional ionization equilibrium than that of Cas A.

  5. Spectral evolution of accelerated particles in supernova remnants

    NASA Astrophysics Data System (ADS)

    Jiang, Z. J.; Zhang, L.; Fang, J.

    2013-08-01

    The spectral evolution of accelerated particles in supernova remnants (SNRs) is studied within the frame of the age-limited acceleration model. Because of possible amplified magnetic field around the shock in SNRs, the Alfvnic effect on the particle distribution accelerated at shock will become important. Based on available evolution models of the amplified magnetic field, the source spectral slope (qtp(t)) in the test particle approximation of shock acceleration evolves with SNR's age and qtp ? 4.2-4.4 depending on assumed values of the maximum energy of the accelerated particles and types of SNRs.

  6. Search for far-infrared emission from young supernova remnants

    NASA Technical Reports Server (NTRS)

    Wright, E. L.; Harper, D. A.; Loewenstein, R. F.; Keene, J.; Whitcomb, S. E.

    1980-01-01

    A search has been conducted for 80-350 micron emission from the Tycho, Kepler, and Cas A supernova remnants. The bolometric fluxes are less than 5 x 10 to the -11th, 4 x 10 to the -12th, and 9 x 10 to the -12th W/sq m, respectively, for the entire radio shell, corresponding to luminosities less than 25,000, 1100, and 1500 solar luminosities (within 2 standard deviations). The ratio of dust to gas in Cas A is at least 10 times less than the 'normal' ratio.

  7. A northwest-southeast asymmetry in the Crab supernova remnant

    NASA Astrophysics Data System (ADS)

    Loll, Allison

    This dissertation presents results from a Hubble Space Telescope WFPC-2 imaging survey of the Crab Nebula in F502N ([O III]), F673N ([S II]), F631N ([O I]) and F547M (continuum). These observations have revealed several Northwest-Southeast (NW-SE) asymmetries in the morphological properties of the nebula that I attribute to the proper motion of the pulsar in the NW direction. The spin-down luminosity of the pulsar generates the pulsar wind nebula (PWN) which remains centered around the pulsar in time. The pressure of the PWN has caused a shock that propagates into freely-expanding ejecta; due to the pulsar's proper motion, the shock has propagated farther in the NW direction than it has in the SE. Assuming that density of the ejecta decreases with distance from the explosion center, I show that the shock is encountering lower density ejecta in the NW causing higher shock speeds there than in the SE. The difference in shock speeds has caused a NW-SE asymmetry in the formation of filaments and the length and development of Rayleigh-Taylor fingers. I applied an existing theoretical model of PWN to the Crab and found that the pulsar's NW motion has prevented acceleration of the filaments in the SE, explaining why the SE shows an unorganized morphology and lacks long R-T fingers. In the NW, the interface has been accelerating for at least 100 years, and the R-T instability has produced very long, well-developed fingers. I utilized the continuum image to study the correlation between dust (seen via extiction of synchrotron emission) and low-ionization gas and found that dust can be found everywhere that there is low-ionization emission; this suggests the dust formed in the supernova explosion and was swept up with the gas as the shock passed through. I have estimated the gas-to-dust ratio of several filaments to be in the range of 0.050-0.100, several times higher than what is typical for the interstellar medium.

  8. A Deep Chandra Observation of Kepler's Supernova Remnant: A Type Ia Supernova with Circumstellar Interaction

    NASA Astrophysics Data System (ADS)

    Reynolds, Stephen P.; Borkowski, K. J.; Badenes, C.; Hughes, J. P.; Hwang, U.; Laming, J. M.; Blondin, J. M.

    2006-12-01

    We present initial results of a 750 ks Chandra observation of the remnant of Kepler's supernova of AD 1604. We are able to separate shocked circumstellar medium, identified by O emission below 0.72 keV, and shocked ejecta, identified by Fe L and Si and S K alpha emission. The strength and prominence of iron emission, and the absence of O-rich ejecta, support the longstanding claim that Kepler resulted from a thermonuclear supernova, even though evidence for circumstellar interaction is also strong. We present images with arcsecond resolution demonstrating that the ejecta are stratified with Si and S extending beyond Fe L emission; we also find evidence for ionization of Fe decreasing inward, i.e., increasing with distance behind the reverse shock. This chemical stratification conflicts with the predictions of some Type Ia explosion models, such as sub-Chandrasekhar models or 3-D deflagrations with well-mixed ejecta. Hard continuum emission, almost certainly synchrotron, surrounds the remnant in thin filaments, as seen in other young remnants. Ejecta blobs reach to the outer blast wave in many locations. Fe K alpha emission can be seen in spectra in almost all parts of the remnant. We observe differences in Fe K alpha line centroids and profiles, due both to ionization effects and to Doppler shifts and broadening, and containing important clues to the dynamics of the remnant. We summarize the significant constraints placed on models of Type Ia supernovae, and on the progenitor of Kepler's supernova in particular, by these observations.

  9. A Detailed X-Ray Investigation of PSR J2021+4026 and the γ-Cygni Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Hui, C. Y.; Seo, K. A.; Lin, L. C. C.; Huang, R. H. H.; Hu, C. P.; Wu, J. H. K.; Trepl, L.; Takata, J.; Wang, Y.; Chou, Y.; Cheng, K. S.; Kong, A. K. H.

    2015-01-01

    We have investigated the field around the radio-quiet γ-ray pulsar, PSR J2021+4026, with a ~140 ks XMM-Newton observation and ~56 ks archival Chandra data. Through analyzing the pulsed spectrum, we show that the X-ray pulsation is purely thermal in nature, which suggests that the pulsation originated from a hot polar cap with T ~ 3 × 106 K on the surface of a rotating neutron star. On the other hand, the power-law (PL) component that dominates the pulsar emission in the hard band is originated from off-pulse phases, which possibly comes from a pulsar wind nebula. In re-analyzing the Chandra data, we have confirmed the presence of a bow-shock nebula that extends from the pulsar to the west by ~10 arcsec. The orientation of this nebular feature suggests that the pulsar is probably moving eastward, which is consistent with the speculated proper motion by extrapolating from the nominal geometrical center of the supernova remnant (SNR) G78.2+2.1 to the current pulsar position. For G78.2+2.1, our deep XMM-Newton observation also enables a study of the central region and part of the southeastern region with superior photon statistics. The column absorption derived for the SNR is comparable to that for PSR J2021+4026, which supports their association. The remnant emission in both of the examined regions is in a non-equilibrium ionization state. Also, the elapsed time of both regions after shock-heating is apparently shorter than the Sedov age of G78.2+2.1. This might suggest that the reverse shock has reached the center not long ago. Apart from PSR J2021+4026 and G78.2+2.1, we have also serendipitously detected an X-ray flash-like event, XMM J202154.7+402855, from this XMM-Newton observation.

  10. Neutron stars, fast pulsars, supernovae and the equation of state of dense matter

    SciTech Connect

    Glendening, N.K.

    1989-06-01

    We discuss the prospects for obtaining constraints on the equation of state from astrophysical sources. Neutron star masses although few are known at present, provide a very direct constraint in as much as the connection to the equation of state involves only the assumption that Einstein's general theory of relativity is correct at the macroscopic scale. If the millisecond pulses briefly observed in the remnant of SN1987A can be attributed to uniform rotation of a pulsar, then a very severe constraint is placed on the equation of state. The theory again is very secure. The precise nature of the constraint is not yet understood, but it appears that the equation of state must be neither too soft nor stiff, and it may be that there is information not only on the stiffness of the equation of state but on its shape. Supernovae simulations involve such a plethora of physical processes including those involved in the evolution of the precollapse configuration, not all of them known or understood, that they provide no constraint at the present time. Not even the broad category of mechanism for the explosion is agreed upon (prompt shock, delayed shock, or nuclear explosion). In connection with very fast pulsars, we include some speculations on pure quark matter stars, and on possible scenarios for understanding the disappearance of the fast pulsar in SN1987A. 47 refs., 16 figs., 1 tab.

  11. The X-ray surface brightness of Kepler's supernova remnant

    NASA Technical Reports Server (NTRS)

    White, R. L.; Long, K. S.

    1983-01-01

    The first X-ray images of Kepler's supernova remnant (SN Ophiuchi 1604) are presented, and consequences for SNR models are discussed. Observations made with the Einstein Observatory Imaging Proportional Counter and High Resolution Imager show the remnant to be circular, with a strong shell brighter in the north than in the south. A flux of 1.2 x 10 to the -10th ergs/sq cm per sec was measured in the 0.15-4.5 keV region, which corresponds to an X-ray luminosity of 1.0 x 10 to the 36th ergs/sec at a distance of 5 kpc and an interstellar medium density of 2.8 x 10 to the 21st/sq cm. The X-ray observations do not allow the determination of whether the SNR is in the adiabatic or free expansion phase, but in either case it is shown that the mean ISM density must be greater than about 0.1/cu cm. In addition, the density of the X-ray emitting gas must be high, and its electron temperature must be fairly low. The high ISM densities derived for Kepler's SNR and other SNRs thus suggest an atypical ISM, possibly influenced by mass lost from the pre-supernova star.

  12. Nonlinear Shock Acceleration and Photon Emission in Supernova Remnants

    NASA Technical Reports Server (NTRS)

    Ellison, Donald C.; Berezhko, Evgeny G.; Baring, Matthew G.

    2000-01-01

    We have extended a simple model of nonlinear diffusive shock acceleration (Berezhko & Ellison 1999: Ellison &, Berezhko 1999a) to include the injection and acceleration of electrons and the production of photons from bremsstrahlung, synchrotron, inverse Compton, and pion-decay processes. We argue that, the results of this model, which is simpler to use than more elaborate ones, offer a significant improvement, over test-particle, power-law spectra which are often used in astrophysical applications of diffusive shock acceleration. With an evolutionary supernova remnant (SNR) model to obtain shock parameters as functions of ambient interstellar medium parameters and time, we predict broad-band continuum photon emission from supernova remnants in general, and SN1006 in particular, showing that our results compare well with the more complete time-dependent and spherically symmetric nonlinear model of Berezhko, Ksenofontov, & Petukhov (1999a). We discuss the implications nonlinear shock acceleration has for X-ray line emission, and use our model to describe how ambient conditions determine the TeV/radio flux ratio, an important parameter for gamma-ray observations of radio SNRs.

  13. Carbon Monoxide in the Cassiopeia A Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Rho, Jeonghee; Jarrett, T.; Reach, W.; Gomez, H.; Andersen, M.

    2009-01-01

    We report the near-infrared detection of first overtone Carbon Monoxide (CO) emission from the young supernova remnant Cassiopeia A. The presence of CO emission implies conditions are conducive to dust formation long after the typically quoted 200--800 days from the explosion event. The CO in Cas A formed in an earlier stage of SNe explosion and has cooled, is now visible in the infrared due to heating from the reverse shock. We present the first map of the CO distribution in the ejecta of a supernova remnant by subtracting the continuum emission from the CO filter map. We compare the first overtone CO emission with SN1987A and find 30 times less CO. The mass of CO in Cas A is at least 1E-6 Msun. Our CO detection suggests that molecule mixing is small in the SN ejecta and during the development of reverse shock. Detection of the CO overtone band in Cas A demonstrates that astrochemical processes and molecule formation continue more than 300 years after the initial explosion.

  14. Planck intermediate results. XXXI. Microwave survey of Galactic supernova remnants

    NASA Astrophysics Data System (ADS)

    Planck Collaboration; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Battaner, E.; Benabed, K.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bobin, J.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Brogan, C. L.; Burigana, C.; Cardoso, J.-F.; Catalano, A.; Chamballu, A.; Chiang, H. C.; Christensen, P. R.; Colombi, S.; Colombo, L. P. L.; Crill, B. P.; Curto, A.; Cuttaia, F.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Désert, F.-X.; Dickinson, C.; Diego, J. M.; Donzelli, S.; Doré, O.; Dupac, X.; Enßlin, T. A.; Eriksen, H. K.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Galeotta, S.; Ganga, K.; Giard, M.; Giraud-Héraud, Y.; González-Nuevo, J.; Górski, K. M.; Gregorio, A.; Gruppuso, A.; Hansen, F. K.; Harrison, D. L.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hobson, M.; Holmes, W. A.; Huffenberger, K. M.; Jaffe, A. H.; Jaffe, T. R.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Kunz, M.; Kurki-Suonio, H.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Lawrence, C. R.; Leonardi, R.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Maino, D.; Maris, M.; Marshall, D. J.; Martin, P. G.; Martínez-González, E.; Masi, S.; Matarrese, S.; Mazzotta, P.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Noviello, F.; Novikov, D.; Novikov, I.; Oppermann, N.; Oxborrow, C. A.; Pagano, L.; Pajot, F.; Paladini, R.; Pasian, F.; Peel, M.; Perdereau, O.; Perrotta, F.; Piacentini, F.; Piat, M.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Popa, L.; Pratt, G. W.; Puget, J.-L.; Rachen, J. P.; Reach, W. T.; Reich, W.; Reinecke, M.; Remazeilles, M.; Renault, C.; Rho, J.; Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Roudier, G.; Rusholme, B.; Sandri, M.; Savini, G.; Scott, D.; Stolyarov, V.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Wade, L. A.; Yvon, D.; Zacchei, A.; Zonca, A.

    2016-02-01

    The all-sky Planck survey in 9 frequency bands was used 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 evident 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, Sν ∝ ν-α, with the spectral index, α, increasing by 0.5-1 above a break frequency in the range 10-60 GHz. The break could be due to synchrotron losses.

  15. Model images of radio halos around supernova remnants

    NASA Technical Reports Server (NTRS)

    Reynolds, Stephen P.

    1994-01-01

    I present model calculations of profiles and two-dimensional images of the radio synchrotron emission of young supernova remnants, concentrating on observable effects of relativistic eletrons diffusing upstream of the shock wave. If the preshock electron scattering mean free path is sufficiently long, observable synchrotron halos outside the bulk of the radio emission can potentially result; their absence can constrain the mean free path from above. If scattering is primarily due, as expected, to Alfven waves with amplitude detla(B), the halo is expected to extend a distance of order r(sub g)c(delta(B)/B)(exp 2)/v(sub s) beyond the shock, where r(sub g) is the gyroradius of the electrons emitting at the observed frequency, B is the upstream magnetic field strength, v(sub s) is the shock velocity, and the amplitude delta(B) refers to wave with wavelength comparable to r(sub g), of order 10(exp 13) cm for typical supernova-remnant parameters. However, the detailed geometry of the halo varies with the assumptions about particle acceleration in the shock wave. I present an atlas of model profiles and images as a function of preshock diffusion length, of aspect angle between the magnetic field and the line of sight, and of other relevant parameters.

  16. 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.

  17. 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.

  18. 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.

  19. X-RAY EJECTA KINEMATICS OF THE GALACTIC CORE-COLLAPSE SUPERNOVA REMNANT G292.0+1.8

    SciTech Connect

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

    2015-02-10

    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 ≲ v{sub r}  ≲ 1400 km s{sup –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 10{sup 51} erg, we estimate the total ejecta mass to be ≲8 M {sub ☉}, and we propose an upper limit of ≲35 M {sub ☉} on the progenitor's mass.

  20. 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.

  1. Diffusive propagation of cosmic rays from supernova remnants in the Galaxy. I: spectrum and chemical composition

    SciTech Connect

    Blasi, Pasquale; Amato, Elena E-mail: amato@arcetri.astro.it

    2012-01-01

    In this paper we investigate the effect of stochasticity in the spatial and temporal distribution of supernova remnants on the spectrum and chemical composition of cosmic rays observed at Earth. The calculations are carried out for different choices of the diffusion coefficient D(E) experienced by cosmic rays during propagation in the Galaxy. In particular, at high energies we assume that D(E)∝E{sup δ}, with δ = 1/3 and δ = 0.6 being the reference scenarios. The large scale distribution of supernova remnants in the Galaxy is modeled following the distribution of pulsars, with and without accounting for the spiral structure of the Galaxy. We find that the stochastic fluctuations induced by the spatial and temporal distribution of supernovae, together with the effect of spallation of nuclei, lead to mild but sensible violations of the simple, leaky-box-inspired rule that the spectrum observed at Earth is N(E)∝E{sup −α} with α = γ+δ, where γ is the slope of the cosmic ray injection spectrum at the sources. Spallation of nuclei, even with the small rates appropriate for He, may account for small differences in spectral slopes between different nuclei, possibly providing an explanation for the recent CREAM observations. For δ = 1/3 we find that the slope of the proton and helium spectra are ∼ 2.67 and ∼ 2.6 respectively (with fluctuations depending on the realization of source distribution) at energies around ∼ 1 TeV (to be compared with the measured values of 2.66±0.02 and 2.58±0.02). For δ = 0.6 the hardening of the He spectra is not observed. The stochastic effects discussed above cannot be found in ordinary propagation calculations, such as GALPROP, where these effects and the point like nature of the sources are not taken into account. We also comment on the effect of time dependence of the escape of cosmic rays from supernova remnants, and of a possible clustering of the sources in superbubbles. In a second paper we will discuss the implications of these different scenarios for the anisotropy of cosmic rays.

  2. Gamma rays from cosmic rays in supernova remnants

    NASA Astrophysics Data System (ADS)

    Dermer, C. D.; Powale, G.

    2013-05-01

    Context. Cosmic rays are thought to be accelerated at supernova remnant (SNR) shocks, but obtaining conclusive evidence for this hypothesis is difficult. Aims: New data from ground-based γ-ray telescopes and the Large Area Telescope on the Fermi Gamma-ray Space Telescope are used to test this hypothesis. A simple model for γ-ray production efficiency is compared with measured γ-ray luminosities of SNRs, and the GeV to TeV fluxes ratios of SNRs are examined for correlations with SNR ages. Methods: The supernova explosion is modeled as an expanding spherical shell of material that sweeps up matter from the surrounding interstellar medium (ISM). The accumulated kinetic energy of the shell, which provides the energy available for nonthermal particle acceleration, changes when matter is swept up from the ISM and the SNR shell decelerates. A fraction of this energy is assumed to be converted into the energy of cosmic-ray electrons or protons. Three different particle radiation processes - nuclear pion-production interactions, nonthermal electron bremsstrahlung, and Compton scattering - are considered. Results: The efficiencies for γ-ray production by these three processes are compared with γ-ray luminosities of SNRs. Our results suggest that SNRs become less γ-ray luminous at ≳104 yr, and are consistent with the hypothesis that supernova remnants accelerate cosmic rays with an efficiency of ≈10% for the dissipation of kinetic energy into nonthermal cosmic rays. Weak evidence for an increasing GeV to TeV flux ratio with SNR age is found.

  3. 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).

  4. Dynamical Evolution of Supernova Remnants Breaking Through Molecular Clouds

    NASA Astrophysics Data System (ADS)

    Cho, Wankee; Kim, Jongsoo; Koo, Bon-Chul

    2015-04-01

    We carry out three-dimensional hydrodynamic simulations of the supernova remnants (SNRs) produced inside molecular clouds (MCs) near their surface using the HLL code tep{har83}. We explore the dynamical evolution and the X-ray morphology of SNRs after breaking through the MC surface for ranges of the explosion depths below the surface and the density ratios of the clouds to the intercloud media (ICM). We find that if an SNR breaks out through an MC surface in its Sedov stage, the outermost dense shell of the remnant is divided into several layers. The divided layers are subject to the Rayleigh-Taylor instability and fragmented. On the other hand, if an SNR breaks through an MC after the remnant enters the snowplow phase, the radiative shell is not divided to layers. We also compare the predictions of previous analytic solutions for the expansion of SNRs in stratified media with our one-dimensional simulations. Moreover, we produce synthetic X-ray surface brightness in order to research the center-bright X-ray morphology shown in thermal composite SNRs. In the late stages, a breakout SNR shows the center-bright X-ray morphology inside an MC in our results. We apply our model to the observational results of the X-ray morphology of the thermal composite SNR 3C 391.

  5. Supernovae. The bubble-like interior of the core-collapse supernova remnant Cassiopeia A.

    PubMed

    Milisavljevic, Dan; Fesen, Robert A

    2015-01-30

    The death of massive stars is believed to involve aspheric explosions initiated by the collapse of an iron core. The specifics of these catastrophic explosions remain uncertain, due partly to limited observational constraints on asymmetries deep inside the star. Here we present near-infrared observations of the young supernova remnant Cassiopeia A, descendant of a type IIb core-collapse explosion, and a three-dimensional map of its interior unshocked ejecta. The remnant's interior has a bubble-like morphology that smoothly connects to and helps explain the multiringed structures seen in the remnant's bright reverse-shocked main shell of expanding debris. This internal structure may originate from turbulent mixing processes that encouraged outwardly expanding plumes of radioactive (56)Ni-rich ejecta. If this is true, substantial amounts of its decay product, (56)Fe, may still reside in these interior cavities. PMID:25635094

  6. G64.5+0.9: a new shell supernova remnant with unusual central emission

    NASA Astrophysics Data System (ADS)

    Hurley-Walker, Natasha; Davies, Matthew L.; Franzen, Thomas M. O.; Grainge, Keith; Green, D. A.; Hobson, Michael P.; Lasenby, Anthony; Pooley, Guy; Rodríguez-Gonzálvez, Carmen; Saunders, Richard D. E.; Scaife, A. M. M.; Scott, Paul F.; Shimwell, Timothy; Titterington, David; Waldram, Elizabeth; Zwart, Jonathan T. L.

    2009-09-01

    We present observations between 1.4 and 18GHz confirming that G64.5+0.9 is a new Galactic shell supernova remnant, using the Very Large Array and the Arcminute Microkelvin Imager. The remnant is a shell ~=8 arcmin in diameter with a spectral index of α = 0.47 +/- 0.03 (with α defined such that flux density S varies with frequency ν as S ~ ν-α). There is also emission near the centre of the shell, ~=1 arcmin in extent, with a spectral index of α = 0.81 +/- 0.02. We do not find any evidence for spectral breaks for either source within our frequency range. The nature of the central object is unclear and requires further investigation, but we argue that it is most unlikely to be extragalactic. It is difficult to avoid the conclusion that it is associated with the shell, although its spectrum is very unlike that of known pulsar wind nebulae. We kindly request that any reference to this paper should be cited as `AMI Consortium: Hurley-Walker et al. 2009'. Issuing author: E-mail: nh313@mrao.cam.ac.uk

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

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

    It is shown that only a small fraction of the many supernovae in the Galaxy produces observable supernova remnants; this fraction, which is found to depend weakly on the lower mass limit of the SN progenitors, and more strongly on the specific characteristics of the associated interstellar medium, decreases from about 15% near the galactic center to 10% at R(gal) of about 10 kpc and drops nearly to zero for R(gal) greater than 15 kpc. Whether an SNR is detectable is determined by the density of the ambient interstellar medium in which it is embedded; it is found that SNRs are detectable only above some critical density (about 0.1 per cu cm). The presence of large low-density superbubble cavities around stellar associations due to the combined effects of stellar winds and supernova shells strongly suggests that a large portion of the detectable SNRs must have runaway stars as their progenitors.

  8. Spectral and morphological analysis of the remnant of supernova 1987A with ALMA and ATCA

    SciTech Connect

    Zanardo, Giovanna; Staveley-Smith, Lister; Indebetouw, Remy; Chevalier, Roger A.; Matsuura, Mikako; Barlow, Michael J.; Gaensler, Bryan M.; Fransson, Claes; Lundqvist, Peter; Manchester, Richard N.; Baes, Maarten; Kamenetzky, Julia R.; Lakićević, Maša; Marcaide, Jon M.; Meixner, Margaret; Ng, C.-Y.; Park, Sangwook; and others

    2014-12-01

    We present a comprehensive spectral and morphological analysis of the remnant of supernova (SN) 1987A with the Australia Telescope Compact Array (ATCA) and the Atacama Large Millimeter/submillimeter Array (ALMA). The non-thermal and thermal components of the radio emission are investigated in images from 94 to 672 GHz (λ 3.2 mm to 450 μm), with the assistance of a high-resolution 44 GHz synchrotron template from the ATCA, and a dust template from ALMA observations at 672 GHz. An analysis of the emission distribution over the equatorial ring in images from 44 to 345 GHz highlights a gradual decrease of the east-to-west asymmetry ratio with frequency. We attribute this to the shorter synchrotron lifetime at high frequencies. Across the transition from radio to far infrared, both the synchrotron/dust-subtracted images and the spectral energy distribution (SED) suggest additional emission beside the main synchrotron component (S {sub ν}∝ν{sup –0.73}) and the thermal component originating from dust grains at T ∼ 22 K. This excess could be due to free-free flux or emission from grains of colder dust. However, a second flat-spectrum synchrotron component appears to better fit the SED, implying that the emission could be attributed to a pulsar wind nebula (PWN). The residual emission is mainly localized west of the SN site, as the spectral analysis yields –0.4 ≲ α ≲ –0.1 across the western regions, with α ∼ 0 around the central region. If there is a PWN in the remnant interior, these data suggest that the pulsar may be offset westward from the SN position.

  9. X-ray Observations of the Vela Supernova Remnant Ejecta Fragments

    NASA Astrophysics Data System (ADS)

    Gaetz, Terrance J.; Edgar, Richard J.; Plucinsky, Paul P.; Smith, Randall K.; Haverkorn, Marijke; Sankrit, Ravi; Aschenbach, Bernd

    2009-08-01

    The Vela Supernova remnant (SNR) is one of the nearest SNRs. At an estimated distance of ~250 pc, it is likely just beyond the edge of the local bubble and there seems to be no direct evidence of interaction with the bubble. The SNR is in a complex environment, though. It is notably brighter and more sharply defined to the east and north, but much fainter and less ordered in the west and south. The age of the SNR is estimated to be ~11000 years, based on the spin-down rate of its associated pulsar, but ages as large as 20000-30000 years have also been argued. This SNR is also notable for a number of protrusions extending well beyond its rim, which were suggested to be fragments of ejecta from the supernova explosion. X-ray spectroscopy has since confirmed several of these protrusions to indeed be strongly enriched with ejecta. We present initial results based on the XMM-Newton and Suzaku X-ray observations of two these ejecta fragments.

  10. A Chandra ACIS Study of 30 Doradus. I. Superbubbles and Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Townsley, Leisa K.; Broos, Patrick S.; Feigelson, Eric D.; Brandl, Bernhard R.; Chu, You-Hua; Garmire, Gordon P.; Pavlov, George G.

    2006-04-01

    We present an X-ray tour of diffuse emission in the 30 Doradus star-forming complex in the Large Magellanic Cloud using high spatial resolution X-ray images and spatially resolved spectra obtained with the Advanced CCD Imaging Spectrometer on board the Chandra X-Ray Observatory. The dominant X-ray feature of the 30 Doradus nebula is the intricate network of diffuse emission generated by interacting stellar winds and supernovae working together to create vast superbubbles filled with hot plasma. We construct maps of the region showing variations in plasma temperature (T=3-9 million degrees), absorption [NH=(1-6)×1021 cm-2], and absorption-corrected X-ray surface brightness [SX=(3-126)×1031 ergs s-1 pc-2]. Enhanced images reveal the pulsar wind nebula in the composite supernova remnant N157B, and the Chandra data show spectral evolution from nonthermal synchrotron emission in the N157B core to a thermal plasma in its outer regions. In a companion paper we show that R136, the central massive star cluster, is resolved at the arcsecond level into almost 100 X-ray sources. Through X-ray studies of 30 Doradus the complete life cycle of such a massive stellar cluster can be revealed.

  11. A New X-Ray View of the Supernova Remnant G272.2-3.2 and Its Environment

    NASA Astrophysics Data System (ADS)

    McEntaffer, R. L.; Grieves, N.; DeRoo, C.; Brantseg, T.

    2013-09-01

    We present an analysis of Chandra X-Ray Observatory data detailing a Galactic supernova remnant, G272.2-3.2. A clear shell of emission is resolved as a series of filaments and knots around the entire rim of the remnant. Spectral analysis of these features show that they are consistent with shock heating of interstellar material in a clumpy medium. We contrast these X-ray images with 22 μm Wide-field Infrared Survey Explorer (WISE) data to verify this interaction. Spatially separated from the shell we see a central diffuse region dominated by harder, hotter emission. Spatial spectroscopy shows a clear enhancement of metals consistent with a Type Ia explosion, namely S, Si, and Fe. We find no clear evidence for a compact object or pulsar wind nebula and argue for a Type Ia origin. Consideration of the ionization timescales suggest an age of 11,000 yr for G272.2-3.2.

  12. Nature Versus Nurture: Do Asymmetries in Supernova Remnant Ejecta Reflect the Explosion or the Environment of the Progenitor?

    NASA Astrophysics Data System (ADS)

    Lopez, Laura A.; Ramirez-Ruiz, E.

    2011-09-01

    Recent work has demonstrated that Type Ia supernova remnants (SNRs) have statistically more spherical and mirror-symmetric X-ray line and continuum emission than core-collapse (CC) SNRs. The ability to type SNRs based on thermal X-ray emission morphology alone could reflect either the distinct explosion mechanisms or the different circumstellar environments of Type Ia and CC SNRs. In this talk, we present new results exploring this "nature" versus "nurture" conundrum. To test if asymmetries arise from explosions, we examine whether pulsar kick velocities are correlated with ejecta (a)symmetries (as measured using Chandra, XMM-Newton, and ROSAT images). We also study Type Ia and CC SNRs in a variety of conditions to search for trends in (a)symmetries with environmental factors (e.g., star-formation activity). Collectively, this work provides new insights into the nature of SN explosions and the dynamical evolution of their remnants.

  13. A NEW X-RAY VIEW OF THE SUPERNOVA REMNANT G272.2-3.2 AND ITS ENVIRONMENT

    SciTech Connect

    McEntaffer, R. L.; Grieves, N.; DeRoo, C.; Brantseg, T.

    2013-09-10

    We present an analysis of Chandra X-Ray Observatory data detailing a Galactic supernova remnant, G272.2-3.2. A clear shell of emission is resolved as a series of filaments and knots around the entire rim of the remnant. Spectral analysis of these features show that they are consistent with shock heating of interstellar material in a clumpy medium. We contrast these X-ray images with 22 {mu}m Wide-field Infrared Survey Explorer (WISE) data to verify this interaction. Spatially separated from the shell we see a central diffuse region dominated by harder, hotter emission. Spatial spectroscopy shows a clear enhancement of metals consistent with a Type Ia explosion, namely S, Si, and Fe. We find no clear evidence for a compact object or pulsar wind nebula and argue for a Type Ia origin. Consideration of the ionization timescales suggest an age of 11,000 yr for G272.2-3.2.

  14. Asymmetric Circumstellar Matter in Type Ia Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Borkowski, Kazimierz J.; Reynolds, S. P.; Blondin, J. M.

    2013-01-01

    The progenitors of Type Ia supernovae (SNe) are not well understood, but are likely to be of diverse origin, including single- and double-degenerate binary systems. Among single-degenerate progenitors, substantial amounts of circumstellar material (CSM) are expelled prior to the SN explosions by asymptotic giant branch (AGB) companions to the accreting white dwarfs. A subsequent collision of SN ejecta with the dense AGB wind has been detected among several distant SNe such as SN 2002ic, SN 2008J, and more recently PTF11kx. Dense CSM ejected by an AGB companion is present in the remnant of Kepler's SN of 1604, a Type Ia event. Observations of distant SNe hint at strongly asymmetric CSM distributions. A recent study of the CSM in Kepler's SNR by Burkey et al. indicates a large (factor of 10) density contrast between the dense, disk-like equatorial outflow and the more tenuous AGB wind above the orbital plane. A significant fraction of mature Type Ia SNRs in the Large Magellanic Cloud (LMC) shows the presence of dense Fe-rich ejecta in their interiors that cannot be explained by standard models of Type Ia explosions in a uniform ambient interstellar medium. We explore the hypothesis that these remnants originated in Type Ia explosions with strongly asymmetric CSM distributions such as found in Kepler's SNR. We present results of 2-D hydrodynamical simulations of the interaction of SN ejecta with asymmetric, disk-like AGB winds throughout the whole adiabatic stage of SNR evolution. Dense, asymmetric, and highly-ionized Fe-rich ejecta are indeed present in the simulated remnants, while the blast wave assumes a spherical shape shortly after passage through the ambient CSM. We also present simulated X-ray images and spectra and compare them with X-ray observations of selected remnants in the LMC. These remnants include DEM L238 and L249, recently observed by Suzaku, whose X-ray emission is strongly dominated by dense Fe-rich ejecta in their interiors. We contrast these remnants to more typical mature Type Ia SNRs such as 0534-69.9 and 0548-70.4 whose Suzaku spectra can be satisfactorily modeled with standard (without any CSM) X-ray models for Type Ia SNRs.

  15. Numerical Study of the Vishniac Instability in Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Michaut, C.; Cavet, C.; Bouquet, S. E.; Roy, F.; Nguyen, H. C.

    2012-11-01

    The Vishniac instability is thought to explain the complex structure of radiative supernova remnants in their Pressure-Driven Thin Shell (PDTS) phase after a blast wave (BW) has propagated from a central explosion. In this paper, the propagation of the BW and the evolution of the PDTS stage are studied numerically with the two-dimensional (2D) code HYDRO-MUSCL for a finite-thickness shell expanding in the interstellar medium (ISM). Special attention is paid to the adiabatic index, γ, and three distinct values are taken for the cavity (γ1), the shell (γ2), and the ISM (γ3) with the condition γ2 < γ1, γ3. This low value of γ2 accounts for the high density in the shell achieved by a strong radiative cooling. Once the spherical background flow is obtained, the evolution of a 2D-axisymmetric perturbation is computed from the linear to the nonlinear regime. The overstable mechanism, previously demonstrated theoretically by E. T. Vishniac in 1983, is recovered numerically in the linear stage and is expected to produce and enhance anisotropies and clumps on the shock front, leading to the disruption of the shell in the nonlinear phase. The period of the increasing oscillations and the growth rate of the instability are derived from several points of view (the position of the perturbed shock front, mass fluxes along the shell, and density maps), and the most unstable mode differing from the value given by Vishniac is computed. In addition, the influence of several parameters (the Mach number, amplitude and wavelength of the perturbation, and adiabatic index) is examined and for wavelengths that are large enough compared to the shell thickness, the same conclusion arises: in the late stage of the evolution of the radiative supernova remnant, the instability is dampened and the angular initial deformation of the shock front is smoothed while the mass density becomes uniform with the angle. As a result, our model shows that the supernova remnant returns to a stable evolution and the Vishniac instability does not lead to the fragmentation of the shock as predicted by the theory.

  16. NUMERICAL STUDY OF THE VISHNIAC INSTABILITY IN SUPERNOVA REMNANTS

    SciTech Connect

    Michaut, C.; Cavet, C.; Bouquet, S. E.; Roy, F.; Nguyen, H. C.

    2012-11-10

    The Vishniac instability is thought to explain the complex structure of radiative supernova remnants in their Pressure-Driven Thin Shell (PDTS) phase after a blast wave (BW) has propagated from a central explosion. In this paper, the propagation of the BW and the evolution of the PDTS stage are studied numerically with the two-dimensional (2D) code HYDRO-MUSCL for a finite-thickness shell expanding in the interstellar medium (ISM). Special attention is paid to the adiabatic index, {gamma}, and three distinct values are taken for the cavity ({gamma}{sub 1}), the shell ({gamma}{sub 2}), and the ISM ({gamma}{sub 3}) with the condition {gamma}{sub 2} < {gamma}{sub 1}, {gamma}{sub 3}. This low value of {gamma}{sub 2} accounts for the high density in the shell achieved by a strong radiative cooling. Once the spherical background flow is obtained, the evolution of a 2D-axisymmetric perturbation is computed from the linear to the nonlinear regime. The overstable mechanism, previously demonstrated theoretically by E. T. Vishniac in 1983, is recovered numerically in the linear stage and is expected to produce and enhance anisotropies and clumps on the shock front, leading to the disruption of the shell in the nonlinear phase. The period of the increasing oscillations and the growth rate of the instability are derived from several points of view (the position of the perturbed shock front, mass fluxes along the shell, and density maps), and the most unstable mode differing from the value given by Vishniac is computed. In addition, the influence of several parameters (the Mach number, amplitude and wavelength of the perturbation, and adiabatic index) is examined and for wavelengths that are large enough compared to the shell thickness, the same conclusion arises: in the late stage of the evolution of the radiative supernova remnant, the instability is dampened and the angular initial deformation of the shock front is smoothed while the mass density becomes uniform with the angle. As a result, our model shows that the supernova remnant returns to a stable evolution and the Vishniac instability does not lead to the fragmentation of the shock as predicted by the theory.

  17. AZIMUTHAL DENSITY VARIATIONS AROUND THE RIM OF TYCHO's SUPERNOVA REMNANT

    SciTech Connect

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

    2013-06-20

    Spitzer images of Tycho's supernova remnant in the mid-infrared reveal limb-brightened emission from the entire periphery of the shell and faint filamentary structures in the interior. As with other young remnants, this emission is produced by dust grains, warmed to {approx}100 K in the post-shock environment by collisions with energetic electrons and ions. The ratio of the 70 to 24 {mu}m fluxes is a diagnostic of the dust temperature, which in turn is a sensitive function of the plasma density. We find significant variations in the 70/24 flux ratio around the periphery of Tycho's forward shock, implying order-of-magnitude variations in density. While some of these are likely localized interactions with dense clumps of the interstellar medium (ISM), we find an overall gradient in the ambient density surrounding Tycho, with densities 3-10 times higher in the northeast than in the southwest. This large density gradient is qualitatively consistent with the variations in the proper motion of the shock observed in radio and X-ray studies. Overall, the mean ISM density around Tycho is quite low ({approx}0.1-0.2 cm{sup -3}), consistent with the lack of thermal X-ray emission observed at the forward shock. We perform two-dimensional hydrodynamic simulations of a Type Ia supernova expanding into a density gradient in the ISM, and find that the overall round shape of the remnant is still easily achievable, even for explosions into significant gradients. However, this leads to an offset of the center of the explosion from the geometric center of the remnant of up to 20%, although lower values of 10% are preferred. The best match with hydrodynamical simulations is achieved if Tycho is located at a large (3-4 kpc) distance in a medium with a mean preshock density of {approx}0.2 cm{sup -3}. Such preshock densities are obtained for highly ({approx}> 50%) porous ISM grains.

  18. Expansion of the Optical Remnant from Tycho’s Supernova

    NASA Astrophysics Data System (ADS)

    Putko, Joseph; Winkler, P. Frank; Blair, William P.

