Sample records for pulsars supernova remnants

  1. Pulsar wind nebulae in supernova remnants

    E-print Network

    E. van der Swaluw; A. Achterberg; Y. A. Gallant; G. Tóth

    2000-12-20

    A spherically symmetric model is presented for the interaction of a pulsar wind with the associated supernova remnant. This results in a pulsar wind nebula whose evolution is coupled to the evolution of the surrounding supernova remnant. This evolution can be divided in three stages. The first stage is characterised by a supersonic expansion of the pulsar wind nebula into the freely expanding ejecta of the progenitor star. In the next stage the pulsar wind nebula is not steady; the pulsar wind nebula oscillates between contraction and expansion due to interaction with the reverse shock of the supernova remnant: reverberations which propagate forward and backward in the remnant. After the reverberations of the reverse shock have almost completely vanished and the supernova remnant has relaxed to a Sedov solution, the expansion of the pulsar wind nebula proceeds subsonically. In this paper we present results from hydrodynamical simulations of a pulsar wind nebula through all these stages in its evolution. The simulations were carried out with the Versatile Advection Code.

  2. Rotating Neutron Stars, Pulsars and Supernova Remnants

    Microsoft Academic Search

    F. Pacini

    1968-01-01

    I SHALL discuss here some problems connected with theories linking the pulsars to the rotation of neutron stars (ref. 1 and a preprint by L. Woltjer). Because neutron stars can be formed during a supernova explosion, their rotation could be coupled with the surrounding gaseous remnant2,3: the following considerations will therefore also refer to the problem of the activity observed

  3. Confinement of the Crab pulsar's wind by its supernova remnant

    Microsoft Academic Search

    C. F. Kennel; F. V. Coroniti

    1984-01-01

    A steady state, spherically symmetric, magnetohydrodynamic model of the Crab nebula is constructed. A highly relativistic positronic pulsar wind is terminated by a strong MHD shock that decelerates the flow and increases its pressure to match boundary conditions imposed by the recently discovered supernova remnant that surrounds the nebula. If the magnetic luminosity of the pulsar wind upstream of the

  4. TeV gamma-rays from Galactic objects: pulsars, pulsar nebulae and supernova remnants

    E-print Network

    Enomoto, Ryoji

    TeV gamma-rays from Galactic objects: pulsars, pulsar nebulae and supernova remnants T. Kifune nebula, supernova remnant and nu- cleus of active galaxy are found as TeV gamma ray emit- ter to investigate production, acceleration and interaction of energetic particles. The ab- soption of TeV gamma rays

  5. Pulsar Wind Nebulae in Evolved Supernova Remnants

    Microsoft Academic Search

    John M. Blondin; Roger A. Chevalier; Dargan M. Frierson

    2001-01-01

    For pulsars similar to the one in the Crab Nebula, most of the energy input\\u000ato the surrounding wind nebula occurs on a timescale of less than 1000 years;\\u000aduring this time, the nebula expands into freely expanding supernova ejecta. On\\u000aa timescale 10,000 years, the interaction of the supernova with the surrounding\\u000amedium drives a reverse shock front toward

  6. Radio-quiet X-ray pulsars in Supernova Remnants and the ``Missing'' Pulsar Problem

    E-print Network

    E. V. Gotthelf

    1998-09-10

    The paradigm that young neutron stars (NSs) evolve as rapidly rotating Crab-like pulsars requires re-examination. Evidence is accumulating that, in fact, many young NS are slowly rotating (P ~ 10-s) X-ray pulsars, lacking in detectable radio emission. We present new results on three radio-quiet NS candidates associated with supernova remnants, which suggests that alternative evolutionary-paths exist for young pulsars. These include the 12-s pulsator in Kes 73, the 7-s pulsar near Kes 75, and the enigmatic X-ray source in RCW 103. We postulate that such objects account for the apparent paucity of radio pulsars in supernova remnants.

  7. X-rays from radio pulsars - The portable supernova remnants

    NASA Technical Reports Server (NTRS)

    Helfand, D. J.

    1983-01-01

    Neutron stars are the longest-lived remnants of supernova explosions. As a reservoir of thermal energy remaining from the explosion and generated by frictional coupling between core and crust, as a storehouse of magnetic and rotational kinetic energy which allows the star to act as a high energy particle accelerator, and as the source of a deep gravitational potential which can generate heat from infalling matter, neutron stars remain capable of producing high energy radiation for a Hubble time. The results of an extensive survey of supernova remnants and radio pulsars performed with the imaging instruments on board the Einstein Observatory are reviewed and the implications of these results for pulsar physics and for the origin and evolution of galactic neutron stars are discussed.

  8. Modeling the Dynamical and Radiative Evolution of a Pulsar Wind Nebula inside a Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Gelfand, Joseph; Slane, Patrick; Zhang, Weiqun

    2009-09-01

    A pulsar wind nebula inside a supernova remnant offers a unique insight into the properties of neutron stars, pulsar winds, and the progenitor supernova. However, this is complicated by the rapid and complicated evolution such a pulsar wind nebulae undergoes. In this talk, I will present a model for the dynamical and radiative evolution of a pulsar wind nebulae inside a remnant which can extract the desired information from observations, and demonstrate its success in reproducing the total radio to X-ray spectrum of the Crab Nebula.

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

    Microsoft Academic Search

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

    2008-01-01

    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

  10. The Dynamical and Radiative Evolution of a Pulsar Wind Nebula inside a Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Gelfand, Joseph; Slane, Patrick; Zhang, Weiqun

    A pulsar wind nebula inside a supernova remnants is probably the best laboratory for deter-mining the birth properties of a neutron star, the properties of its progenitor supernova, and studying the properties of the pulsar wind. Thanks to new observing facilities, such as the Ex-tended Very Large Array, Fermi Gamma-ray Space Telescope, HESS, and VERITAS, both the broadband spectrum and morphology of these objects can now be measured with much higher precision than before. In this talk, I will present an evolutionary model for a pulsar wind nebula inside a supernova remnant which simultaneously predicts both the dynamical and radiative properties of the pulsar wind nebula, and demonstrate how this model can explain the observed properties of some of these systems.

  11. BeppoSAX Observations of the Young Pulsar in the Kes 75 Supernova Remnant

    Microsoft Academic Search

    S. Mereghetti; R. Bandiera; F. Bocchino; G. L. Israel

    2002-01-01

    We present the results of BeppoSAX observations of the young X-ray pulsar PSR J1846-0258, recently discovered at the center of the composite supernova remnant Kes 75. The pulsar (plus nebula) spectrum can be fitted by an absorbed power law with photon index alphaph=2.16+\\/-0.15, NH=(4.7+\\/-0.8)×1022 cm-2, and unabsorbed flux ~3.9×10-11 ergs cm-2 s-1 (2-10 keV). By joining two observations taken at

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

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

  13. Optical observations of the young supernova remnant SNR 0540-69.3 and its pulsar

    E-print Network

    Serafimovich, N I; Shibanov, Y A; Sollerman, J; Shibanov, Yu. A.

    2005-01-01

    We have used the ESO NTT/EMMI and VLT/FORS1 instruments to examine the LMC supernova remnant 0540-69.3 as well as its pulsar (PSR B0540-69) and pulsar-powered nebula in the optical range.Spectroscopic observations of the remnant covering the range of 3600-7350 A centered on the pulsar produced results consistent with those of Kirshner et al. (1989), but also revealed many new emission lines. The most important are [Ne III] 3869, 3967 and Balmer lines of hydrogen. In both the central part of the remnant, as well as in nearby H II regions, the [O III] temperature is higher than about 20 000 K, but lower than previously estimated. For PSR B0540-69, previous optical data are mutually inconsistent: HST/FOS spectra indicate a significantly higher absolute flux and steeper spectral index than suggested by early time-resolved groundbased UBVRI photometry. We show that the HST and VLT spectroscopic data for the pulsar have more then about 50% nebular contamination, and that this is the reason for the previous differen...

  14. Constraining the Evolutionary Fate of Central Compact Objects: "Old" Radio Pulsars in Supernova Remnants

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

    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 (~1010-11 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 gsim10 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.

  15. 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.

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

    PubMed

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

    2008-11-21

    Energetic young pulsars and expanding blast waves [supernova remnants (SNRs)] are the most visible remains after massive stars, ending their lives, explode in core-collapse supernovae. The Fermi Gamma-Ray Space Telescope has unveiled a radio quiet pulsar located near the center of the compact synchrotron nebula inside the supernova remnant CTA 1. The pulsar, discovered through its gamma-ray pulsations, has a period of 316.86 milliseconds and a period derivative of 3.614 x 10(-13) seconds per second. Its characteristic age of 10(4) years is comparable to that estimated for the SNR. We speculate that most unidentified Galactic gamma-ray sources associated with star-forming regions and SNRs are such young pulsars. PMID:18927355

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

    E-print Network

    Abdo, A A; 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; Jhannesson, 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; Kndlseder, J; Kocian, M L; Komin*, N; Kühn, F; Kuss, M; Latronico, L; Lemoine-Goumard, M; Longo, F; Lonjou, V; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; 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; Pepé, M; Pesce-Rollins, M; Piano, G; Pieri, L; Piron, F; Porter, T A; Rain, 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; Sánchez, D; Sander, A; Saz-Parkinson, P M; Schalk, T L; Sellerholm, A; Sgr, 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

    2008-01-01

    Energetic young pulsars and expanding blast waves (supernova remnants, SNRs) are the most visible remains after massive stars, ending their lives, explode in core-collapse supernovae. The Fermi Gamma-Ray Space Telescope has unveiled a radio quiet pulsar located near the center of the compact synchrotron nebula inside the supernova remnant CTA 1. The pulsar, discovered through its gamma-ray pulsations, has a period of 316.86 ms, a period derivative of 3.614 x 10-13 s s-1 . Its characteristic age of 104 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.

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

    SciTech Connect

    Ng, C.-Y.; Bouchard, A. [Department of Physics, McGill University, Montreal, QC H3A 2T8 (Canada); Bucciantini, N. [NORDITA, Albanova Research Center, 106 91 Stockholm (Sweden); Gaensler, B. M. [Sydney Institute for Astronomy, School of Physics, The University of Sydney, NSW 2006 (Australia); Camilo, F. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Chatterjee, S., E-mail: ncy@physics.mcgill.ca [Astronomy Department, Cornell University, Ithaca, NY 14853 (United States)

    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.

  19. A Dynamical Model for the Evolution of a Pulsar Wind Nebula Inside a Nonradiative Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Gelfand, Joseph D.; Slane, Patrick O.; Zhang, Weiqun

    2009-10-01

    A pulsar wind nebula (PWN) inside a supernova remnant provides a unique insight into the properties of the central neutron star, the relativistic wind powered by its loss of rotational energy, its progenitor supernova, and the surrounding environment. In this paper, we present a new semianalytic model for the evolution of such a PWN throughout its lifetime. This model couples the dynamical and radiative evolution of the PWNe, and predicts both the dynamical (e.g., radius and expansion velocity) and radiative (radio to TeV ?-ray spectrum) properties of the PWN during this period. As a result, it is well suited for using the observed properties of a PWN to constrain the physical characteristics of the neutron star, pulsar wind, progenitor supernova, and surrounding environment. We also discuss the expected evolution for a particular set of these parameters, and show that it reproduces the large spectral break inferred from the radio and X-ray spectrum of many young PWNe, and the low break frequency, low radio luminosity, high TeV ?-ray luminosity, and high magnetization observed for several older PWNe. The predicted spectrum of this PWN also contains spectral features which appear during different evolutionary phases detectable with new radio and ?-ray observing facilities such as the Extended Very Large Array and the Fermi Gamma-ray Space Telescope. Finally, this model has implications for determining if PWNe can inject a sufficient number of energetic electrons and positrons into their surroundings to explain the recent measurements of the cosmic-ray positron fraction by PAMELA and the cosmic-ray lepton spectrum by ATIC and HESS.

  20. Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Blair, William P.

    The FUSE Team Project on supernova remnants includes an absorption study of the young Type 1a SN remnant SN1006 and studies of selected filamentary emission regions in evolved galactic SNRs. Observations of the "Schweizer-Middleditch" star behind SN1006 will be used to search for a broad absorption from Fe III 1123, using FUSE's high dispersion to resolve contaminating stellar photospheric lines from the broad line. The presence of this line would indicate iron in the cool ejecta of the supernova. Observations of key, well-studied SNR emission filaments will be used to study different kinds of shock wave-ISM interactions, including nonradiative and radiative shocks, and thermally unstable regions. FUSE coverage of a range of ions and ionization stages at high spectral resolution will provide a unique capability to diagnose the thermal, chemical, and kinematic properties of these interactions. Observations of an X-ray bright region will be used to search for faint, high-ionization lines never observed previously in spectra of SNRs.

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

    Microsoft Academic Search

    E. A. Ariyibi

    2009-01-01

    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

  2. Deep optical observations of the ?-ray pulsar PSR J0007+7303 in the CTA 1 supernova remnant

    NASA Astrophysics Data System (ADS)

    Mignani, R. P.; de Luca, A.; Rea, N.; Shearer, A.; Collins, S.; Torres, D. F.; Hadasch, D.; Caliandro, A.

    2013-04-01

    The Fermi Large Area Telescope discovered the time signature of a radio-silent pulsar coincident with RX J0007.0+7302, a plerion-like X-ray source at the centre of the CTA 1 supernova remnant. The inferred timing parameters of the ?-ray pulsar PSR J0007+7303 (P = 315.8 ms; dot{P} ˜ 3.6× 10^{-13} s s-1) point to a Vela-like neutron star, with an age comparable to that of CTA 1. The PSR J0007+7303 low distance (˜1.4 kpc), interstellar absorption (AV ˜ 1.6), and relatively high energy loss rate (dot{E} ˜ 4.5× 10^{35} erg s-1), make it a suitable candidate for an optical follow-up. Here, we present deep optical observations of PSR J0007+7303. The pulsar is not detected in the Gran Telescopio Canarias images down to a limit of r' ˜ 27.6 (3?), the deepest ever obtained for this pulsar, while William Herschel Telescope images yield a limit of V ˜ 26.9. Our r'-band limit corresponds to an optical emission efficiency ? _opt equiv L_opt/dot{E} lesssim 9.4 × 10^{-8}. This limit is more constraining than those derived for other Vela-like pulsars, but is still above the measured optical efficiency of the Vela pulsar. We compared the optical upper limits with the extrapolation of the XMM-Newton X-ray spectrum and found that the optical emission is compatible with the extrapolation of the X-ray power-law component, at variance with what is observed, e.g. in the Vela pulsar.

  3. NuSTAR Observations of Supernova Remnants and Pulsar-Wind Nebulae

    NASA Astrophysics Data System (ADS)

    Reynolds, Stephen; Zoglauer, A.; Harrison, Fiona A.; Grefenstette, Brian; Madsen, Kristin; Nynka, Melania

    NuSTAR is the first astronomical X-ray observatory able to image hard X-rays up to 78 keV. For the NuSTAR team, I report early results on the two youngest Galactic shell supernova remnants, Cas A and G1.9+0.3, and on two pulsar-wind nebulae: the Crab Nebula and G21.5-0.9. For Cas A, we show the spatial distribution of synchrotron continuum, visible up to 30 keV, and of (44) Ti, detected in the 68 and 78 keV nuclear de-excitation lines of its daughter (44) Sc. G1.9+0.3 is dominated by synchrotron continuum; we show images and spectra above 10 keV. (44) Ti has not yet been detected; the current upper limits are still somewhat above the amount inferred from Chandra observations of the 4.1 keV (44) Sc electron-capture line. Both PWNe shrink with increasing photon energy, presumably due to synchrotron burnoff, at rates which can be explained by simple models of electron advection in the nebular outflows. The Crab Nebula shrinks at different rates in different directions, most rapidly to the NW. The rates in the other directions are consistent with predictions by Kennel & Coroniti (1984). We detect slight spectral steepening in both the nebular (unpulsed) and pulsed spectrum. The pulsed spectrum steepens by 0.1 - 0.3 in the power-law index Gamma (varying with pulse phase), with an average value of Delta Gamma ˜ 0.3. The unpulsed (nebular) spectrum also steepens, by about 0.25 above ˜ 9} keV. Prior observations showed a hint of this steepening. In G21.5-0.9, NuSTAR detects emission both from the bright PWN itself and from the shell above 10 keV, confirming that some shell emission is synchrotron. We find a small steepening in the spectrum, well described by a power-law steepening by about 0.2 above 9 keV. The PWN radius is observed to shrink as E(-0.21) . A simple advection model can reproduce both the integrated spectrum from radio to X-rays, which steepens by 0.9 at at sub-mm wavelengths, and this shrinkage rate, but requires either magnetic-field amplification or mass loading of the outflow, for instance by evaporation of thermal material.