    2015-01-01

    Tycho's supernova remnant (SNR) is the expanding remnant from SN 1572, the penultimate Galactic supernova to have been recorded by contemporary observers. Its optical light is almost exclusively faint hydrogen Balmer emission around the periphery of the SNR, produced where fast nonradiative shocks encounter partly neutral preshock interstellar material. A variety of filaments, presumably thin sheets oriented tangentially, surround about one-third of the radio/X-ray shell. We have used CCD images, taken from KPNO over seven epochs from 1986 to 2009, to give the first optical expansion measurement of Tycho's SNR of the CCD era. Thirty filaments were identified and measured; the majority of them are at or near the remnant's outer rim and have proper motions from 0.19‧‧ ± 0.01‧‧ yr-1 to 0.26‧‧ ± 0.02‧‧ yr-1. The associated expansion indices, defined as the ratio of the current expansion rate to the historical mean, range from 0.35 ± 0.03 to 0.52 ± 0.05. Our measurements are consistent with those from the classic study by Kamper & van den Bergh (1978, ApJ, 224, 851) for the same filaments, but the CCD measurements have higher precision, and we have measured several additional fainter filaments. For direct comparison with X-ray and radio measurements, we selected the subset of optical filaments lying exactly at the outer rim, as identified in Chandra and VLA images. Considering only these filaments, virtually all have expansion indices greater than 0.40, the Sedov value. In addition to the rim filaments, there are several seen in the interior (in projection) that have smaller proper motions; these may have been decelerated, and/or they could be directed non-tangentially. Our final epoch of images, taken from the 3.5m WIYN telescope in 2009, reveals previously undetected extremely faint optical emission surrounding well over half of the remnant shell. This newly detected faint emission agrees well with the limb as defined in X-ray and radio images.This work has been supported in part by NSF grant AST-098566.

  19. The Likely Fermi Detection of the Supernova Remnant SN 1006

    NASA Astrophysics Data System (ADS)

    Xing, Yi; Wang, Zhongxiang; Zhang, Xiao; Chen, Yang

    2016-05-01

    We report the likely detection of γ-ray emission from the northeast shell region of the historical supernova remnant (SNR) SN 1006. Having analyzed seven years of Fermi Large Area Telescope Pass 8 data for the region of SN 1006, we found a GeV gamma-ray source detected with ∼ 4σ significance. Both the position and spectrum of the source match those of HESS J1504‑418, respectively, which is TeV emission from SN 1006. Considering the source as the GeV γ-ray counterpart to SN 1006, the broadband spectral energy distribution is found to be approximately consistent with the leptonic scenario that has been proposed for the TeV emission from the SNR. Our result has likely confirmed the previous study of the SNRs with TeV shell-like morphology: SN 1006 is one of them sharing very similar peak luminosity and spectral shape.

  20. 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.

  1. High-Resolution Polarimetry of Supernova Remnant Kesteven 69

    NASA Astrophysics Data System (ADS)

    Wood, C. A.; Mufson, S. L.; Dickel, J. R.

    2008-06-01

    Reported here are high-resolution 6 cm measurements of the adolescent supernova remnant (SNR) Kesteven 69 made with the hybrid BnC configuration of the Very Large Array. Several three-field mosaics of the polarized and total intensity have been used to study this SNR. These investigations lead to a coherent picture of this region. The expanding shock defines an outer rim of high total intensity, suggesting the front is running into large dense clouds with random magnetic field directions. The SNR consists of predominantly of two types of regions, those with high total and relatively weak polarized emission and those with relatively weak total and strong polarized emission. This morphology can be generally explained by the number of clouds with organized magnetic field along the line of sight. Within this SNR there are regions where the field is varying from radial to tangential. As the SN shock encounters clouds, magnetic fields within clouds will strongly affect cloud dynamics.

  2. Grain destruction in a supernova remnant shock wave

    SciTech Connect

    Raymond, John C.; Gaetz, Terrance J.; Ghavamian, Parviz; Williams, Brian J.; Blair, William P.; Borkowski, Kazimierz J.; Sankrit, Ravi

    2013-12-01

    Dust grains are sputtered away in the hot gas behind shock fronts in supernova remnants (SNRs), gradually enriching the gas phase with refractory elements. We have measured emission in C IV λ1550 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 μm 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 C IV intensity 10'' behind the shock is too high compared with 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.

  3. Spitzer Space Telescope Spectroscopy of the Kepler Supernova Remnant

    NASA Technical Reports Server (NTRS)

    Roellig, T. L.; Onaka, T.

    2004-01-01

    The Infrared Spectrograph on the Spitzer Space Telescope was used for observations of the Kepler supernova remnant, with all four instrument modules targeted on the bright infrared knot located at 17h30m35.80s,-21d28m54.0s (J2000). The low spectral resolution modules data show a dust continuum spectrum consistent with dust grains heated by high-energy electrons, while the high resolution modules data show atomic emission line ratios consistent with excitation by a high velocity shock of greater than 100 kilometers per second and electron densities of approximately 1,000 per centimeter. The abundance ratios for the six detected elements show signs of heavy-element enhancement. This work is based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology. Support for this work was provided by NASA's Office of Space Science.

  4. Phosphorus in the young supernova remnant Cassiopeia A.

    PubMed

    Koo, Bon-Chul; Lee, Yong-Hyun; Moon, Dae-Sik; Yoon, Sung-Chul; Raymond, John C

    2013-12-13

    Phosphorus ((31)P), which is essential for life, is thought to be synthesized in massive stars and dispersed into interstellar space when these stars explode as supernovae (SNe). Here, we report on near-infrared spectroscopic observations of the young SN remnant Cassiopeia A, which show that the abundance ratio of phosphorus to the major nucleosynthetic product iron ((56)Fe) in SN material is up to 100 times the average ratio of the Milky Way, confirming that phosphorus is produced in SNe. The observed range is compatible with predictions from SN nucleosynthetic models but not with the scenario in which the chemical elements in the inner SN layers are completely mixed by hydrodynamic instabilities during the explosion. PMID:24337291

  5. 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.

  6. Type Ia supernova remnants: shaping by iron bullets

    NASA Astrophysics Data System (ADS)

    Tsebrenko, Danny; Soker, Noam

    2015-10-01

    Using 2D numerical hydrodynamical simulations of Type Ia supernova remnants (SNR Ia) we show that iron clumps few times denser than the rest of the SN ejecta might form protrusions in an otherwise spherical SNR. Such protrusions exist in some SNR Ia, e.g. SNR 1885 and Tycho. Iron clumps are expected to form in the deflagration to detonation explosion model. In SNR Ia where there are two opposite protrusions, termed `ears', such as Kepler's SNR and SNR G1.9+0.3, our scenario implies that the dense clumps, or iron bullets, were formed along an axis. Such a preferred axis can result from a rotating white dwarf progenitor. If our claim holds, this offers an important clue to the SN Ia explosion scenario.

  7. The Extraordinary Supernova Remnant in NGC 4449 Revisited

    NASA Astrophysics Data System (ADS)

    Long, Knox S.; Blair, William P.; Fesen, Robert A.; Milisavljevic, Dan; Winkler, P. Frank

    2015-01-01

    NGC 4449, a Magellanic-type irregular galaxy at a distance of about 4 Mpc, contains the most luminous known supernova remnant (SNR) in both X-ray and optical bands. Its optical spectrum is characterized by broad lines from O, Ne, S, Ar, and Ca, and its size and expansion velocity (6000 km/s) suggest that the unobserved SN exploded about 65 years ago. The remnant¹s extraordinary brightness can be attributed to the interaction of supernova ejecta with unusually dense and extensive circumstellar material. We will present new Chandra imaging, together with UV/Optical spectra of the SNR from HST/STIS and the MMT. The X-ray luminosity of the SNR is less than when it was detected with Einstein in 1980, but the luminosity and X-ray spectral shape have remained relatively constant over the last 10 years. In the FUV, the HST spectra show for the first time broad line emission from C IV 1550 Å, as well as Si IV + O IV at 1400 Å and O III] at 1660 Å. The new NUV and optical spectra are fairly similar to earlier HST/FOS spectra and to ground-based spectra we have obtained over the last decade. Here we describe these new observations, and our attempts to understand the nature of the progenitor of the SNR.We acknowledge support for this effort from NASA through grant GO-12462 from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc, under NASA contract NAS5-26555, and through Chandra Award Number GO9-0075, issued by the Chandra X-ray Observatory Center, which is operated by the Smithsonian Astrophysical Observatory, under NASA contract NAS8-03060.

  8. Forward Shock Proper Motions of Kepler's Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Katsuda, S.; Tsunemi, H.; Uchida, H.; Kimura, M.

    2008-12-01

    The X-ray structure of Kepler's supernova remnant shows a rounded shape delineated by forward shocks. We measure proper motions of the forward shocks on overall rims of the remnant, by using archival Chandra data taken in two epochs with time difference of 6.09 yr. The proper motions of the forward shocks on the northern rim are measured to be 0.076'' (±0.032'' ±0.016'') to 0.11'' (±0.014'' ±0.016'') yr-1, while those on the rest of the rims are measured to be 0.15'' (±0.017'' ±0.016'') to 0.30'' (±0.048'' ±0.016'') yr-1 here the first-term errors are statistical uncertainties and the second-term errors are systematic uncertainties. Combining the best-estimated shock velocity of 1660 +/- 120 km s-1 measured for Balmer-dominated filaments in the northern and central portions of the remnant (Sankrit et al. 2005) with the proper motions derived for the forward shocks on the northern rim, we estimate a distance of 3.3+1.6-0.4 kpc to the remnant. We measure the expansion indices, m (defined as R propto tm), to be 0.47-0.82 for most of the rims. These values are consistent with those expected in Type Ia SN explosion models, in which the ejecta and the circumstellar medium have power-law density profiles whose indices are 5-7 and 0-2, respectively. In addition, we should note the slower expansion on the northern rim than that on the southern rim. This is likely caused by the inhomogeneous circumstellar medium; the density of the circumstellar medium is higher in the north than that in the south of the remnant. The newly estimated geometric center, around which we believe the explosion point exists, is located at ~5'' offset to the north of the radio center.

  9. Radio Observations of Supernova Remnants in the M82 Starburst

    NASA Astrophysics Data System (ADS)

    Pedlar, Alan; Muxlow, Tom; Riley, Jon

    We report on recent MERLIN, VLA and VLBI observations of the compact radio sources in the nearby starburst M82, with angular resolutions ranging from arcseconds to milliarcseconds. The spectral properties of the compact sources have been investigated by 15 GHz VLA-Pie Town observations which show that 16 of the less luminous compact sources are, in fact, HII regions. However the steep non-thermal spectrum, parsec size and small variability of the remaining sources is consistent with their being supernova remnants. Several show clear shell structures at MERLIN resolution (˜50 mas) and 5 have been resolved further using VLBI. Measurements of the most compact source (41.95+575) shows an expansion velocity of ˜ 2000 km s-1, and one of the best defined SNR shells (43.31+592) shows an expansion velocity of ˜ 104 km s-1. Recent VLBI and MERLIN measurements confirm this expansion velocity and show little evidence for deceleration. We comment on the discrepancy between this measured expansion velocity and the low expansion velocities predicted theoretically for remnants in M82.

  10. X-ray Spectroscopy of Tycho's Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Stadlbauer, Th.; Aschenbach, B.

    During the calibration phase in June 2000 the XMM-Newton telescope was pointed at the location of Tycho's supernova remnant (SNR). Using the data of the EPIC-PN camera together with archival X-ray data of previous missions we analyzed the morphological structure of the SNR and its dynamical behaviour with 4.1 arcsec spatial resolution. The X-ray emission of the SNR is clearly dominated by dense ejecta being shock-heated by the passage of the reverse shock. Spectra of various regions reveal line emission from highly ionized elements (O, Mg, Si, S, Ar, Ca, Fe) with a wide range of ionization times, temperatures and abundance varying with radius. Whereas the eastern half of the remnant shows individual clumps with varying elemental composition, most of the western bright shell of the SNR is spherical symmetric with a certain radial stratification of the X-ray emission. The high sensitivity of XMM-Newton allowed extracting spectra with good photon statistics and mapping of both the line emission of individual elements and the continuum emission ranging from energies 4.2 to 10.0 keV.

  11. Search for Surviving Companions in Type Ia Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Pan, Kuo-Chuan; Ricker, Paul M.; Taam, Ronald E.

    2014-09-01

    The nature of the progenitor systems of type Ia supernovae (SNe Ia) is still unclear. One way to distinguish between the single-degenerate scenario and double-degenerate scenario for their progenitors is to search for the surviving companions (SCs). Using a technique that couples the results from multi-dimensional hydrodynamics simulations with calculations of the structure and evolution of main-sequence- (MS-) and helium-rich SCs, the color and magnitude of MS- and helium-rich SCs are predicted as functions of time. The SC candidates in Galactic type Ia supernova remnants (Ia SNR) and nearby extragalactic Ia SNRs are discussed. We find that the maximum detectable distance of MS SCs (helium-rich SCs) is 0.6-4 Mpc (0.4-16 Mpc), if the apparent magnitude limit is 27 in the absence of extinction, suggesting that the Large and Small Magellanic Clouds and the Andromeda Galaxy are excellent environments in which to search for SCs. However, only five Ia SNRs have been searched for SCs, showing little support for the standard channels in the singe-degenerate scenario. To better understand the progenitors of SNe Ia, we encourage the search for SCs in other nearby Ia SNRs.

  12. IS THERE A HIDDEN HOLE IN TYPE Ia SUPERNOVA REMNANTS?

    SciTech Connect

    Garcia-Senz, D.; Badenes, C.; Serichol, N. E-mail: carles@astro.tau.ac.il

    2012-01-20

    In this paper, we report on the bulk features of the hole carved by the companion star in the material ejected during a Type Ia supernova (SN Ia) explosion. In particular we are interested in the long-term evolution of the hole as well as in its fingerprint in the geometry of the supernova remnant (SNR) after several centuries of evolution, which is a hot topic in current SN Ia studies. We use an axisymmetric smoothed particle hydrodynamics code to characterize the geometric properties of the SNR resulting from the interaction of this ejected material with the ambient medium. Our aim is to use SNR observations to constrain the single degenerate scenario for SN Ia progenitors. Our simulations show that the hole will remain open during centuries, although its partial or total closure at later times due to hydrodynamic instabilities is not excluded. Close to the edge of the hole, the Rayleigh-Taylor instability grows faster, leading to plumes that approach the edge of the forward shock. We also discuss other geometrical properties of the simulations, like the evolution of the contact discontinuity.

  13. 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.

  14. Life after stellar death: Planetary Nebulae and Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Boumis, P.

    2013-09-01

    Planetary nebulae (PNe) are powerful tracers of our Galaxy's star formation history. Their study can provide insight to the late stages of stellar evolution, the nucleosynthesis in low and intermediate mass stars (1-8Mo) and the chemical evolution of galaxies. Supernova explosions belong to the most spectacular events in the Universe. Supernova remnants (SNRs), which are the consequent results of these events and come from the late stages of massive stars (>8Mo), are among the strongest radio sources observed. They have a major influence on both the properties of the interstellar medium (ISM) and the evolution of galaxies as a whole. They enrich the ISM with heavy elements, release about 1051 ergs of energy, heat the ISM, compress the magnetic field, and efficiently accelerate, by their shock waves, energetic cosmic rays observed throughout the Galaxy. I will present results of our work on PNe and SNRs, which aims to (a) discover optical SNRs in the Galaxy, (b) study their morphology and kinematics, (c) characterize their properties (such as density, shock velocity etc.) and (d) provide information on their interaction with the ISM, using the "Aristarchos" among other telescopes.

  15. Search for surviving companions in type Ia supernova remnants

    SciTech Connect

    Pan, Kuo-Chuan; Ricker, Paul M.; Taam, Ronald E. E-mail: pmricker@illinois.edu E-mail: taam@asiaa.sinica.edu.tw

    2014-09-01

    The nature of the progenitor systems of type Ia supernovae (SNe Ia) is still unclear. One way to distinguish between the single-degenerate scenario and double-degenerate scenario for their progenitors is to search for the surviving companions (SCs). Using a technique that couples the results from multi-dimensional hydrodynamics simulations with calculations of the structure and evolution of main-sequence- (MS-) and helium-rich SCs, the color and magnitude of MS- and helium-rich SCs are predicted as functions of time. The SC candidates in Galactic type Ia supernova remnants (Ia SNR) and nearby extragalactic Ia SNRs are discussed. We find that the maximum detectable distance of MS SCs (helium-rich SCs) is 0.6-4 Mpc (0.4-16 Mpc), if the apparent magnitude limit is 27 in the absence of extinction, suggesting that the Large and Small Magellanic Clouds and the Andromeda Galaxy are excellent environments in which to search for SCs. However, only five Ia SNRs have been searched for SCs, showing little support for the standard channels in the singe-degenerate scenario. To better understand the progenitors of SNe Ia, we encourage the search for SCs in other nearby Ia SNRs.

  16. THE MIPSGAL VIEW OF SUPERNOVA REMNANTS IN THE GALACTIC PLANE

    SciTech Connect

    Pinheiro Goncalves, D.; Noriega-Crespo, A.; Paladini, R.; Carey, S. J.; Martin, P. G.

    2011-08-15

    We report the detection of Galactic supernova remnants (SNRs) in the mid-infrared (at 24 and 70 {mu}m), in the coordinate ranges 10{sup 0} < l < 65{sup 0} and 285{sup 0} < l < 350{sup 0}, |b| < 1{sup 0}, using MIPS aboard the Spitzer Space Telescope. We search for infrared counterparts to SNRs in Green's catalog and identify 39 out of 121, i.e., a detection rate of about 32%. Such a relatively low detection fraction is mainly due to confusion with nearby foreground/background sources and diffuse emission. The SNRs in our sample show a linear trend in [F{sub 8}/F{sub 24}] versus [F{sub 70}/F{sub 24}]. We compare their infrared fluxes with their corresponding radio flux at 1.4 GHz and find that most remnants have a ratio of 70 {mu}m to 1.4 GHz which is similar to those found in previous studies of SNRs (with the exception of a few that have ratios closer to those of H II regions). Furthermore, we retrieve a slope close to unity when correlating infrared (24 and 70 {mu}m) with 1.4 GHz emission. Our survey is more successful in detecting remnants with bright X-ray emission, which we find is well correlated with the 24 {mu}m morphology. Moreover, by comparing the power emitted in the X-ray, infrared, and radio, we conclude that the energy released in the infrared is comparable to the cooling in the X-ray range.

  17. PHYSICAL STRUCTURE AND NATURE OF SUPERNOVA REMNANTS IN M101

    SciTech Connect

    Franchetti, Nicholas A.; Gruendl, Robert A.; Chu, You-Hua; Dunne, Bryan C.; Pannuti, Thomas G.; Grimes, Caleb K.; Kuntz, Kip D.; Chen, C.-H. Rosie; Aldridge, Tabitha M. E-mail: gruendl@astro.illinois.edu E-mail: bdunne@astro.illinois.edu E-mail: ckgrim01@moreheadstate.edu E-mail: rchen@mpifr-bonn.mpg.de

    2012-04-15

    Supernova remnant (SNR) candidates in the giant spiral galaxy M101 have been previously identified from ground-based H{alpha} and [S II] images. We have used archival Hubble Space Telescope (HST) H{alpha} and broadband images as well as stellar photometry of 55 SNR candidates to examine their physical structure, interstellar environment, and underlying stellar population. We have also obtained high-dispersion echelle spectra to search for shocked high-velocity gas in 18 SNR candidates, and identified X-ray counterparts to SNR candidates using data from archival observations made by the Chandra X-Ray Observatory. Twenty-one of these 55 SNR candidates studied have X-ray counterparts, although one of them is a known ultraluminous X-ray source. The multi-wavelength information has been used to assess the nature of each SNR candidate. We find that within this limited sample, {approx}16% are likely remnants of Type Ia SNe and {approx}45% are remnants of core-collapse SNe. In addition, about {approx}36% are large candidates which we suggest are either superbubbles or OB/H II complexes. Existing radio observations are not sensitive enough to detect the non-thermal emission from these SNR candidates. Several radio sources are coincident with X-ray sources, but they are associated with either giant H II regions in M101 or background galaxies. The archival HST H{alpha} images do not cover the entire galaxy and thus prevents a complete study of M101. Furthermore, the lack of HST [S II] images precludes searches for small SNR candidates which could not be identified by ground-based observations. Such high-resolution images are needed in order to obtain a complete census of SNRs in M101 for a comprehensive investigation of the distribution, population, and rates of SNe in this galaxy.

  18. An origin for pulsar kicks in supernova hydrodynamics

    NASA Astrophysics Data System (ADS)

    Burrows, Adam; Hayes, John

    1996-04-01

    It is now believed that pulsars comprise the fastest population of stars in the galaxy. With inferred mean, root-mean-square, and maximum 3-D pulsar speeds of ~300-500 km/s, ~500 km/s, and ~2000 km/s, respectively, the question of the origin of such singular proper motions becomes acute. What mechanism can account for speeds that range from zero to twice the galactic escape velocity? We speculate that a major vector component of a neutron star's proper motion comes from the hydrodynamic recoil of the nascent neutron star during the supernova explosion in which it is born. Recently, theorists have shown that asymmetries and instabilities are a natural aspect of supernova dynamics. In this paper, we highlight two phenomena: 1) the ``Brownian-like'' stochastic motion of the core in response to the convective ``boiling'' of the mantle of the protoneutron star during the post-bounce, pre-explosion accretion phase, and 2) the asymmetrical bounce and explosion of an aspherically collapsing Chandrasekhar core. In principle, either phenomenon can leave the young neutron star with a speed of hundreds of kilometers per second. However, neither has yet been adequately simulated or explored. The two-dimensional radiation/hydrodynamic calculations we present here provide only crude estimates of the potential impulses due to mass motions and neutrino emissions. A comprehensive and credible investigation will require fully three-dimensional numerical simulations not yet possible. Nevertheless, we have in the asymmetric hydrodynamics of supernovae a natural means of imparting respectable kicks to neutron stars at birth, though speeds approaching 1000 km/s are still problematic.

  19. 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.

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

    NASA Astrophysics Data System (ADS)

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

    1983-05-01

    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.

  1. SPIN TILTS IN THE DOUBLE PULSAR REVEAL SUPERNOVA SPIN ANGULAR-MOMENTUM PRODUCTION

    SciTech Connect

    Farr, Will M.; Kremer, Kyle; Kalogera, Vassiliki; Lyutikov, Maxim E-mail: kylekremer2012@u.northwestern.edu E-mail: lyutikov@purdue.edu

    2011-12-01

    The system PSR J0737-3039 is the only binary pulsar known to consist of two radio pulsars (PSR J0737-3039 A and PSR J0737-3039 B). This unique configuration allows measurements of spin orientation for both pulsars: pulsar A's spin is tilted from the orbital angular momentum by no more than 14 deg at 95% confidence; pulsar B's by 130 {+-} 1 deg at 99.7% confidence. This spin-spin misalignment requires that the origin of most of B's present-day spin is connected to the supernova that formed pulsar B. Under the simplified assumption of a single, instantaneous kick during the supernova, the spin could be thought of as originating from the off-center nature of the kick, causing pulsar B to tumble to its misaligned state. With this assumption, and using current constraints on the kick magnitude, we find that pulsar B's instantaneous kick must have been displaced from the center of mass of the exploding star by at least 1 km and probably 5-10 km. Regardless of the details of the kick mechanism and the process that produced pulsar B's current spin, the measured spin-spin misalignment in the double pulsar system provides an empirical, direct constraint on the angular momentum production in this supernova. This constraint can be used to guide core-collapse simulations and the quest for understanding the spins and kicks of compact objects.

  2. Fermi-LAT Observation of Supernova Remnant S147

    SciTech Connect

    Katsuta, J.; Uchiyama, Y.; Tanaka, T.; Tajima, H.; Bechtol, K.; Funk, S.; Lande, J.; Ballet, J.; Hanabata, Y.; Lemoine-Goumard, M.; Takahashi, T.; /JAXA, Sagamihara

    2012-08-17

    We present an analysis of gamma-ray data obtained with the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope in the region around SNR S147 (G180.0-1.7). A spatially extended gamma-ray source detected in an energy range of 0.2-10 GeV is found to coincide with SNR S147. We confirm its spatial extension at >5{sigma} confidence level. The gamma-ray flux is (3.8 {+-} 0.6) x 10{sup -8} photons cm{sup -2} s{sup -1}, corresponding to a luminosity of 1.3 x 10{sup 34} (d/1.3 kpc){sup 2} erg s{sup -1} in this energy range. The gamma-ray emission exhibits a possible spatial correlation with prominent H{alpha} filaments of S147. There is no indication that the gamma-ray emission comes from the associated pulsar PSR J0538+2817. The gamma-ray spectrum integrated over the remnant is likely dominated by the decay of neutral {pi} mesons produced through the proton-proton collisions in the filaments. Reacceleration of pre-existing CRs and subsequent adiabatic compression in the filaments is sufficient to provide the required energy density of high-energy protons.

  3. 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.

  4. Fermi Proves Supernova Remnants Make Cosmic Rays - Duration: 3 minutes, 40 seconds.

    NASA Video Gallery

    The husks of exploded stars produce some of the fastest particles in the cosmos. New findings by NASA's Fermi show that two supernova remnants accelerate protons to near the speed of light. The pro...

  5. Studying Young and Old Supernova Remnants with the Upcoming ASTRO-H X-ray Mission

    NASA Astrophysics Data System (ADS)

    Safi-Harb, Samar; Hughes, John P.; Long, Knox; Bamba, Aya; Aharonian, Felix; Foster, Adam; Funk, Stefan; Hiraga, Junko; Ishida, Manabu; Katsuda, Satoru; Koyama, Katsuji; Leutenegger, Maurice; Maeda, Yoshitomo; Matsumoto, Hironori; Mori, Koji; Nakajima, Hiroshi; Nakamori, Takashi; Nobukawa, Masayoshi; Ozaki, Masanobu; Petre, Robert; Sawada, Makoto; Tamagawa, Toru; Tamura, Keisuke; Tanaka, Takaaki; Tomida, Hiroshi; Tsunemi, Hiroshi; Uchida, Hiroyuki; Uno, Shin'ichiro; Uchiyama, Yasunobu; Yamaguchi, Hiroya; Yamauchi, Shigeo; ASTRO-H Science Working Group

    2015-01-01

    The upcoming X-ray mission ASTRO-H will open a new discovery window to the high-energy Universe thanks to the unprecedented high-resolution spectroscopy (~7eV) to be achieved with the Soft X-ray Spectrometer (SXS) combined with its broadband coverage (0.5-600 keV) with the Soft X-ray Imager (SXI), Hard X-ray Imager (HXI) and the Soft Gamma-ray Detector (SGD). Supernova remnants (SNRs) are a prime science focus for ASTRO-H, particularly with the SXS providing accurate plasma diagnostics of line-rich spectra expected from the youngest, ejecta-dominated, SNRs to the oldest SNRs impacted by their interaction with the Interstellar Medium (ISM). We here highlight the SNR science topics and program that the ASTRO-H team considers of highest priority and impact. For the younger SNRs, the primary science goals are (1) using abundance measurements to unveil SNR progenitors, (2) using spatial and velocity distribution of the ejecta to understand supernova explosion mechanisms, and (3) revealing the link between the thermal plasma state of SNRs and the efficiency of their particle acceleration. For the older SNRs where thermal emission is dominated or heavily impacted by the ISM, the primary goals are (1) constraining metal abundances and physical processes in the mature limb-brightened SNRs, and (2) understanding the puzzling nature of the `mixed-morphology' SNRs and the physics of recombining plasma. For the pulsar-powered nebulae, also known as Pulsar Wind Nebulae (PWNe) or plerions with many still lacking thermal X-ray emission from their supernova shells, ASTRO-H will shed light on their progenitors and environment. The hard X-ray coverage on board ASTRO-H will further allow a study of their broadband spectra (for the brightest objects), beyond NuSTAR's range, filling the gap between the soft X-ray regime (with current X-ray missions) and the gamma-ray regime (with Fermi in the GeV and H.E.S.S. in the TeV), allowing the search for spectral breaks in the hard X-ray band.

  6. Distribution of novae and supernova remnants in the Large Magellanic Cloud

    SciTech Connect

    Van den Bergh, S.

    1988-12-01

    Novae in the LMC appear to be distributred like an old disk population. The fact that no concentration of novae is seen within the Bar of the Large Cloud suggests that this feature is of relatively recent origin. Supernova remnants are seen to exhibit concentrations in the 30 Dor region, in the Bar of the Large Cloud, and in Constellation III. This distribution supports the idea that most of the supernova remnants in the LMC had young massive progenitors. 11 references.

  7. The Properties of the Progenitor Supernova, Pulsar Wind, and Neutron Star inside PWN G54.1+0.3

    NASA Astrophysics Data System (ADS)

    Gelfand, Joseph D.; Slane, Patrick O.; Temim, Tea

    2015-07-01

    The evolution of a pulsar wind nebula (PWN) inside a supernova remnant (SNR) is sensitive to the properties of the central neutron star, pulsar wind, progenitor supernova, and interstellar medium. These properties are both difficult to measure directly and critical for understanding the formation of neutron stars and their interaction with the surrounding medium. In this paper, we determine these properties for PWN G54.1+0.3 by fitting its observed properties with a model for the dynamical and radiative evolution of a PWN inside an SNR. Our modeling suggests that the progenitor of G54.1+0.3 was an isolated ˜15-20 {M}⊙ star which exploded inside a massive star cluster, creating a neutron star initially spinning with a period of {P}0 ˜ 30-80 ms. We also find that ≳99.9% of the pulsar’s rotational energy is injected into the PWN as relativistic electrons and positrons whose energy spectrum is well characterized by a broken power law. Finally, we propose future observations which can both test the validity of this model and better determine the properties of this source—in particular, its distance and the initial spin period of the central pulsar.

  8. Interstellar and Ejecta Dust in the Cas A Supernova Remnant

    NASA Technical Reports Server (NTRS)

    Arendt, Richard G.; Dwek, Eli; Kober, Gladys; Rho, Jonghee; Hwang, Una

    2013-01-01

    The ejecta of the Cas A supernova remnant has a complex morphology, consisting of dense fast-moving line emitting knots and diffuse X-ray emitting regions that have encountered the reverse shock, as well as more slowly expanding, unshocked regions of the ejecta. Using the Spitzer 5-35 micron IRS data cube, and Herschel 70, 100, and 160 micron PACS data, we decompose the infrared emission from the remnant into distinct spectral components associated with the different regions of the ejecta. Such decomposition allows the association of different dust species with ejecta layers that underwent distinct nuclear burning histories, and determination of the dust heating mechanisms. Our decomposition identified three characteristic dust spectra. The first, most luminous one, exhibits strong emission features at approx. 9 and 21 micron, and a weaker 12 micron feature, and is closely associated with the ejecta knots that have strong [Ar II] 6.99 micron and [Ar III] 8.99 micron emission lines. The dust features can be reproduced by magnesium silicate grains with relatively low MgO-to-SiO2 ratios. A second, very different dust spectrum that has no indication of any silicate features, is best fit by Al2O3 dust and is found in association with ejecta having strong [Ne II] 12.8 micron and [Ne III] 15.6 micron emission lines. A third characteristic dust spectrum shows features that best matched by magnesium silicates with relatively high MgO-to-SiO2 ratio. This dust is primarily associated with the X-ray emitting shocked ejecta and the shocked interstellar/circumstellar material. All three spectral components include an additional featureless cold dust component of unknown composition. Colder dust of indeterminate composition is associated with [Si II] 34.8 micron emission from the interior of the SNR, where the reverse shock has not yet swept up and heated the ejecta. The dust mass giving rise to the warm dust component is about approx. 0.1solar M. However, most of the dust mass is associated with the unidentified cold dust component. Its mass could be anywhere between 0.1 and 1 solar M, and is primarily limited by the mass of refractory elements in the ejecta. Given the large uncertainty in the dust mass, the question of whether supernovae can produce enough dust to account for ISM dust masses in the local and high-z universe remains largely unresolved.

  9. Supernova remnant W49B and its environment

    SciTech Connect

    Zhu, H.; Tian, W. W.; Zuo, P. E-mail: tww@bao.ac.cn

    2014-10-01

    We study gamma-ray supernova remnant (SNR) W49B and its environment using recent radio and infrared data. Spitzer Infrared Spectrograph low resolution data of W49B shows shocked excitation lines of H{sub 2} (0,0) S(0)-S(7) from the SNR-molecular cloud interaction. The H{sub 2} gas is composed of two components with temperatures of ∼260 K and ∼1060 K, respectively. Various spectral lines from atomic and ionic particles are detected toward W49B. We suggest that the ionic phase has an electron density of ∼500 cm{sup –3} and a temperature of ∼10{sup 4} K by the spectral line diagnoses. The mid- and far-infrared data from MSX, Spitzer, and Herschel reveal a 151 ± 20 K hot dust component with a mass of 7.5 ± 6.6 × 10{sup –4} M {sub ☉} and a 45 ± 4 K warm dust component with a mass of 6.4 ± 3.2 M {sub ☉}. The hot dust is likely from materials swept up by the shock of W49B. The warm dust may possibly originate from the evaporation of clouds interacting with W49B. We build the H I absorption spectra of W49B and four nearby H II regions (W49A, G42.90+0.58, G42.43-0.26, and G43.19-0.53) and study the relation between W49B and the surrounding molecular clouds by employing the 2.12 μm infrared and CO data. We therefore obtain a kinematic distance of ∼10 kpc for W49B and suggest that the remnant is likely associated with the CO cloud at about 40 km s{sup –1}.

  10. Supernova remnant evolution in uniform and non-uniform media

    NASA Astrophysics Data System (ADS)

    Ferreira, S. E. S.; de Jager, O. C.

    2008-01-01

    Aims:In this work numerical simulations showing the time evolution of supernova remnants (SNRs) in uniform and non-uniform interstellar medium (ISM) are presented. Methods: We use a hydrodynamic model including a kinematic calculation of the interstellar magnetic field. Important parameters influencing SNR evolution include the ejecta mass and energy of the remnant, as well as the ISM density and adiabatic index. Results: By varying these parameters we constructed an analytical expression giving the return time of the SNR reverse shock to the origin, in terms of these parameters. We also found that the reverse shock spends half of its time moving outward and the other half returning to the origin. Also computed is SNR evolution in non-uniform media where the blast wave moves from one medium into either a less or more dense medium. As the SNR moves into a medium of higher density a reflection wave is created at the interface between the two media which is driven back toward the center. This drives mass via a nonspherical flow away from the discontinuity. As this wave moves inward it also drags some of the ISM field lines (if the field is parallel with the interface) with it and heats the inside of the SNR resulting in larger temperatures in this region. When a SNR explodes in a medium with a high density and the blast wave propagates into a medium with a lower density, a cavity is being blown away changing the geometry of the high density region. Also, once the forward shock moves into the medium of less density a second reverse shock will start to evolve in this region.

  11. ALEXIS Observations of the Monogem Ring Supernova Remnant

    NASA Technical Reports Server (NTRS)

    Plucinsky, Paul; West, Donald (Technical Monitor)

    2001-01-01

    The subject grant is for the analysis of ALEXIS observations of the Monogem Ring supernova remnant using the diffuse all-sky maps produced from the ALEXIS all-sky survey. The work is to produce ratio maps of the three energy bands provided by ALEXIS, analyze the ratio data to constrain the intervening neutral hydrogen column density and the temperature and elemental abundances of the X-ray emitting gas, compare the structure to that observed in the ROSAT maps, and incorporate the results into current supenova remnant evolution models. The work outlined above has been significantly delayed since the ALEXIS diffuse all-sky maps took longer to produce than anticipated. Unfortunately, the ALEXIS satellite suffered a failure of the Pegasus launch vehicle which left the satellite in a partially functioning condition. The attitude control system of the spacecraft was unable to operate as planned and this has greatly increased the complexity of the aspect solution. Our colleagues at Los Alamos have made progress in producing these maps and are nearing completion of the final maps. However, the quality of the data have been significantly compromised by the overall lower exposure due to the spacecraft problems and the higher background of the micro-channel plate detectors. We have compared the ALEXIS and ROSAT maps of this region of the sky and there is no obvious signal in the ALEXIS maps of the Monogem Ring. We are now exploring correlation techniques to determine if there is indeed a faint signal in the ALEXIS maps. Although, the project has been a disappointment so far, the data may still provide a valuable lower limit on the neutral hydrogen column density. This is a far cry from our original intentions, but would still be valuable science. Given the large delays in producing the ALEXIS sky maps, this work will continue past the end of the grant period.

  12. X-Ray Observations of the Supernova Remnant G21.5-0.9

    NASA Astrophysics Data System (ADS)

    Safi-Harb, S.; Harrus, I. M.; Petre, R.; Pavlov, G. G.; Koptsevich, A. B.; Sanwal, D.

    2001-11-01

    We present the analysis of archival X-ray observations of the supernova remnant (SNR) G21.5-0.9. Based on its morphology and spectral properties, G21.5-0.9 has been classified as a Crab-like SNR. For that reason, it was chosen as a Chandra calibration target. In their early analysis of part of these calibration data, Slane and coworkers discovered a low surface brightness, extended emission. They interpreted this component as the blast wave formed in the supernova explosion. XMM-Newton observations by Warwick and coworkers revealed the nonthermal nature of this emission, suggesting that it is instead an extension of the synchrotron nebula. In this paper, we revisit the Chandra analysis using new calibration data, improving the statistics by a factor of 2. We also include ROSAT and ASCA observations. Our analysis confirms the nonthermal nature of the extended emission. Advanced CCD Imaging Spectrometer images indicate that this component is not limb-brightened and that it shows knotty structures and a bright filament 2' north of the center. We find no evidence of line emission from any part of the remnant. We can reject a collisional equilibrium ionization thermal model at solar abundances and nonequilibrium ionization (NEI) models (such as a plane-parallel shock model with different ionization ages and constant temperature or an NEI model with a single ionization age and a constant temperature). The entire remnant is best fitted with a power-law model with a photon index steepening away from the center. The total unabsorbed flux FX(0.5-10 keV) is 1.110-10 ergs cm-2 s-1 with an 85% contribution from the 40" radius core. Timing analysis of the High-Resolution Camera data failed to detect any pulsations. We put a 16% upper limit on the pulsed fraction. We derive the physical parameters of the putative pulsar and compare them with those of other plerions (such as the Crab nebula and 3C 58).