  4. The Duck Redux: An Improved Proper Motion Upper Limit for the Pulsar B1757-24 Near the Supernova Remnant G5.4-1.2

    E-print Network

    J. A. Blazek; B. M. Gaensler; S. Chatterjee; E. van der Swaluw; F. Camilo; B. W. Stappers

    2006-07-26

    "The Duck" is a complicated non-thermal radio system, consisting of the energetic radio pulsar B1757-24, its surrounding pulsar wind nebula G5.27-0.90 and the adjacent supernova remnant (SNR) G5.4-1.2. PSR B1757-24 was originally claimed to be a young (~15 000 yr) and extreme velocity (>~1500 km/s) pulsar which had penetrated and emerged from the shell of the associated SNR G5.4-1.2, but recent upper limits on the pulsar's motion have raised serious difficulties with this interpretation. We here present 8.5 GHz interferometric observations of the nebula G5.27-0.90 over a 12-year baseline, doubling the time-span of previous measurements. These data correspondingly allow us to halve the previous upper limit on the nebula's westward motion to 14 milliarcseconds/yr (5-sigma), allowing a substantive reevaluation of this puzzling object. We rule out the possibility that the pulsar and SNR were formed from a common supernova explosion ~15 000 yrs ago as implied by the pulsar's characteristic age, but conclude that an old (>~70 000 yr) pulsar / SNR association, or a situation in which the pulsar and SNR are physically unrelated, are both still viable explanations.

  5. 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.

  6. Neutron Stars in Supernova Remnants

    NASA Technical Reports Server (NTRS)

    Slane, Patrick; Kaluzienski, Lou (Technical Monitor)

    2002-01-01

    The grant provided funds for a conference entitled 'Neutron Stars in Supernova Remnants' held in Boston on 14-17 August 2001, in part to support invited speakers and students attending the meeting. The conference was completed on the specified dates and was a considerable success, attracting over 100 scientists from around the world. The conference included talks and papers on the most recent work in this field, including results from the Chandra X-ray Observatory, XMM-Newton, the Parkes Multibeam Pulsar Survey, the Very Large Array, and many other facilities. Theoretical work based on the latest results was also highlighted. The Proceedings of the conference have now been published as 'Neutron Stars in Supernova Remnants'. In addition, a large fraction of the papers from the conference have been submitted to astro-ph, and the volume in indexed through the Astronomical Data System.

  7. Pulsar Wind Nebulae and Their Supernovae

    E-print Network

    Roger A. Chevalier

    2003-10-24

    Young supernova remnants that contain pulsar wind nebulae provide diagnostics for both the inner part of the supernova and the interaction with the surrounding medium, providing an opportunity to relate these objects to supernova types. Among observed young nebulae, there is evidence for a range of supernova types, including Type IIP (Crab Nebula and SN 1054) and Type IIb/IIn/IIL (G292.0+1.8).

  8. The Duck Redux: An Improved Proper Motion Upper Limit for the Pulsar B1757-24 Near the Supernova Remnant G5.4-1.2

    E-print Network

    Blazek, J A; Chatterjee, S; Van der Swaluw, E; Camilo, F; Stappers, B W

    2005-01-01

    "The Duck" is a complicated non-thermal radio system, consisting of the energetic radio pulsar B1757-24, its surrounding pulsar wind nebula G5.27-0.90 and the adjacent supernova remnant (SNR) G5.4-1.2. PSR B1757-24 was originally claimed to be a young (~15 000 yr) and extreme velocity (>~1500 km/s) pulsar which had penetrated and emerged from the shell of the associated SNR G5.4-1.2, but recent upper limits on the pulsar's motion have raised serious difficulties with this interpretation. We here present 8.5 GHz interferometric observations of the nebula G5.27-0.90 over a 12-year baseline, doubling the time-span of previous measurements. These data correspondingly allow us to halve the previous upper limit on the nebula's westward motion to 14 milliarcseconds/year (5-sigma), allowing a substantive reevaluation of this puzzling object. We rule out the possibility that the slow motion of the pulsar can be explained in the context of a highly off-center supernova explosion, but conclude that an old (>~70 000 yr) ...

  9. Recent VERITAS results on galactic supernova remnants

    NASA Astrophysics Data System (ADS)

    Pohl, Martin

    The VERITAS array of atmospheric Cherenkov telescope has observed TeV-band emission from a number of galactic supernova remnants, including both pulsar-wind nebula and shell-type remnants. We present an overview of recent results with emphasis on IC443, Cas A, and G106.3+2.7/Boomerang, and discuss them in the context of measurements at lower photon energy and theoretical expectations.

  10. 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.

  11. 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.

  12. Search for the Optical Counterparts of Southern Anomalous X-Ray Pulsars and Radio-Quiet Neutron Stars in Young Supernova Remnants

    E-print Network

    Zhongxiang Wang; Deepto Chakrabarty

    2001-12-05

    We report on our search for the optical counterparts of the Southern Hemisphere anomalous X-ray pulsar 1E1048.1-5937 and the radio-quiet neutron stars in supernova remnants Puppis A, RCW 103, and PKS 1209-52. The observations were carried out with the new MIT/CfA MagIC camera on the Magellan-I 6.5 m telescope in Chile. We present deep multiband optical images of the X-ray error circles for each of these targets and discuss the resulting candidates and limits.

  13. The Honeycomb supernova remnant

    NASA Technical Reports Server (NTRS)

    Chu, You-Hua; Dickel, John R.; Staveley-Smith, Lister; Osterberg, Juergen; Smith, R. Chris

    1995-01-01

    At 2.5 min southeast of SN 1987A, the Honeycomb Nebula Supernova remnant (SNR) is named after its interesting morphology, which consists of over ten loops with sizes of 2-3 pc. High-dispersion spectra of these loops show hemispheres expanding toward the observer at 100-300 km/s. Using archival data X-ray data and a combination of new and archival radio data, we find bright X-ray and nonthermal radio emisssion associated with the Honeycomb Nebula. New CCD images further show enhanced (S II) H-alpha ratios. These results confirm a model in which the Honeycomb Nebula is due to a supernova shock front, traveling toward the observer, encountering an intervening sheet of dense, but porous, interstellar gas. The bulk of the supernova remnant resides in a low-density cavity, and is not otherwise visible. The situation is similar to the hidden supernova remnants postulated for the X-ray bright superbubbles. The Honeycomb Nebula has an unusually steep radio spectral index (S(sub nu) is proportional to nu(exp -1.2)), normally associated with young SNRs.

  14. 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

    E-print Network

    Temim, Tea; 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 ...

  15. 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.

  16. Pulsars, supernovae, and ultrahigh energy cosmic rays

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

    The acceleration of ultrahigh energy nuclei in fast spinning newborn pulsars can explain the observed spectrum of ultrahigh energy cosmic rays and the trend towards heavier nuclei for energies above 10^{19} eV as indicated by air shower studies reported by the Auger Observatory. By assuming a normal distribution of pulsar birth periods centered at 300 ms, we show that the contribution of extragalactic pulsar births to the ultrahigh energy cosmic ray spectrum naturally gives rise to a contribution to very high energy cosmic rays (VHECRs, between 10^{16} and 10^{18} eV) by Galactic pulsar births. The required injected composition to fit the observed spectrum depends on the absolute energy scale, differing considerably between the energy scale used by Auger and that used by the Telescope Array. Depending on the composition of the cosmic rays that escape the supernova remnant and the diffusion behavior of VHECRs in the Galaxy, the contribution of Galactic pulsar births can also bridge the gap between predictions for cosmic ray acceleration in supernova remnants and the observed spectrum below the ankle. Fast spinning newborn pulsars that could produce UHECRs would be born in supernovae that could present interesting specific radiative features, due to the interaction of the pulsar wind with the surrounding ejecta. The resulting supernova lightcurves could present a high luminosity plateau over a few years, and a bright X-ray and gamma-ray peak around one or two years after the onset of the explosion. If such signatures were observed, they could have important implications both for UHECR astrophysics and for the understanding of core-collapse supernovae.

  17. OH Masers and Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Wardle, Mark; McDonnell, Korinne

    2012-07-01

    OH(1720 MHz) masers are created by the interaction of supernova remnants with molecular clouds. These masers are pumped by collisions in warm, shocked molecular gas with OH column densities in the range 1016-1017, cm-2. Excitation calculations suggest that inversion of the 6049 MHz OH line may occur at the higher column densities that have been inferred from main-line absorption studies of supernova remnants with the Green Bank Telescope. OH(6049 MHz) masers have therefore been proposed as a complementary indicator of remnant-cloud interaction. This motivated searches for 6049 MHz maser emission from supernova remnants using the Parkes 63 m and Effelsberg 100 m telescopes, and the Australia Telescope Compact Array. A total of forty-one remnants have been examined by one or more of these surveys, but without success. To check the accuracy of the OH column densities inferred from the single-dish observations we modelled OH absorption at 1667 MHz observed with the Very Large Array towards three supernova remnants, IC 443, W44 and 3C 391. The results are mixed - the OH column is revised upwards in IC443, downwards in 3C391, and is somewhat reduced in W44. We conclude that OH columns exceeding 1017 cm-2 are indeed present in some supernova remnants and so the lack of any detections is not explained by low OH column density. We discuss the possibility that non-local line overlap is responsible for suppressing the inversion of the 6049 MHz line.

  18. Axially symmetric relativistic MHD simulations of Pulsar Wind Nebulae in Supernova Remnants - On the origin of torus and jet-like features

    E-print Network

    L. Del Zanna; E. Amato; N. Bucciantini

    2004-04-19

    The structure and the evolution of Pulsar Wind Nebulae (PWNe) are studied by means of two-dimensional axisymmetric relativistic magnetohydrodynamic (RMHD) simulations. After the first imaging of the Crab Nebula with Chandra, a growing number of objects has been found to show in the X-rays spatial features such as rings and jets, that clearly cannot be accounted for within the standard framework of one-dimensional semi-analytical models. The most promising explanation suggested so far is based on the combined effects of the latitude dependence of the pulsar wind energy flux, shaping the wind termination shock and naturally providing a higher equatorial emission, and of the wind magnetization, likely responsible for the jet collimation by hoop stresses downstream of the shock. This scenario is investigated here by following the evolution of a PWN interacting with the confining Supernova Remnant (SNR), from the free expansion to the beginning of the reverberation phase. Our results confirm the oblate shape of the wind termination shock and the formation of a polar jet with supersonic velocities (v~0.5-0.7 c) for high enough values of the equatorial wind magnetization parameter (sigma~0.01).

  19. Neutron Stars in Supernova Remnants

    Microsoft Academic Search

    Franco Pacini

    1999-01-01

    I briefly summarize some facts and ideas concerning the presence of neutron\\u000astars in Supernova remnants. While sources similar to the Crab Nebula require\\u000athe presence of a central energetic object, shell-type remnants such as Cas A\\u000aare compatible with the presence of neutron stars releasing a weak relativistic\\u000awind.

  20. The remnants of historical supernovae

    NASA Astrophysics Data System (ADS)

    Green, D. A.

    Over the last two millennia the supernova explosions of about ten stars in our Galaxy have been seen historically. These historical supernovae include those observed in detail by Tycho Brahe in AD 1572 and by Johannes Kepler in AD 1604, plus several `guest stars' chronicled earlier in China, Japan and/or Korea. The oriental records provide convincing and reliable constraints on the positions of the guest stars of AD1181, AD1054 and AD1006, plus less secure information about possible or probable guest stars dating back to AD185. These historical observations are very useful for the modern astrophysical interpretation of observations of the remnants of these supernovae. First, and most importantly, the age of the remnants of these historical supernovae -- which include the Crab Nebula, the remnant of the supernova of AD1054 -- is known, which greatly aids understanding of the nature of these objects. Second, the fact that the parent supernova was seen implies that it was relatively nearby in the Galaxy, giving further constraints on the distance, and hence other properties of their remnants. Here I will review the historical supernovae in our Galaxy, in the context of our understanding of their remnants from modern radio, X-ray and other observations.

  1. DISCOVERY OF A HIGHLY ENERGETIC X-RAY PULSAR POWERING HESS J1813-178 IN THE YOUNG SUPERNOVA REMNANT G12.82-0.02

    SciTech Connect

    Gotthelf, E. V.; Halpern, J. P. [Columbia Astrophysics Laboratory, Columbia University, 550 West 120th Street, New York, NY 10027 (United States)

    2009-08-01

    We report the discovery of 44.7 ms pulsations from the X-ray source CXOU J181335.1-174957 using data obtained with the XMM-Newton Observatory. PSR J1813-1749 lies near the center of the young radio supernova remnant G12.82-0.02, which overlaps the compact TeV source HESS J1813-178. This rotation-powered pulsar is the second most energetic in the Galaxy, with a spin-down luminosity of E-dot=(6.8{+-}2.7)x10{sup 37} erg s{sup -1}. In the rotating dipole model, the surface dipole magnetic field strength is B{sub s} = (2.7 {+-} 0.6) x 10{sup 12} G and the spin-down age {tau}{sub c}{identical_to}P/2P-dot=3.3-7.5 kyr, consistent with the location in the small, shell-type radio remnant. At an assumed distance of 4.7 kpc by association with an adjacent young stellar cluster, the efficiency of PSR J1813-1749 in converting spin-down luminosity to radiation is {approx}0.03% for its 2-10 keV flux, {approx}0.1% for its 20-100 keV INTEGRAL flux, and {approx}0.07% for the >200 GeV emission of HESS J1813-178, making it a likely power source for the latter. The nearby young stellar cluster is possibly the birthplace of the pulsar progenitor, as well as an additional source of seed photons for inverse Compton scattering to TeV energies.

  2. Supernovae, supernova remnants, and superbubbles

    NASA Technical Reports Server (NTRS)

    Shull, J. Michael

    1995-01-01

    Supernovae, supernova remmants, and superbubbles in the interstellar medium are reviewed, with an emphasis on infrared studies of these phenomena. Superbubbles are likely to be relevant for understanding such Galactic and extragalactic issues as the photoionization of gas in the Galactic halo, 'superwinds,' and the contribution of 'starbursts' to photoionization of the intergalactic medium.

  3. On understanding the lives of dead stars : Supernova Remnant N103B, radio pulsar B1951+32, and the Rabbit

    E-print Network

    Migliazzo, Joshua Marc, 1977-

    2003-01-01

    Using the Chandra High Energy Transmission Grating Spectrometer, we observed the young Supernova Remnant N103B in the Large Magellanic Cloud as part of the Guaranteed Time Observation program. N103B has a small overall ...

  4. OH Masers and Supernova Remnants

    E-print Network

    Wardle, Mark

    2012-01-01

    OH(1720 MHz) masers are created by the interaction of supernova remnants with molecular clouds. These masers are pumped by collisions in warm, shocked molecular gas with OH column densities in the range 10^{16}--10^{17} cm^{-2}. Excitation calculations suggest that inversion of the 6049 MHz OH line may occur at the higher column densities that have been inferred from main-line absorption studies of supernova remnants with the Green Bank Telescope. OH(6049 MHz) masers have therefore been proposed as a complementary indicator of remnant-cloud interaction. This motivated searches for 6049 MHz maser emission from supernova remnants using the Parkes 63 m and Effelsberg 100 m telescopes, and the Australia Telescope Compact Array. A total of forty-one remnants have been examined by one or more of these surveys, but without success. To check the accuracy of the OH column densities inferred from the single-dish observations we modelled OH absorption at 1667 MHz observed with the Very Large Array towards three supernov...

  5. TWO MAGNETAR CANDIDATES IN HESS SUPERNOVA REMNANTS

    SciTech Connect

    Halpern, J. P.; Gotthelf, E. V., E-mail: jules@astro.columbia.ed, E-mail: eric@astro.columbia.ed [Columbia Astrophysics Laboratory, Columbia University, 550 West 120th Street, New York, NY 10027-6601 (United States)

    2010-02-20

    We identify two candidate magnetars in archival X-ray observations of HESS-detected shell-type supernova remnants (SNRs). X-ray point sources in CTB 37B coincident with HESS J1713 - 381 and in G353.6 - 0.7 coincident with HESS J1731 - 347 both have anomalous X-ray pulsar (AXP) like spectra, much softer than those of ordinary, rotation-powered pulsars, and no optical/IR counterparts. The spectrum of CXOU J171405.7 - 381031 in CTB 37B has a hard excess above 6 keV, which may be similar to such components seen in some AXPs. A new Chandra observation of this object reveals a highly significant pulsed signal at P = 3.82 s with pulsed fraction f{sub p} = 0.31. Analysis of an XMM-Newton observation of the second candidate, XMMU J173203.3 - 344518 in G353.6 - 0.7, yields only marginal evidence for a 1 s period. If it is not a magnetar, then it could be a weakly magnetized central compact object. Considering that these HESS sources previously attributed to the SNR shells are possibly centrally peaked, we hypothesize that their pulsars may contribute to diffuse TeV emission. These identifications potentially double the number of magnetar/SNR associations in the Galaxy and can be used to investigate the energetics and asymmetries of the supernovae that give rise to magnetars.

  6. Identifying Elements in Supernova Remnants

    NSDL National Science Digital Library

    This activity has students use X-ray line data to identify elements contained in supernova remnants. In groups of 2 or more, they will be given several X-ray spectra from the ASCA X-ray satellite and will be asked to determine what elements are present, using a chart listing elements and the energies of their emission lines. Following a class discussion of their results, they will be given ASTRO-E spectra of the same sources and asked to determine which elements are present. Finally, they will be given spectra from Constellation-X and asked to determine what elements are present. Students will then compare and contrast Supernova Remnant Spectral Data from the three different X-ray observatories as a class. This site contains links to the simulated spectra, chart, student worksheet, and instructions.

  7. Magnetohydrodynamic turbulence in supernova remnants

    E-print Network

    Nirupam Roy; Somnath Bharadwaj; Prasun Dutta; Jayaram N. Chengalur

    2009-07-23

    We present estimates of the angular power spectra of the synchrotron radiation intensity fluctuations at 6 and 20 cm for the shell type supernova remnant Cas A and the filled-centre Crab supernova remnant. We find that the intensity fluctuations of both sources have a power law power spectrum with index -3.24 +/- 0.03. This power law power spectrum is consistent with the magnetohydrodynamic turbulence in the synchrotron emitting plasma. For Cas A, there is a break in the power spectrum and the power law index changes from -3.2 to -2.2 at large angular scale. This transition occurs at an angular scale that corresponds to the shell thickness of Cas A. We interpret this as a transition from three dimensional turbulence to two dimensional turbulence on scales that are respectively smaller and larger than the shell thickness.

  8. 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.

  9. Supernovae, young remnants, and nucleosynthesis

    NASA Technical Reports Server (NTRS)

    Kirshner, R. P.

    1982-01-01

    Chemical abundance data from extragalactic supernovae and from supernova remnants (SNR) less than 1000 yrs old are employed to show that nuclear burning beyond helium synthesis actually occurs. Supernova (SN) are classified into types I or II, having no hydrogen lines or featuring hydrogen lines, respectively. The SN I's have been observed as having a preponderance of Fe lines, and emitting from a source at around 12,000 K with a center continuum of approximately 10 AU. Decay chains which could account for detected luminosities and spectra are presented, noting a good fit of Fe II spectrum with observed SN spectra. SNR pass through younger and older stages, going from the outpouring of material to diffusion in the interstellar medium. Expanding flocculi from young SNR show oxygen abundances as well as lines from sulfur, calcium, and argon, with a corresponding necessity of an explosive source of 15 solar masses.

  10. Neutron Stars in Supernova Remnants and Beyond

    E-print Network

    V. V. Gvaramadze

    2002-12-26

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

  11. Stellar masers, circumstellar envelopes, and supernova remnants

    E-print Network

    Athol J. Kemball

    2007-05-15

    This paper reviews recent advances in the study or circumstellar masers and masers found toward supernova remnants. The review is organized by science focus area, including the astrophysics of extended stellar atmospheres, stellar mass-loss processes and outflows, late-type evolved stellar evolution, stellar maser excitation and chemistry, and the use of stellar masers as independent distance estimators. Masers toward supernova remnants are covered separately. Recent advances and open future questions in this field are explored.

  12. Supernova remnants: the X-ray perspective

    NASA Astrophysics Data System (ADS)

    Vink, Jacco

    2012-12-01

    Supernova remnants are beautiful astronomical objects that are also of high scientific interest, because they provide insights into supernova explosion mechanisms, and because they are the likely sources of Galactic cosmic rays. X-ray observations are an important means to study these objects. And in particular the advances made in X-ray imaging spectroscopy over the last two decades has greatly increased our knowledge about supernova remnants. It has made it possible to map the products of fresh nucleosynthesis, and resulted in the identification of regions near shock fronts that emit X-ray synchrotron radiation. Since X-ray synchrotron radiation requires 10-100 TeV electrons, which lose their energies rapidly, the study of X-ray synchrotron radiation has revealed those regions where active and rapid particle acceleration is taking place. In this text all the relevant aspects of X-ray emission from supernova remnants are reviewed and put into the context of supernova explosion properties and the physics and evolution of supernova remnants. The first half of this review has a more tutorial style and discusses the basics of supernova remnant physics and X-ray spectroscopy of the hot plasmas they contain. This includes hydrodynamics, shock heating, thermal conduction, radiation processes, non-equilibrium ionization, He-like ion triplet lines, and cosmic ray acceleration. The second half offers a review of the advances made in field of X-ray spectroscopy of supernova remnants during the last 15 year. This period coincides with the availability of X-ray imaging spectrometers. In addition, I discuss the results of high resolution X-ray spectroscopy with the Chandra and XMM-Newton gratings. Although these instruments are not ideal for studying extended sources, they nevertheless provided interesting results for a limited number of remnants. These results provide a glimpse of what may be achieved with future microcalorimeters that will be available on board future X-ray observatories. In discussing the results of the last 15 years I have chosen to discuss a few topics that are of particular interest. These include the properties of Type Ia supernova remnants, which appear to be regularly shaped and have stratified ejecta, in contrast to core collapse supernova remnants, which have patchy ejecta distributions. For core collapse supernova remnants I discuss the spatial distribution of fresh nucleosynthesis products, but also their properties in connection to the neutron stars they contain. For the mature supernova remnants I focus on the prototypal supernova remnants Vela and the Cygnus Loop. And I discuss the interesting class of mixed-morphology remnants. Many of these mature supernova remnants contain still plasma with enhanced ejecta abundances. Over the last five years it has also become clear that many mixed-morphology remnants contain plasma that is overionized. This is in contrast to most other supernova remnants, which contain underionized plasmas. This text ends with a review of X-ray synchrotron radiation from shock regions, which has made it clear that some form of magnetic-field amplification is operating near shocks, and is an indication of efficient cosmic-ray acceleration.

  13. THE VLT-FLAMES TARANTULA SURVEY: THE FASTEST ROTATING O-TYPE STAR AND SHORTEST PERIOD LMC PULSAR-REMNANTS OF A SUPERNOVA DISRUPTED BINARY?

    SciTech Connect

    Dufton, P. L.; Dunstall, P. R.; Fraser, M. [Astrophysics Research Centre, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN (United Kingdom); Evans, C. J. [UK Astronomy Technology Centre, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Brott, I. [University of Vienna, Department of Astronomy, Tuerkenschanzstr. 17, A-1180 Vienna (Austria); Cantiello, M.; Langer, N. [Argelander Institut fuer Astronomie der Universitaet Bonn, Auf dem Huegel 71, 53121 Bonn (Germany); De Koter, A.; Sana, H. [Astronomical Institute 'Anton Pannekoek', University of Amsterdam, Postbus 94249, 1090 GE Amsterdam (Netherlands); De Mink, S. E. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Henault-Brunet, V.; Taylor, W. D. [Scottish Universities Physics Alliance, Institute for Astronomy, University of Edinburgh, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Howarth, I. D. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Lennon, D. J. [ESA, Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Markova, N., E-mail: p.dufton@qub.ac.uk [Institute of Astronomy with NAO, Bulgarian Academy of Sciences, P.O. Box 136, 4700 Smoljan (Bulgaria)

    2011-12-10

    We present a spectroscopic analysis of an extremely rapidly rotating late O-type star, VFTS102, observed during a spectroscopic survey of 30 Doradus. VFTS102 has a projected rotational velocity larger than 500 km s{sup -1} and probably as large as 600 km s{sup -1}; as such it would appear to be the most rapidly rotating massive star currently identified. Its radial velocity differs by 40 km s{sup -1} from the mean for 30 Doradus, suggesting that it is a runaway. VFTS102 lies 12 pc from the X-ray pulsar PSR J0537-6910 in the tail of its X-ray diffuse emission. We suggest that these objects originated from a binary system with the rotational and radial velocities of VFTS102 resulting from mass transfer from the progenitor of PSR J0537-691 and the supernova explosion, respectively.

  14. The VLT-FLAMES Tarantula Survey: The Fastest Rotating O-type Star and Shortest Period LMC Pulsar—Remnants of a Supernova Disrupted Binary?

    NASA Astrophysics Data System (ADS)

    Dufton, P. L.; Dunstall, P. R.; Evans, C. J.; Brott, I.; Cantiello, M.; de Koter, A.; de Mink, S. E.; Fraser, M.; Hénault-Brunet, V.; Howarth, I. D.; Langer, N.; Lennon, D. J.; Markova, N.; Sana, H.; Taylor, W. D.

    2011-12-01

    We present a spectroscopic analysis of an extremely rapidly rotating late O-type star, VFTS102, observed during a spectroscopic survey of 30 Doradus. VFTS102 has a projected rotational velocity larger than 500 km s-1 and probably as large as 600 km s-1 as such it would appear to be the most rapidly rotating massive star currently identified. Its radial velocity differs by 40 km s-1 from the mean for 30 Doradus, suggesting that it is a runaway. VFTS102 lies 12 pc from the X-ray pulsar PSR J0537-6910 in the tail of its X-ray diffuse emission. We suggest that these objects originated from a binary system with the rotational and radial velocities of VFTS102 resulting from mass transfer from the progenitor of PSR J0537-691 and the supernova explosion, respectively.

  15. 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.

  16. Suzaku view of supernova remnants

    NASA Astrophysics Data System (ADS)

    Yamaguchi, H.; Koyama, K.

    We present the spectral studies of thermal emissions from supernova remnants (SNRs) with the latest Japanese X-ray astronomy satellite Suzaku. In the X-ray spectrum from the southeast region of SN 1006, we robustly detected the K-shell emission from Fe, for the first time. Fe was found to be less ionized than the other lighter elements, such as Si and S. This fact strongly suggests that Fe has been heated by the reverse shock more recently than the other elements, consistent with a picture where the ejecta are stratified by composition with Fe in the interior. From the several other Type Ia SNRs, Tycho, Kepler, and N103B, Suzaku successfully detected emission lines of low-abundant elements, Cr, Mn, and/or Ni. A number ratio of Mn/Cr in Type Ia SNRs would especially be a good probe for an initial metallicity of the progenitor, because the product of Mn is sensitive to the neutron excess in the white dwarf. We finally report on the recent results concerning the middle-aged SNRs, IC 443 and W49B. We discovered strong free-bound emission from these SNRs, the firm evidences of peculiar recombining (overionized) plasma.

  17. High Energy Emission from Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Vink, Jacco

    This paper discusses several aspects of current research on high energy emission from supernova remnants, covering the following main topics: 1) The recent evidence for magnetic field amplification near supernova remnant shocks, which makes that cosmic rays are more efficiently accelerated than previously thought. 2) The evidence that ions and electrons in some remnants have very different temperatures, and only equilibrate through Coulomb interactions. 3) The evidence that the explosion that created Cas A was asymmetric, and seems to have involved a jet/counter jet structure. And finally, 4), I will argue that the unremarkable properties of supernova remnants associated with magnetar candidates, suggest that magnetars are not formed from rapidly (P? 1 ms) rotating proto-neutron stars. It is therefore more likely that they are formed from massive progenitor stars with high magnetic fields.

  18. X-ray emission from supernova remnants

    Microsoft Academic Search

    P. A. Charles

    1976-01-01

    Using data from the Mullard Space Science Laboratory's X-ray telescopes on the satellite OAO-Copernicus, the five supernova remnants, the Crab Nebula, the Cygnus Loop, IC443, Cas A and Pup A, have been studied in detail in the 0.5 - 7.5 keV range. Both spectral and spatial information are available for each remnant, from which the following conclusions may be drawn.

  19. Cosmic-ray acceleration in supernova remnants

    NASA Astrophysics Data System (ADS)

    Helder, E. A.

    2010-09-01

    Supernovae are among the most energetic events in the Universe. During the event, they expel their material with enormous speeds into the surroundings. In addition, supernovae are thought to transfer a sizable fraction of their energy into just a few particles: cosmic rays. These cosmic rays acquire so much energy that they escape the supernova material with almost the speed of light. Some of these cosmic rays arrive on Earth, where in an unfortunate case, they can do damage to the electronics onboard satellites. This thesis describes several studies on the observational imprints of cosmic-ray acceleration in supernova remnants. We use optical and X-ray data to study how much energy is lost from the remnants to cosmic rays and how this energy is transferred to the particles.

  20. Supernova remnants and plerions in the Compton Gamma-Ray Observatory era

    Microsoft Academic Search

    Ocker C. de Jager; Matthew G. Baring

    1997-01-01

    Due to observations made by the Compton Gamma-Ray Observatory over the last six years, it appears that a number of galactic supernova remnants may be candidates for sources of cosmic gamma-rays. These include shell-type remnants such as IC443 and ? Cygni, which have no known parent pulsars, but have significant associations with unidentified EGRET sources, and others that appear to

  1. "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.

  2. 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.

  3. Supernova Remnants and Plerions in the Compton Gamma-Ray Observatory Era

    E-print Network

    Ocker C. de Jager; Matthew G. Baring

    1997-11-19

    Due to observations made by the Compton Gamma-Ray Observatory over the last six years, it appears that a number of galactic supernova remnants may be candidates for sources of cosmic gamma-rays. These include shell-type remnants such as IC443 and $\\gamma$ Cygni, which have no known parent pulsars, but have significant associations with unidentified EGRET sources, and others that appear to be composite, where a pulsar is embedded in a shell (e.g. W44 and Vela), or are purely pulsar-driven, such as the Crab Nebula. This review discusses our present understanding of gamma-ray production in plerionic and non-plerionic supernova remnants, and explores the relationship between such emission and that in other wavebands. Focuses include models of the Crab and Vela nebulae, the composite nature of W44, the relationship of shell-type remnants to cosmic ray production, the relative importance of shock-accelerated protons and electrons, constraints on models placed by TeV, X-ray and radio observations, and the role of electrons injected directly into the remnants by parent pulsars.

  4. Emission Line Studies of the Supernova Remnant IC443

    Microsoft Academic Search

    S. B. Cooper; W. W. Craig; S. M. Kahn; C. J. Hailey; J. P. Brodie

    1993-01-01

    We present preliminary results from a comprehensive study of optical emission lines in the intermediate age supernova remnant IC443. This remnant has been well-studied at all wavelengths in the bright northeast limb where the remnant is interacting with a molecular cloud. We have obtained ~ 60 spectra at positions throughout the remnant. The spectra were obtained with the Automated Multi

  5. 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.

  6. Shocked Clouds in the Vela Supernova Remnant

    NASA Technical Reports Server (NTRS)

    Nichols, Joy S.; Slavin, Jonathan D.

    2004-01-01

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

  7. The NuSTAR Program for Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Grefenstette, Brian; An, H.; Boggs, S. E.; Christensen, F.; Craig, W. W.; Freyer, C.; Hailey, C. J.; Harrison, F.; Humensky, B.; Jakobsen, S.; Kaspi, V.; Kitaguchi, T.; Lopez, L. A.; Madsen, K.; Miyasaka, H.; Mori, K.; Nynka, M.; Pivovaroff, M.; Reynolds, S. P.; Stern, D.; Westergaard, N. J.; Wik, D. R.; Zhang, W.; Zoglauer, A.; NuSTAR Team

    2013-01-01

    The Nuclear Spectroscopic Telescope Array (NuSTAR), successfully launched in June 2012, is the first telescope to bring the the hard X-ray (3 to 79 keV) sky into focus. One of NuSTAR's prime science goals is to study the morphology of the previously unresolved hard X-ray emission from supernova remnants (SNRs). Spatial and spectral characterization of the hard X-ray synchrotron emission is essential to understanding the physics of particle acceleration in SNR and has implications for origin of galactic cosmic rays. Young (< 1 kyr) remnants may also show emission from decay products of Ti-44, which has great importance in understanding supernova explosion mechanisms. In this poster we present NuSTAR plans for observing SNRs as well as early results from SNRs observed in the first six months since launch, including preliminary results for Cassiopeia A. Discussions of Pulsar Wind Nebulae (PWNe) and G21.5-0.9 are presented in a companion posters by K. Madsen and M. Nynka, respectively.