  13. Multi-messenger Tests for Fast-spinning Newborn Pulsars Embedded in Stripped-envelope Supernovae

    NASA Astrophysics Data System (ADS)

    Kashiyama, Kazumi; Murase, Kohta; Bartos, Imre; Kiuchi, Kenta; Margutti, Raffaella

    2016-02-01

    Fast-spinning strongly magnetized newborn neutron stars (NSs), including nascent magnetars, are popularly implemented as the engine of luminous stellar explosions. Here, we consider the scenario that they power various stripped-envelope (SE) supernovae (SNe), not only superluminous SNe Ic but also broad-line (BL) SNe Ibc and possibly some ordinary SNe Ibc. This scenario is also motivated by the hypothesis that Galactic magnetars largely originate from fast-spinning NSs as remnants of SE SNe. By consistently modeling the energy injection from magnetized wind and {}56{Ni} decay, we show that proto-NSs with ≳ 10 {ms} rotation and a poloidal magnetic field of {B}{{dip}}≳ 5× {10}14 {{G}} can be harbored in ordinary SNe Ibc. On the other hand, millisecond proto-NSs can solely power BL SNe Ibc if they are born with {B}{{dip}}≳ 5× {10}14 {{G}} and superluminous SNe Ic with {B}{{dip}}≳ {10}13 {{G}}. Then, we study how multi-messenger emission can be used to discriminate such pulsar-driven SN models from other competitive scenarios. First, high-energy X-ray and gamma-ray emission from embryonic pulsar wind nebulae can probe the underlying newborn pulsar. Follow-up observations of SE SNe using NuSTAR ∼ 50{--}100 {days} after the explosion are strongly encouraged for nearby objects. We also discuss possible effects of gravitational waves (GWs) on the spin-down of proto-NSs. If millisecond proto-NSs with {B}{{dip}}\\lt {{a}} {few}× {10}13 {{G}} emit GWs through, e.g., non-axisymmetric rotation deformed by the inner toroidal fields of {B}{{t}}≳ {10}16 {{G}}, the GW signal can be detectable from ordinary SNe Ibc in the Virgo cluster by Advanced LIGO, Advanced Virgo, and KAGRA.

  14. An Optical Survey of Supernova Remnants in M83

    NASA Astrophysics Data System (ADS)

    Blair, William P.; Long, Knox S.

    2004-11-01

    Observations of the face-on spiral galaxy M83 (NGC 5236) performed at the Cerro Tololo Inter-American Observatory in Chile have yielded a catalog of optical supernova remnant (SNR) candidates. These observations were performed with the 4 m Blanco telescope and a prime focus CCD imaging system using narrowband interference filters centered on the light of [S II], Hα, [O III], and red and blue continuum bands. Based on strong relative [S II]:Hα emission, 71 emission nebulae have been identified as SNR candidates. Positions and Hα fluxes of the candidates are presented. Follow-up spectra of 25 of the SNR candidates, also performed at CTIO, have confirmed many of the SNR identifications, although the spectra of a few objects are discrepant, perhaps because of inaccurate aperture placement. In addition, the low mean excitation of M83 H II regions has allowed a separate search for young oxygen-dominated (core collapse) SNRs similar to Cas A in our Galaxy, using [O III]:Hα. This search found a number of the same objects as the [S II]:Hα search, indicating that many of these SNRs have shock velocities in excess of 100 km s-1. However, no bona fide young core-collapse SNRs were detected with this technique, with the possible exception of the independent recovery of SN 1957D, which had been seen previously. We have also attempted to identify optical counterparts for the six historical supernovae that have occurred in M83. Except for SN 1957D, none of the historical supernovae have been detected by this survey. We compare our SNR candidate list against the Chandra X-ray source list of Soria and Wu and identify 15 X-ray sources as likely SNRs, based on positional coincidence within 1". The sources identified have hardness ratios that are soft compared to the general X-ray source population in M83. Based on observations made with the Cerro Tololo Inter-American Observatory, La Serena, Chile.

  15. Cosmic Ray Acceleration at Perpendicular Shocks in Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Ferrand, Gilles; Danos, Rebecca J.; Shalchi, Andreas; Safi-Harb, Samar; Edmon, Paul; Mendygral, Peter

    2014-09-01

    Supernova remnants (SNRs) are believed to accelerate particles up to high energies through the mechanism of diffusive shock acceleration (DSA). Except for direct plasma simulations, all modeling efforts must rely on a given form of the diffusion coefficient, a key parameter that embodies the interactions of energetic charged particles with magnetic turbulence. The so-called Bohm limit is commonly employed. In this paper, we revisit the question of acceleration at perpendicular shocks, by employing a realistic model of perpendicular diffusion. Our coefficient reduces to a power law in momentum for low momenta (of index α), but becomes independent of the particle momentum at high momenta (reaching a constant value κ∞ above some characteristic momentum p c). We first provide simple analytical expressions of the maximum momentum that can be reached at a given time with this coefficient. Then we perform time-dependent numerical simulations to investigate the shape of the particle distribution that can be obtained when the particle pressure back-reacts on the flow. We observe that for a given index α and injection level, the shock modifications are similar for different possible values of p c, whereas the particle spectra differ markedly. Of particular interest, low values of p c tend to remove the concavity once thought to be typical of non-linear DSA, and result in steep spectra, as required by recent high-energy observations of Galactic SNRs.

  16. HST/ACS Narrowband Imaging of the Kepler Supernova Remnant

    NASA Technical Reports Server (NTRS)

    Sankrit, Ravi; Blair, William P.; Frattare, Lisa M.; Rudnick, Lawrence; DeLaney, Tracey; Harrus, Ilana M.; Ennis, Jessica A.

    2007-01-01

    We present narrowband images of the Kepler supernova remnant obtained with the Advanced Camera for Surveys aboard the Hubble Space Telescope. The images, with an angular resolution of 0.05" reveal the structure of the emitting gas in unprecedented detail. Radiative and nonradiative shocks are found in close proximity, unresolvable in gromd-based spectra, indicating that the pre-shock medium is highly clumped. The ionization structure, traced by differences in the [0 111] to [N 11] flux ratio, varies on subarcsecond scales. The variation is due to 110th differences in shock velocity as well as gradients in the evolutionary stage of the shocks. A prollinent complex of knots protruding beyond the boundary of the rennallt in the northwest is found to consist of bright radiative knots, collected by arcuate nonradiative filaments. Based on the coincidence of the optical emission with a bright isolated knot of X-ray emission, we infer that this feature is due to a Rayleigh-Taylor finger that formed at the contact discontinuity and overtook the primary blast wave.

  17. WHAM Observations of High-latitude Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Orchard, Alexander; Haffner, L. Matthew; Benjamin, Robert A.; Gostisha, Martin

    2016-01-01

    The Wisconsin H-Alpha Mapper Sky Survey (WHAM-SS) traces numerous large-angle, diffuse regions containing filamentary and shell-like structures. The largest of these are complex supershells that harbor recent and on-going star formation, such as the Orion-Eridanus complex, the Gum Nebula, and the extended emission above and below the W3/W4/W5 star-forming regions in the Perseus Arm. Several large-diameter regions with simpler morphologies are also present, which we focus on here. While some of these structures are diffuse H II regions powered by nearby, isolated stars, others are clearly supernova remnants (SNRs) due to their association with X-ray or non-thermal radio emission. We highlight the structure, kinematics, and multi-wavelength properties of several SNRs using Hα maps from the WHAM-SS and data from on-going WHAM multi-wavelength surveys. WHAM research and operations are supported through NSF Award AST-1108911.

  18. XMM-Newton observation of the Tycho supernova remnant

    NASA Astrophysics Data System (ADS)

    Decourchelle, A.; Sauvageot, J. L.; Audard, M.; Aschenbach, B.; Sembay, S.; Rothenflug, R.; Ballet, J.; Stadlbauer, T.; West, R. G.

    2001-01-01

    We present the observation of the Tycho supernova remnant obtained with the EPIC and RGS instruments onboard the XMM-Newton satellite. We compare images and azimuthally averaged radial profiles in emission lines from different elements (silicon and iron) and different transition lines of iron (Fe L and Fe K). While the Fe Xvii L line and Si Xiii K line images are globally spatially coincident, the Fe K emission clearly peaks at a smaller radius, indicating a higher temperature toward the reverse shock. This is qualitatively the profile expected when the reverse shock, after travelling through the outer power-law density profile, has entered the central plateau of the ejecta. The high energy continuum map has an overall smooth distribution, with a similar extent to the radio emission. Its radial profile peaks further out than the lines emission. Brighter and harder continuum regions are observed with a rough bipolar symmetry in the eastern and western edges. The spectral analysis of the southeastern knots supports spatial variations of the relative abundance of silicon and iron, which implies an incomplete mixing of the silicon and iron layers. Based on an observation obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and the USA (NASA).

  19. SLOW DIFFUSION OF COSMIC RAYS AROUND A SUPERNOVA REMNANT

    SciTech Connect

    Fujita, Yutaka; Ohira, Yutaka; Takahara, Fumio

    2010-04-01

    We study the escape of cosmic-ray protons accelerated at a supernova remnant (SNR). We are interested in their propagation in the interstellar medium (ISM) after they leave the shock neighborhood where they are accelerated, but when they are still near the SNR with their energy density higher than that in the average ISM. Using Monte Carlo simulations, we found that the cosmic rays with energies of {approx}< TeV excite Alfven waves around the SNR on a scale of the SNR itself if the ISM is highly ionized. Thus, even if the cosmic rays can leave the shock, scattering by the waves prevents them from moving further away from the SNR. The cosmic rays form a slowly expanding cosmic-ray bubble, and they spend a long time around the SNR. This means that the cosmic rays cannot actually escape from the SNR until a fairly late stage of the SNR evolution. This is consistent with some results of Fermi and H.E.S.S. observations.

  20. A SEARCH FOR RADIO SUPERNOVA REMNANTS IN FOUR IRREGULAR GALAXIES

    SciTech Connect

    Chomiuk, Laura; Wilcots, Eric M.

    2009-04-15

    We survey four nearby irregular galaxies for radio supernova remnants (SNRs) using deep (1{sigma} {approx} 20 {mu}Jy), high-resolution ({approx}20 pc) Very Large Array continuum data at 20, 6, and 3.6 cm. We identify discrete sources in these galaxies and use radio spectral indices and H{alpha} images to categorize them as SNRs, H II regions, or background radio galaxies. Our classifications are generally in good agreement with the literature. We identify a total of 43 SNR candidates: 23 in NGC 1569, seven in NGC 4214, five in NGC 2366, and eight in NGC 4449. Only one SNR-the well-studied object J1228+441 in NGC 4449-is more luminous at 20 cm than Cas A. By comparing the total thermal flux density in each galaxy with that localized in H II regions, we conclude that a significant fraction must be in a diffuse component or in low-luminosity H II regions.

  1. SUPERNOVA REMNANTS AND STAR FORMATION IN THE LARGE MAGELLANIC CLOUD

    SciTech Connect

    Desai, Karna M.; Chu, You-Hua; Gruendl, Robert A.; Dluger, William; Katz, Marshall; Wong, Tony; Looney, Leslie W.; Chen, C.-H. Rosie; Hughes, Annie; Muller, Erik; Ott, Juergen; Pineda, Jorge L.

    2010-08-15

    It has often been suggested that supernova remnants (SNRs) can trigger star formation. To investigate the relationship between SNRs and star formation, we have examined the known sample of 45 SNRs in the Large Magellanic Cloud (LMC) to search for associated young stellar objects (YSOs) and molecular clouds. We find seven SNRs associated with both YSOs and molecular clouds, three SNRs associated with YSOs but not molecular clouds, and eight SNRs near molecular clouds but not associated with YSOs. Among the 10 SNRs associated with YSOs, the association between the YSOs and SNRs either can be rejected or cannot be convincingly established for eight cases. Only two SNRs have YSOs closely aligned along their rims; however, the time elapsed since the SNR began to interact with the YSOs' natal clouds is much shorter than the contraction timescales of the YSOs, and thus we do not see any evidence of SNR-triggered star formation in the LMC. The 15 SNRs that are near molecular clouds may trigger star formation in the future when the SNR shocks have slowed down to <45 km s{sup -1}. We discuss how SNRs can alter the physical properties and abundances of YSOs.

  2. Cosmic ray acceleration at perpendicular shocks in supernova remnants

    SciTech Connect

    Ferrand, Gilles; Danos, Rebecca J.; Shalchi, Andreas; Safi-Harb, Samar; Edmon, Paul; Mendygral, Peter

    2014-09-10

    Supernova remnants (SNRs) are believed to accelerate particles up to high energies through the mechanism of diffusive shock acceleration (DSA). Except for direct plasma simulations, all modeling efforts must rely on a given form of the diffusion coefficient, a key parameter that embodies the interactions of energetic charged particles with magnetic turbulence. The so-called Bohm limit is commonly employed. In this paper, we revisit the question of acceleration at perpendicular shocks, by employing a realistic model of perpendicular diffusion. Our coefficient reduces to a power law in momentum for low momenta (of index α), but becomes independent of the particle momentum at high momenta (reaching a constant value κ{sub ∞} above some characteristic momentum p {sub c}). We first provide simple analytical expressions of the maximum momentum that can be reached at a given time with this coefficient. Then we perform time-dependent numerical simulations to investigate the shape of the particle distribution that can be obtained when the particle pressure back-reacts on the flow. We observe that for a given index α and injection level, the shock modifications are similar for different possible values of p {sub c}, whereas the particle spectra differ markedly. Of particular interest, low values of p {sub c} tend to remove the concavity once thought to be typical of non-linear DSA, and result in steep spectra, as required by recent high-energy observations of Galactic SNRs.

  3. The likely Fermi detection of the supernova remnant RCW 103

    SciTech Connect

    Xing, Yi; Wang, Zhongxiang; Zhang, Xiao; Chen, Yang

    2014-02-01

    We report on the results from our γ-ray analysis of the supernova remnant (SNR) RCW 103 region. The data were taken with the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. An extended source is found at a position consistent with that of RCW 103 and its emission was only detected above 1 GeV (10σ significance), with a power-law spectrum with a photon index of 2.0 ± 0.1. We obtain its 1-300 GeV spectrum and the total flux gives a luminosity of 8.3 × 10{sup 33} erg s{sup –1} at a source distance of 3.3 kpc. Given the positional coincidence and property similarities of this source with other SNRs, we identify it as the likely Fermi γ-ray counterpart to RCW 103. Including radio measurements of RCW 103, the spectral energy distribution (SED) is modeled by considering emission mechanisms based on both hadronic and leptonic scenarios. We find that models in the two scenarios can reproduce the observed SED, while in the hadronic scenario the existence of SNR-molecular cloud interactions is suggested as a high density of the target protons is required.

  4. XMM-Newton observation of the Galactic supernova remnant W51C (G49.1-0.1)

    NASA Astrophysics Data System (ADS)

    Sasaki, Manami; Heinitz, Cornelia; Warth, Gabriele; Pühlhofer, Gerd

    2014-03-01

    Context. The supernova remnant (SNR) W51C is a Galactic object located in a strongly inhomogeneous interstellar medium with signs of an interaction of the SNR blast wave with dense molecular gas. Aims: Diffuse X-ray emission from the interior of the SNR can reveal element abundances in the different emission regions and shed light on the type of supernova (SN) explosion and its progenitor. The hard X-ray emission helps to identify possible candidates for a pulsar formed in the SN explosion and for its pulsar wind nebula (PWN). Methods: We have analysed X-ray data obtained with XMM-Newton. Spectral analyses in selected regions were performed. Results: Ejecta emission in the bright western part of the SNR, located next to a complex of dense molecular gas, was confirmed. The Ne and Mg abundances suggest a massive progenitor with a mass of >20 M⊙. Two extended regions emitting hard X-rays were identified (corresponding to the known sources [KLS2002] HX3 west and CXO J192318.5+140305 discovered with ASCA and Chandra, respectively), each of which has an additional point source inside and shows a power-law spectrum with Γ ≈ 1.8. Based on their X-ray emission, both sources can be classified as PWN candidates. Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA.

  5. SUPERNOVA REMNANT KES 17: AN EFFICIENT COSMIC RAY ACCELERATOR INSIDE A MOLECULAR CLOUD

    SciTech Connect

    Gelfand, Joseph D.; Castro, Daniel; Slane, Patrick O.; Temim, Tea; Hughes, John P.; Rakowski, Cara E-mail: cara.rakowski@gmail.com

    2013-11-10

    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.

  6. A DETAILED X-RAY INVESTIGATION OF PSR J2021+4026 AND THE γ-CYGNI SUPERNOVA REMNANT

    SciTech Connect

    Hui, C. Y.; Seo, K. A.; Lin, L. C. C.; Huang, R. H. H.; Wu, J. H. K.; Kong, A. K. H.; Hu, C. P.; Chou, Y.; Trepl, L.; Takata, J.; Wang, Y.; Cheng, K. S.

    2015-01-20

    We have investigated the field around the radio-quiet γ-ray pulsar, PSR J2021+4026, with a ∼140 ks XMM-Newton observation and ∼56 ks archival Chandra data. Through analyzing the pulsed spectrum, we show that the X-ray pulsation is purely thermal in nature, which suggests that the pulsation originated from a hot polar cap with T ∼ 3 × 10{sup 6} K on the surface of a rotating neutron star. On the other hand, the power-law (PL) component that dominates the pulsar emission in the hard band is originated from off-pulse phases, which possibly comes from a pulsar wind nebula. In re-analyzing the Chandra data, we have confirmed the presence of a bow-shock nebula that extends from the pulsar to the west by ∼10 arcsec. The orientation of this nebular feature suggests that the pulsar is probably moving eastward, which is consistent with the speculated proper motion by extrapolating from the nominal geometrical center of the supernova remnant (SNR) G78.2+2.1 to the current pulsar position. For G78.2+2.1, our deep XMM-Newton observation also enables a study of the central region and part of the southeastern region with superior photon statistics. The column absorption derived for the SNR is comparable to that for PSR J2021+4026, which supports their association. The remnant emission in both of the examined regions is in a non-equilibrium ionization state. Also, the elapsed time of both regions after shock-heating is apparently shorter than the Sedov age of G78.2+2.1. This might suggest that the reverse shock has reached the center not long ago. Apart from PSR J2021+4026 and G78.2+2.1, we have also serendipitously detected an X-ray flash-like event, XMM J202154.7+402855, from this XMM-Newton observation.

  7. Spatially resolved X-ray spectroscopy of the Vela supernova remnant

    NASA Astrophysics Data System (ADS)

    Lu, F. J.; Aschenbach, B.

    2000-10-01

    Spatially resolved (typically 10') soft X-ray spectral analyses of the whole Vela supernova remnant (SNR) are presented. The X-ray data were obtained in the ROSAT all-sky survey (RASS). The spectra can be well represented by two-temperature Raymond-Smith thermal plasma models. The spatial distributions of the temperatures of the hot component show that most of the central and the southern parts of the remnant are significantly hotter (1.2 keV) than the northern half (0.5 keV). The temperatures of the cool component range from 0.09 keV to 0.25 keV and have a distribution similar to that of the hot component. The emission measure of the cool component dominates the X-ray emission. It is distributed like the observed brightness, bright in the north and east and it shows filamentary structure. The distribution of the hot component emission measure appears to be flatter and it is significantly different from the intensity map. The absorption column densities NH range from 5x1019 cm-2 to 6x1020 cm-2. The distribution shows that a large region in the north-east and the entire south-west are strongly absorbed. These strong absorption regions probably correspond to shocked low density HI clouds. We show that the Vela pulsar X-ray jet corresponds to an enhanced thermal pressure region south of the Vela pulsar. Both the thermal pressure map and the 0.9-2.4 keV intensity map show that the X-ray jet is 40arcmin longer than previously claimed. The total X-ray flux of the Vela SNR in the 0.1-2.5 keV band is about 1.3x 10-8 erg cm-2 s-1. It corresponds to a luminosity of 2.2x1035 erg s-1 for a distance of 250 pc.

  8. Experimental clues on pulsar energy losses and the role of circumpulsar supernova fallback disks

    NASA Astrophysics Data System (ADS)

    Grimani, C.

    2009-12-01

    Positron measurements in cosmic rays, studies of gravitational wave emission from isolated pulsars and observations of circumpulsar supernova fallback disks allow us to set upper limits on several energy loss mechanisms of young and mature pulsars. Presently, the above experimental evidences do not lead to conflicting scenarios. In particular, we focus on pulsar spin down due to friction or propeller torque from supernova fallback disks. Gravitational wave emission from circumpulsar planetary systems or precessing disks does not play a relevant role in pulsar spin down. However, the detection of gravitational waves from these systems with future space interferometers would allow us to estimate the fraction of pulsars surrounded by disks. While the planetary system detection appears to be unfeasible, the DECI-Hertz Interferometer Gravitational Wave Observatory (DECIGO) and the Big Bang Observatory (BBO) might reveal the presence of precessing disks.

  9. Toward an Empirical Theory of Pulsar Emission. XI. Understanding the Orientations of Pulsar Radiation and Supernova “Kicks”

    NASA Astrophysics Data System (ADS)

    Rankin, Joanna M.

    2015-05-01

    Two entwined problems have remained unresolved since pulsars were discovered nearly 50 yr ago: the orientation of their polarized emission relative to the emitting magnetic field and the direction of putative supernova “kicks” relative to their rotation axes. The rotational orientation of most pulsars can be inferred only from the (“fiducial”) polarization angle of their radiation, when their beam points directly at the Earth and the emitting polar fluxtube field is ∥ to the rotation axis. Earlier studies have been unrevealing owing to the admixture of different types of radiation (core and conal, two polarization modes), producing both ∥ or ⊥ alignments. In this paper we analyze some 50 pulsars having three characteristics: core radiation beams, reliable absolute polarimetry, and accurate proper motions (PMs). The “fiducial” polarization angle of the core emission, we then find, is usually oriented ⊥ to the PM direction on the sky. The primary core emission is polarized ⊥ to the projected magnetic field in Vela and other pulsars where X-ray imaging reveals the orientation. This shows that the PMs usually lie ∥ to the rotation axes on the sky. Two key physical consequences then follow: first, to the extent that supernova “kicks” are responsible for pulsar PMs, they are mostly ∥ to the rotation axis; and, second, most pulsar radiation is heavily processed by the magnetospheric plasma such that the lowest altitude “parent” core emission is polarized ⊥ to the emitting field, propagating as the extraordinary (X) mode.

  10. Expanding Ejecta in the Oxygen-Rich Supernova Remnant G292.0+1.8: Direct Measurement Through Proper Motions

    NASA Astrophysics Data System (ADS)

    Winkler, P. Frank; Twelker, Karl; Reith, Claudine N.; Long, Knox S.

    2009-02-01

    We report here the first study of proper motions of fast filaments in the young, oxygen-rich supernova remnant G292.0+1.8, carried out using a series of [O III] 5007 Å emission-line images taken over a period of more than 21 years. Images taken at seven epochs from 1986 to 2008, all from telescopes at the Cerro Tololo Inter-American Observatory, show oxygen-emitting filaments, presumably ejecta fragments, throughout most of the remnant. We have measured the proper motions for 67 discrete filaments through two-dimensional correlations between images from different epochs. While the motions are small, mostly 20-100 mas yr-1, they are nevertheless measurable through a robust technique of averaging measurements from many epoch pairs. The data are qualitatively consistent with a free-expansion model, and clearly show systematic motions outward from a point near the center of the radio/X-ray shell. Global fits using this model indicate an expansion center at R.A.(2000.) = 11h24m34..s4, decl.(2000.) = -59°15'51'', and a kinematic age of 2990 ± 60 years. The young pulsar PSR J1124-5916 is located 46'' southeast of the expansion center. Assuming that it was launched by the supernova, we expect the pulsar to be moving southeastward at 16 mas yr-1, or a transverse velocity of 440 km s-1. We find the fastest ejecta along an axis oriented roughly N-S in the plane of the sky, suggesting that a bipolar explosion produced G292.0+1.8, as appears to have been the case for Cas A.

  11. Interstellar and ejecta dust in the cas a supernova remnant

    SciTech Connect

    Arendt, Richard G.; Dwek, Eli; Kober, Gladys; Rho, Jeonghee; Hwang, Una

    2014-05-01

    Infrared continuum observations provide a means of investigating the physical composition of the dust in the ejecta and swept up medium of the Cas A supernova remnant (SNR). Using low-resolution Spitzer IRS spectra (5-35 μm), and broad-band Herschel PACS imaging (70, 100, and 160 μm), we identify characteristic dust spectra, associated with ejecta layers that underwent distinct nuclear burning histories. The most luminous spectrum exhibits strong emission features at ∼9 and 21 μm and is closely associated with ejecta knots with strong Ar emission lines. The dust features can be reproduced by magnesium silicate grains with relatively low Mg to Si ratios. Another dust spectrum is associated with ejecta having strong Ne emission lines. It has no indication of any silicate features and is best fit by Al{sub 2}O{sub 3} dust. A third characteristic dust spectrum shows features that are best matched by magnesium silicates with a relatively high Mg to Si ratio. This dust is primarily associated with the X-ray-emitting shocked ejecta, but it is also evident in regions where shocked interstellar or circumstellar material is expected. However, the identification of dust composition is not unique, and each spectrum includes an additional featureless dust component of unknown composition. Colder dust of indeterminate composition is associated with emission from the interior of the SNR, where the reverse shock has not yet swept up and heated the ejecta. Most of the dust mass in Cas A is associated with this unidentified cold component, which is ≲ 0.1 M {sub ☉}. The mass of warmer dust is only ∼0.04 M {sub ☉}.

  12. STAR FORMATION ASSOCIATED WITH THE SUPERNOVA REMNANT IC443

    SciTech Connect

    Xu Jinlong; Wang Junjie; Miller, Martin

    2011-02-01

    We have performed submillimeter and millimeter observations in CO lines toward supernova remnant (SNR) IC443. The CO molecular shell coincides well with the partial shell of the SNR detected in radio continuum observations. Broad emission lines and three 1720 MHz OH masers were detected in the CO molecular shell. The present observations have provided further evidence in support of the interaction between the SNR and the adjoining molecular clouds (MCs). The total mass of the MCs is 9.26 x 10{sup 3} M{sub sun}. The integrated CO line intensity ratio (R{sub I{sub CO(3-2)}/I{sub CO(2-1)}}) for the whole MC is between 0.79 and 3.40. The average value is 1.58, which is much higher than previous measurements of individual Galactic MCs. Higher line ratios imply that shocks have driven into the MCs. We conclude that high R{sub I{sub CO(3-2)}/I{sub CO(2-1)}} is identified as a good signature of the SNR-MC interacting system. Based on the IRAS Point Source Catalog and the Two Micron All Sky Survey near-infrared database, 12 protostellar object and 1666 young stellar object (YSO) candidates (including 154 classical T Tauri stars and 419 Herbig Ae/Be stars) are selected. In the interacting regions, the significant enhancement of the number of protostellar objects and YSOs indicates the presence of some recently formed stars. After comparing the characteristic timescales of star formation with the age of IC443, we conclude that the protostellar objects and YSO candidates are not triggered by IC443. For the age of the stellar winds shell, we have performed our calculation on the basis of a stellar wind shell expansion model. The results and analysis suggest that the formation of these stars may be triggered by the stellar winds of the IC443 progenitor.

  13. Escape of cosmic-ray electrons from supernova remnants

    NASA Astrophysics Data System (ADS)

    Ohira, Yutaka; Yamazaki, Ryo; Kawanaka, Norita; Ioka, Kunihito

    2012-11-01

    We investigate the escape of cosmic ray (CR) electrons from a supernova remnant (SNR) to interstellar space. We show that CR electrons escape in order, from high energies to low energies, like CR nuclei. However, the escape starts later than the beginning of the Sedov phase at an SNR age of 103 to 7 × 103 yr, and the maximum energy of runaway CR electrons is below the knee at about 0.3-50 TeV because, unlike CR nuclei, CR electrons lose their energy as a result of synchrotron radiation. The highest-energy CR electrons might have already been detected by the High Energy Stereoscopic System (HESS) and MAGIC as a cut-off in the CR electron spectrum, and it will be probed by the Alpha Magnetic Spectrometer (AMS-02), the Calorimeteric Electron Telescope (CALET), the Cherenkov Telescope Array (CTA) and the Large High Altitude Air Shower Observatory (LHAASO) experiments. We also calculate the spatial distribution of runaway CR electrons and their radiation spectra around SNRs. Contrary to common belief, maximum-energy photons of synchrotron radiation around 1 keV are emitted by runaway CR electrons, which have been caught up by the shock. Inverse Compton scattering by runaway CR electrons can dominate the gamma-ray emission from runaway CR nuclei via pion decay. Both are detectable by CTA and LHAASO and they can give clues to the origin of CRs and the amplification of magnetic fluctuations around the SNR. We also discuss middle-aged and/or old SNRs as unidentified very-high-energy gamma-ray sources.

  14. 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.

  15. Inverse Compton Emission from Galactic Supernova Remnants: Effect of the Interstellar Radiation Field

    SciTech Connect

    Porter, Troy A.; Moskalenko, Igor V.; Strong, Andrew W.; /Garching, Max Planck Inst., MPE

    2006-08-01

    The evidence for particle acceleration in supernova shells comes from electrons whose synchrotron emission is observed in radio and X-rays. Recent observations by the HESS instrument reveal that supernova remnants also emit TeV {gamma}-rays; long awaited experimental evidence that supernova remnants can accelerate cosmic rays up to the ''knee'' energies. Still, uncertainty exists whether these {gamma}-rays are produced by electrons via inverse Compton scattering or by protons via {pi}{sup 0}-decay. The multi-wavelength spectra of supernova remnants can be fitted with both mechanisms, although a preference is often given to {pi}{sup 0}-decay due to the spectral shape at very high energies. A recent study of the interstellar radiation field indicates that its energy density, especially in the inner Galaxy, is higher than previously thought. In this paper we evaluate the effect of the interstellar radiation field on the inverse Compton emission of electrons accelerated in a supernova remnant located at different distances from the Galactic Centre. We show that contribution of optical and infra-red photons to the inverse Compton emission may exceed the contribution of cosmic microwave background and in some cases broaden the resulted {gamma}-ray spectrum. Additionally, we show that if a supernova remnant is located close to the Galactic Centre its {gamma}-ray spectrum will exhibit a ''universal'' cutoff at very high energies due to the Klein-Nishina effect and not due to the cut-off of the electron spectrum. As an example, we apply our calculations to the supernova remnants RX J1713.7-3946 and G0.9+0.1 recently observed by HESS.

  16. N157B: X-ray evidence for a Crab-like supernova remnant

    NASA Technical Reports Server (NTRS)

    Gotthelf, Eric V.; Wang, Q. Daniel

    1996-01-01

    The X-ray observation of the supernova remnant N 157B is described. The Rosat High Resolution Imager (HRI) X-ray emission from the remnant was decomposed into point-like sources. The spectra showed abundance-enhanced neon and magnesium lines, indicating that the remnant originated in a massive progenitor. The flat and featureless data from the Advanced Satellite for Cosmology and Astrophysics (ASCA) confirm the Crab-like nature of the remnant. By interpreting both the thermal spectral component and the shell as representing the remnant's outer shock, the age of the remnant was estimated to be 4 x 10(exp 3) yr and the energy release approximately 2 x 10(exp 50) erg.

  17. X-ray emission from supernova remnants near gamma-ray sources

    NASA Technical Reports Server (NTRS)

    Lamb, R. C.; Markert, T. H.

    1981-01-01

    It is noted that the imaging proportional of the Einstein Observatory has been used to search for X-ray emission from eight radio supernova remnants which are near three of the Cos-B unidentified gamma-ray sources: 2CG 311-01, CG 327-0, and CG 333+0. Emissions are observed from three of the remnants and upper limits on the remainder which are consistent with the luminosity expected from a simple blast-wave heated plasma model of the process. Thus none of the remnants are superluminous as might be expected if the pattern of the Crab Nebula were followed. It is thought that the remnant RCW 103 may be Vela-like. It is noted that another of the remnants, Kes 27, has centrally peaked X-ray emission which is unlike the shell-like emission seen for many remnants and which does not correlate well with its asymmetric radio emission.

  18. Transition to the radiative phase in supernova remnant evolution

    NASA Astrophysics Data System (ADS)

    Wright, Eric Boyd

    1999-11-01

    The evolution of a supernova remnant (SNR) through the transition from an adiabatic Sedov-Taylor blastwave to a radiative pressure-driven snowplow phase is studied through a series of one-, two- and three-dimensional hydrodynamic (HD) and magnetohydrodynamic (MHD) simulations. This transition is marked by a catastrophic collapse of the postshock gas, forming a thin, dense shell behind the forward shock. Previous studies have shown that the thin, dense shell of gas present during this transition is susceptible to both radiative and dynamical instabilities. One-dimensional HD studies indicate the presence of a radial oscillation between the forward shock and the thin shell, due to the rapid cooling of the gas in the immediate postshock region. Two-dynamical HD simulations of this transition indicate the presence of violent dynamical instabilities that alter the initially spherical morphology of the blastwave, specifically, the Pressure-driven Thin Shell Overstability (PDTSO) and the Non-linear Thin Shell Instability (NTSI). Hydrodynamical simulations, by their very nature, ignore the effects of magnetic forces on moving fluids. In general, interstellar magnetic fields will be weak enough that their effects may be safely ignored. However, the transition to the radiative phase in SNR evolution is often triggered when the blastwave interacts with dense clouds of gas in the interstellar medium (ISM). The resulting compression of the gas during the transition also compresses the magnetic fields in the cloud, possibly enhancing the field sufficiently to play a role in the further evolution of the SNR. To better understand the role of the NTSI during the transition, and to study the effects of magnetic fields on the instability itself, we performed idealized two- and three-dimensional MHD simulations. The results of the two-dimensional simulations were found to depend strongly on the orientation of the ambient magnetic field when the postshock field is dynamically significant. To accurately model the evolution of the NTSI, only three-dimensional simulations will suffice. However, the three-dimensional simulations performed were unable to run long enough to detect characteristic exponential growth of the NTSI, but initial studies indicate the presence of the instability.

  19. Supernova remnants and diffuse ionized gas in M31

    NASA Technical Reports Server (NTRS)

    Walterbos, Rene; Braun, Robert

    1990-01-01

    Researchers have compiled an initial list of radio/optical supernova remnants (SNRs) in M31, by searching for radio identifications of emission-line sources with a high (SII)/H alpha ratio (greater than 0.60). The (SII) filter included both sulfur lines and the H alpha filter did not include (NII). This search revealed 11 SNRs, of which only two were known. In addition, researchers detected radio emission from 3 SNRs that were identified in previous optical surveys (D'Odorico et al., 1980), but that were outside the charge coupled device (CCD) fields. The 14 objects only include the most obvious candidates, but a full search is in progress and the researchers expect to find several more SNRs. Also not all optical SNRs show detectable radio emission and a pure optical list of SNR candidates based only on the ratio of (SII)/H alpha emission contains many more objects. Two conclusions are apparent. First, the radio properties of the SNRs in M31 are quite similar to those of Galactic SNRs as is illustrated. The brightnesses are not systematically lower as has been suggested in the past (Dickel and D'Odorico, 1984). Second, the slope of the relation is close to -2; this slope is expected from the intrinsic dependence between surface brightness and diameter. The radio luminosity of the SNRs does not seem to depend strongly on diameter, or age, contrary to model predictions. Selection effects, however, play an important role in these plots. The CCD images show widespread diffuse ionized gas with a ratio of (SII)/H alpha that is higher than that of discrete HII regions. Discrete HII regions typically show ratios between 0.2 to 0.3, while the diffuse gas in the arms consistently shows ratios of 0.5. Researchers can trace this gas across the spiral arms to emission measures below 5 pc cm (-6). Its properties seem to be similar to that of the diffuse gas in the solar neighborhood.

  20. 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.

  1. Hidden supernova remnants in the Large Magellanic Cloud H II complex N44

    NASA Technical Reports Server (NTRS)

    Chu, You-Hua; Low, Mordecai-Mark M.; Garcia-Segura, Gullermo; Wakker, Bart; Kennicutt, Robert C., Jr.

    1993-01-01

    We have obtained ROSAT PSPC observations of N44, one of the largest H II complexes in the Large Magellanic Cloud. The X-ray emission mostly fails within the ionized shell structures in N44. We find that one faint shell is a classical supernova remnant overlooked by previous surveys. If we model the two largest shells as pressure-driven superbubbles, the predicted X-ray luminosity falls far below the observed value. Instead, we show that off-center supernova remnants hitting superbubble shells can explain the excess X-ray emission.

  2. 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.

  3. Ongoing cosmic ray acceleration in the supernova remnant W51C revealed with the MAGIC telescopes

    NASA Astrophysics Data System (ADS)

    Krause, J.; Reichardt, I.; Carmona, E.; Gozzini, S. R.; Jankowski, F.; MAGIC Collaboration

    2012-12-01

    The supernova remnant (SNR) W51C interacts with the molecular clouds of the star-forming region W51B, making the W51 complex one of the most promising targets to study cosmic ray acceleration. Gamma-ray emission from this region was discovered by Fermi/LAT and H.E.S.S., although its location was compatible with the SNR shell, the molecular cloud (MC) and a pulsar wind nebula (PWN) candidate. The modeling of the spectral energy distribution presented by the Fermi/LAT collaboration suggests a hadronic emission mechanism. Furthermore indications of an enhanced flux of low energy cosmic rays in the interaction region between SNR and MC have been reported based on ionization measurements in the mm regime. MAGIC conducted deep observations of W51, yielding a detection of an extended emission with more than 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. We restrict the main part of the emission region to the zone where the SNR interacts with the molecular clouds. We also find a tail extending towards the PWN candidate CXO J192318.5+140305, possibly contributing up to 20% of the total flux. The broad band spectral energy distribution can be explained with a hadronic model that implies proton acceleration at least up to 50 TeV. This result, together with the morphology of the source, suggests that we observe ongoing acceleration of ions in the interaction zone between the SNR and the cloud.

  4. X-ray emission from the galactic supernova remnant G12.0-0.1

    NASA Astrophysics Data System (ADS)

    Yamauchi, Shigeo; Bamba, Aya; Koyama, Katsuji

    2014-02-01

    We present results of the Suzaku/XIS observation around the radio supernova remnant (SNR) G12.0-0.1. No significant diffuse emission extending in or along the radio shell was observed. Instead, two compact X-ray sources, Suzaku J181205-1835 and Suzaku J181210-1842, were found in or near G12.0-0.1. Suzaku J181205-1835 is located at the north-west of the radio shell of G12.0-0.1. The X-ray profile is slightly extended over the point spread function of the Suzaku telescope. The X-ray spectrum has no line-like structure and is well represented by a power-law model with a photon index of 2.2 and an absorption column of NH = 4.9 × 1022 cm-2. The distances of Suzaku J181205-1835 and G12.0-0.1 are estimated from the absorption column and the Σ-D relation, respectively, and are nearly the same as each other. These results suggest that Suzaku J181205-1835 is a candidate for a pulsar wind nebula associated with G12.0-0.1. From its location, Suzaku J181210-1842 is expected to be unrelated to G12.0-0.1. The X-ray profile is point-like and the spectrum shows thin thermal emission with Fe K-lines at 6.4, 6.7, and 6.97 keV, similar to those of cataclysmic variables.

  5. 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.

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

    NASA Technical Reports Server (NTRS)

    Slane, Patrick O.

    2001-01-01

    The proposed study entails use of archival data, primarily from past and active X-ray observatories, to study the properties of a class of supernova remnants (SNRs) which display a centrally-bright X-ray morphology. Several models which have been proposed to explain the morphology are being investigated for comparisons with measured characteristics of several remnants: nonthermal emission from a central synchrotron nebula; thermal emission enhanced by slow evaporation of cool clouds in the hot SNR interior; and relic thermal emission from the SNR interior after the remnant has entered the radiative phase of evolution, thus causing the shell emission to cease.

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

    SciTech Connect

    Seward, F. D.; Charles, P. A.; Foster, D. L.; Dickel, J. R.; Romero, P. S.; Edwards, Z. I.; Perry, M.; Williams, R. M.

    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}.

  8. Supernova Remnants and Cosmic Ray Acceleration in Nearby Galaxies

    NASA Astrophysics Data System (ADS)

    Pannuti, T. G.

    Supernova remnants (SNRs) have attracted a considerable amount of interest in modern astrophysics from both observational and theoretical perspectives. SNRs play an integral role in numerous processes associated with the evolution of galaxies, including the injection of significant amounts of kinetic energy and heavy-element enriched material into the interstellar medium (ISM). In addition, SNRs have emerged as the leading candidates for the acceleration of cosmic rays within the disks of galaxies through the proposed diffusive shock acceleration (DSA) mechanism. Observations of SNRs have been conducted at three particular wavelengths, based on distinct processes of energy emission associated with these objects. Thermal bremsstrahlung emission from gas shock-heated to temperatures of 10^6 - 10^7 K, recombination radiation from ionized atomic species such as [S II] and non-thermal synchrotron emission from relativistic electrons gyrating in the SNR's magnetic field produce X-ray, optical and radio emission, respectively. Studies of SNRs within our own Galaxy have been hampered by considerable distance uncertainties and massive extinction along Galactic lines of sight, particularly at the X-ray and optical wavelengths. In contrast, the study of SNRs located in nearby galaxies -- particularly galaxies located at high Galactic latitudes with face-on or nearly face-on orientations -- offers the opportunity to examine equidistant samples of SNRs that are nearly free of obscuration. We present a multi-wavelength (X-ray, optical and radio) study of the resident SNR populations of the Sculptor Group galaxies NGC 300 and NGC 7793 and the northern grand-design spiral NGC 6946. These three galaxies are nearby (2.1 Megaparsecs, 3.34 Megaparsecs and 5.1 Megaparsecs distant, respectively), located at high Galactic latitudes and clearly exhibit extensive massive star formation throughout their disks. We have observed these galaxies at the wavelengths of 6 and 20 cm with the Very Large Array (VLA), and complemented this data with our own H-alpha images and archived X-ray observations made with the Positional Sensitive Proportional Counter (PSPC) instrument aboard the ROSAT satellite. We have searched for X-ray and radio emission from previously-known SNRs identified in the optical using the [S II]/H-alpha method, and searched for new candidate X-ray and radio SNRs. We have found that remarkably few of the optically-identified SNRs possess counterparts at either of the other two wavelengths: of the 83 optically-identified SNRs in these galaxies, only four (N300-S10, N300-S26, N7793-S26 and N6946-S16) were also detected in the X-ray and the radio. N7793-S26 is a very noteworthy source: in the optical and radio it shows a remarkable filamentary structure approximately 450 parsecs in size, and its radio emission is nearly twice as luminous as the most radio-luminous Galactic SNR, Cassiopeia A. Three other optically-identified SNRs -- N300-S11, N7793-S11 and NGC 6946-S9 -- feature strong radio emission but no X-ray emission. Our search for new SNRs in NGC 300 and NGC 7793 has produced 21 candidates: fourteen candidate radio SNRs and two X-ray candidate SNRs in NGC 300, and five candidate radio SNRs in NGC 7793. Very limited intersection is seen between the sets of X-ray, optical and radio-selected SNRs in these three galaxies. These results indicate possible selection effects inherent in these surveys: optical surveys favor the detection of SNRs in low density regions which are nearly devoid of optical confusion. In contrast, radio and X-ray surveys are biased toward the detection of SNRs in high-density regions where optical surveys are severely impeded. Such selection effects may also indicate selection effects for the type of supernova that parents the SNR: the optical surveys are more likely to detect SNRs produced by the explosion of low mass stars in Type Ia supernovae, while radio and X-ray surveys are more likely to identify SNRs produced by the explosion of high mass stars in Type II supernovae. To investigate these selection effects, we have conducted a simulation designed to evaluate the dependence of the optical detections of SNRs with distance to the target galaxy. By distributing artificial SNRs within the galaxy at positions corresponding to differing amounts of ambient density and varying the distance to the target galaxy, we find that the detection of SNRs using optical methods becomes increasingly difficult with distance, and that SNRs that are embedded in regions of high density are not detected even when the galaxy is rather near. These results indicate the need for a multi-wavelength campaign to detect a maximum number of SNRs in a galaxy of interest. A study of the average minimum energies of the radio SNRs in NGC 300, NGC 7793, NGC 6946 and the Local Group spiral M33 (which we have included for comparison purposes) finds that the radio SNR population in NGC 6946 has a considerably higher average minimum energy than the radio SNR populations in the other three galaxies. We believe that this result originates in the considerably larger size of NGC 6946 compared to the other three galaxies, and therefore NGC 6946 has a larger radio SNR population with more luminous radio SNRs than the radio SNR populations in NGC 300, NGC 7793 and M33. Estimates of the efficiency of cosmic ray acceleration by SNRs in these four galaxies based on equipartition calculations gives efficiencies in the range of 3% through 16%, consistent with the efficiencies predicted by the DSA mechanism. Finally, to understand the correlations between a galaxy's population of SNRs and its diffuse radio emission, we have observed NGC 6946 using the VLA and the Effelsberg 100-meter radio telescope at the wavelengths of 6 and 20 cm. Data from these two sets of observations were combined to simultaneously compare both diffuse structure and point sources (namely candidate radio SNRs) within this galaxy. The amount of diffuse emission in the vicinities of both optically-identified and radio-identified SNRs has been measured at both 6 and 20 cm, and we find that the diffuse emission is better correlated with the positions of the candidate radio SNRs than with the optically-identified SNRs. The correlation is very apparent when the populations of SNRs in the luminous northeastern arm of this galaxy are compared. If we interpret the separate sets of SNRs identified through optical and radio observations to correspond to SNRs parents by Type Ia and Type II SNe, respectively, and if the diffuse emission corresponds to relativisitic cosmic ray electrons accelerated by the SNRs in this galaxy, our results therefore indicate the SNRs associated with Type II SNe are the agents responsible for cosmic ray acceleration within this galaxy, and by extension other galaxies as well.

  9. Diffusive propagation of cosmic rays from supernova remnants in the Galaxy. II: anisotropy

    SciTech Connect

    Blasi, Pasquale; Amato, Elena E-mail: amato@arcetri.astro.it

    2012-01-01

    In this paper we investigate the effects of stochasticity in the spatial and temporal distribution of supernova remnants on the anisotropy of cosmic rays observed at Earth. The calculations are carried out for different choices of the diffusion coefficient D(E) experienced by cosmic rays during propagation in the Galaxy. The propagation and spallation of nuclei (with charge 1 ? Z ? 26) are taken into account. At high energies (E > 1 TeV) we assume that D(E)?(E/Z){sup ?}, with ? = 1/3 and ? = 0.6 being the reference scenarios. The large scale distribution of supernova remnants in the Galaxy is modeled following the distribution of pulsars with and without accounting for the spiral structure of the Galaxy. Our calculations allow us to determine the contribution to anisotropy resulting from both the large scale distribution of SNRs in the Galaxy and the random distribution of the nearest remnants. The naive expectation that the anisotropy amplitude scales as ?{sub A}?D(E) is shown to be a wild oversimplification of reality which does not reflect in the predicted anisotropy for any realistic distribution of the sources. The fluctuations in the anisotropy pattern are dominated by nearby sources, so that predicting or explaining the observed anisotropy amplitude and phase becomes close to impossible. Nevertheless, the results of our calculations, when compared to the data, allow us to draw interesting conclusions in terms of the propagation scenario to be preferred both in terms of the energy dependence of the diffusion coefficient and of the size of the halo. We find that the very weak energy dependence of the anisotropy amplitude below 10{sup 5} GeV, as observed by numerous experiments, as well as the rise at higher energies, can best be explained if the diffusion coefficient is D(E)?E{sup 1/3}. Faster diffusion, for instance with ? = 0.6, leads in general to an exceedingly large anisotropy amplitude. The spiral structure introduces interesting trends in the energy dependence of the anisotropy pattern, which qualitatively reflect the trend seen in the data. The inhomogeneous spatial distribution of the sources in the Galactic disc induces a large scale anisotropy which is not sensitive to the stochastic nature of nearby SNRs: we find that this additional contribution to ?{sub A} becomes more important for large values of the size of the halo, H. The two terms are comparable in size for H ? 2 kpc which corresponds to the scale height of the gradient of the spatial distribution of SNRs in the Galaxy. The dependence on energy of ?{sub A}(E) is close to monotonic when the large-scale, regular term dominates, and does not seem to reflect the observed anisotropy amplitude. Both contributions to the total anisotropy are illustrated and discussed with the help of semi-analytical results.

  10. RADIO DETECTION OF A CANDIDATE NEUTRON STAR ASSOCIATED WITH GALACTIC CENTER SUPERNOVA REMNANT SAGITTARIUS A EAST

    SciTech Connect

    Zhao, Jun-Hui; Morris, Mark R.; Goss, W. M. E-mail: morris@astro.ucla.edu

    2013-11-10

    We report the Very Large Array (VLA) detection of the radio counterpart of the X-ray object referred to as the 'Cannonball', which has been proposed to be the remnant neutron star resulting from the creation of the Galactic center supernova remnant, Sagittarius A East. The radio object was detected both in our new VLA image from observations in 2012 at 5.5 GHz and in archival VLA images from observations in 1987 at 4.75 GHz and in the period from 1990 to 2002 at 8.31 GHz. The radio morphology of this object is characterized as a compact, partially resolved point source located at the northern tip of a radio 'tongue' similar to the X-ray structure observed by Chandra. Behind the Cannonball, a radio counterpart to the X-ray plume is observed. This object consists of a broad radio plume with a size of 30''×15'', followed by a linear tail having a length of 30''. The compact head and broad plume sources appear to have relatively flat spectra (∝ν{sup α}) with mean values of α = –0.44 ± 0.08 and –0.10 ± 0.02, respectively, and the linear tail shows a steep spectrum with the mean value of –1.94 ± 0.05. The total radio luminosity integrated from these components is ∼8 × 10{sup 33} erg s{sup –1}, while the emission from the head and tongue amounts for only ∼1.5 × 10{sup 31} erg s{sup –1}. Based on the images obtained from the two epochs' observations at 5 GHz, we infer the proper motion of the object: μ{sub α} = 0.001 ± 0.003 arcsec yr{sup –1} and μ{sub δ} = 0.013 ± 0.003 arcsec yr{sup –1}. With an implied velocity of 500 km s{sup –1}, a plausible model can be constructed in which a runaway neutron star surrounded by a pulsar wind nebula was created in the event that produced Sgr A East. The inferred age of this object, assuming that its origin coincides with the center of Sgr A East, is approximately 9000 yr.

  11. X-ray emission from the remnant of a carbon deflagration supernova - SN 1572 (Tycho)

    SciTech Connect

    Itoh, H.; Masai, K.; Nomoto, K.

    1988-11-01

    A spherically symmetric hydrodynamic code is used to study the evolution of a young supernova remnant on the basis of a carbon deflagration model for type Ia supernovae. The nonequilibrium X-ray emission has been determined for the elemental composition of the model. The discrepancy between the derived intensity of the Fe D-alpha line blend and the observed value is eliminated by assuming that the stratification of the elemental composition in the supernova ejecta is partially removed by mixing. 59 references.

  12. High angular resolution study of the J1400-6325 pulsar wind nebula and its host remnant G310.6-1.6 with the ATCA

    NASA Astrophysics Data System (ADS)

    Kirichenko, Aida; Voronkov, Maxim; Shibanov, Yuri; Danilenko, Andrey; Zyuzin, Dima

    2014-10-01

    The very young (<10^3 years) Crab-like pulsar J1400-6325 was only recently discovered in the radio and X-rays. It powers a bright pulsar wind nebula (PWN) and it is associated with a previously unknown supernova remnant (SNR) G310.6-1.6. In X-rays, the remnant has a circular outer shell, while the PWN, like the Crab, contains a torus and a jet. Unlike other powerful Crab-like PWN/SNR systems, this remarkable object located at 7 kpc remains unresolved in the radio. We therefore propose an ATCA observation of this system to analyse the PWN fine structure and spectrum and compare them with the X-ray data. The requested ATCA observation would also allow to reveal the fundamental spectral break which is likely present in the PWN spectrum and typical of other PWNe with similar properties. This will contribute significantly to our understanding of the particle acceleration mechanisms working at various parts of such systems.

  13. 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.

  14. VizieR Online Data Catalog: MOST supernova remnant catalogue (MSC) (Whiteoak+ 1996)

    NASA Astrophysics Data System (ADS)

    Whiteoak, J. B. Z.; Green, A. J.

    1999-02-01

    A catalogue of supernova remnants in the southern Galaxy within the area 245°<=l<=355°, |b|<~1.5° has been produced from observations made at 0.843GHz with a resolution of 43" using the Molonglo Observatory Synthesis Telescope (MOST). (2 data files).

  15. Acceleration of cosmic rays and gamma-ray emission from supernova remnant/molecular cloud associations

    NASA Astrophysics Data System (ADS)

    Gabici, Stefano; Krause, Julian; Morlino, Giovanni; Nava, Lara

    2015-12-01

    The gamma-ray observations of molecular clouds associated with supernova remnants are considered one of the most promising ways to search for a solution of the problem of cosmic ray origin. Here we briefly review the status of the field, with particular emphasis on the theoretical and phenomenological aspects of the problem.

  16. Discriminating the Progenitor Type of Supernova Remnants with Iron K-shell Emission

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Hiroya; Badenes, Carles; Petre, Robert; Nakano, Toshio; Castro, Daniel; Enoto, Teruaki; Hiraga, Junko S.; Hughes, John P.; Maeda, Yoshitomo; Nobukawa, Masayoshi; Safi-Harb, Samar; Slane, Patrick O.; Smith, Randall K.; Uchida, Hiroyuki

    2014-04-01

    Supernova remnants (SNRs) retain crucial information about both their parent explosion and circumstellar material left behind by their progenitor. However, the complexity of the interaction between supernova ejecta and ambient medium often blurs this information, and it is not uncommon for the basic progenitor type (Ia or core-collapse) of well-studied remnants to remain uncertain. Here we present a powerful new observational diagnostic to discriminate between progenitor types and constrain the ambient medium density of SNRs using solely Fe K-shell X-ray emission. We analyze all extant Suzaku observations of SNRs and detect Fe Kα emission from 23 young or middle-aged remnants, including five first detections (IC 443, G292.0+1.8, G337.2-0.7, N49, and N63A). The Fe Kα centroids clearly separate progenitor types, with the Fe-rich ejecta in Type Ia remnants being significantly less ionized than in core-collapse SNRs. Within each progenitor group, the Fe Kα luminosity and centroid are well correlated, with more luminous objects having more highly ionized Fe. Our results indicate that there is a strong connection between explosion type and ambient medium density, and suggest that Type Ia supernova progenitors do not substantially modify their surroundings at radii of up to several parsecs. We also detect a K-shell radiative recombination continuum of Fe in W49B and IC 443, implying a strong circumstellar interaction in the early evolutionary phases of these core-collapse remnants.

  17. Fermi-LAT and WMAP observations of the supernova remnant Puppis A

    NASA Astrophysics Data System (ADS)

    Grondin, Marie-Hlne; Hewitt, John W.; Lemoine-Goumard, Marianne; Reposeur, Thierry; Reposeur

    2014-01-01

    The supernova remnant (SNR) Puppis A (aka G260.4-3.4) is a middle-aged supernova remnant, which displays increasing X-ray surface brightness from West to East corresponding to an increasing density of the ambient interstellar medium at the Eastern and Northern shell. The dense IR photon field and the high ambient density around the remnant make it an ideal case to study in ?-rays. Gamma-ray studies based on three years of observations with the Large Area Telescope (LAT) aboard Fermi have revealed the high energy gamma-ray emission from SNR Puppis A. The ?-ray emission from the remnant is spatially extended, and nicely matches the radio and X-ray morphologies. Its ?-ray spectrum is well described by a simple power law with an index of ~2.1, and it is among the faintest supernova remnants yet detected at GeV energies. To constrain the relativistic electron population, seven years of Wilkinson Microwave Anisotropy Probe (WMAP) data were also analyzed, and enabled to extend the radio spectrum up to 93 GHz. The results obtained in the radio and ?-ray domains are described in detail, as well as the possible origins of the high energy ?-ray emission (Bremsstrahlung, Inverse Compton scattering by electrons or decay of neutral pions produced by proton interactions).

  18. DISCRIMINATING THE PROGENITOR TYPE OF SUPERNOVA REMNANTS WITH IRON K-SHELL EMISSION

    SciTech Connect

    Yamaguchi, Hiroya; Petre, Robert; Enoto, Teruaki; Badenes, Carles; Nakano, Toshio; Hiraga, Junko S.; Castro, Daniel; Hughes, John P.; Maeda, Yoshitomo; Nobukawa, Masayoshi; Uchida, Hiroyuki; Safi-Harb, Samar; Slane, Patrick O.; Smith, Randall K.

    2014-04-20

    Supernova remnants (SNRs) retain crucial information about both their parent explosion and circumstellar material left behind by their progenitor. However, the complexity of the interaction between supernova ejecta and ambient medium often blurs this information, and it is not uncommon for the basic progenitor type (Ia or core-collapse) of well-studied remnants to remain uncertain. Here we present a powerful new observational diagnostic to discriminate between progenitor types and constrain the ambient medium density of SNRs using solely Fe K-shell X-ray emission. We analyze all extant Suzaku observations of SNRs and detect Fe Kα emission from 23 young or middle-aged remnants, including five first detections (IC 443, G292.0+1.8, G337.2-0.7, N49, and N63A). The Fe Kα centroids clearly separate progenitor types, with the Fe-rich ejecta in Type Ia remnants being significantly less ionized than in core-collapse SNRs. Within each progenitor group, the Fe Kα luminosity and centroid are well correlated, with more luminous objects having more highly ionized Fe. Our results indicate that there is a strong connection between explosion type and ambient medium density, and suggest that Type Ia supernova progenitors do not substantially modify their surroundings at radii of up to several parsecs. We also detect a K-shell radiative recombination continuum of Fe in W49B and IC 443, implying a strong circumstellar interaction in the early evolutionary phases of these core-collapse remnants.

  19. 3D Simulations of the Emission from Young Supernova Remnants Including Efficient Particle Acceleration

    NASA Astrophysics Data System (ADS)

    Ferrand, Gilles; Safi-Harb, Samar; Decourchelle, Anne

    2015-08-01

    Within our Galaxy, supernova remnants (SNRs) are believed to be the major sources of cosmic rays up to the “knee” (~1 PeV). The detection of non-thermal radiation from these objects, in X-rays over the past two decades, and finally in gamma-rays over the past decade, has proved the presence of energetic particles. However important questions remain regarding the share of the hadronic and leptonic components as well as the fraction of the supernova energy channelled into these components. We will show how such questions can be addressed by means of 3D numerical simulations of SNRs that combine a hydrodynamic treatment of the shock wave with a kinetic treatment of particle acceleration. Performing 3D simulations of SNRs allows us to produce synthetic projected maps and spectra, that can be compared with observations (in X-rays for the thermal emission and multi-wavelength for the non-thermal emission). In particular, we will show how the presence of energetic protons can be inferred from the broadband emission of the remnant. We will contrast the properties of the remnants from the two different kinds of supernovae: thermonuclear supernovae (like Tycho) that usually occur in a mostly undisturbed medium, and core-collapse supernovae (like Cas A) that occur in a more complex medium bearing the imprint of the winds of the progenitor star.

  20. An XMM-Newton Search for Crab-like Supernova Remnants

    NASA Technical Reports Server (NTRS)

    Mushotzky, Richard (Technical Monitor); Slane, Patrick

    2005-01-01

    The primary goals of the study are to search for evidence of non-thermal emission that would suggest the presence of a pulsar in this compact SNR. We have performed the reduction of the EPIC data for this observation, cleaning the data to remove time intervals of enhanced particle background, and have created maps in several energy bands, and on a variety of smoothing scales. We find no evidence for emission from the SNR. Given the small angular size of the SNR, we conclude that rather than being a young remnant, it is actually fairly old, but distant. At its current stage of evolution, the remnant shell has apparently entered the radiative phase, wherein the shell temperature has cooled sufficiently to be either below X-ray-emitting temperatures or at temperatures easily absorbed the foreground interstellar material. We have thus concluded that this SNR is not a viable candidate for a young ejecta-rich or pulsar-driven SNR.

  1. Neutral hydrogen in the vicinity of the supernova remnant HB 9

    NASA Astrophysics Data System (ADS)

    Gosachinskii, I. V.

    2013-03-01

    The neutral hydrogen emission at 21 cm has been investigated with the RATAN-600 radio telescope in the vicinity of the supernova remnant HB9. A clumpyHI shell with radial motions surrounding the remnant has been detected. Its measured parameters contradict the connection with a shock wave from a supernova explosion. The shell formation under the action of a wind from a star that exploded as a supernova at the end of its evolution seems more realistic. The characteristics of the star obtained from the observed shell parameters are the following: a wind power of 0.5 × 1038 erg s-1, a mass-loss rate of 3.7 × 10-5 M ⊙ yr-1, and an age of 3 × 106 yr. Given the measurement errors, the mass of the star is estimated to be >8 M ⊙.

  2. Interactions Between CRs and MCs in the Vicinity of Supernova Remnants

    NASA Technical Reports Server (NTRS)

    Hewitt, John W.

    2011-01-01

    Supernovae are incredibly energetic events which drive the dynamic state of the interstellar medium and accelerate cosmic rays up to energies of a few PeV. I present multi-wavelength observations constraining the shocks, chemistry, dust grain processing, and magnetic fields in a large sample of supernova remnants interacting with dense clouds. These are among the most luminous Galactic sources detected by the Fermi Gamma-Ray Space Telescope. Surprisingly, spectral breaks are seen between GeV and TeV energies. Radio spectral breaks have also been detected for a few remnants, providing clear evidence that supernovae are a significant source of hadronic cosmic rays in the Galaxy. Resolving the origin of these spectral breaks will allow the physics of cosmic ray acceleration and diffusion to be probed.

  3. Connecting the high- and low-energy Universe: dust processing inside Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Micelotta, Elisabetta; Dwek, Eli; Slavin, Jonathan

    2015-09-01

    The recent detection of large amounts of dust (> 10(7) M_⊙) at very high redshift (z > 6) raises a fundamental question about the origin of such dust. The main dust producers, i. e., the stars populating the Red Giant Branch and the Asymptotic Giant Branch (RGB and AGB stars) did not have time to evolve. From an evolutionary point of view, young supernovae (SNe) could represent a viable source of dust in high-redshift galaxies, however, a critical issue still needs to be addressed. While recent observations have demonstrated that supernovae are indeed efficient dust factories, at the same time SNe represent the major agent responsible for dust destruction. Supernova blast waves propagating into the interstellar medium destroy the dust residing there, while the fresh dust produced by the supernova itself is threatened by the reverse shock which propagates through the expanding ejecta towards the center of the remnant. We focus here on this second destruction mechanism, with the aim of quantifying the amount of dust able to survive the heavy processing by the reverse shock and to reach the interstellar medium. We present our results for the textbook supernova remnant Cassiopeia A (Cas A). Using recent X-ray and infrared observations, we have developed a model for the evolution of the remnant and the simultaneous processing of the dust by the reverse shock, and derived the expected amount of surviving dust. In addition, we will briefly illustrate the impact of the capabilities of the Athena 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. These range from individual supernova remnants, to starburst super winds up to AGN outflows and the hot intra-cluster medium. The study of dust processing by a shocked gas truly connects the high-energy Universe with the low-energy Universe, and Athena will play a major role in it.

  4. The youngest known X-ray binary: Circinus X-1 and its natal supernova remnant

    SciTech Connect

    Heinz, S.; Sell, P.; Fender, R. P.; Jonker, P. G.; Brandt, W. N.; Calvelo-Santos, D. E.; Tzioumis, A. K.; Nowak, M. A.; Schulz, N. S.; Wijnands, R.; Van der Klis, M.

    2013-12-20

    Because supernova remnants are short-lived, studies of neutron star X-ray binaries within supernova remnants probe the earliest stages in the life of accreting neutron stars. However, such objects are exceedingly rare: none were known to exist in our Galaxy. We report the discovery of the natal supernova remnant of the accreting neutron star Circinus X-1, which places an upper limit of t < 4600 yr on its age, making it the youngest known X-ray binary and a unique tool to study accretion, neutron star evolution, and core-collapse supernovae. This discovery is based on a deep 2009 Chandra X-ray observation and new radio observations of Circinus X-1. Circinus X-1 produces type I X-ray bursts on the surface of the neutron star, indicating that the magnetic field of the neutron star is small. Thus, the young age implies either that neutron stars can be born with low magnetic fields or that they can rapidly become de-magnetized by accretion. Circinus X-1 is a microquasar, creating relativistic jets that were thought to power the arcminute-scale radio nebula surrounding the source. Instead, this nebula can now be attributed to non-thermal synchrotron emission from the forward shock of the supernova remnant. The young age is consistent with the observed rapid orbital evolution and the highly eccentric orbit of the system and offers the chance to test the physics of post-supernova orbital evolution in X-ray binaries in detail for the first time.

  5. Adiabatic Expansion of Supernova Remnants - an Explicit, Analytical Approximation in Two Dimensions

    NASA Astrophysics Data System (ADS)

    Maciejewski, W.; Shelton, R. L.; Cox, D. P.

    1996-05-01

    We propose a simple, analytical approximation for an adiabatic shock wave propagating in an exponentially stratified ambient medium. We aim to provide an effective tool for exploring the parameter space of 2-dimensional numerical models of supernova remnants (SNRs). We start from Kompaneets's (1960, Soviet Phys. Doklady, 5, 46) axisymmetric generalization of Sedov's spherically symmetric problem, to which he derived an implicit solution. We notice that the SNR shape in his solution can be closely approximated as an ellipsoid. In this case, an explicit solution for the size, eccentricity and expansion velocity of the remnant can be found. Our results are in excellent agreement with Kompaneets's solution, even when the ambient density varies across the remnant by factors as large as 1000. Beyond that, the blowout occurs, and Kompaneets's assumptions no longer hold. The remnant shapes are remarkably close to spherical for moderate density gradients. Using Kahn's cooling law (alpha T(-1/2) ) we derived a formula to estimate how long it takes for a cold shell to form. Even a small gradient in ambient density causes this time to vary substantially within a single remnant, so that for a period the H I shell will be only partially formed. To demonstrate how our approximation can be used, the parameter space for models of the supernova remnant W44 is explored.

  6. EVOLUTION OF POST-IMPACT REMNANT HELIUM STARS IN TYPE Ia SUPERNOVA REMNANTS WITHIN THE SINGLE-DEGENERATE SCENARIO

    SciTech Connect

    Pan, Kuo-Chuan; Ricker, Paul M.; Taam, Ronald E. E-mail: pmricker@illinois.edu

    2013-08-10

    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} 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.

  7. The bubble-like interior of the core-collapse supernova remnant Cassiopeia A

    NASA Astrophysics Data System (ADS)

    Milisavljevic, Dan; Fesen, Robert A.

    2015-01-01

    The death of massive stars is believed to involve aspheric explosions initiated by the collapse of an iron core. The specifics of these catastrophic explosions remain uncertain, due partly to limited observational constraints on asymmetries deep inside the star. Here we present near-infrared observations of the young supernova remnant Cassiopeia A, descendant of a type IIb core-collapse explosion, and a three-dimensional map of its interior unshocked ejecta. The remnants interior has a bubble-like morphology that smoothly connects to and helps explain the multiringed structures seen in the remnant's bright reverse-shocked main shell of expanding debris. This internal structure may originate from turbulent mixing processes that encouraged outwardly expanding plumes of radioactive 56Ni-rich ejecta. If this is true, substantial amounts of its decay product, 56Fe, may still reside in these interior cavities.

  8. Two-temperature models of old supernova remnants with ion and electron thermal conduction

    NASA Technical Reports Server (NTRS)

    Cui, Wei; Cox, Donald P.

    1992-01-01

    To investigate the potential effects thermal conduction may have on the evolution of old supernova remnants, we present the results of 1D (spherically symmetric) numerical simulations of a remnant in a homogeneous interstellar medium for four different cases: (1) without thermal conduction; (2) with both electron and ion thermal conduction assuming equal temperatures; (3) with electron thermal conduction only, following electron and ion temperatures separately; and (4) with both electron and ion thermal conduction following separate temperatures. We followed the entire evolution until the completion of the remnant bubble collapse. Our most significant result is that in remnant evolution studies concerned principally with either the shell or bubble evolution at late times, reasonable results are obtained with single-temperature models. When the electron and ion temperatures are followed separately, however, ion thermal conduction cannot safely be ignored.

  9. Limits on Planet Formation Around Young Pulsars and Implications for Supernova Fallback Disks

    NASA Astrophysics Data System (ADS)

    Kerr, M.; Johnston, S.; Hobbs, G.; Shannon, R. M.

    2015-08-01

    We have searched a sample of 151 young, energetic pulsars for periodic variation in pulse time-of-arrival arising from the influence of planetary companions. We are sensitive to objects with masses two orders of magnitude lower than those detectable with optical transit timing, but we find no compelling evidence for pulsar planets. For the older pulsars most likely to host planets, we can rule out Mercury analogs in one third of our sample and planets with masses >0.4 M⨁ and periods {P}b\\lt 1 year in all but 5% of such systems. If pulsar planets form primarily from supernova fallback disks, these limits imply that such disks do not form, are confined to <0.1 AU radii, are disrupted, or form planets more slowly (>2 Myr) than their protoplanetary counterparts.

  10. 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.

  11. Synchrotron X-Ray Rims in Tycho's Supernova Remnant are Energy Dependent

    NASA Astrophysics Data System (ADS)

    Tran, Aaron; Williams, Brian J.; Petre, Robert; Ressler, Sean; 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 have been taken to indicate that shock-accelerated electrons rapidly cool downstream of the shock, requiring strong magnetic field amplification. But, magnetic field damping immediately behind the shock could produce similarly thin rims. Synchrotron loss-limited rim widths should decrease with energy whereas damping limited rims should be relatively energy-independent. To discriminate between models, 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, favoring loss-limited radiation over magnetic damping and corroborating similar observations in the remnant of SN 1006. Observed widths are best fit by electron transport models requiring amplified magnetic fields of ~200-1000 µG and particle diffusion coefficients ~1-100x Bohm values, consistent with prior work on Tycho's SNR. Non-negligible diffusion results in some degeneracy between magnetic field strength and diffusion coefficient in setting observed rim widths, but strong magnetic fields are required for all measurements. A different approach may be needed to better constrain diffusion at supernova remnant shocks.

  12. Uncovering the Properties of Young Neutron Stars and their Surrounding Supernova Remnants

    NASA Technical Reports Server (NTRS)

    Oliversen, Ronald J. (Technical Monitor); Slane, Patrick O.

    2004-01-01

    This five-year grant involves the study of young neutron stars, particularly those in supernova remnants.In the fourth year of this program, the following studies have been undertaken in support of this effort: 1.CTA 1: Following up on our ROSAT and ASCA studies of this SNR, we obtained observations with the XMM-Newton observatory to investigate the central compact source and surrounding nebula. 2. 3C 58: Based upon our earlier Chandra observations, we submitted a successful Chandra Large Project proposal for a 350 ks observation of this young neutron star and its wind nebula. 3. G347.3 - - 0.5: Our Chandra observations of portions of this SNR were aimed at studying the nonthermal X-ray emission from the remnant shell. 4. Chandra Survey for Compact Objects in Supernova Remnants: We have formed a collaboration to carry out an extensive search for young neutron stars in nearby supernova remnants. Using X-ray observations from an approved Chandra Large Project, as well as from additional approved XMM observations, we are investigating a volume-limited sample of SNRs for which there is currently no evidence of associated neutron stars.

  13. INVESTIGATION OF THE PROGENITORS OF THE TYPE Ia SUPERNOVAE ASSOCIATED WITH THE LMC SUPERNOVA REMNANTS 0505-67.9 AND 0509-68.7

    SciTech Connect

    Pagnotta, Ashley; Schaefer, Bradley E.

    2015-01-20

    Although Type Ia supernovae have been heavily scrutinized due to their use in making cosmological distance estimates, we are still unable to definitively identify the progenitors for the entire population. While answers have been presented for certain specific systems, a complete solution remains elusive. We present observations of two supernova remnants (SNRs) in the Large Magellanic Cloud, SNR 0505-67.9 and SNR 0509-68.7, for which we have identified the center of the remnant and the 99.73% containment central region in which any companion star left over after the supernova must be located. Both remnants have a number of potential ex-companion stars near their centers; all possible single and double degenerate progenitor models remain viable for these two supernovae. Future observations may be able to identify the true ex-companions for both remnants.

  14. Swift/BAT Detection of Hard X-Rays from Tycho's Supernova Remnant: Evidence for Titanium-44

    NASA Astrophysics Data System (ADS)

    Troja, E.; Segreto, A.; La Parola, V.; Hartmann, D.; Baumgartner, W.; Markwardt, C.; Barthelmy, S.; Cusumano, G.; Gehrels, N.

    2014-12-01

    We report Swift/Burst Alert Telescope survey observations of the Tycho's supernova remnant, performed over a period of 104 months since the mission's launch. The remnant is detected with high significance (>10σ) below 50 keV. We detect significant hard X-ray emission in the 60-85 keV band, above the continuum level predicted by a simple synchrotron model. The location of the observed excess is consistent with line emission from radioactive titanium-44, so far reported only for Type II supernova explosions. We discuss the implications of these results in the context of the galactic supernova rate, and nucleosynthesis in Type Ia supernova.

  15. Determining Progenitors of Young Supernova Remnants from Their Fe K-Shell Emission

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Hiroya; Smith, R. K.; Slane, P. O.

    2013-04-01

    Young Supernova Remnants (SNRs) retain crucial information about their explosion and nucleosynthesis mechanisms. However, interactions with the surrounding circumstellar and interstellar medium can conceal these data and so it is not unusual that even the basic progenitor type (i.e., Ia or core-collapse) of a remnant remains controversial. Here we propose a new method to discriminate the progenitors solely using the Fe K-shell X-ray spectrum. We systematically analyzed Suzaku and Chandra observations of young ejecta-dominated SNRs to determine the intensity and centroid of the Fe-K emission lines. We found that the Fe ejecta in Type Ia SNRs are commonly less ionized than those in core-collapse SNRs. It was found, moreover, that luminosity and centroid of the Fe-K emission are well correlated among each group of Type Ia or core-collapse remnants, and that the more luminous remnants tend to be more highly ionized. These results may reflect the pre-explosion density of the remnants. Evidence of overionization was observed only in core-collapse SNRs, implying their origin to be related to interaction with stellar wind material. Our method can potentially be utilized in systematic studies of extragalactic SNRs with future missions, such as AXSIO, that have high-resolution imaging and spectroscopic capabilities. This will help study, for example, the supernova rate in different ISM environments.

  16. Utilizing Supernova Remnants as Probes of Explosion Mechanisms and Progenitor Systems

    NASA Astrophysics Data System (ADS)

    Milisavljevic, Dan

    2015-08-01

    Theory and observation strongly favor the notion that asymmetric explosions drive core-collapse supernovae. Where and how this asymmetry is introduced is uncertain, in part because of limited constraints on the various processes that may be taking place deep inside massive stars. Observations of extragalactic supernovae have shed some light on the issue. However, distant supernovae, by nature, appear as unresolved point sources, which severely restricts our ability to extract key properties of the explosion dynamics via detailed knowledge of the three-dimensional kinematics of the expanding ejecta. Progress requires an alternative approach, and to this end there have been successful efforts towards understanding core-collapse supernova explosions through studies of their remnants in our own Milky Way galaxy. Such investigations provide information about the explosion-driven mixing of the progenitor star's chemically distinct layers, the star's mass loss history before explosion, and the fate of its remnant core - all at extremely fine scales. Particularly of note are observations of the young supernova remnant Cassiopeia A, which is the descendant of a massive star that was mostly stripped of its hydrogen envelope. Cassiopeia A's debris field has a bubble-like morphology that may have originated from turbulent mixing processes that encouraged the development of outwardly expanding plumes of radioactive 56Ni-rich ejecta. Important aspects of these observations conflict with sophisticated explosion models and we presently do not have a good understanding of how the 56Ni was mixed. Considering Cassiopeia A's kinematic properties are not unique and likely reflect a common phenomenon of core-collapse supernovae, this conflict represents a big problem that cannot be ignored. Unraveling whether the mixing that we see originates from an asymmetric explosion mechanism or is more tightly associated with a turbulent interior structure will be a challenge, but there is hope.

  17. 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.

  18. Spatially resolved X-ray line spectroscopy of Tycho's supernova remnant

    NASA Technical Reports Server (NTRS)

    Gotthelg, Eric V.; Hwang, Una

    1996-01-01

    Narrow band X-ray images of Tycho's supernova remnant, acquired with the solid-state spectrometer onboard the Advanced Satellite for Cosmology and Astrophysics (ASCA), are presented. The remnant is mapped in several prominent emission lines and in the 1.4 keV to 1.7 keV and 4 keV to 6 keV continua. A spatial resolution of approximately 0.5 min was obtained. No significant correlation was found for Tycho between the X-ray 4 keV to 6 keV continuum and the radio morphology.