  8. Low Frequency Insights Into Supernova Remnants

    E-print Network

    Kristy K. Dyer; Stephen P. Reynolds; Kazik J. Borkowski

    2000-01-26

    Low frequency observations at 330 and 74 MHz can provide new insights into supernova remnants (SNR). We can test theoretical predictions for spectral index variations. Nonlinear models of shock acceleration predict that the spectra from young SNR should be slightly concave rather than power laws -- flattening toward higher energies. However, few SNR are bright and compact enough to be studied at millimeter wavelengths, restricting studies to the small range from 6 to 20 cm (a factor of 1.7 in electron energies). Observations at 330 MHz increase the electron energy baseline to a factor of 4, while providing sensitivity to larger spatial scales that are resolved out by centimeter-wavelength interferometers. Such observations can also separate thermal from nonthermal emission and detect excess free-free absorption associated with cool gas in remnants. Wide field images also provide an efficient census of both thermal and nonthermal sources over a large region.

  9. Magnetic fields in old supernova remnants

    NASA Astrophysics Data System (ADS)

    Gusdorf, A.; Hezareh, T.; Anderl, S.; Wiesemeyer, H.

    2013-11-01

    We review the motivations and methods for studying magnetic fields in relatively old supernova remnants (SNRs), such as W28, W44, 3C 391, and IC 443. We first explain the common methods of determination of interstellar magnetic fields through measurements of polarization levels in cosmic dust and spectral line emission. We then present the methods used in our study, i.e., shock modelling of molecular line emission, and application of non-Zeeman circular polarization of spectral lines. We finalize with the new perspectives of this study.

  10. On neutron star/supernova remnant associations

    E-print Network

    V. V. Gvaramadze

    2001-04-01

    It is pointed out that a cavity supernova (SN) explosion of a moving massive star could result in a significant offset of the neutron star (NS) birth-place from the geometrical centre of the supernova remnant (SNR). Therefore: a) the high implied transverse velocities of a number of NSs (e.g. PSR B1610-50, PSR B1757-24, SGR0525-66) could be reduced; b) the proper motion vector of a NS should not necessarily point away from the geometrical centre of the associated SNR; c) the circle of possible NS/SNR associations could be enlarged. An observational test is discussed, which could allow to find the true birth-places of NSs associated with middle-aged SNRs, and thereby to get more reliable estimates of their transverse velocities.

  11. The molecular emission from old supernova remnants

    NASA Astrophysics Data System (ADS)

    Gusdorf, A.; Güsten, R.; Anderl, S.; Hezareh, T.; Wiesemeyer, H.

    2014-01-01

    Supernovae constitute a critical source of energy input to the interstellar medium (ISM). In this short review, we focus on their latest phase of evolution, the supernova remnants (SNRs). We present observations of three old SNRs that have reached the phase where they interact with the ambient interstellar medium: W28, IC443, and 3C391. We show that such objects make up clean laboratories to constrain the physical and chemical processes at work in molecular shock environments. Our studies subsequently allow us to quantify the impact of SNRs on their environment in terms of mass, momentum, and energy dissipation. In turn, their contribution to the energy balance of galaxies can be assessed. Their potential to trigger a further generation of star formation can also be investigated. Finally, our studies provide strong support for the interpretation of ?-ray emission in SNRs, a crucial step to answer questions related to cosmic rays population and acceleration.

  12. The molecular emission from old supernova remnants

    E-print Network

    Gusdorf, Antoine; Anderl, Sibylle; Hezareh, Talayeh

    2014-01-01

    Supernovae constitute a critical source of energy input to the interstellar medium (ISM). In this short review, we focus on their latest phase of evolution, the supernova remnants (SNRs). We present observations of three old SNRs that have reached the phase where they interact with the ambient ISM: W28, IC443, and 3C391. We show that such objects make up clean laboratories to constrain the physical and chemical processes at work in molecular shock environments. Our studies subsequently allow us to quantify the impact of SNRs on their environment in terms of mass, momentum, and energy dissipation. In turn, their contribution to the energy balance of galaxies can be assessed. Their potential to trigger a further generation of star formation can also be investigated. Finally, our studies provide strong support for the interpretation of gamma-ray emission in SNRs, a crucial step to answer questions related to cosmic rays population and acceleration.

  13. Surprisingly high pressure shocks in the supernova remnant IC443

    E-print Network

    Burton, Michael

    Surprisingly high pressure shocks in the supernova remnant IC443 A. Moorhouse, 1 P.W.J.L. Brand, 1/molecular cloud shock in IC443. The lines measured have upper state energies ranging from 7000 K to 23000 K Introduction Observations of high velocity neutral atomic hydrogen in the supernova remnant (SNR) IC443 by (De

  14. INTEGRAL observations of the region of the supernova remnant IC443

    Microsoft Academic Search

    F. Bocchino; A. M. Krassilchtchikov; P. Kretschmar; A. M. Bykov; Yu. A. Uvarov; S. M. Osipov

    2006-01-01

    IC433 is a supernova remnant SNR interacting with a molecular cloud The field of IC443 also contains an unidentified gamma-ray source 3EG J0617 2238 Recent observations with XMM-Newton and Chandra have revealed a number of hard X-ray sources in the field of the extended SNR including a pulsar wind nebula and an enigmatic hard X-ray source in the SNR --

  15. Color Composite Image of the Supernova Remnant

    NASA Technical Reports Server (NTRS)

    2000-01-01

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

  16. 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.; Katarzy?ski, 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, ?.; 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 ? = 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 ? G.

  17. Supernova Remnants and Plerions in the Compton Gamma-Ray Observatory Era

    E-print Network

    De Jager, O C; Jager, Ocker C. de; Baring, Matthew G.

    1997-01-01

    Due to observations made by the Compton Gamma-Ray Observatory over the last six years, it appears that a number of galactic supernova remnants may be candidates for sources of cosmic gamma-rays. These include shell-type remnants such as IC443 and $\\gamma$ Cygni, which have no known parent pulsars, but have significant associations with unidentified EGRET sources, and others that appear to be composite, where a pulsar is embedded in a shell (e.g. W44 and Vela), or are purely pulsar-driven, such as the Crab Nebula. This review discusses our present understanding of gamma-ray production in plerionic and non-plerionic supernova remnants, and explores the relationship between such emission and that in other wavebands. Focuses include models of the Crab and Vela nebulae, the composite nature of W44, the relationship of shell-type remnants to cosmic ray production, the relative importance of shock-accelerated protons and electrons, constraints on models placed by TeV, X-ray and radio observations, and the role of el...

  18. 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.

  19. Searches for continuous gravitational waves from nine young supernova remnants

    E-print Network

    J. Aasi; B. P. Abbott; R. Abbott; T. Abbott; M. R. Abernathy; F. Acernese; K. Ackley; C. Adams; T. Adams; T. Adams; P. Addesso; R. X. Adhikari; V. Adya; C. Affeldt; M. Agathos; K. Agatsuma; N. Aggarwal; O. D. Aguiar; A. Ain; P. Ajith; A. Alemic; B. Allen; A. Allocca; D. Amariutei; S. B. Anderson; W. G. Anderson; K. Arai; M. C. Araya; C. Arceneaux; J. S. Areeda; S. Ast; S. M. Aston; P. Astone; P. Aufmuth; C. Aulbert; B. E. Aylott; S. Babak; P. T. Baker; F. Baldaccini; G. Ballardin; S. W. Ballmer; J. C. Barayoga; M. Barbet; S. Barclay; B. C. Barish; D. Barker; F. Barone; B. Barr; L. Barsotti; M. Barsuglia; J. Bartlett; M. A. Barton; I. Bartos; R. Bassiri; A. Basti; J. C. Batch; Th. S. Bauer; C. Baune; V. Bavigadda; B. Behnke; M. Bejger; C. Belczynski; A. S. Bell; C. Bell; M. Benacquista; J. Bergman; G. Bergmann; C. P. L. Berry; D. Bersanetti; A. Bertolini; J. Betzwieser; S. Bhagwat; R. Bhandare; I. A. Bilenko; G. Billingsley; J. Birch; S. Biscans; M. Bitossi; C. Biwer; M. A. Bizouard; J. K. Blackburn; L. Blackburn; C. D. Blair; D. Blair; S. Bloemen; O. Bock; T. P. Bodiya; M. Boer; G. Bogaert; P. Bojtos; C. Bond; F. Bondu; L. Bonelli; R. Bonnand; R. Bork; M. Born; V. Boschi; Sukanta Bose; C. Bradaschia; P. R. Brady; V. B. Braginsky; M. Branchesi; J. E. Brau; T. Briant; D. O. Bridges; A. Brillet; M. Brinkmann; V. Brisson; A. F. Brooks; D. A. Brown; D. D. Brown; N. M. Brown; S. Buchman; A. Buikema; T. Bulik; H. J. Bulten; A. Buonanno; D. Buskulic; C. Buy; L. Cadonati; G. Cagnoli; J. Calderón Bustillo; E. Calloni; J. B. Camp; K. C. Cannon; J. Cao; C. D. Capano; F. Carbognani; S. Caride; S. Caudill; M. Cavaglià; F. Cavalier; R. Cavalieri; G. Cella; C. Cepeda; E. Cesarini; R. Chakraborty; T. Chalermsongsak; S. J. Chamberlin; S. Chao; P. Charlton; E. Chassande-Mottin; Y. Chen; A. Chincarini; A. Chiummo; H. S. Cho; M. Cho; J. H. Chow; N. Christensen; Q. Chu; S. Chua; S. Chung; G. Ciani; F. Clara; J. A. Clark; F. Cleva; E. Coccia; P. -F. Cohadon; A. Colla; C. Collette; M. Colombini; L. Cominsky; M. Constancio, Jr.; A. Conte; D. Cook; T. R. Corbitt; N. Cornish; A. Corsi; C. A. Costa; M. W. Coughlin; J. -P. Coulon; S. Countryman; P. Couvares; D. M. Coward; M. J. Cowart; D. C. Coyne; R. Coyne; K. Craig; J. D. E. Creighton; T. D. Creighton; J. Cripe; S. G. Crowder; A. Cumming; L. Cunningham; E. Cuoco; C. Cutler; K. Dahl; T. Dal Canton; M. Damjanic; S. L. Danilishin; S. D'Antonio; K. Danzmann; L. Dartez; V. Dattilo; I. Dave; H. Daveloza; M. Davier; G. S. Davies; E. J. Daw; R. Day; D. DeBra; G. Debreczeni; J. Degallaix; M. De Laurentis; S. Deléglise; W. Del Pozzo; T. Denker; T. Dent; H. Dereli; V. Dergachev; R. De Rosa; R. T. DeRosa; R. DeSalvo; S. Dhurandhar; M. Díaz; L. Di Fiore; A. Di Lieto; I. Di Palma; A. Di Virgilio; G. Dojcinoski; V. Dolique; E. Dominguez; F. Donovan; K. L. Dooley; S. Doravari; R. Douglas; T. P. Downes; M. Drago; J. C. Driggers; Z. Du; M. Ducrot; S. Dwyer; T. Eberle; T. Edo; M. Edwards; M. Edwards; A. Effler; H. -B. Eggenstein; P. Ehrens; J. Eichholz; S. S. Eikenberry; R. Essick; T. Etzel; M. Evans; T. Evans; M. Factourovich; V. Fafone; S. Fairhurst; X. Fan; Q. Fang; S. Farinon; B. Farr; W. M. Farr; M. Favata; M. Fays; H. Fehrmann; M. M. Fejer; D. Feldbaum; I. Ferrante; E. C. Ferreira; F. Ferrini; F. Fidecaro; I. Fiori; R. P. Fisher; R. Flaminio; J. -D. Fournier; S. Franco; S. Frasca; F. Frasconi; Z. Frei; A. Freise; R. Frey; T. T. Fricke; P. Fritschel; V. V. Frolov; S. Fuentes-Tapia; P. Fulda; M. Fyffe; J. R. Gair; L. Gammaitoni; S. Gaonkar; F. Garufi; A. Gatto; N. Gehrels; G. Gemme; B. Gendre; E. Genin; A. Gennai; L. Á. Gergely; S. Ghosh; J. A. Giaime; K. D. Giardina; A. Giazotto; J. Gleason; E. Goetz; R. Goetz; L. Gondan; G. González; N. Gordon; M. L. Gorodetsky; S. Gossan; S. Goßler; R. Gouaty; C. Gräf; P. B. Graff; M. Granata; A. Grant; S. Gras; C. Gray; R. J. S. Greenhalgh; A. M. Gretarsson; P. Groot; H. Grote; S. Grunewald; G. M. Guidi; C. J. Guido; X. Guo; K. Gushwa; E. K. Gustafson; R. Gustafson; J. Hacker; E. D. Hall; G. Hammond; M. Hanke; J. Hanks; C. Hanna; M. D. Hannam; J. Hanson; T. Hardwick; J. Harms; G. M. Harry; I. W. Harry; M. Hart; M. T. Hartman; C. -J. Haster; K. Haughian; S. Hee; A. Heidmann; M. Heintze; G. Heinzel; H. Heitmann; P. Hello; G. Hemming; M. Hendry; I. S. Heng; A. W. Heptonstall; M. Heurs; M. Hewitson; S. Hild; D. Hoak; K. A. Hodge; D. Hofman; S. E. Hollitt; K. Holt; P. Hopkins; D. J. Hosken; J. Hough; E. Houston; E. J. Howell; Y. M. Hu; E. Huerta; B. Hughey; S. Husa; S. H. Huttner; M. Huynh; T. Huynh-Dinh; A. Idrisy; N. Indik; D. R. Ingram; R. Inta; G. Islas; J. C. Isler; T. Isogai; B. R. Iyer; K. Izumi; M. Jacobson; H. Jang; P. Jaranowski; S. Jawahar; Y. Ji; F. Jiménez-Forteza; W. W. Johnson; D. I. Jones; R. Jones; R. J. G. Jonker; L. Ju; Haris K; V. Kalogera; S. Kandhasamy; G. Kang; J. B. Kanner; M. Kasprzack; E. Katsavounidis; W. Katzman

    2014-12-18

    We describe directed searches for continuous gravitational waves in data from the sixth 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 ten. 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 credible gravitational-wave signals. We set 95% confidence upper limits as strong (low) as $4\\times10^{-25}$ on intrinsic strain, $2\\times10^{-7}$ on fiducial ellipticity, and $4\\times10^{-5}$ 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.

  20. 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.

  1. 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.

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

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

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

  4. Cosmic Ray Spectrum in Supernova Remnant Shocks

    NASA Astrophysics Data System (ADS)

    Kang, H.

    2011-10-01

    We performed kinetic simulations of diffusive shock acceleration in Type Ia supernova remnants (SNRs) expanding into a uniform interstellar medium (ISM). The preshock gas temperature is the primary parameter that governs the cosmic ray (CR) acceleration, while magnetic field strength and CR injection rate are secondary parameters. SNRs in the hot ISM, with an injection fraction smaller than 10-4, are inefficient accelerators with less than 10 % energy getting converted to CRs. The shock structure is almost test-particle like and the ensuing CR spectrum can be steeper than E-2. Although the particles can be accelerated to the knee energy of 1015.5ZeV with amplified magnetic fields in the precursor, Alfvénic drift of scattering centers softens the source spectrum as steep as E-2.1 and reduces the CR acceleration efficiency.

  5. Studies of Supernova Remnants with VERITAS

    NASA Astrophysics Data System (ADS)

    Humensky, Brian; VERITAS Collaboration

    2010-02-01

    The radio and X-ray synchrotron radiation from supernova remnants (SNRs) and a growing collection of dynamical evidence points to the acceleration of cosmic rays at the strong shocks the. Gamma-ray observations of SNRs provide direct access to information about the population of high-energy particles present in SNRs, and in combination with multi-wavelength observations promise to elucidate the nature of the particles (electrons vs. ions), the efficiency of acceleration, and the properties of the confinement, diffusion, and propagation of high-energy particles. This talk will review VERITAS observations of SNRs, including IC 443 and Cassiopeia A, in light of new results from the Fermi Gamma-ray Space Telescope. This research was supported by grants from the U.S. Department of Energy, the U.S. National Science Foundation and the Smithsonian Institution, by NSERC in Canada, by Science Foundation Ireland and by STFC in the UK.