  19. Five Years in the Mid-Infrared Development of the SN 1987A Supernova Remnant

    NASA Technical Reports Server (NTRS)

    Dwek, Eliahu

    2009-01-01

    Spitzer has been used to monitor the mid-IR evolution of SN 1987A over a 5 year period as it develops into a supernova remnant through interaction with its surrounding environment. This interaction is dominated by the collision of the ejecta with the pre-existing equatorial ring. The mid-IR continuum indicates an increasing mass of shock-heated silicate dust, but without any significant change in temperature of the dust grains. Comparison of the IR and X-ray evolution of the remnant can be used to infer plasma conditions and the processing of the dust in the shock-heated X-ray emitting gas.

  20. Pulsar spins from an instability in the accretion shock of supernovae.

    PubMed

    Blondin, John M; Mezzacappa, Anthony

    2007-01-01

    Rotation-powered radio pulsars are born with inferred initial rotation periods of order 300 ms (some as short as 20 ms) in core-collapse supernovae. In the traditional picture, this fast rotation is the result of conservation of angular momentum during the collapse of a rotating stellar core. This leads to the inevitable conclusion that pulsar spin is directly correlated with the rotation of the progenitor star. So far, however, stellar theory has not been able to explain the distribution of pulsar spins, suggesting that the birth rotation is either too slow or too fast. Here we report a robust instability of the stalled accretion shock in core-collapse supernovae that is able to generate a strong rotational flow in the vicinity of the accreting proto-neutron star. Sufficient angular momentum is deposited on the proto-neutron star to generate a final spin period consistent with observations, even beginning with spherically symmetrical initial conditions. This provides a new mechanism for the generation of neutron star spin and weakens, if not breaks, the assumed correlation between the rotational periods of supernova progenitor cores and pulsar spin. PMID:17203055

  1. XMM-Newton Observations of HESSJ1813-178 Reveal a Composite Supernova Remnant

    SciTech Connect

    Funk, S.; Hinton, J.A.; Moriguchi, Y.; Aharonian, F.A.; Fukui, Y.; Hofmann, W.; Horns, D.; Puehlhofer, G.; Reimer, O.; Rowell, G.; Terrier, R.; Vink, J.; Wagner, S.

    2006-11-27

    Aims--We present X-ray and {sup 12}CO(J=1-0) observations of the very-high-energy (VHE) {gamma}-ray source HESS J1813-178 with the aim of understanding the origin of the {gamma}-ray emission. Methods--High-angular resolution X-ray studies of the VHE {gamma}-ray emission region are performed using 18.6 ks of XMM-Newton data, taken on HESS J1813-178 in October 2005. Using this dataset we are able to undertake spectral and morphological studies of the X-ray emission object with greater precision than previous studies. NANTEN {sup 12}CO(J=1-0) data are used to search for correlations of the {gamma}-ray emission with molecular clouds which could act as target material for {gamma}-ray production in a hadronic scenario. Results--The NANTEN {sup 12}CO(J=1-0) observations show a giant molecular cloud of mass 2.5 x 10{sup 5} M{sub {circle_dot}} at a distance of 4 kpc in the vicinity of HESS J1813-178. Even though there is no direct positional coincidence, this giant cloud might have influenced the evolution of the {gamma}-ray source and its surroundings. The X-ray data show a highly absorbed (n{sub H} {approx} 1 x 10{sup 23} cm{sup -2}) non-thermal X-ray emitting object coincident with the previously known ASCA source AXJ1813-178 showing a compact core and an extended tail towards the north-east, located in the center of the radio shell-type Supernova remnant (SNR) G12.82-0.2. This central object shows morphological and spectral resemblance to a Pulsar Wind Nebula (PWN) and we therefore consider that this object is very likely to be a composite SNR. Nevertheless, we cannot distinguish between the scenarios in which the {gamma}-rays originate in the shell of the SNR and the one in which they originate in the central object. We discuss both scenarios in terms of a one-zone leptonic model and demonstrate, that in order to connect the core X-ray emission to the VHE {gamma}-ray emission electrons have to be accelerated to energies of at least 1 PeV. We conclude that if indeed the X-rays are connected to the VHE {gamma}-rays HESS J1813-178 has to be a Galactic Pevatron.

  2. The supernova remnant W51C: a plausible source of galactic cosmic rays?

    NASA Astrophysics Data System (ADS)

    Gozzini, S. R.; Carmona, E.; Jankowski, F.; Krause, J.; Reichardt, I.; MAGIC Collaboration

    2013-02-01

    Supernova remnants are a probable site of acceleration of particles via diffusive shock processes. High energies carried by electrons or protons are radiated into photons detectable from radio to γ rays. MAGIC has recently observed W51C, one of the most luminous galactic supernova remnants, and completed its spectrum between 50 GeV and 5 TeV. We modelled different processes for high energy photon emission of this source, and compared the predictions with the measured spectral energy distribution. It is plausible that hadrons are accelerated in the expansion front of this source, in interaction with the surrounding molecular cloud, and photons are produced in the decay of neutral mesons created in hadronic collisions.

  3. FERMI LARGE AREA TELESCOPE DETECTION OF THE YOUNG SUPERNOVA REMNANT TYCHO

    SciTech Connect

    Giordano, F.; Naumann-Godo, M.; Ballet, J.; Mazziotta, M. N.; Raino, S.; Tibolla, O. E-mail: Melitta.Naumann-Godo@cea.fr

    2012-01-15

    After almost three years of data taking in sky-survey mode, the Fermi Large Area Telescope has detected {gamma}-ray emission toward 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 {gamma}-ray integral flux from 400 MeV up to 100 GeV has been measured to be (3.5 {+-} 1.1{sub stat} {+-} 0.7{sub syst}) Multiplication-Sign 10{sup -9} cm{sup -2} s{sup -1} with a photon index of 2.3 {+-} 0.2{sub stat} {+-} 0.1{sub syst}. A simple model consistent with TeV, X-ray, and radio data is sufficient to explain the observed emission as originating from {pi}{sup 0} decays as a result of cosmic-ray acceleration and interaction with the ambient medium.

  4. Fermi Large Area Telescope Detection of the Young Supernova Remnant Tycho

    NASA Astrophysics Data System (ADS)

    Giordano, F.; Naumann-Godo, M.; Ballet, J.; Bechtol, K.; Funk, S.; Lande, J.; Mazziotta, M. N.; Rainò, S.; Tanaka, T.; Tibolla, O.; Uchiyama, Y.

    2012-01-01

    After almost three years of data taking in sky-survey mode, the Fermi Large Area Telescope has detected γ-ray emission toward 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-2 s-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 π0 decays as a result of cosmic-ray acceleration and interaction with the ambient medium.

  5. 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.

  6. 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

    2015-10-01

    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 Ly? of Al XIII and He? 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.

  7. X-ray emission from the supernova remnant G287.8-0.5

    NASA Technical Reports Server (NTRS)

    Becker, R. H.; Boldt, E. A.; Holt, S. S.; Pravdo, S. H.; Rothschild, R. E.; Serlemitsos, P. J.; Swank, J. H.

    1976-01-01

    The GSFC Cosmic X-ray spectroscopy experiment on OSO-8 observed a weak galactic X-ray source near theta 2 at 288 deg, b2 at -1 deg. The spectrum for this source between 2-20 keV is well represented by a thermal spectrum of kT = 7.34(+3.6), sub -2.6 keV with an intense iron emission line centered at 6.5 + or - .2 keV. The error box of the Uhuru source 4U1043-59, the only known X-ray source in our field of view, contains the radio supernova remnant G287.8-0.5. The possible association of the X-ray source with this supernova remnant is discussed.

  8. 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.

  9. X-RAY EMISSION FROM STRONGLY ASYMMETRIC CIRCUMSTELLAR MATERIAL IN THE REMNANT OF KEPLER'S SUPERNOVA

    SciTech Connect

    Burkey, Mary T.; Reynolds, Stephen P.; Borkowski, Kazimierz J.; Blondin, John M.

    2013-02-10

    Kepler's supernova remnant resulted from a thermonuclear explosion, but is interacting with circumstellar material (CSM) lost from the progenitor system. We describe a statistical technique for isolating X-ray emission due to CSM from that due to shocked ejecta. Shocked CSM coincides well in position with 24 {mu}m emission seen by Spitzer. We find most CSM to be distributed along the bright north rim, but substantial concentrations are also found projected against the center of the remnant, roughly along a diameter with position angle {approx}100 Degree-Sign . We interpret this as evidence for a disk distribution of CSM before the supernova, with the line of sight to the observer roughly in the disk plane. We present two-dimensional hydrodynamic simulations of this scenario in qualitative agreement with the observed CSM morphology. Our observations require Kepler to have originated in a close binary system with an asymptotic giant branch star companion.

  10. ROSAT/ASCA observations of the mixed-morphology supernova remnant W28

    NASA Technical Reports Server (NTRS)

    Rho, J.; Borkowski, K. J.

    2002-01-01

    We present three sets of ROSAT PSPC and four sets of ASCA observations of the supernova remnant (SNR) W28. The overall shape of x-ray emission in W28 is elliptical, dominated by a centrally-concentrated interior emission, sharply peaked at the center. There are also partial northeastern and southwestern shells, and both central and shell x-ray emission is highly patchy.

  11. CANGAROO-III Search for Gamma Rays from Kepler's Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Enomoto, R.; Higashi, Y.; Yoshida, T.; Tanimori, T.; Bicknell, G. V.; Clay, R. W.; Edwards, P. G.; Gunji, S.; Hara, S.; Hara, T.; Hattori, T.; Hayashi, S.; Hirai, Y.; Inoue, K.; Kabuki, S.; Kajino, F.; Katagiri, H.; Kawachi, A.; Kifune, T.; Kiuchi, R.; Kubo, H.; Kushida, J.; Matsubara, Y.; Mizukami, T.; Mizumoto, Y.; Mizuniwa, R.; Mori, M.; Muraishi, H.; Muraki, Y.; Naito, T.; Nakamori, T.; Nakano, S.; Nishida, D.; Nishijima, K.; Ohishi, M.; Sakamoto, Y.; Seki, A.; Stamatescu, V.; Suzuki, T.; Swaby, D. L.; Thornton, G.; Tokanai, F.; Tsuchiya, K.; Watanabe, S.; Yamada, Y.; Yamazaki, E.; Yanagita, S.; Yoshikoshi, T.; Yukawa, Y.

    2008-08-01

    Kepler's supernova, discovered in 1604 October, produced a remnant that has been well studied observationally in the radio, infrared, optical, and X-ray bands, and theoretically. Some models have predicted a TeV gamma-ray flux that is detectable with current Imaging Cerenkov Atmospheric Telescopes. We report on observations carried out in 2005 April with the CANGAROO-III Telescope. No statistically significant excess was observed, and limitations on the allowed parameter range in the model are discussed.

  12. Multi-dimensional Simulations of the Expanding Supernova Remnant of SN 1987A

    NASA Astrophysics Data System (ADS)

    Potter, T. M.; Staveley-Smith, L.; Reville, B.; Ng, C.-Y.; Bicknell, G. V.; Sutherland, R. S.; Wagner, A. Y.

    2014-10-01

    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 an 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 & McKee progenitor with an envelope mass of 10 M ⊙ and an energy of 1.5 × 1044 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) × 107 m-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.

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

    SciTech Connect

    Potter, T. M.; Staveley-Smith, L.; Reville, B.; Ng, C.-Y.; Bicknell, G. V.; Sutherland, R. S.; Wagner, A. Y.

    2014-10-20

    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 an 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.

  14. In my Beginning is my End: Dust Destruction in the Cassiopeia A Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Micelotta, E.; Dwek, E.

    It has been demonstrated by observations that young supernovae (SNe) are indeed able to efficiently synthesize dust. However, it is unclear how much of the freshly formed dust can reach the interstellar medium and contribute to the observed emission. At the same time, SNe represent the major agent responsible for dust destruction. Because SNe are possibly the only viable dust factory in the early Universe, it is extremely important to establish the fate of the newly formed dust. Our work explores the possibility that a significant fraction of any dust formed after the explosion is destroyed within the supernova remnant itself. In the Cassiopeia A supernova remnant, dust emission has been observed associated with optical knots containing recently formed material. The dust present in such clumps is threatened by the reverse shock traveling through the ejecta toward the center of the remnant. The shock is able to disrupt the clumps and will inject the dust grains into a hot gas, where they will be eroded and possibly destroyed by thermal and inertial sputtering. We present a model that describes the propagation of the reverse shock into the supernova cavity and evaluates the modifications in the grain size distribution due to the encounter with the reverse shock. This is the first step required to quantify the amount of dust ultimately able to survive. Our model accounts for the variation of the physical properties of both the shock and the ejecta across the remnant. In particular, this means taking explicitly into consideration, for the first time in this kind of studies, the effect of clumping of the ejecta.

  15. MODIFIED EQUIPARTITION CALCULATION FOR SUPERNOVA REMNANTS. CASES α = 0.5 AND α = 1

    SciTech Connect

    Arbutina, B.; Urošević, D.; Vučetić, M. M.; Pavlović, M. Z.; Vukotić, B.

    2013-11-01

    The equipartition or minimum energy calculation is a well-known procedure for estimating the magnetic field strength and the total energy in the magnetic field and cosmic ray particles by using only the radio synchrotron emission. In one of our previous papers, we have offered a modified equipartition calculation for supernova remnants (SNRs) with spectral indices 0.5 < α < 1. Here we extend the analysis to SNRs with α = 0.5 and α = 1.

  16. Discriminating the Progenitor Type of Supernova Remnants with Iron K-Shell Emission

    NASA Technical Reports Server (NTRS)

    Yamaguchi, Hiroya; Badenes, Carles; Petre, Robert; Nakano, Toshio; Castro, Daniel; Enoto, Teruaki; Hiraga, Junko S.; Hughes, John P.; Maeda, Yoshitomo; Nobukawa, Masayoshi

    2014-01-01

    Supernova remnants (SNRs) retain crucial information about both their parent explosion and circumstellar material left behind by their progenitor. However, the complexity of the interaction between supernova ejecta and ambient medium often blurs this information, and it is not uncommon for the basic progenitor type (Ia or core-collapse) of well-studied remnants to remain uncertain. Here we present a powerful new observational diagnostic to discriminate between progenitor types and constrain the ambient medium density of SNRs using solely Fe K-shell X-ray emission. We analyze all extant Suzaku observations of SNRs and detect Fe K-alpha emission from 23 young or middle-aged remnants, including five first detections (IC 443, G292.0+1.8, G337.2-0.7, N49, and N63A). The Fe K-alpha centroids clearly separate progenitor types, with the Fe-rich ejecta in Type Ia remnants being significantly less ionized than in core-collapse SNRs. Within each progenitor group, the Fe K-alpha luminosity and centroid are well correlated, with more luminous objects having more highly ionized Fe. Our results indicate that there is a strong connection between explosion type and ambient medium density, and suggest that Type Ia supernova progenitors do not substantially modify their surroundings at radii of up to several parsecs. We also detect a K-shell radiative recombination continuum of Fe in W49B and IC 443, implying a strong circumstellar interaction in the early evolutionary phases of these core-collapse remnants.

  17. The kinematics of the bi-lobal supernova remnant G 65.3+5.7. II..

    NASA Astrophysics Data System (ADS)

    Boumis, P.; Meaburn, J.; López, J. A.; Mavromatakis, F.; Redman, M. P.; Harman, D. J.; Goudis, C. D.

    2004-09-01

    Further deep, narrow-band images in the light of [O I] 6300Åii have been added to the previous mosaic of the faint galactic supernova remnant G 65.3+5.7. Additionally, long-slit spatially resolved [O I] 6300Åii line profiles have been obtained at sample positions using the Manchester Echelle Spectrometer at the San Pedro Martir observatory. The remnant is shown to be predominantly bi-lobal with an EW axis. However, a faint additional northern lobe has now been revealed. The splitting of the profiles along the slit lengths, when extrapolated to the centre of the remnant, although uncertain, suggests that the expansion velocity of this remnant is between 124 and 187 kms i.e. much lower than the 400 kms previously predicted for the forward shock velocity from the X-ray emission. An expansion proper motion measurement of 2.1 ± 0.4 arcsec in 48 years for the remnant's filamentary edge in the light of Hα + NII has also been made. This is combined with an expansion velocity of ≈155 kms, a distance of ≈800 pc is derived. Several possibilities are considered for the large difference in the expansion velocity measured here and the 400 kms shock velocity required to generate the X-ray emission. It is also suggested that the morphology of the remnant may be created by a tilt in the galactic magnetic field in this vicinity.

  18. Imaging and Spectroscopy of a New, Nearby Supernova Remnant and a Potentially Ejected Neutron Star.

    NASA Astrophysics Data System (ADS)

    Miller, Jon

    We request funding to support an XMM-Newton Cycle 11 observation (Priority B, unfunded, 56 ksec) of the newly-discovered supernova remnant Swift J132150.9-633350, and a nearby point source that may be an ejected neutron star. The remnant was discovered in the Swift Galactic Plane Survey (PI Miller), and confirmed via a 5 ksec Chandra snapshot. The spectrum of the remnant indicates enhances abundances, especially in Fe and Ni, and points to a young age for the remnant. The distance to the remnant is not yet know, but for plausible distances it is one of the 10-20 youngest remnants known. The deep XMM-Newton observation we have obtained is therefore an important look at an important source; it can help to reveal the nature of the explosion and the progenitor star. Moreover, only XMM-Newton has the field of view and CCD chip geometry that will allow for a simultaneous study of a nearby point source. Few young neutron stars are known, and this observation marks a rare chance to study one in detail. Our funding request is based on the work required to complete the analysis of this observation, and to publish the results. This research addresses NASA science goals for astrophysics, including "How do matter, energy, space, and time behave under the extraordinary diverse conditions of the cosmos?"

  19. An extended source of GeV gamma rays coincident with the supernova remnant HB 21

    NASA Astrophysics Data System (ADS)

    Reichardt, Ignasi; Oña-Wilhelmi, Emma De; Rico, Javier; Yang, Rui-zhi

    2012-12-01

    We analyze 3.5 years of public Fermi/LAT data around the position of the supernova remnant HB 21, where four point-like sources from the 2nd Fermi/LAT catalog are located. We determine that the gamma-ray source is produced by a single extended source. We model the observed morphology as a uniform circle. The spectral energy distribution is best described by a curved power law, with a maximum at 413+/-11 MeV. We divide the circle into three regions defined by previously identified shocked molecular clouds, and find that one of the se regions has a softer spectrum. The > 3GeV gamma-ray emission of the soft spectrum region is bow-shaped and coincident with the supernova remnant shell seen at radio wavelengths. We suggest that the gamma-ray emission from HB 21 can be understood as a combination of emission from shocked/illuminated molecular clouds, one of them coincident with the supernova remnant shell itself.

  20. An extended source of GeV gamma rays coincident with the supernova remnant HB 21

    NASA Astrophysics Data System (ADS)

    Reichardt, I.; de Oña-Wilhelmi, E.; Rico, J.; Yang, R.

    2012-10-01

    We analyze 3.5 years of public Fermi/LAT data around the position of the supernova remnant HB 21, where four point-like sources from the 2nd Fermi/LAT catalog are located. We determine that the gamma-ray source is produced by a single extended source. We model the observed morphology as a uniform circle. The spectral energy distribution is best described by a curved power law, with a maximum at 413 ± 11 MeV. We divide the circle into three regions defined by previously identified shocked molecular clouds, and find that one of these regions has a softer spectrum. The >3 GeV gamma-ray emission of the soft spectrum region is bow-shaped and coincident with the supernova remnant shell seen at radio wavelengths. We suggest that the gamma-ray emission from HB 21 can be understood as a combination of emission from shocked/illuminated molecular clouds, one of them coincident with the supernova remnant shell itself.

  1. Observations of supernova remnants in the Large Magellanic Cloud with the Einstein Observatory

    NASA Technical Reports Server (NTRS)

    Helfand, D. J.; Long, K. S.

    1980-01-01

    Consideration is given to the Large Magellanic Cloud (LMC), noting that above 2 keV, the X-ray luminosity of the LMC is dominated by emission from 3-5 point sources similar to the bright sources near the center of our own Galaxy. The imaging proportional counter aboard the Einstein Observatory has been used to locate about 40 X-ray sources in the LMC. Supernova remnants observed in the LMC are presented, noting X-ray position, X-ray counting rate, and radio flux. For the six brightest sources, X-ray spectra have been analyzed to determine temperatures and intrinsic luminosity corrected for the interstellar absorption. These data are compared for parameters for the young galactic remnant of Tycho's supernova. Attention is given to the ratio of X-ray luminosity to radio luminosity, and the data are discussed within the framework of the standard blast-wave theory. The results of applying the model to recorded observations are numerically presented. In addition to providing a sample of objects for investigations of supernova remnants, the data are applicable to studies of galaxies of other morphological types and individual objects, such as N49.

  2. Gamma-ray emitting supernova remnants as the origin of Galactic cosmic rays

    NASA Astrophysics Data System (ADS)

    Kroll, M.; Becker Tjus, J.; Eichmann, B.; Nierstenhöfer, N.

    2015-11-01

    It is generally believed that the cosmic ray spectrum below the knee is of Galactic origin, although the exact sources making up the entire cosmic ray energy budget are still unknown. Including effects of magnetic amplification, Supernova Remnants (SNR) could be capable of accelerating cosmic rays up to a few PeV and they represent the only source class with a sufficient non-thermal energy budget to explain the cosmic ray spectrum up to the knee. Now, gamma-ray measurements of SNRs for the first time allow to derive the cosmic ray spectrum at the source, giving us a first idea of the concrete, possible individual contributions to the total cosmic ray spectrum. In this contribution, we use these features as input parameters for propagating cosmic rays from its origin to Earth using GALPROP in order to investigate if these supernova remnants reproduce the cosmic ray spectrum and if supernova remnants in general can be responsible for the observed energy budget.

  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; Kuin, Paul; Moss, Vanessa; Reeves, Sarah; Robbins, William J.; Gaensler, B. M.; Reis, Rubens C.; Petre, Robert

    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. Overionization in supernova remnants: a deep look at the SNR IC 443

    NASA Astrophysics Data System (ADS)

    Troja, Eleonora

    2008-10-01

    IC 443 is a Galactic supernova remnant with a peculiar morphology: a center-filled thermal X-ray emission within a radio/optical shell. The presence of overionized plasma, addressed in previous works, would be a robust clue to the nature of the center-bright X-rays, which is not yet understood. Our studies show significant spectral variations across the remnant, which may lead to the fictitious detection of overionization. We propose a deep observation of the northeast region in order to obtain a high-quality dataset, and perform a spatially resolved spectroscopy of the brightest X-ray emission of IC 443. We aim to decisively address the issue of overionization, and to constrain the mechanisms of X-ray production from the center of this remnant.

  5. Mechanism for spectral break in cosmic ray proton spectrum of supernova remnant W44

    NASA Astrophysics Data System (ADS)

    Malkov, M. A.; Diamond, P. H.; Sagdeev, R. Z.

    2011-02-01

    Recent observations of supernova remnant W44 by the Fermi spacecraft observatory support the idea that the bulk of galactic cosmic rays is accelerated in such remnants by a Fermi mechanism, also known as diffusive shock acceleration. However, the W44 expands into weakly ionized dense gas, and so a significant revision of the mechanism is required. Here, we provide the necessary modifications and demonstrate that strong ion-neutral collisions in the remnant surrounding lead to the steepening of the energy spectrum of accelerated particles by exactly one power. The spectral break is caused by Alfven wave evanescence leading to the fractional particle losses. The gamma-ray spectrum generated in collisions of the accelerated protons with the ambient gas is calculated and successfully fitted to the Fermi Observatory data. The parent proton spectrum is best represented by a classical test particle power law ~E-2, steepening to E-3 at Ebr~7GeV due to deteriorated particle confinement.

  6. High resolution X-ray spectroscopy of supernova remnants with ASTRO-H

    NASA Astrophysics Data System (ADS)

    Hughes, John

    The high spectral resolution and sensitivity of the Soft X-ray Spectrometer (SXS) on the upcoming ASTRO-H mission will open a new window of discovery for the study of supernova remnants. In this presentation, I will offer some illustrative examples of the types of science that the ASTRO-H team hopes to pursue. In young, ejecta-dominated remnants, abundance measurements based on emission line diagnostics will allow for a closer link to the different types of supernova progenitor models. Line widths probe ion temperatures and turbulent gas velocities on small scales, while offsets in observed line centroids characterize the bulk expansion motion of a remnant. For older remnants, much of the line-rich thermal plasma arises from shocks in the ambient, interstellar material. SXS observations will address a number of existing concerns with the intepretation of low resolution CCD spectra, including for example the issue of low inferred abundances at the rims of the Cygnus Loop, Puppis A, and others; and the physical origin of recombination-dominated plasmas.

  7. High-resolution IUE observations of interstellar absorption lines in the Vela supernova remnant

    NASA Technical Reports Server (NTRS)

    Jenkins, E. B.; Wallerstein, G.; Silk, J.

    1984-01-01

    Ultraviolet spectra of 45 stars in the vicinity of the Vela supernova remnant were recorded by the short-wavelength echelle spectrograph aboard the International Ultraviolet Explorer (IUE). Over one-third of the stars show interstellar absorption lines at large radial velocities (greater than 60 km/s). The mapping of these high-velocity components in the sky suggests the motions are chaotic, rather than from a coherent expansion of the remnant material. In accord with earlier conclusions from Copernicus data, the gas at high velocity exhibits higher than normal ionization and shows substantially less depletion of nonvolatile elements than normal interstellar material at low velocities. Relatively strong lines from neutral carbon in the two excited fine-structure states indicate that the neutral clouds within the remnant have had their pressures enhanced by the passage of the blast wave from the supernova. Also, the remnant seems to show a significant enhancement in the abundances of low-velocity Si IV, C IV, and N V over those found in the general interstellar medium.

  8. The Distance and Age of the Supernova Remnants Kes 73 and AXP 1E 1841-045

    NASA Astrophysics Data System (ADS)

    Tian, W. W.; Leahy, D. A.

    2008-04-01

    We provide a new distance estimate to the supernova remnant (SNR) Kes 73 and its associated anomalous X-ray pulsar (AXP) 1E 1841-045. 21 cm H I images and H I absorption/emission spectra from new VLA observations, and 13CO emission spectra of Kes 73 and two adjacent compact H II regions (G27.276+0.148 and G27.491+0.189) are analyzed. The H I images show prominent absorption features associated with Kes 73 and the H II regions. The absorption appears up to the tangent point velocity giving a lower distance limit to Kes 73 of 7.5 kpc, which has previously been given as the upper limit. In addition, G27.276+0.148 and G27.491+0.189 are at the far kinematic distances of their radio recombination line velocities. There is prominent H I emission in the range 80-90 km s-1 for all three objects. The two H II regions show H I absorption at ~84 km s-1, but there is no absorption in the Kes 73 absorption spectrum. This implies an upper distance limit of ~9.8 kpc to Kes 73. This corrected larger distance to Kes 73/AXP 1E 1841-045 system leads to a refined age of the SNR of 500-1000 yr, and a ~50% larger AXP X-ray luminosity.

  9. Using Poisson statistics to analyze supernova remnant emission in the low counts X-ray regime

    NASA Astrophysics Data System (ADS)

    Roper, Quentin Jeffrey

    We utilize a Poisson likelihood in a maximum likelihood statistical analysis to analyze X-ray spectragraphic data. Specifically, we examine four extragalactic supernova remnants (SNR). IKT 5 (SNR 0047-73.5), IKT 25 (SNR 0104-72.3), and DEM S 128 (SNR 0103-72.4) which are designated as Type Ia in the literature due to their spectra and morphology. This is troublesome because of their asymmetry, a trait not usually associated with young Type Ia remnants. We present Chandra X-ray Observatory data on these three remnants, and perform a maximum likelihood analysis on their spectra. We find that the X-ray emission is dominated by interactions with the interstellar medium. In spite of this, we find a significant Fe overabundance in all three remnants. Through examination of radio, optical, and infrared data, we conclude that these three remnants are likely not "classical" Type Ia SNR, but may be examples of so-called "prompt" Type Ia SNR. We detect potential point sources that may be members of the progenitor systems of both DEM S 128 and IKT 5, which could suggest a new subclass of prompt Type Ia SNR, Fe-rich CC remnants. In addition, we examine IKT 18. This remnant is positionally coincident with the X-ray point source HD 5980. Due to an outburst in 1994, in which its brightness changed by 3 magnitudes (corrsponding to an increase in luminosity by a factor of 16) HD 5980 was classified as a luminous blue variable star. We examine this point source and the remnant IKT 18 in the X-ray, and find that its non-thermal photon index has decreased from 2002 to 2013, corresponding to a larger proportion of more energetic X-rays, which is unexpected.

  10. Chandra and XMM-Newton Study of the Supernova Remnant Kes 73 Hosting the Magnetar 1E 1841-045

    NASA Astrophysics Data System (ADS)

    Kumar, Harsha S.; Safi-Harb, Samar; Slane, Patrick O.; Gotthelf, E. V.

    2014-01-01

    We present a Chandra and XMM-Newton study of the supernova remnant (SNR) Kes 73 hosting the anomalous X-ray pulsar 1E 1841-045. The Chandra image reveals clumpy structures across the remnant with enhanced emission along the western rim. The X-ray emission fills the radio shell and spatially correlates with the infrared image. The global X-ray spectrum is described by a two-component thermal model with a column density N H = 2.6^{+0.4}_{-0.3}\\times1022 cm-2 and a total luminosity of LX = 3.3^{+0.7}_{-0.5}\\times1037 erg s-1 (0.5-10 keV, at an assumed distance of 8.5 kpc). The soft component is characterized by a temperature kTs = 0.5^{+0.1}_{-0.2} keV, a high ionization timescale, and enhanced Si and S abundances, suggesting emission that is dominated by shocked ejecta. The hard component has a temperature kTh = 1.6^{+0.8}_{-0.7} keV, a relatively low ionization timescale, and mostly solar abundances suggesting emission that is dominated by interstellar/circumstellar shocked material. A spatially resolved spectroscopy study reveals no significant variations in the spectral properties. We infer an SNR age ranging between 750 yr and 2100 yr, an explosion energy of 3.0^{+2.8}_{-1.8}\\times1050 erg and a shock velocity of (1.2 ± 0.3)×103 km s-1 (under the Sedov phase assumption). We also discuss the possible scenario for Kes 73 expanding into the late red-supergiant wind phase of its massive progenitor. Comparing the inferred metal abundances to core-collapse nucleosynthesis model yields, we estimate a progenitor mass gsim20 M ⊙, adding a candidate to the growing list of highly magnetized neutron stars proposed to be associated with very massive progenitors.

  11. Unpulsed X-rays from pulsars

    NASA Technical Reports Server (NTRS)

    Helfand, D. J.

    1981-01-01

    Preliminary results of several programs to detect thermal X-ray emission from isolated neutron stars are presented. Results of Einstein pulsar surveys indicate that either the majority of supernovas which leave remnants do not produce neutron stars, or the cooling calculations are in need of substantial revision. When appropriate relativistic thermodynamics and updated high energy nuclear physics are included, the new calculations predict significantly lower temperatures for standard neutron star equations of state. X-ray results give strong evidence that five of the seven historical remnants and a large majority of the other remnants of less than 1000 yr do not contain radio pulsars. A survey of known radio pulsars is also presented, which is designed to test the heating mechanisms required by various theories of pulsar emission and neutron star structure, and consists of a survey of all known pulsars within 300 pc.

  12. Failed Supernovae Explain the Compact Remnant Mass Function

    NASA Astrophysics Data System (ADS)

    Kochanek, C. S.

    2014-04-01

    One explanation for the absence of higher mass red supergiants (16.5 M ⊙ <~ M <~ 25 M ⊙) as the progenitors of Type IIP supernovae (SNe) is that they die in failed SNe creating black holes. Simulations show that such failed SNe still eject their hydrogen envelopes in a weak transient, leaving a black hole with the mass of the star's helium core (5-8 M ⊙). Here we show that this naturally explains the typical masses of observed black holes and the gap between neutron star and black hole masses without any fine-tuning of stellar mass loss, binary mass transfer, or the SN mechanism, beyond having it fail in a mass range where many progenitor models have density structures that make the explosions more likely to fail. There is no difficulty including this ~20% population of failed SNe in any accounting of SN types over the progenitor mass function. And, other than patience, there is no observational barrier to either detecting these black hole formation events or limiting their rates to be well below this prediction.

  13. An atlas of supernova remnant candidates in Messier 31

    NASA Technical Reports Server (NTRS)

    Braun, R.; Walterbos, R. A. M.

    1993-01-01

    Narrow-band CCD imagery in H-alpha and forbidden SII of a large fraction of the spiral arms in the Northeast half of Messier 31 has been used to isolate a sample of 52 'forbidden-line' SNR candidates for which the integrated ratio forbidden SII:H-alpha is greater than 0.5. An atlas of images in these emission lines, red optical continuum, and 1465 MHz radio continuum is presented, together with the tabulated integral properties of these sources. Assessing the completeness of the sample yields a crude estimate of the massive supernova rate (due to stars more massive than 7 solar masses) of 1 in 80 yr. The range of measured luminosities in both H-alpha and radio continuum is fully consistent with those found for 'forbidden-line' SNR in Messier 33, the LMC, and the Galaxy. With the inclusion of our candidates the number of extragalactic SNRs (with well-known distances) now exceeds the number of known galactic SNRs.

  14. Failed supernovae explain the compact remnant mass function

    SciTech Connect

    Kochanek, C. S.

    2014-04-10

    One explanation for the absence of higher mass red supergiants (16.5 M {sub ☉} ≲ M ≲ 25 M {sub ☉}) as the progenitors of Type IIP supernovae (SNe) is that they die in failed SNe creating black holes. Simulations show that such failed SNe still eject their hydrogen envelopes in a weak transient, leaving a black hole with the mass of the star's helium core (5-8 M {sub ☉}). Here we show that this naturally explains the typical masses of observed black holes and the gap between neutron star and black hole masses without any fine-tuning of stellar mass loss, binary mass transfer, or the SN mechanism, beyond having it fail in a mass range where many progenitor models have density structures that make the explosions more likely to fail. There is no difficulty including this ∼20% population of failed SNe in any accounting of SN types over the progenitor mass function. And, other than patience, there is no observational barrier to either detecting these black hole formation events or limiting their rates to be well below this prediction.

  15. A kinematic search for supernova remnants in giant extragalactic H II regions

    NASA Technical Reports Server (NTRS)

    Yang, Hui; Skillman, Evan D.; Sramek, Richard A.

    1994-01-01

    We have obtained velocity fields of the Giant H II complexes NGC 5471 in M101, NGC 2363 in NGC 2366, and the largest H II region in NGC 2403 from H-alpha observations using the TAURUS imaging Fabry-Perot interferometer. We have detected five H-alpha sources with velocity profiles which are broad when compared with the surrounding H II region. Region B in NGC 5471 has been previously determined to contain a supernova remnant by the presence of nonthermal radio continuum radiation and enhanced (O I) and (S II) emission (Skillman 1985) and broad H-alpha emission (Chu & Kennicutt 1986). Two broad H-alpha sources in NGC 2363 coincide with regions where strong splitting has been found in the (O III) line (Roy et al. 1991). Two more broad H-alpha sources have been identified in the largest H II region in NGC 2403. Very Large Array (VLA) radio continuum observations with a resolution of 2 sec at lambda(6) and lambda(20) cm of all 3 H II complexes are presented. In addition, high resolution (subarcsecond) VLA images of NGC 5471 were made at lambda(2) and lambda(6) cm. The presence of a nonthermal source in region NGC 5471 B was confirmed while region NGC 5471 A appears to be dominated by thermal emission. The nonthermal spectral index in NGC 2363 A indicates the existence of none or more supernova remnants at the position of a large velocity width source detected in H-alpha emission. No similar nonthermal sources were detected in NGC 2403 #1. Supernovae explosions and stellar winds are considered as causes for these large velocity width sources (LVWS). If the emission from the LVWSs is attributed to single supernova remnants, they are unusually luminous in both nonthermal radio continuum and H-alpha emision. The very large H-alpha luminosities could be a result of high velocity gas being ionized by the neighboring stellar cluster.

  16. HFPK 334: An unusual supernova remnant in the Small Magellanic Cloud

    SciTech Connect

    Crawford, E. J.; Filipović, M. D.; McEntaffer, R. L.; Brantseg, T.; Heitritter, K.; Roper, Q.; Haberl, F.; Urošević, D.

    2014-11-01

    We present new Australia Telescope Compact Array radio-continuum and XMM-Newton/Chandra X-ray Observatory observations of the unusual supernova remnant (SNR) HFPK 334 in the Small Magellanic Cloud (SMC). The remnant follows a shell-type morphology in the radio continuum and has a size of ∼20 pc at the SMC distance. The X-ray morphology is similar; however, we detect a prominent point source close to the center of the SNR exhibiting a spectrum with a best-fit power law with a photon index of Γ = 2.7 ± 0.5. This central point source is most likely a background object and cannot be directly associated with the remnant. The high temperature, nonequilibrium conditions in the diffuse region suggest that this gas has been recently shocked and points toward a younger SNR with an age of ≲ 1800 yr. With an average radio spectral index of α = –0.59 ± 0.09, we find that an equipartition magnetic field for the remnant is ∼90 μG, a value typical of younger SNRs in low-density environments. Also, we report the detection of scattered radio polarization across the remnant at 20 cm, with a peak fractional polarization level of 25% ± 5%.

  17. HFPK 334: An Unusual Supernova Remnant in the Small Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Crawford, E. J.; Filipović, M. D.; McEntaffer, R. L.; Brantseg, T.; Heitritter, K.; Roper, Q.; Haberl, F.; Urošević, D.

    2014-11-01

    We present new Australia Telescope Compact Array radio-continuum and XMM-Newton/Chandra X-ray Observatory observations of the unusual supernova remnant (SNR) HFPK 334 in the Small Magellanic Cloud (SMC). The remnant follows a shell-type morphology in the radio continuum and has a size of ~20 pc at the SMC distance. The X-ray morphology is similar; however, we detect a prominent point source close to the center of the SNR exhibiting a spectrum with a best-fit power law with a photon index of Γ = 2.7 ± 0.5. This central point source is most likely a background object and cannot be directly associated with the remnant. The high temperature, nonequilibrium conditions in the diffuse region suggest that this gas has been recently shocked and points toward a younger SNR with an age of <~ 1800 yr. With an average radio spectral index of α = -0.59 ± 0.09, we find that an equipartition magnetic field for the remnant is ~90 μG, a value typical of younger SNRs in low-density environments. Also, we report the detection of scattered radio polarization across the remnant at 20 cm, with a peak fractional polarization level of 25% ± 5%.