  6. Cosmic Ray Acceleration in Historical Supernova Remnants in Our Galaxy

    NASA Astrophysics Data System (ADS)

    Sinitsyna, V. G.; Sinitsyna, V. Y.

    2012-08-01

    We present the results of our observations of two types of Galactic supernova remnants with the SHALON mirror Cherenkov telescope: the plerion Crab Nebula, Geminga (probably plerion) and the shell-type supernova remnants Cassiopeia A and Tycho. The experimental data have confirmed the prediction of the theory about the hadronic generation mechanism of very high energy (800 GeV - 100 TeV) ?-rays in Tycho's supernova remnant. The data obtained suggest that the very high energy ?-ray emission in the objects being discussed is different in origin.

  7. Generation of Cosmic rays in Historical Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Sinitsyna, V. G.; Sinitsyna, V. Y.

    2013-06-01

    We present the results of observations of two types of Galactic supernova remnants with the SHALON mirror Cherenkov telescope of Tien-Shan high-mountain Observatory: the shell-type supernova remnants Tycho, Cas A and IC 443; plerions Crab Nebula, 3c58(SN1181) and Geminga (probably plerion). The experimental data have confirmed the prediction of the theory about the hadronic generation mechanism of very high energy (800 GeV - 100 TeV) gamma-rays in Tycho's supernova remnant. The data obtainedsuggest that the very high energy gamma-ray emission in the objects being discussedis different in origin.

  8. Evidence of Bohm Diffusion in Historical Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Allen, G. E.; Stage, M. D.; Houck, J. C.

    2004-12-01

    Some shell-type supernova remnants are reported to emit X-ray synchrotron radiation. The values of the ``cut-off'' frequencies obtained by fitting the X-ray spectra with models of synchrotron emission have been used to estimate the ``maximum'' electron energies and magnetic field strengths of the remnants. We show that the cut-off frequencies and shock velocities can be used to set upper limits on the electron diffusion coefficient of the remnants. The limits for some historical remnants are very close to the Bohm limit. Therefore these remnants are accelerating electrons about as fast as possible. While the remnants cannot accelerate electrons beyond about 100 TeV, they may be capable of accelerating protons to energies of about 1000 TeV (i.e. to energies near the ``knee'' in the cosmic-ray spectrum). These results support the hypothesis that Galactic cosmic rays are predominantly accelerated in the shocks of supernova remnants.

  9. Observations of Supernova Remnants with VERITAS

    NASA Astrophysics Data System (ADS)

    Humensky, Brian; VERITAS Collaboration

    2009-12-01

    Supernova remnants (SNRs) are widely considered to be the strongest candidate for the source of cosmic rays below the knee around 3×1015 eV. In the last few years, TeV gamma-ray observations of SNRs have opened a new window on the high-energy processes occurring in their shock fronts. VERITAS, an array of four gamma-ray telescopes located at the Whipple Observatory in southern Arizona, has an active program of SNR observations. Recent results include a confirmation of TeV gamma-ray emission from Cassiopeia A and the co-discovery (along with MAGIC) of TeV emission from IC 443. In the case of IC 443, the emission appears coincident in space with the site of interaction between the expanding shell of the SNR and a nearby molecular cloud. These results and their implications for the nature of the cosmic rays - hadronic or electronic - accelerated in the remnants will be discussed.

  10. 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.

  11. 44Ti Content of Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Iyudin, Anatoli F.

    2007-08-01

    It is known that radioactive 44Ti is mostly produced in supernovae explosions and is a primary isotope in the radioactive decay chain of 44Ti-44Sc-44Ca. Here we present a critical review of the amount of radioactive 44Ti produced by the core-collapse supernovae (SNe) that have given birth to the Cas A and RX J0852.0-4622/GRO J0852-4642 supernova remnants (SNRs) [1]. The 1.157 MeV line detections by COMPTEL [2,3,4] and the following from those detections the 44Ti mass estimates, derived with the use of the 1.157 MeV line flux, are compared to the mass estimates based on the measurements of Beppo-SAX PDS [5] and IBIS (ISGRI) [6] of the 44Sc line intensities at ~68 and ~78 keV, for Cas A. The non-detection of 44Sc lines from RX J0852.0-4622/GRO J0852-4642 by IBIS (ISGRI) and SPI instruments of INTEGRAL is confronted with the COMPTEL detection of the 44Ti (44Ca) line flux, as well as with the derived by COMPTEL shape of the 1.157 MeV line. Most recent results on the expansion velocity of the high-velocity debris of Cas A SNR [7], and XMM-Newton results on the expansion velocity of RX J0852.0-4622/GRO J0852-4642 [8] are compared to the COMPTEL derived expansion velocities of both SNRs, and are used to evaluate possible consequences of the heavy ions interaction with the ambient and/or SNR shell matter and the contribution of such interactions to the 44Ca line shape and intensity. The X-ray and optical observations that can be, and were used to derive an amount of 44Ti produced in SNRs are described and discussed. Undisputable advantages of using multiwavelength observations to derive 44Ti mass in SNR are confronted with the critical restrictions of the appropriate observations. Difficulties of such measurements for point-like and extended sources are evaluated for each of the potential wavelength range available at present or in future experiments. The derived quantities of 44Ti and of 44Sc are compared with the latest nucleosynthesis theory predictions. The new estimates of the 44Ti masses that were derived with the use of the above analysis for two SNRs, as well as the dynamical properties of remnants are used to constrain SN explosion models [9,10].

  12. 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.

  13. Excited-state OH Masers and Supernova Remnants

    Microsoft Academic Search

    Ylva M. Pihlström; Vincent L. Fish; Loránt O. Sjouwerman; Laura K. Zschaechner; Philip B. Lockett; Moshe Elitzur

    2007-01-01

    The collisionally pumped, ground-state 1720 MHz maser line of OH is widely\\u000arecognized as a tracer for shocked regions and observed in star forming regions\\u000aand supernova remnants. Whereas some lines of excited states of OH have been\\u000adetected and studied in star forming regions, the subject of excited-state OH\\u000ain supernova remnants -- where high collision rates are to

  14. X-ray emission from supernova remnants observed with ROSAT

    Microsoft Academic Search

    B. Aschenbach

    1993-01-01

    Spectrally resolved X-ray images of galactic supernova remnants (SNRs) have been obtained both from the ROSAT all-sky survey and a number of pointed observations. There is substantial evidence for significant spatial variation in temperature, density and pressure across the older, thermal remnants like the Vela SNR, the Cygnus Loop and the North Polar Spur. Both the brightness distribution and the

  15. Shock Destruction of Dust in Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Shull, J.

    2009-07-01

    In this AR-Theory program, we propose to carry out a series of investigations of grain injection, transport, and destruction using hydrodynamical models of reverse-shocked SN ejecta. In a young supernova remnant {SNR} such as Cas A or SN 1987A the outer blast wave strikes surrounding circumstellar matter, and reverse shocks propagate inward toward the interior debris, which may contain large amounts of newly formed dust. Our major theoretical goals are to determine how much dust is destroyed in shocked SNR ejecta, as they are decelerated by the reverse shocks, and to study how these ejecta are lighted up in optical, X-ray, andIR line emission. Numerical codes will be used to study grain destruction in metal-enriched ejecta and to interpret the morphologies, proper motions, and emissivities of these fast-moving ejecta, observed by Hubble in many young SNRs. We intend to undertake the following tasks: {1} Compile the latest gas-grain data {sputtering yields vs projectile energy for H, He, and heavy ions}; {2} Incorporate gas-grain and grain-grain interactions with radiative cooling rates {X-ray, optical, IR line emission} of sputtered atoms and ions; {3} Compute adaptive-mesh hydrodynamical models of ejecta-shock interactions; {4} Use these ejecta models to compute grain destruction, grain heating, plasma cooling, and spectral diagnostics in metal-enriched environments; {5} Apply our results to specific SNRs {Cas A, SN 1987A, G292, etc} to interpret ejecta morphologies, proper motions, and emissivities; {6} assess the net efficiency of supernova dust injection.

  16. XMM-NEWTON OBSERVATIONS OF TWO CANDIDATE SUPERNOVA REMNANTS

    SciTech Connect

    Kargaltsev, O. [Department of Astronomy, University of Florida, Gainesville, FL 32611-2055 (United States); Schmitt, B. M.; Pavlov, G. G. [Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Lab., University Park, PA 16802 (United States); Misanovic, Z. [School of Physics, Monash University, Melbourne, 3800 VIC (Australia)

    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.

  17. 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.

  18. Cosmic Ray Spectrum in Supernova Remnant Shocks

    NASA Astrophysics Data System (ADS)

    Kang, Hyesung

    According to kinetic simulations of diffusive shock acceleration (DSA) in Type Ia supernova remnants (SNRs) expanding into a uniform interstellar medium (ISM), the preshock gas tem-perature is the primary parameter that governs the cosmic ray (CR) acceleration efficiency and energy spectrum, while the CR injection rate is a secondary parameter. For SNRs in the warm ISM, if the injection fraction is larger than 10-4 , the DSA is efficient enough to convert more than 20 % of the SN explosion energy into CRs and the accelerated CR spectrum exhibits a concave curvature flattening to E -1.6 . Such a flat source spectrum near the knee energy, how-ever, may not be reconciled with the CR spectrum observed at Earth. On the other hand, SNRs in the hot ISM, with an injection fraction smaller than 10-4 , are inefficient accelerators with less than 10 energy getting converted to CRs. Also the shock structure is almost test-particle like and the ensuing CR spectrum can be steeper than E -2 . With amplified magnetic field strength of order of 30microG, Alfven waves generated by the streaming instability may drift upstream fast enough to make the modified test-particle power-law as steep as E -2.3 , which is more consistent with the observed CR spectrum.

  19. MODIFIED EQUIPARTITION CALCULATION FOR SUPERNOVA REMNANTS

    SciTech Connect

    Arbutina, B.; Urosevic, D.; Andjelic, M. M.; Pavlovic, M. Z. [Department of Astronomy, Faculty of Mathematics, University of Belgrade, Studentski trg 16, 11000 Belgrade (Serbia); Vukotic, B., E-mail: arbo@math.rs [Astronomical Observatory, Volgina 7, 11060 Belgrade (Serbia)

    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. The Crab nebula and other historical supernova remnants

    NASA Astrophysics Data System (ADS)

    Trimble, V.; Clark, D. H.

    1985-06-01

    Historical records are investigated to obtain information on historical supernovae. Chinese astronomical records provide the most useful data on solar system events. The reliability and completeness of the Chinese records are evaluated; examples of events recorded and substantiated are given. A historical review of the observations of the Crab nebula, the first historical supernova to be identified, is presented. Detected Crab-like supernova remnants and the properties and cause of its luminous jet are studied.

  1. Multicycle Monitoring of the Young Galactic Supernova Remnant Cassiopeia A

    NASA Astrophysics Data System (ADS)

    Patnaude, Daniel

    2012-09-01

    Cas A is one of only a handful of young supernova remnants to exhibit time variations in thermal and nonthermal emission, and is the only remnant to show direct evidence for an evolving, young central neutron star. Here we propose for three 50 ksec observations of Cas A spaced by approximately one year, which are designed to (1): probe the structure and composition of supernova ejecta by following its evolution as it is heated by the reverse shock, (2): test theories of particle acceleration at supernova shocks, and (3): monitor the surface temperature evolution of the neutron star to test theories of nuclear and condensed matter physics, and in particular superfluidity and superconductivity.

  2. The Properties of the Progenitor Supernova and Central Neutron Star in Pulsar Wind Nebula PWN G54.1+0.3

    NASA Astrophysics Data System (ADS)

    Gelfand, Joseph; Slane, P. O.

    2011-01-01

    By comparing the predicts of a semi-analytic model for the evolution of a pulsar wind nebula inside a supernova remnant with the observed dynamical and radiative properties of PWN G54.1+0.3 we are able to constrain the properties of the progenitor supernova and the birth properties of the central neutron star. This has significant implications for both the progenitor star of this system and the magnetosphere of this pulsar.

  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 H? + [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 ?m and 22 ?m 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] ?? 6716/6731 ratio indicates that the electron densities are below 240 cm-3, while the H? 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. The prevalence of supernova remnants among unidentified Galactic radio sources

    NASA Technical Reports Server (NTRS)

    Helfand, David J.; Velusamy, T.; Becker, R. H.; Lockman, Felix J.

    1989-01-01

    Nine Galactic radio sources were mapped to identify new Crab-like and composite supernova remnants. The sources were selected on the basis of existing stringent upper limits on their hydrogen recombination line fluxes. One new Cracb-like remnant, one new composite remnant, at least one, and probably two, new shell-like remnants, and a compact H II region were found, along with the expected collection of extragalactic objects. The results suggest that there are several hundred SNRs in the Galaxy which are detectable with current instruments, but which have yet to be identified.

  5. The prevalence of supernova remnants among unidentified Galactic radio sources

    SciTech Connect

    Helfand, D.J.; Velusamy, T.; Becker, R.H.; Lockman, F.J. (Columbia Univ., New York, NY (USA); Tata Institute for Fundamental Research, Bombay (India); California Univ., Davis (USA); Lawrence Livermore National Lab., CA (USA); National Radio Astronomy Observatory, Charlottesville, VA (USA))

    1989-06-01

    Nine Galactic radio sources were mapped to identify new Crab-like and composite supernova remnants. The sources were selected on the basis of existing stringent upper limits on their hydrogen recombination line fluxes. One new Cracb-like remnant, one new composite remnant, at least one, and probably two, new shell-like remnants, and a compact H II region were found, along with the expected collection of extragalactic objects. The results suggest that there are several hundred SNRs in the Galaxy which are detectable with current instruments, but which have yet to be identified. 15 refs.

  6. High-Energy Emission From the Composite Supernova Remnant MSH 15-56

    NASA Astrophysics Data System (ADS)

    Temim, Tea; Slane, P.; Plucinsky, P.; Gelfand, J.; Castro, D.

    2012-05-01

    Composite supernova remnants (SNRs) are those consisting of a central pulsar that produces a wind of synchrotron-emitting relativistic particles, and a supernova (SN) blast wave that expands into the surrounding interstellar medium (ISM). At the late stages of a composite SNR's evolution, the SN reverse shock crushes the pulsar wind nebula (PWN), resulting in complex filamentary structures and mixing of the PWN material with ejecta gas. This interaction is even more complex in cases where the PWN is displaced from the SNR center, either due to the pulsar's motion or an asymmetric reverse shock resulting from a density gradient in the ambient ISM. The composite nature of the SNR MSH 15-56 is clearly seen in the radio observations that show an SNR shell with a displaced PWN. We present an updated analysis of the XMM-Newton and Chandra X-ray observations of this remnant that reveals complex structures indicative of a disrupted PWN and provides evidence for mixing of the SN ejecta with PWN material following a reverse shock interaction. The increase in the magnetic field due to such an interaction produces an excess of low energy particles and may give rise to gamma-ray emission through inverse Compton scattering. Indeed, a gamma-ray source recently detected by Fermi appears to spatially coincide with the SNR, and may originate from the PWN. We discuss the SNR parameters derived from the X-ray observations and the possible origin of the high-energy gamma-ray emission.

  7. Investigating Molecular Shocks in Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Hewitt, John W.

    2009-01-01

    Maser emission from the 1720-MHz transition of hydroxyl(OH) has identified shock interactions in 10% of all supernova remnants(SNRs). Such maser-emitting SNRs are also bright in molecular line emission. Though somewhat rare, SNRs interacting with dense molecular clouds are an important class in which to study cosmic ray acceleration, SNR evolution, and effects on the energetics and chemistry of the interstellar medium. We have investigate such molecular shocks in the following ways: (i) With the GBT we observe widespread OH(1720 MHz) emission and absorption in other OH lines across the interaction site. Observations of all four ground-state transitions at 1720, 1667/5 and 1612 MHz allows us to model OH excitation, yielding the temperature, density and OH abundance in the post-shock gas. Maser emission is found to be significantly brighter with the GBT than with high-resolution VLA observations for 10 of 15 observed remnants. (ii) Sensitive VLA observations of select SNRs (W44, IC443, Kes69, 3C391, G357.7+0.3) reveal the nature of enhanced 1720 MHz emission. Numerous weak compact masers as well as diffuse extended emission are detected tracing the shock-front. Zeeman splitting of masers located across the shock interaction permits mapping of the post-shock magnetic field. (iii) Rotational lines of molecular hydrogen are detected at the position of several masers with Spitzer IRS spectroscopy between 5 and 35 microns. We find excitation of the S(0)-S(7) lines requires the passage of a C-type shock through dense molecular gas, in good agreement with the physical conditions derived from OH excitation. (iv) A new survey for SNR-masers has identified four new interacting SNRs within 10 degrees of the Galactic Center. We find Maser-emitting SNRs are preferentially distributed in the inner Galaxy. Two of the new SNRs are coincident with TeV gamma-ray sources. Nine maser-emitting SNRs are now identified with a gamma-ray association indicating possible cosmic-ray acceleration.