  18. A 3D cell-centered Lagrangian scheme applied to the simulation of 3D non-stationary Rayleigh-Taylor Instability in supernova remnants

    NASA Astrophysics Data System (ADS)

    Georges, G.; Breil, J.; Ribeyre, X.; Le Bel, E.

    2015-12-01

    Several astronomical flows can be studied thanks to the gas dynamics equations under the Lagrangian formalism. Here we propose to study the plerion dynamic, i.e. supernova remnants blown-up by a central pulsar as well as the Rayleigh-Taylor Instability (RTI) development at the inner interface of this gas shell. The scheme used is a multi-dimensional second order cell-centered Lagrangian scheme. It satisfies the Geometric Conservation Law (GCL), a semi-discrete entropy inequality and it conserves globally the momentum and the total energy. The convergence of the scheme towards the analytical solution is tested for the plerion test case and in the case of an axi-symmetric perturbation. Finally, the scheme is used to study the perturbation growth on the shell inner face perturbed with spherical harmonics.

  19. Nonthermal X-rays and Gamma Rays from Supernova Remnants in Stellar-Wind Bubbles

    NASA Astrophysics Data System (ADS)

    Reynolds, S. P.

    1997-12-01

    Electrons are expected to be accelerated in strong shock waves to energies limited by radiative losses, by the finite age of the shock, or by escape. Young supernova remnants can easily produce electron distributions that, while steepening from the slope at radio energies, still contain significant numbers of electrons at energies of 100 TeV or higher, where they produce synchrotron X-rays to 10 keV and above. In addition, these electrons can inverse-Compton scatter cosmic microwave background photons up to energies in excess of 100 GeV. For remnants of core-collapse supernovae expanding into stellar-wind bubbles, the upstream density is likely to drop as r(-2) while the upstream magnetic field is wrapped into a tight spiral, resulting in an almost perpendicular shock everywhere. Such shocks can be extremely effective in accelerating electrons to high energies. I describe spectra and images for spherical remnants, assuming the dynamics are given by the Sedov self-similar solution appropriate for an ambient r(-2) density profile (r_sh t(2/3) ). Both images and spectra differ significantly from those for remnants expanding into uniform magnetic fields, and should be distinguishable. Remnants expanding into spherical wind bubbles should show little azimuthal variation in synchrotron brightness for any viewing angle. Except at the highest photon energies, their brightness profiles peak somewhat inside the outermost edge of emission. X-ray halos caused by electrons diffusing ahead of the shock are generally narrow and faint. I shall describe inverse-Compton gamma-ray spectra produced by these electron distributions as well.

  20. 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.

  1. The Subparsec-Scale Radio Properties of Southern Starburst Galaxies. I. Supernova Remnants, the Supernova Rate, and the Ionized Medium in the NGC 253 Starburst

    NASA Astrophysics Data System (ADS)

    Lenc, E.; Tingay, S. J.

    2006-09-01

    Wide-field, very long baseline interferometry observations of the nearby starburst galaxy NGC 253, obtained with the Australian Long Baseline Array, have produced a 2.3 GHz image with a maximum angular resolution of 15 mas (0.3 pc). Six sources were detected, all corresponding to sources identified in higher frequency (>5 GHz) VLA images. One of the sources, supernova remnant 5.48-43.3, is resolved into a shell-like structure approximately 90 mas (1.7 pc) in diameter. From these data and data from the literature, the spectra of 20 compact radio sources in NGC 253 were modeled and found to be consistent with free-free absorbed power laws. Broadly, the free-free opacity is highest toward the nucleus but varies significantly throughout the nuclear region (τ0~1 to >20), implying that the overall structure of the ionized medium is clumpy. Of the 20 sources, 9 have flat intrinsic spectra associated with thermal radio emission, and the remaining 11 have steep intrinsic spectra associated with synchrotron emission from supernova remnants. A supernova rate upper limit of 2.4 yr-1 is determined for the inner 320 pc region of the galaxy at the 95% confidence level, based on the lack of detection of new sources in observations spanning almost 17 yr and a simple model for the evolution of supernova remnants. A supernova rate of >0.14(v/104) yr-1 is implied from estimates of supernova remnant source counts, sizes, and expansion rates, where v is the radial expansion velocity of the supernova remnant in kilometers per second. A star formation rate of 3.4(v/104) Msolar yr-1=5 Msolar)<59 Msolar yr-1 has been estimated directly from the supernova rate limits and is of the same order of magnitude as rates determined from integrated far-IR and radio luminosities.

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

    SciTech Connect

    Eriksen, Kristoffer A.; Hughes, John P.; Badenes, Carles; Fesen, Robert; Ghavamian, Parviz; Moffett, David; Plucinksy, Paul P.; Slane, Patrick; Rakowski, Cara E.; Reynoso, Estela M.

    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 a 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.

  3. Evidence for Particle Acceleration to the Knee of the Cosmic Ray Spectrum in Tycho's Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Eriksen, Kristoffer A.; Hughes, John P.; Badenes, Carles; Fesen, Robert; Ghavamian, Parviz; Moffett, David; Plucinksy, Paul P.; Rakowski, Cara E.; Reynoso, Estela M.; Slane, Patrick

    2011-02-01

    Supernova remnants (SNRs) have long been assumed to be the source of cosmic rays (CRs) up to the "knee" of the CR spectrum at 1015 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 a 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 1014-1015 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.

  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. Recoil of the Stellar Remnant from the Puppis A Supernova: Proper-Motion Measurement from Chandra

    NASA Technical Reports Server (NTRS)

    Petre, Robert; Winkler, P. F.

    2006-01-01

    A sequence of three Chandra X-ray Observatory High Resolution Camera images taken over a span of five years reveals arc-second-scale displacement of RX-J0822--4300, the stellar remnant near the center of the Puppis A supernova remnant. We measure its proper motion to be 0.16+/-0.02 arcsec/yr toward the west-southwest. At a distance of 2 kpc, this corresponds to a transverse space velocity of approx. 1500 km/s. This is the first case of a compact X-ray source with a directly measured proper motion. The space velocity is consistent with the explosion center inferred from proper motions of the oxygen-rich optical filaments, and confirms the idea that Puppis A resulted from an asymmetric explosion accompanied by a kick that imparted on the order of 3 x 10(exp 49) ergs of kinetic energy (some 3 percent of the supernova kinetic energy) to the stellar remnant. We will summarize this measurement and discuss possible mechanisms for producing such a violent kick. This research has been supported by NASA grant G04-5062X.

  6. 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".

  7. The Chandra ACIS Survey of M33: X-ray, Optical, and Radio Properties of the Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Long, Knox S.; Blair, William P.; Winkler, P. Frank; Becker, Robert H.; Gaetz, Terrance J.; Ghavamian, Parviz; Helfand, David J.; Hughes, John P.; Kirshner, Robert P.; Kuntz, Kip D.; McNeil, Emily K.; Pannuti, Thomas G.; Plucinsky, Paul P.; Saul, Destry; Tüllmann, Ralph; Williams, Benjamin

    2010-04-01

    M33 contains a large number of emission nebulae identified as supernova remnants (SNRs) based on the high [S II]:Hα ratios characteristic of shocked gas. Using Chandra data from the ChASeM33 survey with a 0.35-2 keV sensitivity of ~2 × 1034 erg s-1, we have detected 82 of 137 SNR candidates, yielding confirmation of (or at least strongly support for) their SNR identifications. This provides the largest sample of remnants detected at optical and X-ray wavelengths in any galaxy, including the Milky Way. A spectral analysis of the seven X-ray brightest SNRs reveals that two, G98-31 and G98-35, have spectra that appear to indicate enrichment by ejecta from core-collapse supernova explosions. In general, the X-ray-detected SNRs have soft X-ray spectra compared to the vast majority of sources detected along the line of sight to M33. It is unlikely that there are any other undiscovered thermally dominated X-ray SNRs with luminosities in excess of ~4 × 1035 erg s-1 in the portions of M33 covered by the ChASeM33 survey. We have used a combination of new and archival optical and radio observations to attempt to better understand why some objects are detected as X-ray sources and others are not. We have also developed a morphological classification scheme for the optically identified SNRs and discussed the efficacy of this scheme as a predictor of X-ray detectability. Finally, we have compared the SNRs found in M33 to those that have been observed in the Galaxy and the Magellanic Clouds. There are no close analogs of Cas A, Kepler's SNR, Tycho's SNR, or the Crab Nebula in the regions of M33 surveyed, but we have found an X-ray source with a power-law spectrum coincident with a small-diameter radio source that may be the first pulsar-wind nebula recognized in M33.

  8. Infrared and X-Ray Spectroscopy of the Kes 75 Supernova Remnant Shell: Characterizing the Dust and Gas Properties

    NASA Technical Reports Server (NTRS)

    Temim, Tea; Slane, Patrick; Arendt, Richard G.; Dwek, Eli

    2011-01-01

    We present deep Chandra observations and Spitzer Space Telescope infrared (IR) spectroscopy of the shell in the composite supernova remnant (SNR) Kes 75 (G29.7-0.3). The remnant is composed of a central pulsar wind nebula and a bright partial shell in the south that is visible at radio, IR, and X-ray wavelengths. The X-ray emission can be modeled by either a single thermal component with a temperature of approximately 1.5 keY, or with two thermal components with temperatures of 1.5 and 0.2 keY. Previous studies suggest that the hot component may originate from reverse-shocked supernova (SN) ejecta. However, our new analysis shows no definitive evidence for enhanced abundances of Si, S, Ar, Mg, and Fe, as expected from SN ejecta, or for the IR spectral signatures characteristic of confirmed SN condensed dust, thus favoring a circumstellar or interstellar origin for the X-ray and IR emission. The X-ray and IR emission in the shell are spatially correlated, suggesting that the dust particles are collisionally heated by the X-ray emitting gas. The IR spectrum of the shell is dominated by continuum emission from dust with little, or no line emission. Modeling the IR spectrum shows that the dust is heated to a temperature of approximately 140 K by a relatively dense, hot plasma that also gives rise to the hot X-my emission component. The density inferred from the IR emission is significantly higher than the density inferred from the X-ray models, suggesting a low filling factor for this X-my emitting gas. The total mass of the warm dust component is at least 1.3 x 10(exp -2) x solar mass, assuming no significant dust destruction has occurred in the shell. The IR data also reveal the presence of an additional plasma component with a cooler temperature, consistent with the 0.2 keV gas component. Our IR analysis therefore provides an independent verification of the cooler component of the X-ray emission. The complementary analyses of the X-ray and IR emission provide quantitative estimates of density and filling factors of the clumpy medium swept up by the SNR.

  9. INFRARED AND X-RAY SPECTROSCOPY OF THE Kes 75 SUPERNOVA REMNANT SHELL: CHARACTERIZING THE DUST AND GAS PROPERTIES

    SciTech Connect

    Temim, Tea; Arendt, Richard G.; Slane, Patrick; Dwek, Eli

    2012-01-20

    We present deep Chandra observations and Spitzer Space Telescope infrared (IR) spectroscopy of the shell in the composite supernova remnant (SNR) Kes 75 (G29.7-0.3). The remnant is composed of a central pulsar wind nebula and a bright partial shell in the south that is visible at radio, IR, and X-ray wavelengths. The X-ray emission can be modeled by either a single thermal component with a temperature of {approx}1.5 keV, or with two thermal components with temperatures of 1.5 and 0.2 keV. Previous studies suggest that the hot component may originate from reverse-shocked supernova (SN) ejecta. However, our new analysis shows no definitive evidence for enhanced abundances of Si, S, Ar, Mg, and Fe, as expected from SN ejecta, or for the IR spectral signatures characteristic of confirmed SN condensed dust, thus favoring a circumstellar or interstellar origin for the X-ray and IR emission. The X-ray and IR emission in the shell are spatially correlated, suggesting that the dust particles are collisionally heated by the X-ray emitting gas. The IR spectrum of the shell is dominated by continuum emission from dust with little, or no line emission. Modeling the IR spectrum shows that the dust is heated to a temperature of {approx}140 K by a relatively dense, hot plasma that also gives rise to the hot X-ray emission component. The density inferred from the IR emission is significantly higher than the density inferred from the X-ray models, suggesting a low filling factor for this X-ray emitting gas. The total mass of the warm dust component is at least 1.3 Multiplication-Sign 10{sup -2} M{sub Sun }, assuming no significant dust destruction has occurred in the shell. The IR data also reveal the presence of an additional plasma component with a cooler temperature, consistent with the 0.2 keV gas component. Our IR analysis therefore provides an independent verification of the cooler component of the X-ray emission. The complementary analyses of the X-ray and IR emission provide quantitative estimates of density and filling factors of the clumpy medium swept up by the SNR.

  10. Infrared and X-Ray Spectroscopy of the KES 75 Supernova Remnant Shell: Characterizing the Dust and Gas Properties

    NASA Technical Reports Server (NTRS)

    Temim, Tea; Dwek, Eli; Slane, Patrick; Arendt, Richard G.

    2009-01-01

    We present deep Chandra observations and Spitzer Space Telescope infrared (IR) spectroscopy of the shell in the composite supernova remnant (SNR) Kes 75 (G29.7-0.3). The remnant is composed of a central pulsar wind nebula and a bright partial shell in the south that is visible at radio, IR, and X-ray wavelengths. The X-ray emission can be modeled by either a single thermal component with a temperature of 1.5 keV, or with two thermal components with temperatures of 1.5 and 0.2 keV. Previous studies suggest that the hot component may originate from reverse-shocked SN ejecta. However, our new analysis shows no definitive evidence for enhanced abundances of Si, S, Ar, Mg, and Fe, as expected from supernova (SN) ejecta, or for the IR spectral signatures characteristic of confirmed SN condensed dust, thus favoring a circumstellar or interstellar origin for the X-ray and IR emission. The X-ray and ill emission in the shell are spatially correlated, suggesting that the dust particles are collisionally heated by the X-ray emitting gas. The IR spectrum of the shell is dominated by continuum emission from dust with little, or no line emission. Modeling the IR spectrum shows that the dust is heated to a temperature of 140 K by a relatively dense, hot plasma, that also gives rise to the hot X-ray emission component. The density inferred from the IR emission is significantly higher than the density inferred from the X-ray models, suggesting a low filling factor for this X-ray emitting gas. The total mass of the warm dust component is at least 1.3 x 10(exp -2) solar mass, assuming no significant dust destruction has occurred in the shell. The IR data also reveal the presence of an additional plasma component with a cooler temperature, consistent with the 0.2 keV gas component. Our IR analysis therefore provides an independent verification of the cooler component of the X-ray emission. The complementary analyses of the X-ray and IR emission provide quantitative estimates of density and filling factors of the clumpy medium swept up by the SNR.

  11. Rayleigh-Taylor instabilities in Type Ia supernova remnants undergoing cosmic ray particle acceleration - low adiabatic index solutions

    NASA Astrophysics Data System (ADS)

    Wang, Chih-Yueh

    2011-07-01

    This study investigates the evolution of Rayleigh-Taylor (R-T) instabilities in Type Ia supernova remnants that are associated with a low adiabatic index γ, where γ < 5/3, which reflects the expected change in the supernova shock structure as a result of cosmic ray particle acceleration. Extreme cases, such as the case with the maximum compression ratio that corresponds to γ= 1.1, are examined. As γ decreases, the shock compression ratio rises, and an increasingly narrow intershock region with a more pronounced initial mixture of R-T unstable gas is produced. Consequently, the remnant outline may be perturbed by small-amplitude, small-wavelength bumps. However, as the instability decays over time, the extent of convective mixing in terms of the ratio of the radius of the R-T fingers to the blast wave does not strongly depend on the value of γ for γ≥ 1.2. As a result of the age of the remnant, the unstable gas cannot extend sufficiently far to form metal-enriched filaments of ejecta material close to the periphery of Tycho's supernova remnant. The consistency of the dynamic properties of Tycho's remnant with the adiabatic model γ= 5/3 reveals that the injection of cosmic rays is too weak to alter the shock structure. Even with very efficient acceleration of cosmic rays at the shock, significantly enhanced mixing is not expected in Type Ia supernova remnants.

  12. Systematic search for molecular clouds near supernova remnants as sources of very-high-energy γ-ray emission

    NASA Astrophysics Data System (ADS)

    Häffner, Stephanie; Stegmann, Christian; Jung-Richardt, Ira

    2015-12-01

    Supernova remnants accelerate particles up to energies of at least 100 TeV as established by observations in very-high-energy γ-ray astronomy. Molecular clouds in their vicinity provide an increased amount of target material for proton-proton interaction and subsequent neutral pion decay into γ-rays of accelerated hadrons escaping the remnant. Therefore, these molecular clouds are potential γ-ray sources. The γ-ray emission from these clouds provides a unique environment to derive information on the propagation of very-high-energy particles through the interstellar medium as well as on the acceleration of hadrons in supernova remnants. Current Imaging Atmospheric Cherenkov Telescope systems are suitable to explore a large parameter space of the propagation properties depending on the age of the supernova remnant and the distance between the remnant and the nearby molecular cloud. In this paper we present our strategy and results of a systematic search for γ-ray emitting molecular clouds near supernova remnants which are potentially detectable with current experiments in the TeV energy range and explore the prospects of future experiments.

  13. XMM-Newton Observations of the Supernova Remnant G299.2-2.9

    NASA Astrophysics Data System (ADS)

    Pittroff, L.; Aschenbach, B.

    G299.2-2.9 is a 15 arcmin diameter shell-type supernova remnant (SNR) in our Galaxy which was discovered in the ROSAT all-sky survey and later confirmed as such by radio and optical observations. The X-ray emitting area of the remnant is resolved into several distinct regions: an almost complete ring interrupted only by a blow-out similar to the one seen in Cas-A, a brightened center, an enhanced knot-like region on the northeastern edge of the ring and diffuse emission extending far beyond the ring both to the northeast and to the south. The EPIC PN spectra demonstrate that the emission is thermal with surprisingly bright Si-K lines, the equivalent width of which changes significantly from place to place. The analysis of the spectra will be presented and discussed.

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

    SciTech Connect

    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 observation 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.

  15. The interaction of the supernova remnant Kes 69 with a molecular cloud

    NASA Astrophysics Data System (ADS)

    Miceli, Marco

    2008-10-01

    We propose to perform a single observation (50 ks) of the mixed-morphology supernova remnant Kes 69. Recent millimeter-wavelength observations proved that Kes 69 is interacting with a molecular cloud and X-ray emitting knots have been observed in the interaction region with ROSAT. Clumps of SNR ejecta moving in a dense cloud are predicted to produce a non-thermal knotty emission characterized by strong lines. This effect has been observed only in IC 443 and with the ROSAT dara it is not possible to perform a spatially resolved spectral analysis on the knots in Kes 69. We aim at studying the physical conditions of the plasma in the interaction region. We will also study the inner part of the remnant to investigate the presence of ejecta, recently detected in other mixed-morphology SNRs.

  16. Second Epoch Hubble Space Telescope Observations of Kepler's Supernova Remnant: The Proper Motions of Balmer Filaments

    NASA Astrophysics Data System (ADS)

    Sankrit, Ravi; Raymond, John C.; Blair, William P.; Long, Knox S.; Williams, Brian J.; Borkowski, Kazimierz J.; Patnaude, Daniel J.; Reynolds, Stephen P.

    2016-01-01

    We report on the proper motions of Balmer-dominated filaments in Kepler’s supernova remnant using high resolution images obtained with the Hubble Space Telescope at two epochs separated by about 10 years. We use the improved proper motion measurements and revised values of shock velocities to derive a distance to Kepler of {5.1}-0.7+0.8 kpc. The main shock around the northern rim of the remnant has a typical speed of 1690 km s-1 and is encountering material with densities of about 8 cm-3. We find evidence for the variation of shock properties over small spatial scales, including differences in the driving pressures as the shock wraps around a curved cloud surface. We find that the Balmer filaments ahead of the ejecta knot on the northwest boundary of the remnant are becoming fainter and more diffuse. We also find that the Balmer filaments associated with circumstellar material in the interior regions of the remnant are due to shocks with significantly lower velocities and that the brightness variations among these filaments trace the density distribution of the material, which may have a disk-like geometry. Based on observations made with the Hubble Space Telescope.

  17. HIGH RESOLUTION 36 GHz IMAGING OF THE SUPERNOVA REMNANT OF SN 1987A

    SciTech Connect

    Potter, T. M.; Staveley-Smith, L.; Zanardo, G.; Ng, C.-Y.; Gaensler, B. M.; Ball, Lewis; Kesteven, M. J.; Manchester, R. N.; Tzioumis, A. K.

    2009-11-01

    The aftermath of supernova (SN) 1987A continues to provide spectacular insights into the interaction between an SN blastwave and its circumstellar environment. We here present 36 GHz observations from the Australia Telescope Compact Array of the radio remnant of SN 1987A. These new images, taken in 2008 April and 2008 October, substantially extend the frequency range of an ongoing monitoring and imaging program conducted between 1.4 and 20 GHz. Our 36.2 GHz images have a diffraction-limited angular resolution of 0.''3-0.''4, which covers the gap between high resolution, low dynamic range VLBI images of the remnant and low resolution, high dynamic range images at frequencies between 1 and 20 GHz. The radio morphology of the remnant at 36 GHz is an elliptical ring with enhanced emission on the eastern and western sides, similar to that seen previously at lower frequencies. Model fits to the data in the Fourier domain show that the emitting region is consistent with a thick inclined torus of mean radius 0.''85, and a 2008 October flux density of 27 +- 6 mJy at 36.2 GHz. The spectral index for the remnant at this epoch, determined between 1.4 GHz and 36.2 GHz, is alpha = -0.83. There is tentative evidence for an unresolved central source with flatter spectral index.

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

    SciTech Connect

    Klimek, Matthew D.; Points, S. D.; Smith, R. C.; Shelton, R. L.; Williams, R. E-mail: spoints@ctio.noao.ed E-mail: rls@physast.uga.ed

    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 optical 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.

  19. Spectra of the HB 21 supernova remnant: Evidence of spectrum flattening at the low frequencies

    NASA Astrophysics Data System (ADS)

    Borka, D.; Borka Jovanovic, V.; Uroševic, D.

    2012-04-01

    We use observations of the continuum radio emission at 1420, 820, 408, 34.5 and 22 MHz to estimate the mean brightness temperatures of the HB 21 supernova remnant (SNR) at five frequencies. We also present mean spectral index of HB1. The spectra of HB 21 are estimated from mean temperatures versus frequency plots for 1420, 820, 408, 34.5 and 22 MHz. We also present T-T plots of three frequency pairs: between 1420-34.5, 1420-22, 34.5-22 MHz. We notice flatter spectral indices at frequencies below 408 MHz. Probably this is due to the absorption by thermal plasma at low frequencies.

  20. 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.

  1. 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.

  2. ANALYTICAL AND MONTE CARLO RESULTS FOR THE SURFACE-BRIGHTNESS-DIAMETER RELATIONSHIP IN SUPERNOVA REMNANTS

    SciTech Connect

    Zaninetti, Lorenzo

    2012-02-10

    The surface-brightness-diameter relationship for supernova remnants is explained by adopting a model of direct conversion of the flux of kinetic energy into synchrotron luminosity. Two laws of motion are adopted: a power-law model for the radius-time relationship and a model that uses the thin layer approximation. The fluctuations in the log-log surface diameter relationship are modeled by a Monte Carlo simulation. In this model, a new probability density function for the density as a function of the galactic height is introduced.

  3. 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.

  4. Dust destruction by the reverse shock in the Cassiopeia A supernova remnant

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

    Context. Core collapse supernovae (CCSNe) are important sources of interstellar dust, which are 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. Aims: We identify the dust destruction mechanisms in the ejecta and derive the net amount of dust that survives the passage of the reverse shock. Methods: We use analytical models for the evolution of a supernova blast wave and of the reverse shock with special application to the clumpy ejecta of the remnant of Cassiopeia A (Cas A). We assume that the dust resides in cool oxygen-rich clumps, which are uniformly distributed within the remnant and surrounded by a hot X-ray emitting plasma (smooth ejecta), and that the dust consists of silicates (MgSiO3) and amorphous carbon grains. 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. Results: We find that 11.8 and 15.9 percent of silicate and carbon dust, respectively, survive the passage of the reverse shock by the time the shock has reached the centre 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.

  5. VizieR Online Data Catalog: Optical supernova remnants in nearby galaxies (Vucetic+, 2015)

    NASA Astrophysics Data System (ADS)

    Vucetic, M. M.; Arbutina, B.; Urosevic, D.

    2015-09-01

    To estimate the contribution from SNRs to the total Hα emission used to determine SFRs in a galaxy, we searched the literature for all galaxies that have optically identified SNRs. In total, there are 25 of them (excluding the Milky Way). In following tables we give data for 18 nearby galaxies which have been surveyed for optical supernova remnants (SNRs). In each table we give coordinates, Hα fluxes, diameters and [SII]/Hα emission line ratios for detected SNRs, found in literature. (19 data files).

  6. 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.

  7. The Expansion Center and Dynamical Age of the Galactic Supernova Remnant Cassiopeia A

    NASA Astrophysics Data System (ADS)

    Thorstensen, John R.; Fesen, Robert A.; van den Bergh, Sidney

    2001-07-01

    We present proper motions for 21 bright main shell and 17 faint, higher velocity, outer ejecta knots in the Cas A supernova remnant and use them to derive new estimates for the remnant's expansion center and age. Our study included 1951-1976 Palomar 5 m prime focus plates, 1988-1999 CCD images from the KPNO 4 m and MDM 2.4 m telescopes, and 1999 HST WFPC2 images. Measurable positions covered a 23 to 41 yr time span for most knots, with a few outer knots followed for almost 48 yr. We derive an expansion center of α(J2000)=23h23m27.77s+/-0.05s, δ(J2000)=58°48'49.4"+/-0.4" (ICRS), with little difference between centers derived using outer or main shell knots. This position is 3.0" due north of that estimated by van den Bergh & Kamper. It also lies 6.6"+/-1.5" almost due north (P.A.=354deg) of the remnant's recently detected central X-ray point source, implying a transverse velocity for the X-ray point source ~=330 km s-1 at a distance of 3.4 kpc. Using the knots which lie out ahead of the remnant's forward blast wave, we estimate a knot convergent date of A.D. 1671.3+/-0.9 assuming no deceleration. However, a deceleration of just ~1.6 km s-1 yr-1 over a 300 yr time span would produce an explosion date ~=A.D. 1680, consistent with the suspected sighting of the Cas A supernova by J. Flamsteed. Based in part on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

  8. Two populations of X-ray pulsars produced by two types of supernova.

    PubMed

    Knigge, Christian; Coe, Malcolm J; Podsiadlowski, Philipp

    2011-11-17

    Two types of supernova are thought to produce the overwhelming majority of neutron stars in the Universe. The first type, iron-core-collapse supernovae, occurs when a high-mass star develops a degenerate iron core that exceeds the Chandrasekhar limit. The second type, electron-capture supernovae, is associated with the collapse of a lower-mass oxygen-neon-magnesium core as it loses pressure support owing to the sudden capture of electrons by neon and/or magnesium nuclei. It has hitherto been impossible to identify the two distinct families of neutron stars produced in these formation channels. Here we report that a large, well-known class of neutron-star-hosting X-ray pulsars is actually composed of two distinct subpopulations with different characteristic spin periods, orbital periods and orbital eccentricities. This class, the Be/X-ray binaries, contains neutron stars that accrete material from a more massive companion star. The two subpopulations are most probably associated with the two distinct types of neutron-star-forming supernova, with electron-capture supernovae preferentially producing systems with short spin periods, short orbital periods and low eccentricities. Intriguingly, the split between the two subpopulations is clearest in the distribution of the logarithm of spin period, a result that had not been predicted and which still remains to be explained. PMID:22080948

  9. 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.

  10. LIMITS ON THE NUMBER OF GALACTIC YOUNG SUPERNOVA REMNANTS EMITTING IN THE DECAY LINES OF {sup 44}Ti

    SciTech Connect

    Dufour, François; Kaspi, Victoria M.

    2013-09-20

    We revise the assumptions of the parameters involved in predicting the number of supernova remnants detectable in the nuclear lines of the decay chain of {sup 44}Ti. Specifically, we consider the distribution of the supernova progenitors, the supernova rate in the Galaxy, the ratios of supernova types, the Galactic production of {sup 44}Ti, and the {sup 44}Ti yield from supernovae of different types to derive credible bounds on the expected number of detectable remnants. We find that, within 1σ uncertainty, the Galaxy should contain an average of 5.1{sup +2.4}{sub -2.0} remnants detectable to a survey with a {sup 44}Ti decay line flux limit of 10{sup –5} photons cm{sup –2} s{sup –1}, with a probability of detecting a single remnant of 2.7{sup +10.0}{sub -2.4}%, and an expected number of detections between two and nine remnants, making the single detection of Cas A unlikely but consistent with our models. Our results show that the probability of detecting the brightest {sup 44}Ti flux source at the high absolute Galactic longitude of Cas A or above is ∼10%. Using the detected flux of Cas A, we attempt to constrain the Galactic supernova rate and Galactic production of {sup 44}Ti, but find the detection to be only weakly informative. We conclude that even future surveys having 200 times more sensitivity than state-of-the-art surveys can be guaranteed to detect only a few new remnants, with an expected number of detections between 8 and 21 at a limiting {sup 44}Ti decay flux of 10{sup –7} photons cm{sup –2} s{sup –1}.

  11. SWIFT/BAT DETECTION OF HARD X-RAYS FROM TYCHO'S SUPERNOVA REMNANT: EVIDENCE FOR TITANIUM-44

    SciTech Connect

    Troja, E.; Baumgartner, W.; Markwardt, C.; Barthelmy, S.; Gehrels, N.; Segreto, A.; La Parola, V.; Cusumano, G.; Hartmann, D.

    2014-12-10

    We report Swift/Burst Alert Telescope survey observations of the Tycho's supernova remnant, performed over a period of 104 months since the mission's launch. The remnant is detected with high significance (>10σ) below 50 keV. We detect significant hard X-ray emission in the 60-85 keV band, above the continuum level predicted by a simple synchrotron model. The location of the observed excess is consistent with line emission from radioactive titanium-44, so far reported only for Type II supernova explosions. We discuss the implications of these results in the context of the galactic supernova rate, and nucleosynthesis in Type Ia supernova.

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

    SciTech Connect

    Tian, W. W.; Leahy, D. A.

    2011-03-10

    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. This 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.

  13. Tycho SN 1572: A Naked Ia Supernova Remnant Without an Associated Ambient Molecular Cloud

    NASA Astrophysics Data System (ADS)

    Tian, W. W.; Leahy, D. A.

    2011-03-01

    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 12CO-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. This 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 γ-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.

  14. RADIOACTIVE SCANDIUM IN THE YOUNGEST GALACTIC SUPERNOVA REMNANT G1.9+0.3

    SciTech Connect

    Borkowski, Kazimierz J.; Reynolds, Stephen P.; Green, David A.; Hwang, Una; Petre, Robert

    2010-12-01

    We report the discovery of thermal X-ray emission from the youngest Galactic supernova remnant G1.9+0.3, from a 237 ks Chandra observation. We detect strong K{alpha} lines of Si, S, Ar, Ca, and Fe. In addition, we detect a 4.1 keV line with 99.971% confidence which we attribute to {sup 44}Sc, produced by electron capture from {sup 44}Ti. Combining the data with our earlier Chandra observation allows us to detect the line in two regions independently. For a remnant age of 100 yr, our measured total line strength indicates synthesis of (1-7) x 10{sup -5} M {sub sun} of {sup 44}Ti, in the range predicted for both Type Ia and core-collapse supernovae (SNe), but somewhat smaller than the 2 x 10{sup -4} M {sub sun} reported for Cas A. The line spectrum indicates supersolar abundances. The Fe emission has a width of about 28,000 km s{sup -1}, consistent with an age of {approx}100 yr and with the inferred mean shock velocity of 14,000 km s{sup -1} deduced assuming a distance of 8.5 kpc. Most thermal emission comes from regions of lower X-ray but higher radio surface brightness. Deeper observations should allow more detailed spatial mapping of {sup 44}Sc, with significant implications for models of nucleosynthesis in Type Ia SNe.

  15. Electron Heating, Magnetic Field Amplification, and Cosmic-Ray Precursor Length at Supernova Remnant Shocks

    NASA Astrophysics Data System (ADS)

    Laming, J. Martin; Hwang, Una; Ghavamian, Parviz; Rakowski, Cara

    2014-07-01

    We investigate the observability, by direct and indirect means, of a shock precursor arising from magnetic field amplification by cosmic rays. We estimate the depth of such a precursor under conditions of nonresonant amplification, which can provide magnetic field strengths comparable to those inferred for supernova remnants. Magnetic field generation occurs as the streaming cosmic rays induce a plasma return current, and it may be quenched by either nonresonant or resonant channels. In the case of nonresonant saturation, the cosmic rays become magnetized and amplification saturates at higher magnetic fields. The precursor can extend out to 1017-1018 cm and is potentially detectable. If resonant saturation occurs, the cosmic rays are scattered by turbulence and the precursor length will likely be much smaller. The dependence of precursor length on shock velocity has implications for electron heating. In the case of resonant saturation, this dependence is similar to that in the more familiar resonantly generated shock precursor, which when expressed in terms of the cosmic-ray diffusion coefficient kappav and shock velocity vs is kappav/vs . In the nonresonantly saturated case, the precursor length declines less quickly with increasing vs . Where precursor length proportional to 1/vs gives constant electron heating, this increased precursor length could be expected to lead to higher electron temperatures for nonresonant amplification. This should be expected at faster supernova remnant shocks than studied by previous works. Existing results and new data analysis of SN 1006 and Cas A suggest some observational support for this idea.

  16. 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.

  17. Microquasar jets in the supernova remnant G11.2-0.3

    NASA Astrophysics Data System (ADS)

    Glushak, A. P.

    2014-01-01

    The radio and X-ray fine structure of the supernova remnant G11.2-0.3 is analyzed using VLA and Chandra data. A possible pair of bipolar X-ray jets inside the remnant shell was reported earlier; caps or terminal X-ray hot spots of these jets have now been discovered outside the shell. These hot spots lie on the jet axis, which is oriented in position angle 66° (measured from North through East). The proper motions of them are measured, and age is determined to be more than 160 years. The estimated physical parameters of the jets agree with the parameters of micro quasar jets. Three broad gaps with opening angles of 9° have been revealed in the radio shell, as well as radio bulges with opening angles of 2°-4° displaying tube-like structures at the shell periphery. Signs of the motion of material along position angle 124.5° have been found in the shell, suggesting the past activity of another pair of bipolar centrally symmetrical jets that were older than those first detected. These structural features provide direct evidence that the shell has been subject to multiple perforation by expanding fragments of matter from the supernova explosion, and by one or two pairs of bipolar jets with different orientations.

  18. Computer simulations of cosmic-ray diffusion near supernova remnant shock waves

    NASA Technical Reports Server (NTRS)

    Max, C. E.; Zachary, A. L.; Arons, J.

    1989-01-01

    A plasma simulation model was used to study the resonant interactions between streaming cosmic-ray ions and a self-consistent spectrum of Alfven waves, such as might exist in the interstellar medium upstream of a supernova remnant shock wave. The computational model is a hybrid one, in which the background interstellar medium is an MHD fluid and the cosmic-rays are discrete kinetic particles. The particle sources for the electromagnetic fields are obtained by averaging over the fast cyclotron motions. When the perturbed magnetic field is larger than 10 percent of the background field, the macro- and microphysics are no longer correctly predicted by quasi-linear theory. The particles are trapped by the waves and show sharp jumps in their pitch-angles relative to the background magnetic field, and the effective ninety-degree scattering time for diffusion parallel to the background magnetic field is reduced to between 5 and 30 cyclotron periods. Simulation results suggest that Type 1 supernova remnants may be the principal sites of cosmic ray acceleration.

  19. AKARI AND BLAST OBSERVATIONS OF THE CASSIOPEIA A SUPERNOVA REMNANT AND SURROUNDING INTERSTELLAR MEDIUM

    SciTech Connect

    Sibthorpe, B.; Ade, P. A. R.; Griffin, M.; Hargrave, P. C.; Mauskopf, P.; Bock, J. J.; Chapin, E. L.; Halpern, M.; Marsden, G.; Devlin, M. J.; Dicker, S.; Klein, J.; Gundersen, J. O.; Hughes, D. H.; Jeong, W.-S.; Kaneda, H.; Koo, B.-C.; Lee, H.-G.; Martin, P. G.; Moon, D.-S.

    2010-08-20

    We use new large area far infrared maps ranging from 65 to 500 {mu}m obtained with the AKARI and the Balloon-borne Large Aperture Submillimeter Telescope missions to characterize the dust emission toward the Cassiopeia A supernova remnant (SNR). Using the AKARI high-resolution data we find a new 'tepid' dust grain population at a temperature of {approx}35 K and with an estimated mass of 0.06 M{sub sun}. This component is confined to the central area of the SNR and may represent newly formed dust in the unshocked supernova ejecta. While the mass of tepid dust that we measure is insufficient by itself to account for the dust observed at high redshift, it does constitute an additional dust population to contribute to those previously reported. We fit our maps at 65, 90, 140, 250, 350, and 500 {mu}m to obtain maps of the column density and temperature of 'cold' dust (near 16 K) distributed throughout the region. The large column density of cold dust associated with clouds seen in molecular emission extends continuously from the surrounding interstellar medium to project on the SNR, where the foreground component of the clouds is also detectable through optical, X-ray, and molecular extinction. At the resolution available here, there is no morphological signature to isolate any cold dust associated only with the SNR from this confusing interstellar emission. Our fit also recovers the previously detected 'hot' dust in the remnant, with characteristic temperature 100 K.

  20. Thermal and non-thermal X-rays from the Galactic supernova remnant G348.5+0.1

    NASA Astrophysics Data System (ADS)

    Yamauchi, Shigeo; Minami, Sari; Ota, Naomi; Koyama, Katsuji

    2014-02-01

    We report on Suzaku results of the two distinct regions in the Galactic supernova remnant G348.5+0.1: extended thermal X-rays ("soft diffuse") at the north-east region and non-thermal X-rays (CXOU J171419.8-383023) at the north-west region. The X-ray spectrum of the soft diffuse X-rays can be fitted with neither an ionization equilibrium nor a non-equilibrium (ionizing) plasma model, leaving saw- tooth residuals in the 1.5-3 keV energy band. The residual structures can be produced when free electrons are recombined to the K-shells of highly ionized Mg and Si ions. In fact, the X-ray spectrum is nicely fitted with a recombination-dominant plasma model. We propose a scenario whereby the plasma in a nearly fully ionized state at high temperature quickly changed to a recombining phase due to selective cooling of electrons to a lower temperature of ˜ 0.5 keV. The spectrum of CXOU J171419.8-383023 is well explained by a simple power-law model with a photon index of 1.9, nearly equal to the typical value for pulsar wind nebulae. Since the distance is estimated to be the same as that of the soft diffuse radiation, we infer that both the soft diffuse X-rays and CXOU J171419.8-383023 are associated with the same object, SNR G348.5+0.1.