  8. Thermal Radiation of Supernova Remnants in Radio Domain

    NASA Astrophysics Data System (ADS)

    Onic, Dusan

    The evolution of supernova remnants is linked to the propagation of a collisionless shock wave, formed during the initial expansion of high-velocity supernova ejecta through the interstellar environment. Theoretical studies of shock waves are very important for the analysis of supernova remnants, as well as processes in the interstellar medium in general. In this doctoral dissertation, some theoretical results based on the magnetohydrodynamical theory of shock waves are presented, with special emphasis on ideal radiative magnetohydrodynamics for the optically thick case. Particularly, solutions for the case when jump in adiabatic index and/or ratio of gas to total pressure is allowed, are discussed. The main hypothesis of this dissertation is that thermal bremsstrahlung radiation at radio continuum frequencies can provide a significant contribution in the case of several Galactic supernova remnants. This hypothesis can give a natural explanation for nearly concave up radio continuum spectra of several Galactic supernova remnants that are expanding in the environment with higher than average density. In this context, it is important to identify the existence of the possible indicators of ensemble of thermal electrons at sufficiently low temperatures and sufficiently high densities so that the thermal bremsstrahlung radiation linked to a particular remnant could be observed at radio continuum frequencies (vicinity, interaction or expansion through the molecular cloud, presence of the cooled thermal X-ray electrons during the post Sedov-Taylor phases, detection of low-frequency turnovers associated with thermal absorption linked to the remnant, detection in Halpha, identification of radio recombination lines linked to the remnant, etc). The significant presence of thermal component could theoretically explain radio-spectral indices less than 0.5 measured for several evolutionary older supernova remnants, (mainly of mixed-morphology class) that expand in the high density region. Actually, these smaller radio-spectral indices, under the assumption of simple power law, would represent a natural manifestation of a significant fraction of thermal emission at radio continuum frequencies. However, present knowledge of the radio continuum spectra of Galactic supernova remnants is still not determined precisely enough for any definite conclusions to be made about the inherent thermal radio-emission from supernova remnants. A thorough analysis is only possible in the case of three Galactic supernova remnants (3C396, IC443, 3C391) for which the thermal contribution is determined despite high associated uncertainties. New observations in the near future will lay the groundwork for making firmer conclusions about the existence of the so-called radio thermally active supernova remnants. This dissertation highlights the importance of observations of supernova remnants in X and gamma-rays, and multiwavelength analysis is general. Besides, it suggests a possible detection of gamma-rays from supernova remnant 3C434.1 based on the observations made by Fermi.

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

    SciTech Connect

    Slane, Patrick; Castro, Daniel; Foight, Dillon, E-mail: slane@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138-1516 (United States); 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.

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

    NASA Astrophysics Data System (ADS)

    Slane, Patrick O.; Hughes, J. P.; Temim, T.; Rousseau, R.; Castro, D.; Foight, D.; Gaensler, B. M.; Funk, S.; Lemoine-Goumard, M.; Gelfand, J. D.; Moffett, D. A.; Dodson, R. G.; Bernstein, J. P.

    2012-05-01

    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 (ATCA). 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 LAT, 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.

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

    NASA Astrophysics Data System (ADS)

    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.; Dodson, Richard G.; Bernstein, Joseph P.

    2012-04-01

    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 ?-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 ?-ray emission.

  12. Cosmic Ray Spectrum in Supernova Remnant Shocks

    NASA Astrophysics Data System (ADS)

    Kang, Hyesung

    2010-04-01

    We perform kinetic simulations of diffusive shock acceleration (DSA) in Type Ia supernova remnants (SNRs) expanding into a uniform interstellar medium (ISM). Bohm-like diffusion due to self-excited Alfvén waves is assumed,and simple models for Alfvénic drift and dissipation are adopted. Phenomenological models for thermal leakage injection are considered as well. We find that the preshock gas temperature is the primary parameter that governs the cosmic ray (CR) acceleration efficiency and energy spectrum,while the CR injection rate is a secondary parameter. For SNRs in the warm ISM of T_0 ? 10^5K, if the injection fraction is ? ? 10^{-4},the DSA is efficient enough to convert more than 20 % of the SN explosion energy into CRs and the accelerated CR spectrum exhibits a concave curvature flattening to E^{-1.6}, which is characteristic of CR modified shocks. Such a flat source spectrum near the knee energy, however, may not be reconciled with the CR spectrum observed at Earth.On the other hand, SNRs in the hot ISM of T_0? 10^6K with a small injection fraction, ? < 10^{-4}, are inefficient accelerators with less than 10 % of the explosion energy getting converted to CRs. Also the shock structure is almost test-particle like and the ensuing CR spectrum can be steeper than E^{-2}. With amplified magnetic field strength of order of 30?G, Alfvén waves generated by the streaming instability may drift upstream fast enough to make the modified test-particle power-law as steep as E^{-2.3}, which is more consistent with the observed CR spectrum.

  13. RXTE Observation of the Tycho Supernova Remnant

    NASA Technical Reports Server (NTRS)

    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 10(exp 5) 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.

  14. Far-Ultraviolet Cooling Features of the Antlia Supernova Remnant

    E-print Network

    Jong-Ho Shinn; Kyoung Wook Min; Ravi Sankrit; Kwang-Sun Ryu; Il-Joong Kim; Wonyong Han; Uk-Won Nam; Jang-Hyun Park; Jerry Edelstein; Eric J. Korpela

    2007-10-09

    We present far-ultraviolet observations of the Antlia supernova remnant obtained with Far-ultraviolet IMaging Spectrograph (FIMS, also called SPEAR). The strongest lines observed are C IV 1548,1551 and C III 977. The C IV emission of this mixed-morphology supernova remnant shows a clumpy distribution, and the line intensity is nearly constant with radius. The C III 977 line, though too weak to be mapped over the whole remnant, is shown to vary radially. The line intensity peaks at about half the radius, and drops at the edge of the remnant. Both the clumpy distribution of C IV and the rise in the C IV to C III ratio towards the edge suggest that central emission is from evaporating cloudlets rather than thermal conduction in a more uniform, dense medium.

  15. Supernova Remnants as the Sources of Galactic Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Vink, J.

    2013-01-01

    The origin of cosmic rays holds still many mysteries hundred years after they were first discovered. Supernova remnants have for long been the most likely sources of Galactic cosmic rays. I discuss here some recent evidence that suggests that supernova remnants can indeed efficiently accelerate cosmic rays. For this conference devoted to the Astronomical Institute Utrecht I put the emphasis on work that was done in my group, but placed in a broader context: efficient cosmic-ray acceleration and the implications for cosmic-ray escape, synchrotron radiation and the evidence for magnetic-field amplification, potential X-ray synchrotron emission from cosmic-ray precursors, and I conclude with the implications of cosmic-ray escape for a Type Ia remnant like Tycho and a core-collapse remnant like Cas A.

  16. An X-Ray Study of Composite Supernova Remnants

    Microsoft Academic Search

    Jeonghee Rho

    1995-01-01

    Composite supernova remnants (SNRs) appear center -filled in X-rays and have a shell-like radio morphology. I have used ROSAT and ASCA data to study a sample of ~20 composite SNR, six of these in detail, to understand the origin of centrally enhanced X-ray emission. Seven of the sample remnants (W44, W28, 3C400.2 Kes 27, MSH 11 -61A, 3C391, and CTB

  17. GSH 90-28-17: a possible old supernova remnant

    NASA Astrophysics Data System (ADS)

    Xiao, L.; Zhu, M.

    2014-02-01

    GSH 90-28-17 is a high-latitude Galactic H I supershell, identified in the H I supershell catalogues with a velocity vlsr ˜ -17 km s-1. We used the new Galactic Arecibo L-band Feed Array (GALFA) H I survey data, which have much higher resolution and sensitivity than was previously available, to re-examine the properties of the supershell. We derived a new distance of 400 pc for GSH 90-28-17 and suggested that it is related to the Lac OB1 association. The radius of GSH 90-28-17 is 66.0 ± 3.5 pc. The H I mass of the shell is (3.1 ± 0.1) × 104 M?. It has an age of ˜4.5 Myr and a total kinetic energy of (8.2 ± 0.3) × 1048 erg. We extracted radio continuum data for the GSH 90-28-17 region from the 408-MHz All-Sky Survey and Bonn 1420-MHz survey and filtered the diffuse background Galactic emission. A radio loop-like ridge is found to be associated with the H I shell at both frequencies and shows a non-thermal origin, with a temperature-temperature (TT)-plot index of ? = -1.35 ± 0.69. In addition, the pulsar J2307+2225, with a similar distance, is found in the shell region. We conclude that GSH 90-28-17 is probably an old, type II supernova remnant in the solar neighbourhood.

  18. Asymmetric supernova remnants generated by Galactic, massive runaway stars

    NASA Astrophysics Data System (ADS)

    Meyer, D. M.-A.; Langer, N.; Mackey, J.; Velázquez, P. F.; Gusdorf, A.

    2015-07-01

    After the death of a runaway massive star, its supernova shock wave interacts with the bow shocks produced by its defunct progenitor, and may lose energy, momentum and its spherical symmetry before expanding into the local interstellar medium (ISM). We investigate whether the initial mass and space velocity of these progenitors can be associated with asymmetric supernova remnants. We run hydrodynamical models of supernovae exploding in the pre-shaped medium of moving Galactic core-collapse progenitors. We find that bow shocks that accumulate more than about 1.5 M? generate asymmetric remnants. The shock wave first collides with these bow shocks 160-750 yr after the supernova, and the collision lasts until 830-4900 yr. The shock wave is then located 1.35-5 pc from the centre of the explosion, and it expands freely into the ISM, whereas in the opposite direction it is channelled into the region of undisturbed wind material. This applies to an initially 20 M? progenitor moving with velocity 20 km s-1 and to our initially 40 M? progenitor. These remnants generate mixing of ISM gas, stellar wind and supernova ejecta that is particularly important upstream from the centre of the explosion. Their light curves are dominated by emission from optically thin cooling and by X-ray emission of the shocked ISM gas. We find that these remnants are likely to be observed in the [O III] ? 5007 spectral line emission or in the soft energy-band of X-rays. Finally, we discuss our results in the context of observed Galactic supernova remnants such as 3C 391 and the Cygnus Loop.

  19. Spitzer Spectral Mapping of Supernova Remnant Cassiopeia a

    Microsoft Academic Search

    J. D. T. Smith; Lawrence Rudnick; Tracey Delaney; Jeonghee Rho; Haley Gomez; Takashi Kozasa; William Reach; Karl Isensee

    2009-01-01

    We present the global distribution of fine-structure infrared line emission in the Cassiopeia A supernova remnant using data from the Spitzer Space Telescope's infrared spectrograph. We identify emission from ejecta materials in the interior, prior to their encounter with the reverse shock, as well as from the postshock bright ring. The global electron density increases by gsim 100 at the

  20. Limits on Enhanced Radio Wave Scattering by Supernova Remnants

    E-print Network

    Laura G. Spitler; Steven R. Spangler

    2005-06-28

    We report multifrequency observations with the NRAO Very Long Baseline Array (VLBA) of the compact radio sources J0128+6306 and J0547+2721, which are viewed through the supernova remnants G127.1+0.5 and S147, respectively. Observations were made at frequencies of 1.427, 1.667, 2.271, and 4.987 GHz. The lines of sight to these sources pass through the shock wave and upstream and downstream turbulent layers of their respective supernova remnants, and thus might detect cosmic-ray generated turbulence produced during the Fermi acceleration process. For both sources, we detect interstellar scattering, characterized by a component of the angular size which scales as the square of the observing wavelength. The magnitude of the scattering is characterized by an effective scattering angular size theta_S0 at a frequency of 1 GHz of 13.2 +/- 2.6 milliarcseconds (mas) for J0128+6306 and 6.7 +/- 2.2 mas for J0547+2721. These angular sizes are consistent with the ``incidental'' scattering for any line of sight out of the galaxy at similar galactic latitudes and longitudes. There is therefore no evidence for enhanced turbulence at these supernova remnants. We establish upper limits to the supernova remnant-associated scattering measures of 8.1-14.8 m^-20/3-pc for J0128+6306 and 3.0 m^-20/3-pc for J0547+2721.

  1. On the origin of two-shell supernova remnants

    E-print Network

    V. V. Gvaramadze

    2007-12-27

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

  2. TWO NEW XRAY/OPTICAL / RADIO SUPERNOVA REMNANTS M31

    E-print Network

    Sjouwerman, Loránt

    region. precisely registered images reveal optical shells with X­ray counterparts. These shells have: individual ( supernova remnants techniques: image processing INTRODUCTION spatial resolution Chandra X­Ray date back Rubin (1972), X­ray surveys to van Speybroeck (1979). Without digital imaging allow

  3. Excited-state OH Masers and Supernova Remnants

    E-print Network

    Pihlström, Ylva M; Sjouwerman, Loránt O; Zschaechner, Laura K; Lockett, Philip B; Elitzur, Moshe

    2008-01-01

    The collisionally pumped, ground-state 1720 MHz maser line of OH is widely recognized as a tracer for shocked regions and observed in star forming regions and supernova remnants. Whereas some lines of excited states of OH have been detected and studied in star forming regions, the subject of excited-state OH in supernova remnants -- where high collision rates are to be expected -- is only recently being addressed. Modeling of collisional excitation of OH demonstrates that 1720, 4765 and 6049 MHz masers can occur under similar conditions in regions of shocked gas. In particular, the 6049 and 4765 MHz masers become more significant at increased OH column densities where the 1720 MHz masers begin to be quenched. In supernova remnants, the detection of excited-state OH line maser emission could therefore serve as a probe of regions of higher column densities. Using the Very Large Array, we searched for excited-state OH in the 4.7, 7.8, 8.2 and 23.8 GHz lines in four well studied supernova remnants with strong 172...

  4. Star Formation Associated with the Supernova Remnant IC443

    Microsoft Academic Search

    Jin-Long Xu; Jun-Jie Wang; Martin Miller

    2011-01-01

    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

  5. The molecular gas in the supernova remnant IC443

    Microsoft Academic Search

    Y. L. Huang; R. L. Dickman; R. L. Snell

    1986-01-01

    Although a few highly perturbed regions characterized by gas motions with velocities larger than 20 km\\/s have been discovered during the last several years in the supernova remnant (SNR) IC 443, the nature of these perturbed clumps and their relationship to the quiescent molecular gas near the SNR remains unknown. In part, this is due to a lack of large-scale,

  6. Supernova Remnants as Cosmic X-Ray Sources. Tycho SNR

    Microsoft Academic Search

    B. Hnatyk; O. Petruk

    1998-01-01

    Basic steps in history of X-ray astronomy and models of the one of the brightest cosmic X-ray sources, supernova remnants (SNRs), are described. The model of evolution of the SNR Tycho which takes into account the nonuniform ambient medium is presented for the first time. Characteristics of the SNR are found: energy of supenova explosion E = 1050 erg, ambient

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

    NASA Technical Reports Server (NTRS)

    Smith, B. W.

    1976-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Temim, Tea; Slane, Patrick; Castro, Daniel; Plucinsky, Paul P.; 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 ?-ray emission detected by Fermi shows that the emission may originate from the reverse shock-crushed PWN.