  1. The End of Amnesia: Measuring the Metallicities of Type Ia SN Progenitors with Manganese Lines in Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Badenes, Carles; Bravo, Eduardo; Hughes, John P.

    2009-05-01

    The Mn to Cr mass ratio in supernova ejecta has recently been proposed as a tracer of Type Ia SN progenitor metallicity. We review the advantages and problems of this observable quantity, and discuss them in the framework of the Tycho Supernova Remnant. The fluxes of the Mn and Cr Kα lines in the X-ray spectra of Tycho observed by the Suzaku satellite suggests a progenitors of supersolar metallicity.

  2. Molecule and dust reprocessing by the reverse shock in the supernova remnant Cas A

    NASA Astrophysics Data System (ADS)

    Biscaro, C.; Cherchneff, I.

    Dust and molecules are observed in various supernovae (SNe) and their remnants, but their formation and evolution in these hostile, shocked environments are still unclear. In some remnants, such as the 330 years-old SN remnant Cas A, the reverse shock (RS) is currently reprocessing the material formed after the SN explosion. Recently, transitions of warm CO have been detected with the Spitzer, AKARI and Herschel telescopes in Cas A ([9], [12]). In particular, CO lines were detected with Herschel in a small O-rich clump, and a high CO column density and temperature, compatible with shocked gas, were derived from line modelling ([12]). These observations thus show that a fair quantity of CO reforms after the passage of the RS. The Cas A remnant results from the explosion of a 19 M star as a Type IIb supernova ([6]), characterised by a lowdensity ejecta. We first model the SN ejecta chemistry to identify the molecules and dust clusters that form after the explosion and are reprocessed by the RS. We find that Cas A progenitor could have formed large quantities of molecules and dust only in a dense ejecta involving clumps. We then model the impact of the RS on an oxygen-rich ejecta clump, considering various RS speeds and investigating the post-shock chemistry. We consider the destruction of molecules and dust clusters by the shock and their reformation using a chemical kinetic model. The impact of UV photons coming from the hot post-shock region on the ionization fraction of the post-shock gas is included. We also model the sputtering (thermal and non-thermal) of the dust by the RS. We found that the reverse shock destroys the molecules and clusters present in the O-rich clump. CO reforms in the post shock gas with abundances that concur with the latest Herschel observations, confirming a post-shock origin for the submm CO lines. We then derive a dust size distribution for the ejecta of the Cas A progenitor, and investigate the effect of different RS velocities on this dust size distribution. Our results show that medium- and large-sized grains can survive the RS and that small dust clusters do not efficiently reform in the shocked gas. This result indicates that the dust formed in the SN ejecta and destroyed by the RS is unable to reform from the gas phase in the SN remnant.

  3. Spitzer Space Telescope Observations of Kepler's Supernova Remnant: A Detailed Look at the Circumstellar Dust Component

    NASA Astrophysics Data System (ADS)

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

    2007-06-01

    We present 3.6-160 μm infrared images of Kepler's supernova remnant (SN 1604) obtained with the IRAC and MIPS instruments on the Spitzer Space Telescope. We also present MIPS SED low-resolution spectra in the 55-95 μm region. The observed emission in the MIPS 24 μm band shows the entire shell. Emission in the MIPS 70 μm and IRAC 8 μm bands is seen only from the brightest regions of 24 μm emission, which also correspond to the regions seen in optical Hα images. Shorter wavelength IRAC images are increasingly dominated by stars, although faint filaments are discernible. The SED spectrum of shows a faint continuum dropping off to longer wavelengths and confirms that strong line emission does not dominate the mid-IR spectral region. The emission we see is due primarily to warm dust emission from dust heated by the primary blast wave; no excess infrared emission is observed in regions where supernova ejecta are seen in X-rays. We use models of the dust to interpret the observed 70/24 μm ratio and constrain the allowed range of temperatures and densities. We estimate the current mass of dust in the warm dust component to be 5.4×10-4 Msolar, and infer an original mass of about 3×10-3 Msolar before grain sputtering. The MIPS 160 μm band shows no emission belonging to the remnant. We place a conservative but temperature-dependent upper limit on any cold dust component roughly a factor of 10 below the cold dust mass inferred from SCUBA observations. Finally, we comment on issues relevant to the possible precursor star and the supernova type. Based on observations made with the NASA Spitzer Space Telescope. Spitzer is operated for NASA by the Jet Propulsion Lab.

  4. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

    Several young supernova remnants (SNRs) 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 SNR in five 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 ˜1%-5% of remnant radius and magnetic field strengths ˜50-400 μG assuming Bohm diffusion. X-ray rim widths are ˜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 ≳20 μG, affirming the necessity of magnetic field amplification beyond simple compression.

  6. Hard X-Ray Emission and 44Ti Line Features of the Tycho Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Li, Zhuo

    2014-07-01

    A deep hard X-ray survey of the International Gamma-Ray Astrophysics Laboratory (INTEGRAL) satellite has detected for the first time non-thermal emission up to 90 keV in the Tycho supernova (SN) remnant. Its 3-100 keV spectrum is fitted with a thermal bremsstrahlung of kT ~ 0.81 ± 0.45 keV plus a power-law model of Γ ~ 3.01 ± 0.16. Based on diffusive shock acceleration theory, this non-thermal emission, together with radio measurements, implies that the Tycho remnant may not accelerate protons up to >PeV but to hundreds TeV. Only heavier nuclei may be accelerated to the cosmic ray spectral "knee." In addition, using INTEGRAL, we search for soft gamma-ray lines at 67.9 and 78.4 keV that come from the decay of radioactive 44Ti in the Tycho remnant. A bump feature in the 60-90 keV energy band, potentially associated with the 44Ti line emission, is found with a marginal significance level of ~2.6σ. The corresponding 3σ upper limit on the 44Ti line flux amounts to 1.5 × 10-5 photon cm-2 s-1. Implications on the progenitor of the Tycho SN, considered to be a Type Ia SN prototype, are discussed.

  7. CCD soft X-ray observations of the Puppis a supernova remnant

    NASA Technical Reports Server (NTRS)

    Berthiaume, G. D.; Burrows, D. N.; Garmire, G. P.; Nousek, J. A.

    1994-01-01

    We present the first images and spectra of an astronomical object, other than the Sun, acquired with a charge coupled device (CCD) imaging X-ray spectrometer. During a 230 s sounding rocket observation, we have acquired moderate-resolution spectra and moderate-resolution images of a portion of the Pup A supernova remnant (SNR). Based on these data, we conclude that the X-ray spectrum of Pup A is inconsistent with any single-temperature equilibrium or nonequilibrium plasma model. We find evidence for variations in the emitting plasma on scales as small as 5.0 min and as large as 30.0 min. The spatial structure of the spectral variations in the remnant is found to be inconsistent with the standard Sedov model for the evolution of a SRN into a homogeneous interstellar medium (ISM). We suggest that the remnant is expanding into a region of the ISM having a density of approximately 1 cm(exp -3) with inhomogeneities on the order of 50%. We have found evidence for the presence of a knot of plasma enriched in neon, but require more data to be conclusive.

  8. 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.

  9. AN ATTEMPT AT A UNIFIED MODEL FOR THE GAMMA-RAY EMISSION OF SUPERNOVA REMNANTS

    SciTech Connect

    Yuan Qiang; Bi Xiaojun; Liu Siming

    2012-12-20

    Shocks of supernova remnants (SNRs) are important (and perhaps the dominant) agents for the production of the Galactic cosmic rays. Recent {gamma}-ray observations of several SNRs have made this case more compelling. However, these broadband high-energy measurements also reveal a variety of spectral shapes demanding more comprehensive modeling of emissions from SNRs. According to the locally observed fluxes of cosmic-ray protons and electrons, the electron-to-proton number ratio is known to be about 1%. Assuming such a ratio is universal for all SNRs and identical spectral shape for all kinds of accelerated particles, we propose a unified model that ascribes the distinct {gamma}-ray spectra of different SNRs to variations of the medium density and the spectral difference between cosmic-ray electrons and protons observed from Earth to transport effects. For low-density environments, the {gamma}-ray emission is inverse-Compton dominated. For high-density environments like systems of high-energy particles interacting with molecular clouds, the {gamma}-ray emission is {pi}{sup 0}-decay dominated. The model predicts a hadronic origin of {gamma}-ray emission from very old remnants interacting mostly with molecular clouds and a leptonic origin for intermediate-age remnants whose shocks propagate in a low-density environment created by their progenitors via, e.g., strong stellar winds. These results can be regarded as evidence in support of the SNR origin of Galactic cosmic rays.

  10. High-resolution X-ray spectroscopy and imaging of supernova remnant N132D

    NASA Astrophysics Data System (ADS)

    Behar, E.; Rasmussen, A. P.; Griffiths, R. G.; Dennerl, K.; Audard, M.; Aschenbach, B.; Brinkman, A. C.

    2001-01-01

    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 emission seems to originate near the centre, all of the other ions are observed along the shell. A high O6+/O7+ emission ratio is detected on the northeastern edge of the remnant. This can be a sign of hot ionising conditions, or it can reflect relatively cool gas. Spectral fitting of the CCD spectrum suggests high temperatures in this region, but a detailed analysis of the atomic processes involved in producing the O6+ spectral lines leads to the conclusion that the intensities of these lines alone cannot provide a conclusive distinction between the two scenarios. Based on observations obtained with \\xmm, an ESA science mission with instruments and contributions directly funded by ESA Member States and USA (NASA).

  11. An Archival X-ray Study of the Large Magellanic Cloud Supernova Remnant N132D

    NASA Astrophysics Data System (ADS)

    Plucinsky, Paul P.; Foster, Adam; Gaetz, Terrance; Jerius, Diab H.; Patnaude, Daniel; Edgar, Richard J.; Smith, Randall K.; Blair, William P.

    2016-01-01

    We present the results of an analysis of the archival XMM-Newton EPIC data (203ks for pn and 556/574ks for MOS1/MOS2) and the Chandra X-ray Observatory ACIS data (89ks) of the brightest X-ray supernova remnant (SNR) in the Large Magellanic Cloud (LMC) N132D. N132D has been classified as an ``O-rich'' remnant based on the UV and optical spectra which show emission from C, O, Ne, Mg, and Si. These spectra of the central optical knots do not show any emission from elements with Z higher than Si, yet the nucleosynthesis models predict significant quantities of these higher Z elements. Our spectral analysis of the deep XMM data clearly shows emission lines from S, Ar, Ca, and Fe, with indications of other possible features between Ca and Fe. We use a combination of the high resolution images from Chandra and the sensitive spectra from XMM to disentangle the emission from swept-up interstellar material and a possible hot ejecta component. We interpret these results in the context of a 3,000 year old remnant from a massive progenitor that has exploded into a cavity created by the progenitor.This research was supported by the NASA Astrophysics Data Analysis Program (ADAP) through grant number NNX11AD17G.

  12. 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.

  13. A CHANDRA X-RAY SURVEY OF EJECTA IN THE CASSIOPEIA A SUPERNOVA REMNANT

    SciTech Connect

    Hwang, Una; Laming, J. Martin E-mail: laming@nrl.navy.mil

    2012-02-20

    We present a survey of the X-ray-emitting ejecta in the Cassiopeia A supernova remnant (SNR) 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, and the implied mass coordinates, are highly peaked and suggest that the ejecta were subjected to multiple secondary shocks following reverse shock interaction with ejecta inhomogeneities. 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 and also show the distribution of the mass of various elements over the remnant. An upper limit to the total shocked Fe mass visible in X-rays appears to be roughly 0.13 M{sub Sun }, 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 possibly associated with {alpha}-rich freezeout, with a mass ratio of approximately 2:1. Essentially all of the observed Fe (both components) lies well outside the central regions of the SNR, possibly having been ejected by hydrodynamic instabilities during the explosion. We discuss this and its implications for the neutron star kick.

  14. Hard X-ray emission and {sup 44}Ti line features of the Tycho supernova remnant

    SciTech Connect

    Wang, Wei; Li, Zhuo E-mail: zhuo.li@pku.edu.cn

    2014-07-10

    A deep hard X-ray survey of the International Gamma-Ray Astrophysics Laboratory (INTEGRAL) satellite has detected for the first time non-thermal emission up to 90 keV in the Tycho supernova (SN) remnant. Its 3-100 keV spectrum is fitted with a thermal bremsstrahlung of kT ∼ 0.81 ± 0.45 keV plus a power-law model of Γ ∼ 3.01 ± 0.16. Based on diffusive shock acceleration theory, this non-thermal emission, together with radio measurements, implies that the Tycho remnant may not accelerate protons up to >PeV but to hundreds TeV. Only heavier nuclei may be accelerated to the cosmic ray spectral 'knee'. In addition, using INTEGRAL, we search for soft gamma-ray lines at 67.9 and 78.4 keV that come from the decay of radioactive {sup 44}Ti in the Tycho remnant. A bump feature in the 60-90 keV energy band, potentially associated with the {sup 44}Ti line emission, is found with a marginal significance level of ∼2.6σ. The corresponding 3σ upper limit on the {sup 44}Ti line flux amounts to 1.5 × 10{sup –5} photon cm{sup –2} s{sup –1}. Implications on the progenitor of the Tycho SN, considered to be a Type Ia SN prototype, are discussed.

  15. Giant-scale supernova remnants - The role of differential galactic rotation and the formation of molecular clouds

    NASA Technical Reports Server (NTRS)

    Tenorio-Tagle, G.; Palous, J.

    1987-01-01

    The evolution of remnants produced by the total supernova power from an evolved OB association in a differentially rotating galactic disk is presented. The calculations at 5 kpc and 10 kpc from the galactic center lead to column densities across the remnant shell, or across sections of the remnants, which eventually exceed the opacity criterion of Franco and Cox (1986) and thus form molecular clouds. The resultant clouds have masses larger than 100,000 solar masses, dimensions of several hundred parsecs, and a separation larger than 1 kpc. In contrast, at 20 kpc from the galactic center the opacity criterion is never fulfilled.

  16. X-ray, optical and UV observations of the young supernova remnant in the irregular galaxy NGC 4449

    NASA Technical Reports Server (NTRS)

    Blair, W. P.; Raymond, J. C.; Kirshner, R. P.; Winkler, P. F.; Fesen, R. A.; Gull, T. R.

    1983-01-01

    A powerful young supernova remnant (SNR) similar to Cas A has recently been discovered in the irregular galaxy NGC 4449. X-ray, optical and ultraviolet data have been obtained which allow possible models for this object to be investigated and its age to be estimated. Several lines of argument indicate a massive star of order 25 solar masses as the precursor to this remnant. If the X-ray emision is attributed to a reverse shock in the ejecta, the remnant should be about 120 years old.

  17. Chandra and XMM-Newton study of the supernova remnant Kes 73 hosting the magnetar 1E 1841-045

    SciTech Connect

    Kumar, Harsha S.; Safi-Harb, Samar; Slane, Patrick O.; Gotthelf, E. V. E-mail: samar@physics.umanitoba.ca E-mail: eric@astro.columbia.edu

    2014-01-20

    We present a Chandra and XMM-Newton study of the supernova remnant (SNR) Kes 73 hosting the anomalous X-ray pulsar 1E 1841–045. The Chandra image reveals clumpy structures across the remnant with enhanced emission along the western rim. The X-ray emission fills the radio shell and spatially correlates with the infrared image. The global X-ray spectrum is described by a two-component thermal model with a column density N {sub H} = 2.6{sub −0.3}{sup +0.4}×10{sup 22} cm{sup –2} and a total luminosity of L{sub X} = 3.3{sub −0.5}{sup +0.7}×10{sup 37} erg s{sup –1} (0.5-10 keV, at an assumed distance of 8.5 kpc). The soft component is characterized by a temperature kT{sub s} = 0.5{sub −0.2}{sup +0.1} keV, a high ionization timescale, and enhanced Si and S abundances, suggesting emission that is dominated by shocked ejecta. The hard component has a temperature kT{sub h} = 1.6{sub −0.7}{sup +0.8} keV, a relatively low ionization timescale, and mostly solar abundances suggesting emission that is dominated by interstellar/circumstellar shocked material. A spatially resolved spectroscopy study reveals no significant variations in the spectral properties. We infer an SNR age ranging between 750 yr and 2100 yr, an explosion energy of 3.0{sub −1.8}{sup +2.8}×10{sup 50} erg and a shock velocity of (1.2 ± 0.3)×10{sup 3} km s{sup –1} (under the Sedov phase assumption). We also discuss the possible scenario for Kes 73 expanding into the late red-supergiant wind phase of its massive progenitor. Comparing the inferred metal abundances to core-collapse nucleosynthesis model yields, we estimate a progenitor mass ≳20 M {sub ☉}, adding a candidate to the growing list of highly magnetized neutron stars proposed to be associated with very massive progenitors.

  18. A Search for Evidence of Non-Thermal Emission from the Supernova Remnants 37A/B

    NASA Technical Reports Server (NTRS)

    Oliversen, R.

    2002-01-01

    The ADP grant NAG5-9211 entitled 'A Search for Evidence of Non-Thermal Emission from the Supernova Remnants 37 A/B' was not used to support an analysis of the ASCA data for these two remnants because the ASCA mission ended before the remnants were observed. The grant was used to support similar research on two remnants in the Large Magellanic Cloud, N132D and N 103B. An analysis of the Chandra data for these two remnants exhibits some evidence of non-thermal emission from small regions in the remnants. The X-ray spectra for these regions can not be adequately described by a single thermal X-ray emission model. However, if an X-ray synchrotron component is also included, the spectral data can be well described by the model and the values of the fit parameters are consistent with the values expected. These results were presented at the 199th Meeting of the American Astronomical Society. In summary, the grant has enabled us to strengthen the evidence that supernova remnants outside our Galaxy can also accelerate electrons to very-high energies. The results of this analysis will be published soon in the Astrophysical Journal,

  19. Chandra X-Ray Observatory Arcsecond Imaging of the Young, Oxygen-rich Supernova Remnant 1E 0102.2-7219.

    PubMed

    Gaetz; Butt; Edgar; Eriksen; Plucinsky; Schlegel; Smith

    2000-05-01

    We present observations of the young, oxygen-rich supernova remnant 1E 0102.2-7219 taken by the Chandra X-Ray Observatory during its orbital activation and checkout phase. The boundary of the blast-wave shock is clearly seen for the first time, allowing the diameter of the remnant and the mean blast-wave velocity to be determined accurately. The prominent X-ray bright ring of material may be the result of the reverse shock encountering ejecta; the radial variation of O vii versus O viii emission indicates an ionizing shock propagating inward, possibly through a strong density gradient in the ejecta. We compare the X-ray emission with Australia Telescope Compact Array 6 cm radio observations (Amy & Ball) and with archival Hubble Space Telescope [O iii] observations. The ring of radio emission is predominantly inward of the outer blast wave, which is consistent with an interpretation of synchrotron radiation originating behind the blast wave but outward of the bright X-ray ring of emission. Many (but not all) of the prominent optical filaments are seen to correspond to X-ray bright regions. We obtain an upper limit of approximately 9x1033 ergs s-1 (3 sigma) on any potential pulsar X-ray emission from the central region. PMID:10790068

  20. Spitzer observations of the type IA supernova remnant N103B: Kepler's older cousin?

    SciTech Connect

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

    2014-08-01

    We report results from Spitzer observations of SNR 0509-68.7, also known as N103B, a young Type Ia supernova remnant (SNR) in the Large Magellanic Cloud (LMC) that shows interaction with a dense medium in its western hemisphere. Our images show that N103B has strong IR emission from warm dust in the post-shock environment. The post-shock gas density we derive, 45 cm{sup –3}, is much higher than in other Type Ia remnants in the LMC, though a lack of spatial resolution may bias measurements toward regions of higher than average density. This density is similar to that in Kepler's SNR, a Type Ia interacting with a circumstellar medium (CSM). Optical images show Hα emission along the entire periphery of the western portion of the shock, with [O III] and [S II] lines emitted from a few dense clumps of material where the shock has become radiative. The dust is silicate in nature, though standard silicate dust models fail to reproduce the '18 μm' silicate feature that peaks instead at 17.3 μm. We propose that the dense material is circumstellar material lost from the progenitor system, as with Kepler. If the CSM interpretation is correct, this remnant would become the second member, along with Kepler, of a class of Type Ia remnants characterized by interaction with a dense CSM hundreds of years post-explosion. A lack of N enhancement eliminates symbiotic asymptotic giant branch progenitors. The white dwarf companion must have been relatively unevolved at the time of the explosion.

  1. EVOLUTION OF THE RADIO REMNANT OF SUPERNOVA 1987A: MORPHOLOGICAL CHANGES FROM DAY 7000

    SciTech Connect

    Ng, C.-Y.; Zanardo, G.; Potter, T. M.; Staveley-Smith, L.; Gaensler, B. M.; Manchester, R. N.; Tzioumis, A. K.

    2013-11-10

    We present radio imaging observations of supernova remnant 1987A at 9 GHz, taken with the Australia Telescope Compact Array over 21 years from 1992 to 2013. By employing a Fourier modeling technique to fit the visibility data, we show that the remnant structure has evolved significantly since day 7000 (mid-2006): the emission latitude has gradually decreased such that the overall geometry has become more similar to a ring structure. Around the same time, we find a decreasing trend in the east-west asymmetry of the surface emissivity. These results could reflect the increasing interaction of the forward shock with material around the circumstellar ring, and the relative weakening of the interaction with the lower-density material at higher latitudes. The morphological evolution caused an apparent break in the remnant expansion measured with a torus model, from a velocity of 4600{sup +150}{sub -}200 km s{sup –1} between day 4000 and 7000 to 2400{sup +100}{sub -200} km s{sup –1} after day 7000. However, we emphasize that there is no conclusive evidence for a physical slowing of the shock at any given latitude in the expanding remnant, and that a change of radio morphology alone appears to dominate the evolution. This is supported by our ring-only fits which show a constant expansion of 3890 ± 50 km s{sup –1} without deceleration between days 4000 and 9000. We suggest that once the emission latitude no longer decreases, the expansion velocity obtained from the torus model should return to the same value as that measured with the ring model.

  2. 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.

  3. THE DOUBLE PULSAR: EVIDENCE FOR NEUTRON STAR FORMATION WITHOUT AN IRON CORE-COLLAPSE SUPERNOVA

    SciTech Connect

    Ferdman, R. D.; Kramer, M.; Stappers, B. W.; Lyne, A. G.; Stairs, I. H.; Breton, R. P.; McLaughlin, M. A.; Freire, P. C. C.; Possenti, A.; Kaspi, V. M.; Manchester, R. N.

    2013-04-10

    The double pulsar system PSR J0737-3039A/B is a double neutron star binary, with a 2.4 hr orbital period, which has allowed measurement of relativistic orbital perturbations to high precision. The low mass of the second-formed neutron star, as well as the low system eccentricity and proper motion, point to a different evolutionary scenario compared to most other known double neutron star systems. We describe analysis of the pulse profile shape over 6 years of observations and present the resulting constraints on the system geometry. We find the recycled pulsar in this system, PSR J0737-3039A, to be a near-orthogonal rotator with an average separation between its spin and magnetic axes of 90 Degree-Sign {+-} 11 Degree-Sign {+-} 5 Degree-Sign . Furthermore, we find a mean 95% upper limit on the misalignment between its spin and orbital angular momentum axes of 3. Degree-Sign 2, assuming that the observed emission comes from both magnetic poles. This tight constraint lends credence to the idea that the supernova that formed the second pulsar was relatively symmetric, possibly involving electron capture onto an O-Ne-Mg core.

  4. 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.

  5. 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.

  6. The End of Amnesia: A New Method for Measuring the Metallicity of Type Ia Supernova Progenitors Using Manganese Lines in Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Badenes, Carles; Bravo, Eduardo; Hughes, John P.

    2008-06-01

    We propose a new method to measure the metallicity of Type Ia supernova progenitors using Mn and Cr lines in the X-ray spectra of young supernova remnants. We show that the Mn-to-Cr mass ratio in Type Ia supernova ejecta is tightly correlated with the initial metallicity of the progenitor, as determined by the neutron excess of the white dwarf material before thermonuclear runaway. We use this correlation, together with the flux of the Cr and Mn Kα X-ray lines in the Tycho supernova remnant recently detected by Suzaku, to derive a metallicity of log (Z) = - 1.32+ 0.67-0.33 for the progenitor of this supernova, which corresponds to log (Z/Z⊙) = 0.60+ 0.31-0.60 according to the latest determination of the solar metallicity by Asplund and coworkers. The uncertainty in the measurement is large, but metallicities much smaller than the solar value can be confidently discarded. We discuss the implications of this result for future research on Type Ia supernova progenitors.

  7. Searching for Planets Around Pulsars

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2015-09-01

    Did you know that the very first exoplanets ever confirmed were found around a pulsar? The precise timing measurements of pulsar PSR 1257+12 were what made the discovery of its planetary companions possible. Yet surprisingly, though weve discovered thousands of exoplanets since then, only one other planet has ever been confirmed around a pulsar. Now, a team of CSIRO Astronomy and Space Science researchers are trying to figure out why.Formation ChallengesThe lack of detected pulsar planets may simply reflect the fact that getting a pulsar-planet system is challenging! There are three main pathways:The planet formed before the host star became a pulsar which means it somehow survived its star going supernova (yikes!).The planet formed elsewhere and was captured by the pulsar.The planet formed out of the debris of the supernova explosion.The first two options, if even possible, are likely to be rare occurrences but the third option shows some promise. In this scenario, after the supernova explosion, a small fraction of the material falls back toward the stellar remnant and is recaptured, forming what is known as a supernova fallback disk. According to this model, planets could potentially form out of this disk.Disk ImplicationsLed by Matthew Kerr, the CSIRO astronomers set out to systematically look for these potential planets that might have formed in situ around pulsars. They searched a sample of 151 young, energetic pulsars, scouring seven years of pulse time-of-arrival data for periodic variation that could signal the presence of planetary companions. Their methods to mitigate pulsar timing noise and model realistic orbits allowed them to have good sensitivity to low-mass planets.The results? They found no conclusive evidence that any of these pulsars have planets.This outcome carries with it some significant implications. The pulsar sample spans 2 Myr in age, in which planets should have had enough time to form in debris disks. The fact that none were detected suggests that long-lived supernova fallback disks may actually be much rarer than thought, or they exist only in conditions that arent compatible with planet formation.So if thats the case, what about the planets found around PSR 1257+12? This pulsar may actually be somewhat unique, in that it was born with an unusually weak magnetic field. This birth defect might have allowed it to form a fallback disk and, subsequently, planets where the sample of energetic pulsars studied here could not.CitationM. Kerr et al.2015 ApJ 809 L11 doi:10.1088/2041-8205/809/1/L11

  8. Very high energy gamma-ray emission from Tycho's supernova remnant

    NASA Astrophysics Data System (ADS)

    Saxon, Dana Boltuch

    Supernova remnant (SNR) G120.1+1.4 (also known as Tycho's SNR) is the remnant of one of only five confirmed historical supernovae. As such, it has been well studied across the electromagnetic spectrum. This thesis describes the first statistically significant detection of very high energy (VHE) ( 100 GeV to 100 TeV) gamma rays from Tycho's SNR, reported in 2011 by the VERITAS collaboration. The analysis that led to that detection was performed by this author, and this dissertation will discuss the process in detail. Subsequently, a statistically significant detection in high energy (HE) ( 30 MeV to 100 GeV) gamma rays was reported by other authors using data from the Fermi Gamma-Ray Space Telescope. Comparison of models to the spectral energy distribution of the photon flux from this remnant in HE and VHE gamma rays favors a hadronic origin for the emission, particularly when combined with current X-ray data, although a leptonic origin cannot be ruled out at this time. This is significant because a confirmed hadronic origin for the gamma-ray emission would identify this SNR as a site of cosmic ray acceleration, providing observational evidence for the idea that SNRs are the source of the Galactic cosmic ray population. Chapter 1 of this dissertation will provide historical background on Tycho's SNR, along with a summary of modern observations of the remnant across the electromagnetic spectrum. Chapter 2 is a discussion of the role played by SNRs in the process of cosmic ray acceleration, including both theoretical underpinnings and observational evidence. Chapter 3 provides an overview of the field of VHE gamma-ray astronomy, with discussions of gamma-ray production mechanisms and gamma-ray source classes. Chapter 4 describes the instruments used to observe HE and VHE gamma rays. Chapter 5 is a discussion of general analysis methods and techniques for data from Imaging Atmospheric Cherenkov Telescopes (IACTs). Chapter 6 provides details about the specific analysis I completed on VERITAS data on Tycho's SNR. Lastly, Chapter 7 discusses the modeling and interpretation of the VHE Tycho detection in the context of current multiwavelength observational results.

  9. 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. PMID:19574346

  10. Interaction between high-velocity pulsar in CTB80 and an infrared emission shell

    NASA Technical Reports Server (NTRS)

    Fesen, Robert A.; Saken, Jon M.; Shull, J. Michael

    1988-01-01

    During a survey of infrared emission detected by IRAS from shock-heated dust associated with Galactic SNRs, a roughly 1 deg diameter supernova remnant shell centered 30 arcmin east of SNR CTB80's core was discovered. The pulsar's projected location inside this infrared emission shell, together with similar distance and age estimates, suggest that both the shell and pulsar were produced by the same supernova event. It is proposed that the interaction between the pulsar's energetic particle emission and the shell's compressed interstellar magnetic field can explain CTB80's remarkable radio structure, and the implications of such pulsar/SNR interactions are discussed.

  11. Analytical methods for the hydrodynamical evolution of supernova remnants. II - Arbitrary form of boundary conditions

    NASA Astrophysics Data System (ADS)

    Gaffet, B.

    1981-10-01

    A generalized formalism is introduced to obtain formulas which are valid for the most general boundary conditions at the outer edge when computing the hydrodynamical evolution of supernova remnants. The higher orders of the approximation are based on an iteration method, and the second-order solution gives the pressure distribution with a relative accuracy of 0.0001 in self-similar cases. The assumption of a linear pressure distribution is shown to imply self-similarity of the flow whenever the entropy distribution is a power law. The problem of adiabatic, spherical self-similar flow is also considered, and the original system of equations is reduced to a single, nonlinear, first-order differential equation in dimensionless coordinates with an explicit parametric family of solutions. A completely integrable family of solutions is obtained, and is found to represent strong shock propagation through a homologously contracting outer medium, where the density distribution is a power law.

  12. 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.

  13. Gamma-ray and X-ray Observations Towards the Gamma-Cygni Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Dwarkadas, Vikram; Weinstein, A.; Theiling, M.; VERITAS Collaboration

    2013-04-01

    We report on observations of the source VER J2019+407 towards the Gamma-Cygni supernova remnant. Very high energy (> 320 GeV) gamma-ray emission from the source was detected by the VERITAS observatory, an array of four 12-meter imaging atmospheric Cherenkov telescopes based near Tucson, Arizona. The proximity of this source to a diffuse region of gamma-ray emission detected by the Fermi Space Telescope increases its significance, and may suggest a connection between the two. To further investigate the properties of VER J2019+407, we have obtained a 50 ks Chandra observation of this region. Analysis of the Chandra data, and implications for the gamma-ray source, will be presented.

  14. XMM-Newton Observations of the Vela Supernova Remnant Fragment D Environs

    NASA Astrophysics Data System (ADS)

    Gaetz, Terrance J.; Edgar, R. J.; Plucinsky, P. P.; Haverkorn, M.; Sankrit, R.; Smith, R. K.; Aschenbach, B.

    2007-12-01

    The Vela Supernova Remnant (SNR) is notable for a number of protrusions extending well beyond its rim, and "Fragment D" is the brightest and largest such feature. The brightest part of Fragment D has been found to be strongly enriched in O, Ne, and Mg (Katsuda et al. 2005). We have now observed a number of adjacent pointings including the very bright and soft Vela rim to the west, and the peculiar "spur"-like feature between the bright Fragment D head and the bright Vela rim. We recently obtained data for a pointing adjacent to the Fragment D head and the spur. In combination, these data provide XMM-Newton coverage of a significant portion of Fragment D, including its trailing wake across the Vela SNR rim. We report on analyses of the imaging data and morphology, and spectral analyses of the enhanced abundances.

  15. Systematic X-ray Mapping of Metal-Rich Ejecta in Bright Supernova Remnants.

    NASA Astrophysics Data System (ADS)

    Schenck, Andrew; Park, Sangwook; Bhalerao, Jayant; Post, Seth; Alan, Neslihan; Abualfoul, Mujahed

    2015-01-01

    We apply our adaptive mesh technique coupled with simple automated NEI spectral modelings for archival Chandra data of several bright supernova remnants (SNRs) DEML71, N132D, E0102-72.3, G292.0+1.8, G299.2-2.9, Kepler, and Tycho. Based on the chi-square distributions of these model fits, we identify regions in which metal elements are enhanced compared to the circumstellar/interstellar abundances, and thus map over-abundant ejecta regions throughout these SNRs. With these maps we also reveal spatial structures of the individual ejecta elements O, Ne, Mg, Si, and Fe. We find that this simple chi-square mapping is effective to study spatial distributions of ejecta elements without performing extensive spectral model fits for individual sub-regions in SNRs. These ejecta maps may also be useful to reveal global structures such as the contact discontinuity. We present our preliminary results demonstrating the utility of this method.

  16. A neutron star with a carbon atmosphere in the Cassiopeia A supernova remnant.

    PubMed

    Ho, Wynn C G; Heinke, Craig O

    2009-11-01

    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. PMID:19890325

  17. Physical processes and infrared emission from the Cassiopeia A supernova remnant

    NASA Technical Reports Server (NTRS)

    Dwek, E.; Hauser, M. G.; Dinerstein, H. L.; Gillett, F. C.; Rice, W. L.

    1987-01-01

    IRAS 12-100 micron data on the Cas A remnant are presented, and various physical mechanisms and astrophysical sites that may contribute to the observed infrared emission are analyzed. The contributions of various sources of infrared emission to the IRAS fluxes are found to be small. The residual infrared emission is attributed to thermal emission from dust which is swept up by the expanding supernova blast wave and collisionally heated by the postshock X-ray emitting gas. The calculations are consistent with a shock velocity of 1800 km/s and a preshock gas density of about 2/cu cm. The mass of the swept-up gas is about 0.6 solar mass. An excess of 12 micron thermal emission in the spectrum of Cas A suggests the presence of very small particles in the preshocked gas.

  18. Studies of molecular gas towards TeV gamma-ray supernova remnants

    NASA Astrophysics Data System (ADS)

    Rowell, Gavin

    The recent discoveries by H.E.S.S., MAGIC and VERITAS of TeV (1012 eV) gamma-ray emission from supernova remnants (SNRs) provides new insight into the 100 year-old question concerning the origin of Galactic cosmic-rays (CRs). Strongly connected with this question is the study of the interstellar medium (ISM) in the vicinity of such SNRs since the ISM acts as a target for CRs produced by SNRs. ISM studies can also provide important clues as to how SNRs interact and modify their local environment. In this talk I will review studies of the molecular ISM towards several key TeV SNRs and highlight some quite recent results.

  19. The modified equipartition calculation for supernova remnants with the spectral index α = 0.5

    NASA Astrophysics Data System (ADS)

    Urošević, Dejan; Pavlović, Marko Z.; Arbutina, Bojan; Dobardžić, Aleksandra

    2015-03-01

    Recently, the modified equipartition calculation for supernova remnants (SNRs) has been derived by Arbutina et al. (2012). Their formulae can be used for SNRs with the spectral indices between 0.5 < α < 1. Here, by using approximately the same analytical method, we derive the equipartition formulae useful for SNRs with spectral index α=0.5. These formulae represent next step upgrade of Arbutina et al. (2012) derivation, because among 30 Galactic SNRs with available observational parameters for the equipartition calculation, 16 have spectral index α = 0.5. For these 16 Galactic SNRs we calculated the magnetic field strengths which are approximately 40 per cent higher than those calculated by using Pacholczyk (1970) equipartition and similar to those calculated by using Beck & Krause (2005) calculation.

  20. DISCOVERY OF THE SMALL-DIAMETER, YOUNG SUPERNOVA REMNANT G354.4+0.0

    SciTech Connect

    Roy, Subhashis; Pal, Sabyasachi E-mail: sabya@csp.res.in

    2013-09-10

    We report the discovery of a shell-like structure G354.4+0.0 of size 1.'6 that shows the morphology of a shell supernova remnant (SNR). Part of the structure shows polarized emission in a NRAO VLA sky survey map. Based on 330 MHz and 1.4 GHz Giant Metrewave Radio Telescope observations and existing observations at higher frequencies, we conclude that the partial shell structure showing synchrotron emission is embedded in an extended H II region of size {approx}4'. The spectrum of the diffuse H II region turns over between 1.4 GHz and 330 MHz. The H I absorption spectrum shows this objected to be located more than 5 kpc from Sun. Based on its morphology, non-thermal polarized emission, and size, this object is one of the youngest SNRs discovered in the Galaxy with an estimated age of {approx}100-500 yr.

  1. 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.

  2. Detection of class I methanol (CH{sub 3}OH) maser candidates in supernova remnants

    SciTech Connect

    Pihlström, Y. M.; Mesler, R. A.; McEwen, B. C.; Sjouwerman, L. O.; Frail, D. A.; Claussen, M. J.

    2014-04-01

    We have used the Karl G. Jansky Very Large Array to search for 36 GHz and 44 GHz methanol (CH{sub 3}OH) lines in a sample of 21 Galactic supernova remnants (SNRs). Mainly the regions of the SNRs with 1720 MHz OH masers were observed. Despite the limited spatial extent covered in our search, methanol masers were detected in both G1.4–0.1 and W28. Additional masers were found in Sgr A East. More than 40 masers were found in G1.4–0.1, which we deduce are due to interactions between the SNR and at least two separate molecular clouds. The six masers in W28 are associated with the molecular cloud that is also associated with the OH maser excitation. We discuss the possibility that the methanol maser may be more numerous in SNRs than the OH maser, but harder to detect due to observational constraints.

  3. Detection of the characteristic pion-decay signature in supernova remnants.

    PubMed

    Ackermann, M; Ajello, M; Allafort, A; Baldini, L; Ballet, J; Barbiellini, G; Baring, M G; Bastieri, D; Bechtol, K; Bellazzini, R; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A W; Bottacini, E; Brandt, T J; Bregeon, J; Brigida, M; Bruel, P; Buehler, R; Busetto, G; Buson, S; Caliandro, G A; Cameron, R A; Caraveo, P A; Casandjian, J M; Cecchi, C; Celik, O; Charles, E; Chaty, S; Chaves, R C G; Chekhtman, A; Cheung, C C; Chiang, J; Chiaro, G; Cillis, A N; Ciprini, S; Claus, R; Cohen-Tanugi, J; Cominsky, L R; Conrad, J; Corbel, S; Cutini, S; D'Ammando, F; de Angelis, A; de Palma, F; Dermer, C D; do Couto e Silva, E; Drell, P S; Drlica-Wagner, A; Falletti, L; Favuzzi, C; Ferrara, E C; Franckowiak, A; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Germani, S; Giglietto, N; Giommi, P; Giordano, F; Giroletti, M; Glanzman, T; Godfrey, G; Grenier, I A; Grondin, M-H; Grove, J E; Guiriec, S; Hadasch, D; Hanabata, Y; Harding, A K; Hayashida, M; Hayashi, K; Hays, E; Hewitt, J W; Hill, A B; Hughes, R E; Jackson, M S; Jogler, T; Jóhannesson, G; Johnson, A S; Kamae, T; Kataoka, J; Katsuta, J; Knödlseder, J; Kuss, M; Lande, J; Larsson, S; Latronico, L; Lemoine-Goumard, M; Longo, F; Loparco, F; Lovellette, M N; Lubrano, P; Madejski, G M; Massaro, F; Mayer, M; Mazziotta, M N; McEnery, J E; Mehault, J; Michelson, P F; Mignani, R P; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nakamori, T; Nemmen, R; Nuss, E; Ohno, M; Ohsugi, T; Omodei, N; Orienti, M; Orlando, E; Ormes, J F; Paneque, D; Perkins, J S; Pesce-Rollins, M; Piron, F; Pivato, G; Rainò, S; Rando, R; Razzano, M; Razzaque, S; Reimer, A; Reimer, O; Ritz, S; Romoli, C; Sánchez-Conde, M; Schulz, A; Sgrò, C; Simeon, P E; Siskind, E J; Smith, D A; Spandre, G; Spinelli, P; Stecker, F W; Strong, A W; Suson, D J; Tajima, H; Takahashi, H; Takahashi, T; Tanaka, T; Thayer, J G; Thayer, J B; Thompson, D J; Thorsett, S E; Tibaldo, L; Tibolla, O; Tinivella, M; Troja, E; Uchiyama, Y; Usher, T L; Vandenbroucke, J; Vasileiou, V; Vianello, G; Vitale, V; Waite, A P; Werner, M; Winer, B L; Wood, K S; Wood, M; Yamazaki, R; Yang, Z; Zimmer, S

    2013-02-15

    Cosmic rays are particles (mostly protons) accelerated to relativistic speeds. Despite wide agreement that supernova remnants (SNRs) are the sources of galactic cosmic rays, unequivocal evidence for the acceleration of protons in these objects is still lacking. When accelerated protons encounter interstellar material, they produce neutral pions, which in turn decay into gamma rays. This offers a compelling way to detect the acceleration sites of protons. The identification of pion-decay gamma rays has been difficult because high-energy electrons also produce gamma rays via bremsstrahlung and inverse Compton scattering. We detected the characteristic pion-decay feature in the gamma-ray spectra of two SNRs, IC 443 and W44, with the Fermi Large Area Telescope. This detection provides direct evidence that cosmic-ray protons are accelerated in SNRs. PMID:23413352

  4. SUBARU HIGH-RESOLUTION SPECTROSCOPY OF STAR G IN THE TYCHO SUPERNOVA REMNANT

    SciTech Connect

    Kerzendorf, Wolfgang E.; Schmidt, Brian P.; Yong, David; Asplund, M.; Nomoto, Ken'ichi; Podsiadlowski, Ph.; Frebel, Anna; Fesen, Robert A. E-mail: brian@mso.anu.edu.au E-mail: nomoto@astron.s.u-tokyo.ac.jp E-mail: anna@astro.as.utexas.edu

    2009-08-20

    It is widely believed that Type Ia supernovae (SNe Ia) originate in binary systems where a white dwarf accretes material from a companion star until its mass approaches the Chandrasekhar mass and carbon is ignited in the white dwarf's core. This scenario predicts that the donor star should survive the supernova (SNe) explosion, providing an opportunity to understand the progenitors of SNe Ia. In this paper, we argue that rotation is a generic signature expected of most nongiant donor stars that is easily measurable. Ruiz-Lapuente et al. examined stars in the center of the remnant of SN 1572 (Tycho SN) and showed evidence that a subgiant star (Star G by their naming convention) near the remnant's center was the system's donor star. We present high-resolution (R {approx_equal} 40, 000) spectra taken with the High Dispersion Spectrograph on Subaru of this candidate donor star and measure the star's radial velocity as 79 {+-} 2 km s{sup -1} with respect to the local standard of rest and put an upper limit on the star's rotation of 7.5 km s{sup -1}. In addition, by comparing images that were taken in 1970 and 2004, we measure the proper motion of Star G to be {mu} {sub l} = -1.6 {+-} 2.1 mas yr{sup -1} and {mu} {sub b} = -2.7 {+-} 1.6 mas yr{sup -1}. We demonstrate that all of the measured properties of Star G presented in this paper are consistent with those of a star in the direction of Tycho SN that is not associated with the SN event. However, we discuss an unlikely, but still viable scenario for Star G to be the donor star, and suggest further observations that might be able to confirm or refute it.

  5. The imprint of a symbiotic binary progenitor on the properties of Kepler's supernova remnant

    NASA Astrophysics Data System (ADS)

    Chiotellis, A.; Schure, K. M.; Vink, J.

    2012-01-01

    We present a model for the type Ia supernova remnant (SNR) of SN 1604, also known as Kepler's SNR. We find that its main features can be explained by a progenitor model of a symbiotic binary consisting of a white dwarf and an AGB donor star with an initial mass of 4-5 M⊙. The slow, nitrogen-rich wind emanating from the donor star has partially been accreted by the white dwarf, but has also created a circumstellar bubble. On the basis of observational evidence, we assume that the system moves with a velocity of 250 km s-1. Owing to the spatial velocity, the interaction between the wind and the interstellar medium has resulted in the formation of a bow shock, which can explain the presence of a one-sided, nitrogen-rich shell. We present two-dimensional hydrodynamical simulations of both the shell formation and the SNR evolution. The SNR simulations show good agreement with the observed kinematic and morphological properties of Kepler's SNR. In particular, the model reproduces the observed expansion parameters (m = V/(R/t)) of m ≈ 0.35 in the north and m ≈ 0.6 in the south of Kepler's SNR. We discuss the variations among our hydrodynamical simulations in light of the observations, and show that part of the blast wave may have completely traversed through the one-sided shell. The simulations suggest a distance to Kepler's SNR of 6 kpc, or otherwise imply that SN 1604 was a sub-energetic type Ia explosion. Finally, we discuss the possible implications of our model for type Ia supernovae and their remnants in general.

  6. Turbulence and particle acceleration in collisionless supernovae remnant shocks. II. Cosmic-ray transport

    NASA Astrophysics Data System (ADS)

    Marcowith, A.; Lemoine, M.; Pelletier, G.

    2006-07-01

    Supernovae remnant shock waves could be at the origin of cosmic rays up to energies in excess of the knee (E?3 1015 eV) if the magnetic field is efficiently amplified by the streaming of accelerated particles in the shock precursor. This paper follows up on a previous paper (Pelletier et al. 2006, A&A, in press) which derived the properties of the MHD turbulence so generated, in particular its anisotropic character, its amplitude and its spectrum. In the present paper, we calculate the diffusion coefficients, also accounting for compression through the shock, and show that the predicted three-dimensional turbulence spectrum k_? S3d(k_?,k_?)? k_?-1k_?-? (with k_? and k_? the wavenumber components along and perpendicular to the shock normal) generally leads to Bohm diffusion in the parallel direction. However, if the anisotropy is constrained by a relation of the form k_? ? k_?2/3, which arises when the turbulent energy cascade occurs at a constant rate independent of scale, then the diffusion coefficient loses its Bohm scaling and scales as in isotropic Kolmogorov turbulence. We show that these diffusion coefficients allow to account for X-ray observations of supernova remnants. This paper also calculates the modification of the Fermi cycle due to the energy lost by cosmic rays in generating upstream turbulence and the concomittant steepening of the energy spectrum. Finally we confirm that cosmic rays can produced an amplified turbulence in young SNr during their free expansion phase such that the maximal energy is close to the knee and the spectral index is close to 2.3 in the warm phase of the interstellar medium.

  7. Studying The Hi Emission Of Supernova Remnants In The I-GALFA Survey

    NASA Astrophysics Data System (ADS)

    Vincent, Chelsea; Kang, J.

    2011-01-01

    A search for expanding, HI shells around galactic supernova remnants (SNR) was conducted using the Inner Galactic Plane Arecibo L-band Feed Array (I-GALFA) HI survey. This survey, which mapped out the distribution of HI emission within the galactic plane, spanned an area that included a total of thirty eight SNR positions. HI intensity was viewed over a velocity range of -150 km/s to +150 km/s, of which five SNRs were found to have an associated expanding HI shell, ten to have central HI emission, and six to have some HI absorption. The SNR G65.3+5.7 was selected to study more in depth because it appears to have HI emission that correlated with the optical and radio continuum emission. This supernova remnant has a very bright optical shell dominated by OIII emission with x-ray radiation at its center. The HI emitting shell was visible within the velocity range of -12 km/s to +10 km/s, which overlaps the systematic velocity of 8 ± 10 km/s derived in previous research, providing further evidence of the shell's association with the SNR. It was found to have a size of approximately 260’ across, yielding a physical radius of 38pc at a distance of 1kpc. The observed HI shell mass was derived by extrapolating the temperature brightness of the shell and the background from the HI images and doing an integration to yield a value of 2000Msolar. This value was then used to calculate a hydrogen number density of 0.353 cm-3. Assuming an initial explosion energy of 1051 ergs and a metallicity of 1, the expansion velocity of this shell was determined as 550 km/s and the age as approximately 21,000 years. These values for physical size, number density, expansion velocity, and age agree well with the values derived in previous optical, x-ray, and radio studies.

  8. Application of a 3D, Adaptive, Parallel, MHD Code to Supernova Remnant Simulations

    NASA Astrophysics Data System (ADS)

    Kominsky, P.; Drake, R. P.; Powell, K. G.

    2001-05-01

    We at Michigan have a computational model, BATS-R-US, which incorporates several modern features that make it suitable for calculations of supernova remnant evolution. In particular, it is a three-dimensional MHD model, using a method called the Multiscale Adaptive Upwind Scheme for MagnetoHydroDynamics (MAUS-MHD). It incorporates a data structure that allows for adaptive refinement of the mesh, even in massively parallel calculations. Its advanced Godunov method, a solution-adaptive, upwind, high-resolution scheme, incorporates a new, flux-based approach to the Riemann solver with improved numerical properties. This code has been successfully applied to several problems, including the simulation of comets and of planetary magnetospheres, in the 3D context of the Heliosphere. The code was developed under a NASA computational grand challenge grant to run very rapidly on parallel platforms. It is also now being used to study time-dependent systems such as the transport of particles and energy from solar coronal mass ejections to the Earth. We are in the process of modifying this code so that it can accommodate the very strong shocks present in supernova remnants. Our test case simulates the explosion of a star of 1.4 solar masses with an energy of 1 foe, in a uniform background medium. We have performed runs of 250,000 to 1 million cells on 8 nodes of an Origin 2000. These relatively coarse grids do not allow fine details of instabilities to become visible. Nevertheless, the macroscopic evolution of the shock is simulated well, with the forward and reverse shocks visible in velocity profiles. We will show our work to date. This work was supported by NASA through its GSRP program.

  9. Electron heating, magnetic field amplification, and cosmic-ray precursor length at supernova remnant shocks

    SciTech Connect

    Laming, J. Martin; Hwang, Una; Ghavamian, Parviz; Rakowski, Cara E-mail: Una.Hwang-1@nasa.gov

    2014-07-20

    We investigate the observability, by direct and indirect means, of a shock precursor arising from magnetic field amplification by cosmic rays. We estimate the depth of such a precursor under conditions of nonresonant amplification, which can provide magnetic field strengths comparable to those inferred for supernova remnants. Magnetic field generation occurs as the streaming cosmic rays induce a plasma return current, and it may be quenched by either nonresonant or resonant channels. In the case of nonresonant saturation, the cosmic rays become magnetized and amplification saturates at higher magnetic fields. The precursor can extend out to 10{sup 17}-10{sup 18} cm and is potentially detectable. If resonant saturation occurs, the cosmic rays are scattered by turbulence and the precursor length will likely be much smaller. The dependence of precursor length on shock velocity has implications for electron heating. In the case of resonant saturation, this dependence is similar to that in the more familiar resonantly generated shock precursor, which when expressed in terms of the cosmic-ray diffusion coefficient kappav and shock velocity v{sub s} is kappav/v{sub s} . In the nonresonantly saturated case, the precursor length declines less quickly with increasing v{sub s} . Where precursor length proportional to 1/v{sub s} gives constant electron heating, this increased precursor length could be expected to lead to higher electron temperatures for nonresonant amplification. This should be expected at faster supernova remnant shocks than studied by previous works. Existing results and new data analysis of SN 1006 and Cas A suggest some observational support for this idea.

  10. Multi-wavelength study of the {G 82.2+5.3} supernova remnant

    NASA Astrophysics Data System (ADS)

    Mavromatakis, F.; Aschenbach, B.; Boumis, P.; Papamastorakis, J.

    2004-03-01

    We present the first CCD flux-calibrated images of the supernova remnant G 82.2+5.3 in major optical emission lines. The medium ionization line of [O I]ii 5007 Å provides the first direct evidence of optical emission originating from G 82.2+5.3. Filamentary emission is detected in the west and east areas of the remnant, roughly defining an ellipsoidal shell. The [O III] emission is rather well correlated with the radio emission suggesting their association, while typical fluxes are found in the range of 20-30 × 10-17 erg s-1 cm-2 arcsec-2. Deep long-slit spectra taken at specific positions of the remnant verify that the detected filamentary emission originates from shock heated gas, while the diffuse [O III] emission in the south results from photoionization processes. The spectra further suggest shock velocities around 100 km s-1 and low electron densities. The X-ray surface brightness is quite patchy, missing obvious limb brightening and is dominated by a bright bar-like emission region which is off-set from the geometric center by ˜9 arcmin. The X-ray emission is thermal and requires two temperatures of 0.2 keV and 0.63 keV. The bright bar region shows overabundant Mg, Si and Fe, which might indicate still radiating ejecta matter. The azimuthally averaged radial surface profile is consistent with the matter density changing with distance r from the center ∝ e-r/r_0 with a characteristic angular length of 36 arcmin, or, alternatively, with an r-1/2 density profile. The matter inside the remnant is quite likely structured like a porous cloudy medium. The average matter density is ˜0.04 × d-0.51.6 with d1.6 the distance in units of 1.6 kpc. Because of the low density and the long cooling times involved the remnant is more likely to be in the adiabatic phase, which is consistent with the densities derived for the X-ray plasma and the optical line emission, but it is not excluded that is has reached the radiating phase. This, however, would imply a lower density, greater age and much larger distance, at the edge of the upper limits obtained from NH and E(B-V).

  11. MULTIBAND NONTHERMAL EMISSION FROM THREE TeV SHELL-TYPE SUPERNOVA REMNANTS

    SciTech Connect

    Fang Jun; Tang Yunyong; Zhang Li

    2011-04-10

    Nonthermal radiative properties of three TeV shell-type supernova remnants (SNRs) RX J1713.7-3946, RX J0852.0-4622, and RCW 86, argued to be expanding into low-density hot bubbles created by the wind of the massive progenitor stars, are investigated based on a semi-analytical solution to diffusive acceleration at nonlinear shocks. In the model, a free-escape boundary upstream of the shock is used to mimic the escape of cosmic rays from the SNR, with the dynamic reaction of the self-generated magnetic field via resonant streaming instability on the shock taken into account. Origins of the {gamma}-rays from the three remnants are studied with appropriate parameters, and consistent results with the multiband observed fluxes are obtained within the nonlinear diffusive shock acceleration regime. The order of the resulting downstream magnetic field strength for the three SNRs is between 60 and 100 {mu}G, and the observed TeV {gamma}-rays are mainly produced via the decay of neutral {pi} mesons produced from the hadronic collisions.

  12. Abundance gradients in M31: Comparison of results from supernova remnants and H II regions

    SciTech Connect

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

    1982-03-01

    We have obtained spectra of 11 H II regions and additional spectra of six previously reported supernova remnants (SNRs) in M31. The SNR spectra have been used in conjunction with shock model calculations to give abundances of oxygen, nitrogen, and sulfur in the interstellar gas comprising each remnant. We have also determined abundances for the H II regions using the empirical method described by Pagel et al. Both nitrogen and oxygen abundances decrease by about a factor of 4 from the innermost regions studied (approx.4 kpc) to the outer regions (approx.23 kpc). These gradients are similar to those found in other intermediate and late type spiral galaxies, including our own. The mean nitrogen and sulfur abundances are similar to those of the Orion Nebula, but the mean oxygen abundance is about a factor of 2 higher, accounting for the low excitation of the M31 h II regions. A comparison of the SNR and H II region abundance gradients shows substantial agreement for nitrogen, but discordant results for oxygen; this may be due to problems with the shock models since they do not reproduce the observed relative line intensities of O/sup 0/, O/sup +/, and O/sup + +/. Finally we present observations of SNR candidates in NGC 2403 and IC 342 and discuss the limitations and accuracy of the methods of detecting extragalactic SNRs.

  13. FERMI-LAT OBSERVATIONS AND A BROADBAND STUDY OF SUPERNOVA REMNANT CTB 109

    SciTech Connect

    Castro, Daniel; Slane, Patrick; Patnaude, Daniel J.; Ellison, Donald C.

    2012-09-01

    CTB 109 (G109.1-1.0) is a Galactic supernova remnant (SNR) with a hemispherical shell morphology in X-rays and in the radio band. In this work, we report the detection of {gamma}-ray emission coincident with CTB 109, using 37 months of data from the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. We study the broadband characteristics of the remnant using a model that includes hydrodynamics, efficient cosmic-ray (CR) acceleration, nonthermal emission, and a self-consistent calculation of the X-ray thermal emission. We find that the observations can be successfully fit with two distinct parameter sets, one where the {gamma}-ray emission is produced primarily by leptons accelerated at the SNR forward shock and the other where {gamma}-rays produced by forward shock accelerated CR ions dominate the high-energy emission. Consideration of thermal X-ray emission introduces a novel element to the broadband fitting process, and while it does not rule out either the leptonic or the hadronic scenarios, it constrains the parameter sets required by the model to fit the observations. Moreover, the model that best fits the thermal and nonthermal emission observations is an intermediate case, where both radiation from accelerated electrons and hadrons contribute almost equally to the {gamma}-ray flux observed.

  14. G33.6 + 0.1 - A shell type supernova remnant with unusual structure

    NASA Technical Reports Server (NTRS)

    Velusamy, T.; Becker, R. H.; Seward, F. D.

    1991-01-01

    The morphology of Supernova Remnant G33.6 + 0.1 (Kes 79) has been studied in the X-rays with Einstein and in the radio wavelengths using the VLA. Multifrequency high resolution observations of the VLA at 327, 1500, and 5000 MHz are used to study the radio spectrum and polarization. The radio emission shows well formed outer shell structure and very bright central emission. Although the overall distribution of spectral index (about -0.6 to -0.75) is consistent with that of shell type remnants, the bright filamentary emission along the 'inner ring' has relatively flatter spectrum (alpha about -0.4). Both radio and X-rays show strong central emission; existence of a plerion near the center cannot be ruled out. The X-ray image does not show the characteristic limb brightening for shell type SNRs. The X-ray and radio morphology may be understood in terms of very thick shell and the bright central emission as due to reverse shock.

  15. Discovery of TeV Gamma-ray Emission from Tycho's Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Acciari, V. A.; Aliu, E.; Arlen, T.; Aune, T.; Beilicke, M.; Benbow, W.; Bradbury, S. M.; Buckley, J. H.; Bugaev, V.; Byrum, K.; Cannon, A.; Cesarini, A.; Ciupik, L.; Collins-Hughes, E.; Cui, W.; Dickherber, R.; Duke, C.; Errando, M.; Finley, J. P.; Finnegan, G.; Fortson, L.; Furniss, A.; Galante, N.; Gall, D.; Gillanders, G. H.; Godambe, S.; Griffin, S.; Grube, J.; Guenette, R.; Gyuk, G.; Hanna, D.; Holder, J.; Hughes, J. P.; Hui, C. M.; Humensky, T. B.; Kaaret, P.; Karlsson, N.; Kertzman, M.; Kieda, D.; Krawczynski, H.; Krennrich, F.; Lang, M. J.; LeBohec, S.; Madhavan, A. S.; Maier, G.; Majumdar, P.; McArthur, S.; McCann, A.; Moriarty, P.; Mukherjee, R.; Ong, R. A.; Orr, M.; Otte, A. N.; Pandel, D.; Park, N. H.; Perkins, J. S.; Pohl, M.; Quinn, J.; Ragan, K.; Reyes, L. C.; Reynolds, P. T.; Roache, E.; Rose, H. J.; Saxon, D. B.; Schroedter, M.; Sembroski, G. H.; Senturk, G. Demet; Slane, P.; Smith, A. W.; Tešić, G.; Theiling, M.; Thibadeau, S.; Tsurusaki, K.; Varlotta, A.; Vassiliev, V. V.; Vincent, S.; Vivier, M.; Wakely, S. P.; Ward, J. E.; Weekes, T. C.; Weinstein, A.; Weisgarber, T.; Williams, D. A.; Wood, M.; Zitzer, B.

    2011-04-01

    We report the discovery of TeV gamma-ray emission from the Type Ia supernova remnant (SNR) G120.1+1.4, known as Tycho's SNR. Observations performed in the period 2008-2010 with the VERITAS ground-based gamma-ray observatory reveal weak emission coming from the direction of the remnant, compatible with a point source located at 00h25m27.s0, + 64°10'50'' (J2000). The TeV photon spectrum measured by VERITAS can be described with a power law dN/dE = C(E/3.42 TeV)-Γ with Γ = 1.95 ± 0.51stat ± 0.30sys and C = (1.55 ± 0.43stat ± 0.47sys) × 10-14 cm-2 s-1 TeV-1. The integral flux above 1 TeV corresponds to ~0.9% of the steady Crab Nebula emission above the same energy, making it one of the weakest sources yet detected in TeV gamma rays. We present both leptonic and hadronic models that can describe the data. The lowest magnetic field allowed in these models is ~80 μG, which may be interpreted as evidence for magnetic field amplification.

  16. CCD mosaic images of the supernova remnant 3C 400.2

    NASA Technical Reports Server (NTRS)

    Winkler, P. F.; Olinger, Todd M.; Westerbeke, Scott A.

    1993-01-01

    We have constructed CCD mosaic images of the old Galactic supernova remnant 3C 400.2 in lines of H-alpha + forbidden N II, forbidden S II, and forbidden O III, plus a continuum band. These are the first CCD images covering the full extent of this remnant, and they reveal significantly more nebulosity than the deepest photographic plates. Comparison with radio and X-ray images indicates dramatically different morphology in the three regimes. The optical images both in H-alpha + forbidden N II and in forbidden S II show an almost complete, irregular shell of emission, with a diameter of about 16 arcmin, little over half that of the radio shell, while the X-ray structure is a centrally peaked ellipsoid. Approximate values for optical line fluxes are obtained; we estimate L(H-alpha) about 3 x 10 exp 35 ergs/s, roughly three times the X-ray luminosity. We also report a previously uncataloged planetary nebula southwest of 3C 400.2.

  17. FERMI-LAT AND WMAP OBSERVATIONS OF THE PUPPIS A SUPERNOVA REMNANT

    SciTech Connect

    Hewitt, J. W.; Grondin, M.-H.; Lemoine-Goumard, M.; Reposeur, T.

    2012-11-10

    We report the detection of GeV {gamma}-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 Multiplication-Sign 10{sup 34} (D/2.2 kpc){sup 2} erg s{sup -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 (SED), from radio to {gamma}-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. 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 {sub CR} Almost-Equal-To (1-5) Multiplication-Sign 10{sup 49} erg.

  18. Supernova Remnants and Nucleosynthesis (fos 30): Augmentation Cycle 2 Observations - Spectroscopy

    NASA Astrophysics Data System (ADS)

    Davidsen, Arthur

    1991-07-01

    Overall program: UV and optical spectra of four supernova remnants (SNRs) will be used to study a number of problems related to abundances, grain destruction, interstellar medium properties and physical conditions in SNR shocks. Representatives of three of the main classes of SNRs (Crab-nebula like, Balmer-line and "normal") will be studied in the LMC, where reasonably low reddening permits UV observations. An oxygen-rich SNR in NGC 4449 will be observed, taking advantage of the small FOS slits to isolate the SNR from surrounding H II emission. Two M33 SNRs that were previously part of this proposal have been dropped due to time limitations. This proposal is augmented time to obtain early acq images of two LMC remnants and spectra of N49, which had early acq images in Cy. 0. NOTE: SPECTROSCOPY AND IMAGING ORIGINALLY IN THIS CYCLE 2 PROPOSAL HAVE BEEN SPLIT BY STSCI INTO TWO SEPARATE PROPOSALS TO ALLOW FOR SCHEDULING OF CYCLE 2 EARLY ACQ IMAGING ( FOR LATER CYCLES ) SINCE CYCLE 2 SPECTROSCOPY DEPENDS ON MEASUREMENT OF EARLY ACQ IMAGING OF OTHER TARGETS FROM EARLIER CYCLES.

  19. An optical search for supernova remnants in the nearby spiral galaxy NGC 2903

    NASA Astrophysics Data System (ADS)

    Sonbas, E.; Akyuz, A.; Balman, S.

    2009-01-01

    Aims: We present the results of an optical search for supernova remnants (SNRs) in the nearby spiral galaxy NGC 2903. Methods: Interference filter images and spectral data were taken in March 2005 with the f/7.7 1.5 m Russian Turkish Telescope (RTT150) at TUBITAK National Observatory (TUG). Spectral data were obtained with the 6 m BTA (Bolshoi Azimuthal Telescope, Russia). We used the SNR identification criterion that consists of constructing the continuum-subtracted Hα and continuum-subtracted [SII]λλ6716, 6731 images and their ratios. Results: Five SNR candidates were identified in NGC 2903 with [SII]/Hα ratios ranging from 0.41-0.74 and Hα intensities ranging from 9.4 × 10-15 to 1.7 × 10-14 erg cm-2 s-1. This work represents the first identification of SNRs by an optical survey in NGC 2903. We present the spectrum of one of the bright candidates and derive an [SII]/Hα emission line ratio of 0.42 for this source. In addition, the weak [OIII]λ5007/Hβ emission line ratio in the spectrum of this SNR indicates an old oxygen-deficient remnant with a low propagation velocity.

  20. Optical imaging and spectroscopic observation of the galactic supernova remnant G85.9-0.6

    NASA Astrophysics Data System (ADS)

    Gök, F.; Sezer, A.; Aktekin, E.; Güver, T.; Ercan, N.

    2009-11-01

    Optical CCD imaging with H α and [SII] filters and spectroscopic observations of the galactic supernova remnant G85.9-0.6 have been performed for the first time. The CCD image data are taken with the 1.5 m Russian-Turkish Telescope (RTT150) at TÜBİTAK National Observatory (TUG) and spectral data are taken with the Bok 2.3 m telescope on Kitt Peak, AZ. The images are taken with narrow-band interference filters H α, [SII] and their continuum. [SII]/H α ratio image is performed. The ratio obtained from [SII]/H α is found to be ˜0.42, indicating that the remnant interacts with HII regions. G85.9-0.6 shows diffuse-shell morphology. [SII] λ λ6716/6731 average flux ratio is calculated from the spectra, and the electron density N e is obtained to be 395 cm-3. From [OIII]/H β ratio, shock velocity has been estimated, pre-shock density of n c =14 cm-3, explosion energy of E=9.2×1050 ergs, interstellar extinction of E( B- V)=0.28, and neutral hydrogen column density of N(HI)=1.53×1021 cm-2 are reported.

  1. Supernova Remnants and Nucleosynthesis (fos 30): Augmentation Cycle 2 Observations - Imaging

    NASA Astrophysics Data System (ADS)

    Davidsen, Arthur

    1991-07-01

    Overall program: UV and optical spectra of four supernova remnants (SNRs) will be used to study a number of problems related to abundances, grain destruction, interstellar medium properties and physical conditions in SNR shocks. Representatives of three of the main classes of SNRs (Crab-nebula like, Balmer-line and "normal") will be studied in the LMC, where reasonably low reddening permits UV observations. An oxygen-rich SNR in NGC 4449 will be observed, taking advantage of the small FOS slits to isolate the SNR from surrounding H II emission. Two M33 SNRs that were previously part of this proposal have been dropped due to time limitations. This proposal is augmented time to obtain early acq images of two LMC remnants and spectra of N49, which had early acq images in Cy. 0. NOTE: SPECTROSCOPY AND IMAGING ORIGINALLY IN THE CYCLE 2 PROPOSAL 4108 HAVE BEEN SPLIT BY STSCI INTO TWO SEPARATE PROPOSALS TO ALLOW FOR SCHEDULING OF CYCLE 2 EARLY ACQ IMAGING ( THIS PROPOSAL ) SINCE CYCLE 2 SPECTROSCOPY DEPENDS ON MEASUREMENT OF EARLY ACQ IMAGING OF OTHER TARGETS FROM EARLIER CYCLES.

  2. Feature-tailored spectroscopic analysis of the supernova remnant Puppis A in X-rays

    NASA Astrophysics Data System (ADS)

    Luna, G. J. M.; Smith, M. J. S.; Dubner, G.; Giacani, E.; Castelletti, G.

    2016-05-01

    We introduce a distinct method for performing spatially resolved spectral analysis of astronomical sources with highly structured X-ray emission. The method measures the surface brightness of neighboring pixels to adaptively size and shape each region, thus the spectra from the bright and faint filamentary structures evident in the broadband images can be extracted. As a test case, we present the spectral analysis of the complete X-ray emitting plasma in the supernova remnant Puppis A observed with XMM-Newton and Chandra. Given the angular size of Puppis A, many pointings with different observational configurations have to be combined, presenting a challenge to any method of spatially resolved spectroscopy. From the fit of a plane-parallel shocked plasma model we find that temperature, absorption column, ionization time scale, emission measure, and elemental abundances of O, Ne, Mg, Si, S, and Fe, are smoothly distributed in the remnant. Some regions with overabundances of O, Ne, and Mg previously characterized as ejecta material, were automatically selected by our method, proving the excellent response of the technique. This method is an advantageous tool for the exploitation of archival X-ray data.

  3. The effects of ejecta on the X-ray luminosities of supernova remnants

    NASA Technical Reports Server (NTRS)

    Long, K. S.; Dopita, M. A.; Tuohy, I. R.

    1982-01-01

    Because X-ray luminosities of most SNRs are dominated by emission from heavy elements, estimates of the X-ray emitting mass based on cosmic abundances may be incorrect. Here we investigate the apparent density evolution of a SNR when substantial amounts of processed material are ejected by the supernova. If this material is shock heated, it will dominate X-ray emission from the remnant long after the SNR has swept up the equivalent amount of interstellar matter (ISM). Emission from metal-rich ejecta may explain why ISM densities of young remnants far from the galactic plane, deduced from standard analysis, are higher than expected, as well as why larger SNRs appear to be lying in regions of lower ISM density. It should be included in detailed calculations of SNR surface brightness distributions, along with effects due to departures from ionization equilibrium and cloudlet evaporation in a multiphase ISM which may also contribute to the apparent evolution of density with radius.

  4. Re-examination of the Expected Gamma-Ray Emission of Supernova Remnant SN 1987A

    NASA Astrophysics Data System (ADS)

    Berezhko, E. G.; Ksenofontov, L. T.; Völk, H. J.

    2015-09-01

    A nonlinear kinetic theory, combining cosmic-ray (CR) acceleration in supernova remnants (SNRs) with their gas dynamics, is used to re-examine the nonthermal properties of the remnant of SN 1987A for an extended evolutionary period of 5-50 year. This spherically symmetric model is approximately applied to the different features of the SNR, consisting of (i) a blue supergiant wind and bubble, and (ii) of the swept-up red supergiant (RSG) wind structures in the form of an H ii region, an equatorial ring (ER), and an hourglass region. The RSG wind involves a mass loss rate that decreases significantly with elevation above and below the equatorial plane. The model adapts recent three-dimensional hydrodynamical simulations by Potter et al. in 2014 that use a significantlysmaller ionized mass of the ER than assumed in the earlier studies by the present authors. The SNR shock recently swept up the ER, which is the densest region in the immediate circumstellar environment. Therefore, the expected gamma-ray energy flux density at TeV energies in the current epoch has already reached its maximal value of ˜10-13 erg cm-2 s-1. This flux should decrease by a factor of about two over the next 10 years.

  5. DISCOVERY OF TeV GAMMA-RAY EMISSION FROM TYCHO'S SUPERNOVA REMNANT

    SciTech Connect

    Acciari, V. A.; Benbow, W.; Aliu, E.; Errando, M.; Arlen, T.; Aune, T.; Beilicke, M.; Buckley, J. H.; Bugaev, V.; Dickherber, R.; Bradbury, S. M.; Byrum, K.; Cannon, A.; Collins-Hughes, E.; Cesarini, A.; Ciupik, L.; Cui, W.; Finley, J. P.; Duke, C.; Finnegan, G. E-mail: wakely@uchicago.edu

    2011-04-01

    We report the discovery of TeV gamma-ray emission from the Type Ia supernova remnant (SNR) G120.1+1.4, known as Tycho's SNR. Observations performed in the period 2008-2010 with the VERITAS ground-based gamma-ray observatory reveal weak emission coming from the direction of the remnant, compatible with a point source located at 00{sup h}25{sup m}27.{sup s}0, + 64{sup 0}10'50'' (J2000). The TeV photon spectrum measured by VERITAS can be described with a power law dN/dE = C(E/3.42 TeV){sup -}{Gamma} with {Gamma} = 1.95 {+-} 0.51{sub stat} {+-} 0.30{sub sys} and C = (1.55 {+-} 0.43{sub stat} {+-} 0.47{sub sys}) x 10{sup -14} cm{sup -2} s{sup -1} TeV{sup -1}. The integral flux above 1 TeV corresponds to {approx}0.9% of the steady Crab Nebula emission above the same energy, making it one of the weakest sources yet detected in TeV gamma rays. We present both leptonic and hadronic models that can describe the data. The lowest magnetic field allowed in these models is {approx}80 {mu}G, which may be interpreted as evidence for magnetic field amplification.

  6. XMM-Newton studies of Supernova Remnants in the Large Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Ambrosino, William; Guinan, E. F.; Maggi, Pierre; Haberl, Frank

    2014-01-01

    Supernova remnants (SNRs) are leading contributors to the energy balance, chemical enrichment, and mixing of the interstellar medium (ISM). The Large Magellanic Cloud (LMC) hosts a large sample of SNRs. The close proximity of the LMC (~50 kpc), combined with moderate foreground ISM absorption, makes it an ideal target for studying these significant objects. In the course of an X-ray survey of the LMC, the space-borne observatory XMM-Newton discovered several new SNRs. A sample of previously known SNRs was observed for the first time with modern X-ray instruments as well. We used these new data to perform X-ray imaging and spectral analyses. We measure properties of the sample such as temperature, composition, and age. Based on the local stellar populations, we also discuss the nature of their parent supernovae. This research is supported by the Villanova Undergraduate Research Fellows (VURF), the Max Planck Society (MPG), and the DAAD-RISE scholarship program. We also acknowledge support from NSF/RUI Grant AST 1009903 to Villanova University.

  7. POLYCYCLIC AROMATIC HYDROCARBON PROCESSING IN THE BLAST WAVE OF THE SUPERNOVA REMNANT N132D

    SciTech Connect

    Tappe, A.; Rho, J.; Micelotta, E. R.

    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 edge 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.

  8. Changes in the optical remnant of Kepler's supernova during the period 1942-1989

    SciTech Connect

    Bandiera, R.; Van den bergh, S. Dominion Astrophysical Observatory, Victoria )

    1991-06-01

    Images of the optical nebulosity associated with Kepler's supernova have been obtained at the Mount Wilson Observatory in 1941-1943, at the Palomar Observatory in 1950-1983, and on La Silla in 1989. These data have been used to study the luminosity evolution of individual knots and the expansion and translation of the optical remnant of Kepler's supernova of 1604. From the study of the motions of 50 long-lived knots, expansion is {minus}0.623 + or {minus} 0.045 arcsec/century, translation is 0.484 + or {minus} 0.049 arcsec/century, and expansion time scale of 32,000 + or {minus} 12,000 yr. For an assumed distance of 4.5 kpc the centroid of the nebulosity tangential velocity is 117 + or {minus} 10 km/s to the W and 105 + or {minus} 11 km/s to the N. By combining astrometric and spectroscopic information, a space velocity of 278 + or {minus} 12 km/s is estimated. This indicates that the progenitor of SN 1604 was a high-velocity object. It could have been either a Population II star or a massive high-velocity runaway star. 30 refs.

  9. A Deep Chandra Observation of Kepler's Supernova Remnant: A Type Ia Event with Circumstellar Interaction

    NASA Astrophysics Data System (ADS)

    Reynolds, Stephen P.; Borkowski, Kazimierz J.; Hwang, Una; Hughes, John P.; Badenes, Carles; Laming, J. M.; Blondin, J. M.

    2007-10-01

    We present initial results of a 750 ks Chandra observation of the remnant of Kepler's supernova of AD 1604. The strength and prominence of iron emission, together with the absence of O-rich ejecta, demonstrate that Kepler resulted from a thermonuclear supernova, even though evidence for circumstellar interaction is also strong. We have analyzed spectra of over 100 small regions, and find that they fall into three classes. (1)