  9. Extended OH(1720 MHz) Maser Emission from Supernova Remnants

    E-print Network

    J. W. Hewitt; F. Yusef-Zadeh; M. Wardle; D. A. Roberts

    2007-05-21

    Compact OH(1720 MHz) masers have proven to be excellent signposts for the interaction of supernova remnants with adjacent molecular clouds. Less appreciated has been the weak, extended OH(1720 MHz) emission which accompanies strong compact maser sources. Recent single-dish and interferometric observations reveal the majority of maser-emitting supernova remnants have accompanying regions of extended maser emission. Enhanced OH abundance created by the passing shock is observed both as maser emission and absorption against the strong background of the remnant. Modeling the observed OH profiles gives an estimate of the physical conditions in which weak, extended maser emission arises. I will discuss how we can realize the utility of this extended maser emission, particularly the potential to measure the strength of the post-shock magnetic field via Zeeman splitting over these large-scales.

  10. OH (1720 MHz) Masers and Mixed-Morphology Supernova Remnants

    E-print Network

    Yusef-Zadeh, F; Rho, J; Sakano, M

    2003-01-01

    Radio surveys of supernova remnants (SNRs) in the Galaxy have uncovered 19 SNRs accompanied by OH maser emission at 1720 MHz. This unusual class of maser sources is suggested to be produced behind a shock front from the expansion of a supernova remnant running into a molecular cloud. An important ingredient of this model is that X-ray emission from the remnant enhances the production of OH molecule. The role of X-ray emission from maser emitting (ME) SNRs is investigated by comparing the X-ray induced ionization rate with theory. One aspect of this model is verified: there is a strong association between maser emitting and mixed-morphology (MM) or thermal composite SNRs --center-filled thermal X-ray emission surrounded by shell-like radio morphology. We also present ROSAT and ASCA observations of two maser emitting SNRs: G21.8--0.6 (Kes 69) and G357.7--0.1 (Tornado).

  11. Excited-State OH Masers and Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Pihlström, Ylva M.; Fish, Vincent L.; Sjouwerman, Loránt O.; Zschaechner, Laura K.; Lockett, Philip B.; Elitzur, Moshe

    2008-03-01

    The collisionally pumped, ground-state 1720 MHz maser line of OH is widely recognized as a tracer for shocked regions and observed in star-forming regions and supernova remnants. Whereas some lines of excited states of OH have been detected and studied in star-forming regions, the subject of excited-state OH in supernova remnants-where high collision rates are to be expected-is only recently being addressed. Modeling of collisional excitation of OH demonstrates that 1720, 4765, and 6049 MHz masers can occur under similar conditions in regions of shocked gas. In particular, the 6049 and 4765 MHz masers become more significant at increased OH column densities where the 1720 MHz masers begin to be quenched. In supernova remnants, the detection of excited-state OH line maser emission could therefore serve as a probe of regions of higher column densities. Using the Very Large Array, we searched for excited-state OH in the 4.7, 7.8, 8.2, and 23.8 GHz lines in four well-studied supernova remnants with strong 1720 MHz maser emission (Sgr A East, W28, W44 and IC 443). No detections were made, at typical detection limits of around 10 mJy beam-1. The search for the 6 GHz lines were done using Effelsberg since the VLA receivers did not cover those frequencies, and are reported on in an accompanying letter (Fish and coworkers). We also cross-correlated the positions of known supernova remnants with the positions of 1612 MHz maser emission obtained from blind surveys. No probable associations were found, perhaps except in the Sgr A East region. The lack of detections of excited-state OH indicates that the OH column densities suffice for 1720 MHz inversion but not for inversion of excited-state transitions, consistent with the expected results for C-type shocks.

  12. Excited-state OH Masers and Supernova Remnants

    E-print Network

    Ylva M. Pihlström; Vincent L. Fish; Loránt O. Sjouwerman; Laura K. Zschaechner; Philip B. Lockett; Moshe Elitzur

    2007-12-29

    The collisionally pumped, ground-state 1720 MHz maser line of OH is widely recognized as a tracer for shocked regions and observed in star forming regions and supernova remnants. Whereas some lines of excited states of OH have been detected and studied in star forming regions, the subject of excited-state OH in supernova remnants -- where high collision rates are to be expected -- is only recently being addressed. Modeling of collisional excitation of OH demonstrates that 1720, 4765 and 6049 MHz masers can occur under similar conditions in regions of shocked gas. In particular, the 6049 and 4765 MHz masers become more significant at increased OH column densities where the 1720 MHz masers begin to be quenched. In supernova remnants, the detection of excited-state OH line maser emission could therefore serve as a probe of regions of higher column densities. Using the Very Large Array, we searched for excited-state OH in the 4.7, 7.8, 8.2 and 23.8 GHz lines in four well studied supernova remnants with strong 1720 MHz maser emission (SgrAEast, W28, W44 and IC443). No detections were made, at typical detection limits of around 10 mJy/beam. The search for the 6 GHz lines were done using Effelsberg since the VLA receivers did not cover those frequencies, and are reported on in an accompanying letter (Fish, Sjouwerman & Pihlstrom 2007). We also cross-correlated the positions of known supernova remnants with the positions of 1612 MHz maser emission obtained from blind surveys. No probable associations were found, perhaps except in the SgrAEast region. The lack of detections of excited-state OH indicates that the OH column densities suffice for 1720 MHz inversion but not for inversion of excited-state transitions, consistent with the expected results for C-type shocks.

  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. The Formation and Evolution of Mixed Morphology Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Smith, Randall

    Supernovae inject metals at high velocities into the interstellar medium (ISM), leading to shocks, plasma heating, and dust destruction and creation in addition to host of other processes. Supernova remnants (SNR) themselves are generally categorized as shell-type, center-filled, or ``mixed morphology.'' These categories, which encapsulate both the structure and evolution of the remnant, seem to depend critically on the precursor star and the surrounding ISM. Mixed morphology remnants, in particular, show a radio shell with a central region that emits primarily thermal X-rays. Observations show that these SNR are typically found near or in molecular clouds and, since they usually contain compact objects, arise from high-mass precursors. However, our theoretical understanding of these remnants lags far behind our observational data. There are at least four distinct models for their appearance, usually explaining observations from one or at most a few of the remnants, but there is no general solution. However, there has been a recent breakthrough in mixed morphology remnants. Suzaku observations of three remnants show that a significant fraction of the thermal X-rays are from a non-equilibrium recombining plasma, a surprising result since SNR are expected to generate ionizing, not recombining, plasmas. This new discovery should severely constrains theoretical predictions. We propose a combined semi-analytic and computational approach to understanding how these remnants develop and evolve. A number of observational studies have already cataloged the emission characteristics and sizes of these remnants. Our study will therefore begin with an exploration of simple 1-D spherically symmetric hydrodynamic plasma models that can generate the observed emission in X-ray and other bandpasses as well as the approximate size of a range of mixed morphology remnants. We will expand these studies using both 2-D and 3-D magnetohydrodynamic explosion models combined with a non-equilibrium plasma code to calculate the thermal X-ray emission. These models will be able to capture the turbulence and ejecta mixing that must happen in these remnants that cannot be simulated in 1-D. We will then determine the emission as a function of position in various bandpasses for our models with a range of initial conditions. This will allow us to determining which observables are the key to understanding the origin and evolution of mixed morphology remnants, and their overall impact on the ISM and the Galaxy. This work will address NASA's Strategic Subgoal 3D, to discover the origin, structure, evolution, and destiny of the universe, and search for Earth-like planets.

  15. 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.

  16. 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.

  17. 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.

  18. Lithium isotope ratios near the supernova remnant IC 443

    NASA Astrophysics Data System (ADS)

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

    The rapid rise in the 7Li abundance for stars of near solar metallicity requires the existence of one or more stellar sources of 7Li. Likely candidates include red giant and asymptotic giant branch stars, which produce 7Li via the Cameron-Fowler mechanism, and Type II supernovae, in which 7Li is synthesized by neutrino-induced spallation. Direct evidence of the neutrino-process remains elusive, yet could be provided by detailed studies of Li isotope ratios in interstellar gas surrounding supernova remnants. Here, we present the results of the first such investigation, based on high-resolution measurements of Li I along four lines of sight through the supernova remnant IC 443. While our observations probe material presumably contaminated by the ejecta of a core-collapse supernova, we find no evidence of 7Li synthesis by neutrino-induced spallation. Rather, our results indicate that the abundance of 6Li relative to 7Li has been enhanced by interactions between shock-accelerated cosmic rays and the molecular cloud surrounding the remnant. Future observations will help to establish unequivocally the role that neutrino spallation plays in 7Li production.

  19. Analysis of Shock Interactions and Supernova Morphology from Molecular Emission Around Young Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Kilpatrick, Charles; Bieging, J. H.; Rieke, G.

    2014-01-01

    We have observed the supernova remnant Cassiopeia A (Cas A) in the mid-infrared from 10-40 microns with the Spitzer Space Telescope and at millimeter wavelengths in 12CO and 13CO J=2-1 (230 and 220 GHz) with the Heinrich Hertz Submillimeter Telescope (HHSMT). Broadened (6 - 10 km/s) CO emission in the millimeter indicates that some molecular clouds towards the line of sight of the Cas A shock front have been shock broadened by ejecta from the remnant. The IR spectra demonstrate high-velocity emission along the northern shock front of the remnant coincident with bright radio continuum emission. These features trace a direct interaction with the Cas A shock front. Furthermore, some of the broadened molecular emission extends 1 - 2 arcminutes beyond the furthest extent of the SNR shock front. We infer from the proximity to the remnant as well as the positions of broadened CO emission that this material is accelerated by ejecta with velocity significantly larger than the observed free-expansion velocity of the Cas A shock front. This observation is consistent with a bipolar outflow as well as fast-moving ejecta pistons inferred in the Cas A remnant, in particular along the southwest to northeast axis of the remnant. We extend this type of analysis to other young, galactic supernova remnants in order to place constraints on the morphology and shock interactions during supernova events.

  20. Decapitating the Duck The (non)association of PSR B1757-24 and supernova remnant G5.4-1.2

    E-print Network

    Thorsett, S E; Goss, W M

    2002-01-01

    We have made the first direct interferometric proper motion measurements of the radio pulsar B1757-24, which sits at the tip of the "beak" of the putative "Duck" supernova remnant. The peculiar morphology of this radio complex has been used to argue alternately that the pulsar's space motion was either surprisingly high or surprisingly low. In fact, we show that the pulsar's motion is so small that it and its associated nonthermal nebula G5.27-0.9 (the "head") are almost certainly unrelated to the much larger G5.4-1.2 (the "wings").

  1. Decapitating the Duck: The (non)association of PSR B1757-24 and supernova remnant G5.4-1.2

    E-print Network

    S. E. Thorsett; W. F. Brisken; W. M. Goss

    2002-06-03

    We have made the first direct interferometric proper motion measurements of the radio pulsar B1757-24, which sits at the tip of the "beak" of the putative "Duck" supernova remnant. The peculiar morphology of this radio complex has been used to argue alternately that the pulsar's space motion was either surprisingly high or surprisingly low. In fact, we show that the pulsar's motion is so small that it and its associated nonthermal nebula G5.27-0.9 (the "head") are almost certainly unrelated to the much larger G5.4-1.2 (the "wings").

  2. FIRST VLBI DETECTION OF THE RADIO REMNANT OF SUPERNOVA 1987A: EVIDENCE FOR SMALL-SCALE FEATURES

    SciTech Connect

    Ng, C.-Y. [Department of Physics, McGill University, Montreal, QC H3A 2T8 (Canada); Potter, T. M.; Staveley-Smith, L.; Zanardo, G. [International Centre for Radio Astronomy Research (ICRAR), University of Western Australia, Crawley, WA 6009 (Australia); Tingay, S. [ICRAR, Curtin University, Bentley, WA 6102 (Australia); Gaensler, B. M. [Sydney Institute for Astronomy, School of Physics, University of Sydney, NSW 2006 (Australia); Phillips, C.; Tzioumis, A. K., E-mail: ncy@hep.physics.mcgill.ca [Australia Telescope National Facility, CSIRO, Marsfield, NSW 1710 (Australia)

    2011-02-10

    We present a detailed analysis of the first very long baseline interferometry (VLBI) detection of the radio remnant of supernova 1987A. The VLBI data taken in 2007 and 2008 at 1.4 and 1.7 GHz, respectively, provide images sensitive to angular scales from 0.''1 to 0.''7, the highest resolution to date at radio frequencies. The results reveal two extended lobes with an overall morphology consistent with observations at lower resolutions. We find evidence of small-scale features in the radio shell, which possibly consist of compact clumps near the inner surface of the shell. These features have angular extent smaller than 0.''2 and contribute less than 13% of the total remnant flux density. No central source is detected in the VLBI images. We place a 3{sigma} flux density limit of 0.3 mJy on any pulsar or pulsar wind nebula at 1.7 GHz.

  3. Chandra observations of Tycho’s supernova remnant

    Microsoft Academic Search

    U. Hwang; R. Petre; A. E. Szymkowiak; S. S. Holt

    2002-01-01

    We present a newChandra observation of Tycho’s supernova remnant with the Advanced CCD Imaging Spectrometer. Multicolor Xray imaging reveals new\\u000a details of the outer shock and ejecta. At energies between 4 and 6 keV, the outline of the outer shock is clearly revealed\\u000a in X-rays for the first time. The distribution of the emission from lines of Si and Fe

  4. The X-Ray Spectrum of Supernova Remnant 1987A

    Microsoft Academic Search

    Eli Michael; Svetozar Zhekov; Richard McCray; Una Hwang; David N. Burrows; Sangwook Park; Gordon P. Garmire; Stephen S. Holt; Günther Hasinger

    2002-01-01

    We discuss the X-ray emission observed from supernova remnant 1987A with the Chandra X-Ray Observatory. We analyze a high-resolution spectrum obtained in 1999 October with the high-energy transmission grating (HETG). From this spectrum we measure the strengths and an average profile of the observed X-ray lines. We also analyze a high signal-to-noise ratio CCD spectrum obtained in 2000 December. The

  5. Molecular emission in the IC443 Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Gusdorf, A.; Gusten, R.; Yuan, Y.; Neufeld, D.; Herschel Wadi Team

    2011-05-01

    Supernovae are an important source of energy input to the interstellar medium. They send shock waves that propagate through and interact with the Interstellar Medium. These shock waves originally create large cavities filled with hot ionized material. At some point, supernova-driven shock waves become radiative, emitting strong line emissions, initially at optical and ultraviolet wavelengths, that are widely observed from supernova remnants. In the interaction region of these remnants with the ambient molecular cloud, slower shock waves heat, accelerate, and compress the surrounding medium. The physical processes at work in such shocked regions (density, temperature and associated timescales) in turn generate a specific chemistry, both in the gas-phase and through grains interactions, that can significantly alter the abundance of certain species. The resulting infra-red, but also sub-mm molecular emission can be used as a diagnostic tool to study the physical and chemical characteristics of the shocked region, yielding constraints on shock parameters such as the pre-shock density, magnetic field, or shock type, velocity or type. IC443 is a typical example of such galactic SuperNova Remnants, at an estimated distance of 1.5 kpc, with a diameter of about 50 arcminutes. In this talk, I will present new extensive maps of CO gas of the whole remnant, at the highest frequencies accessible from the ground. I will also explain how the use of such observations on selected positions, in combination with pure rotational H_2 transitions acquired with the Spitzer telescope (IRS) can allow us to place constraints on shock model parameters through comparisons with a grid of shock models. Based on this preliminary study, I will also show how the additional comparison of water observations (as provided by the HIFI receiver onboard the Herschel telescope) with our shock simulations is a good way to refine these constraints and test our understanding of the water formation processes in shocked regions.

  6. Soft X-Ray Observation of Supernova Remnant IC443

    Microsoft Academic Search

    C. M. F. Galas; D. Venkatesan; G. Garmire

    1981-01-01

    The low-energy X-ray spectrum (0.15-3.0 keV) and X-ray centroid position of the supernova remnant IC 443 have been determined using data obtained by the HEAO-1 A-2 experiment. The spectrum exhibits a low-energy excess over and above that predicted by an extrapolation of the higher-energy spectrum determined by Parkes et al (1976). The excess can be attributed to line emission, predominately

  7. The Shock Structure of Supernova Remnant IC443

    Microsoft Academic Search

    M. R. Haas; S. J. U. Higdon; M. G. Burton; D. J. Hollenbach

    2003-01-01

    We present and discuss ISO observations of IC443, a supernova remnant interacting with a molecular cloud. An SWS spectrum centered on molecular hydrogen clump R10E (RA(2000) = 6 17 7.6, Decl(2000) = 22 25 34.6) is dominated by strong [SiII] (34 microns) emission and the pure rotational transitions of molecular hydrogen ranging from 0-0 S(1) to 0-0 S(13). Fits to

  8. Neutron star/supernova remnant associations: the view from Tbilisi

    E-print Network

    V. V. Gvaramadze

    2002-08-01

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

  9. CGRO/OSSE observations of the Cassiopeia A Supernova remnant

    NASA Technical Reports Server (NTRS)

    The, L.-S.; Leising, M. D.; Clayton, D. D.; Johnson, W. N.; Kinzer, R. L.; Kurfess, J. D.; Strickman, M. S.; Jung, G. V.; Grabelsky, D. A.; Purcell, W. R.

    1995-01-01

    Cassipeia A, the youngest known supernova remnant in the Galaxy and a strong radio and X-ray source, was observed by OSSE 1992 July 16-August 6. Its close distance (approximately 3 kpc) and its young age (approximately 300 yr) make Cas A the best candidate among known supernova remnants for detecting Ti-44 gamma-ray lines. We find no evidence of emission at 67.9 keV, 78.4 keV, or 1.157 MeV, the three strongest Ti-44 decay lines. From simultaneous fits to the three lines our 99% confidence upper limit to the flux in each line is 5.5 x 10(exp -5) gamma/sq cm s. We also report upper limits for the 4.44 MeV C-12 nuclear de-excitation line, which could be produced by interactions of acclerated particles in the supernova remnant, and for the hard X-ray continuum.

  10. 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~t0.5, but there are significant differences in different parts of the remnant: the bright northwestern part expands as r~t0.35, whereas the rest of the remnant's expansion shows an expansion r~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 (?~v-n) of n=7, or with an exponential density profile [?~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~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.

  11. 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.

  12. A Newly Recognized Very Young Supernova Remnant in M83

    E-print Network

    Blair, William P; 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 H$\\alpha$, [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 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 $\\rm M_{sun}$, and the presence of broad H$\\alpha$ in the spectrum makes a type II supernova likely....

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

    SciTech Connect

    Su, Yang; Fang, Min; Yang, Ji [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Zhou, Ping; Chen, Yang [Department of Astronomy, Nanjing University, Nanjing 210093 (China)

    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.

  14. Molecular Environment of the Supernova Remnant IC 443: Discovery of the Molecular Shells Surrounding the Remnant

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

    We have carried out 12CO, 13CO, and C18O 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-1 to -2 km s-1, which is consistent with that of the -4 km s-1 molecular clouds. We suggest that the half-ring structure of the CO emission at V LSR ~ -4 km s-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.

  15. Maximum Energies of Electron Acceleration in Young Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Reynolds, S. P.; Keohane, J. W.

    1997-05-01

    Young supernova remnants are often assumed to be the source of cosmic rays up to energies approaching the slight steepening at around 1000 TeV known as the ``knee'' in the cosmic-ray energy spectrum. We show that the observed X-ray emission of seven shell remnants, including all five historical shells, can be used to put limits on E_m, the energy at which the electron energy distribution must steepen from its slope at radio-emitting energies. Six of the remnants show thermal spectra, so any nonthermal component must fall below the observed X-ray fluxes. Assuming homogeneous emitting volumes with a mean magnetic-field strength of 10 \\ mu G, no object could reach 1000 TeV, and only one, Cas A, has an upper limit on E_m near 100 TeV. All the other historical shells have limits at or below 50 TeV. These limits scale as B(-1/2) , so absurdly low magnetic fields would be required to get E_m much higher. E_m 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 implies that the proton spectrum should steepen at that energy as well. More complicated, inhomogeneous models could allow higher values of E_m in parts of the remnant, but the emission-weighted average value, that characteristic of typical electrons, should obey these limits. The historical remnants should be among the best in the Galaxy at producing the highest-energy Galactic cosmic rays; if they cannot do it, this picture of cosmic-ray origin may need major alteration.

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

    SciTech Connect

    Brantseg, T.; McEntaffer, R. L.; Grieves, N. [Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 (United States); Bozzetto, L. M.; Filipovic, M., E-mail: thomas-brantseg@uiowa.edu [School of Computing, Engineering, and Mathematics, University of Western Sydney, Penrith, New South Wales 2751 (Australia)

    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.

  17. 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 (?) before trials and 7.5? 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)-?) 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.

  18. Study of the extended radio emission of two supernova remnants and four planetary nebulae associated with MIPSGAL bubbles

    NASA Astrophysics Data System (ADS)

    Ingallinera, A.; Trigilio, C.; Umana, G.; Leto, P.; Agliozzo, C.; Buemi, C.

    2014-12-01

    We present radio observations, made using the Very Large Array and the Green Bank Telescope, of two supernova remnants and four planetary nebulae. These objects are part of a larger sample of radio sources, discussed in a previous paper, a counterpart of the MIPSGAL 24-?m compact bubbles. For the two supernova remnants, we have combined the interferometric observations with single-dish data to obtain both a high resolution and a good sensitivity to extended structures. We discuss in detail the entire combination procedure adopted and the reliability of the resulting maps. For one supernova remnant, we pose a more stringent upper limit for the flux density of its undetected pulsar, and we also show prominent spectral index spatial variations, probably resulting either from inhomogeneities in the magnetic field and in its ejecta or from an interaction between the supernova shock and molecular clouds. We eventually use the 5-GHz maps of the four planetary nebulae to estimate their distances and their ionized masses.

  19. 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.

  20. Gamma-Ray Emission of Supernova Remnants and the Origin of Galactic Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Aharonian, F. A.

    The recent surveys of the Milky Way with space and ground-based gamma-ray detectors revealed hundreds of high energy (HE) and tens of very high energy (VHE) gamma-ray emitters representing several galactic source populations - supernova remnants, giant molecular clouds, star forming regions, pulsars, pulsar wind nebulae, binary systems. The major fraction of these objects remains however unidentified. In this chapter I discuss the astrophysical implications of VHE gamma-ray observations of supernova remnants (SNRs) in the context of the origin of galactic cosmic rays. These observations confirm the earlier theoretical predictions of effective acceleration of multi-TeV particles in young SNRs by strong shock waves. The interpretation of VHE gamma-ray data from several prominent representatives of young SNRs within the so-called hadronic models requires hard energy spectra of protons extending to 100 TeV, with total energy released in relativistic protons and nuclei as large as 1050 erg. Formally, this can be considered as an observational proof of the so-called SNR paradigm of the origin of galactic cosmic rays. However, the hadronic models are not free of problems related to interpretation of multi-wavelength properties of these objects. Moreover, in most of the cases the gamma-ray data can be explained by the inverse Compton scattering of electrons which are responsible also for the synchrotron X-radiation of young SNRs. These circumstances prevent us from a firm statement about the contribution of SNRs to the overall flux of galactic cosmic rays. Further observations of young SNRs, especially in the highest energy band (well above 10 TeV), can be crucial in this regard. Quite important are also the complementary observations from massive molecular clouds located within the close proximity of mid-age SNRs.

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

    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., 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?1 for which the remnant is just beginning to go radiative. Assuming SNRs evolve in a warm phase dominated ISM, we find dust destruction timescales are increased by a factor of ?2 compared to those of Jones et al., who assumed a hot gas dominated ISM. Recent estimates of supernova rates and ISM mass lead to another factor of ?3 increase in the destruction timescales, resulting in a silicate grain destruction timescale of ?2–3 Gyr. These increases, while not able to resolve the problem of the discrepant timescales for silicate grain destruction and creation, are an important step toward understanding the origin and evolution of dust in the ISM.

  2. Hot interstellar tunnels. I - Simulation of interacting supernova remnants

    NASA Technical Reports Server (NTRS)

    Smith, B. W.

    1977-01-01

    It has been suggested that intersecting supernova remnants (SNRs) contribute to the production of gas at about 1 million K which is apparently observed in the interstellar medium. This suggestion is evaluated through a fairly detailed numerical simulation that is used to investigate the large-scale three-dimensional behavior of a test section of the gaseous galactic disk under the influence of evolving and interacting SNRs. Models for a noninteracting 'isolated' SNR and the ambient medium are discussed, pairs of interacting remnants are examined along with the mechanism by which their central cavities can become connected, and the evolution of larger aggregates of SNRs is analyzed. Results are presented for a sequence of simulations having the same values of supernova blast energy, ambient ion density, and isolated SNR lifetime, but different supernova rates per unit volume. These results show that SNR intersections can quickly generate large volumes, or 'tunnels', of very hot gas from a cold starting medium under conservative and reasonable assumptions, the most important of which are that SNRs can be treated as spheres and mass motions can be treated implicitly.

  3. 84 gigahertz observations of five Crab-like supernova remnants

    SciTech Connect

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

    1989-03-01

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

  4. VERITAS Observations of the Supernova Remnant IC 443

    NASA Astrophysics Data System (ADS)

    Humensky, Brian

    2009-05-01

    Supernova remnants (SNRs) are widely considered to be the strongest candidate for the source of cosmic rays below the knee around 3 .10^15 eV. In the last few years, TeV gamma-ray observations of SNRs have opened a new window on the high-energy processes occurring in their shock fronts. VERITAS, an array of four gamma-ray telescopes located at the Whipple Observatory in southern Arizona, has an active program of SNR observations. Recent results include the co-discovery (along with MAGIC) of TeV emission from IC 443. In the case of IC 443, a deep observation reveals that the emission is extended and coincident in space with the site of interaction between the expanding shell of the SNR and a nearby molecular cloud. These results and their implications for the nature of the cosmic rays - hadronic or electronic - accelerated in the remnants will be discussed.

  5. ASYMMETRIES IN THE EXPANSION AND EMISSION FROM YOUNG SUPERNOVA REMNANTS

    SciTech Connect

    Vigh, Carlos D.; Gomez, Daniel O.; Reynoso, Estela M. [Departamento de Fisica, Facultad de Ciencias Exactas y Naturales de la Universidad de Buenos Aires, Buenos Aires (Argentina); Velazquez, Pablo F.; Esquivel, Alejandro; Schneiter, E. Matias, E-mail: carlos@iafe.uba.ar, E-mail: gomez@iafe.uba.ar, E-mail: ereynoso@iafe.uba.ar, E-mail: pablo@nucleares.unam.mx, E-mail: esquivel@nucleares.unam.mx, E-mail: mschneiter@gmail.com [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apdo. Postal 70-543, CP 04510, Mexico D.F. (Mexico)

    2011-01-20

    We present two-dimensional and three-dimensional numerical simulations of asymmetric young supernova remnants (SNRs) carried out with the hydrodynamical code YGUAZU, aiming to quantitatively assess the role of different factors that may give origin to such asymmetries in their expansion. In particular, we are interested in modeling the morphology of Tycho's SNR to address whether the companion star of a Type Ia supernova progenitor has played a role in the subsequent evolution of the remnant. With the results from the numerical simulations, we can not only study the morphology of the SNR but also compute the emission of the remnant in different spectral bands. In particular, we simulate X-ray maps, which can be directly compared to recent and previous observations of Tycho's SNR. Our results suggest that the most likely explanation for Tycho's morphology is that after the supernova (SN) explosion the shock front stripped the envelope of its companion. We represent this effect by adding a conical region with an enhanced density into the initial sphere immediately after the explosion. Assuming that Tycho's companion was a massive red giant star, we explore different values of the angle of aperture and mass excess of the conical region. A good agreement with observational data was found for the model with a mass excess of 0.3 M{sub sun} and an aperture of 90{sup 0}. After the collision with the SN shock wave, the companion would become an He-rich star. This scenario would gain observational support if a star with these characteristics is found in the vicinity of the center of the SN explosion.

  6. The Unusual Young Supernova Remnant Population in M83

    NASA Astrophysics Data System (ADS)

    Blair, William P.; Dopita, M. A.; Ghavamian, P.; Kuntz, K. D.; Long, K. S.; Plucinsky, P. P.; Soria, R.; Winkler, P. F.

    2014-01-01

    The face-on grand design spiral galaxy M83 (d=4.6 Mpc) is a veritable supernova factory, having generated six known SNe in less than 100 years. Hence, one might expect of order 60 or more supernova remnants (SNRs) less than a thousand years old that might shed light on the poorly understood ejecta-dominated phase of early SNR evolution, as well as many more older, ISM-dominated remnants that should still be visible. We are conducting a multi-wavelength Chandra/Hubble/ground-based campaign to find and characterize the SNRs in M83, concentrating especially on the younger population. HST/WFC3 emission-line data for seven fields covering the bulk of the bright optical disk have allowed us to identify ~50 optical SNR candidates with angular sizes below 0.5” (<11 pc), many with corresponding Chandra X-ray counterparts. However, with the singular exception of the remnant of SN1957D, we are not finding the expected population of ejecta-dominated young SNRs. Rather, most of the young SNRs appear to have quickly evolved into the radiative phase. Gemini-S GMOS spectra of selected objects confirm the lack of observed high velocities or obvious ejecta-enhancement of abundances. This unexpected result implies that the CSM/ISM environments for most young remnants in M83 are very dense, perhaps due in part to the super-solar metal abundances in much of this galaxy. We will show representative data from all relevant data sets that lead us to this conclusion. This work is supported in part by STScI grant HST-GO-12513.01-A and Chandra grant SAO-GO1-12115C to Johns Hopkins University.

  7. Cosmic-ray acceleration and escape from supernova remnants

    NASA Astrophysics Data System (ADS)

    Bell, A. R.; Schure, K. M.; Reville, B.; Giacinti, G.

    2013-05-01

    Galactic cosmic-ray (CR) acceleration to the knee in the spectrum at a few PeV is only possible if the magnetic field ahead of a supernova remnant (SNR) shock is strongly amplified by CRs escaping the SNR. A model formulated in terms of the electric charge carried by escaping CRs predicts the maximum CR energy and the energy spectrum of CRs released into the surrounding medium. We find that historical SNRs such as Cas A, Tycho and Kepler may be expanding too slowly to accelerate CRs to the knee at the present time.

  8. SPECTRUM OF GALACTIC COSMIC RAYS ACCELERATED IN SUPERNOVA REMNANTS

    SciTech Connect

    Ptuskin, Vladimir; Zirakashvili, Vladimir [Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation of the Russian Academy of Science (IZMIRAN), Troitsk, Moscow Region 142190 (Russian Federation); Seo, Eun-Suk [Department of Physics and Institute of Physical Science and Technology, University of Maryland, College Park, MD 20742 (United States)

    2010-07-20

    The spectra of high-energy protons and nuclei accelerated by supernova remnant (SNR) shocks are calculated, taking into account magnetic field amplification and Alfvenic drift both upstream and downstream of the shock for different types of SNRs during their evolution. The maximum energy of accelerated particles may reach 5 x 10{sup 18} eV for Fe ions in Type IIb SNRs. The calculated energy spectrum of cosmic rays after propagation through the Galaxy is in good agreement with the spectrum measured at the Earth.

  9. Analytic Solutions for the Evolution of Radiative Supernova Remnants

    E-print Network

    R. Bandiera; O. Petruk

    2004-02-25

    We present the general analytic solution for the evolution of radiative supernova remnants in a uniform interstellar medium, under thin-shell approximation. This approximation is shown to be very accurate approach to this task. For a given set of parameters, our solution closely matches the results of numerical models, showing a transient in which the deceleration parameter reaches a maximum value of 0.33, followed by a slow convergence to the asymptotic value 2/7. Oort (1951) and McKee and Ostriker (1977) analytic solutions are discussed, as special cases of the general solution we have found.

  10. AGILE observations of Middle-aged supernova remnants

    NASA Astrophysics Data System (ADS)

    Giuliani, G.; AGILE Team

    The gamma-ray imager on-board the AGILE satellite detected several middle-aged Supernova Remnants. Unlike young SNRs, these objects are bright also for energies greater than some tens of MeV. Here we present an overview of the AGILE observations of middle-aged SNRs in the "low energy" band (50-400 MeV) and the spectral and morphological studies performed for some of them (IC443, W28, W44. W51C). These data, combined with the results from instruments operating at higher energy (Fermi, HESS, MAGIC, Veritas) can constrain the theoretical models for the gamma ray production in SNRs.

  11. Biermann Mechanism in Primordial Supernova Remnant and Seed Fields

    E-print Network

    Hidekazu Hanayama; Keitaro Takahashi; Kei Kotake; Masamune Oguri; Kiyotomo Ichiki; Hiroshi Ohno

    2006-01-24

    We have studied the generation of magnetic fields by the Biermann mechanism in the pair-instability supernovae explosions of the first stars. The Biermann mechanism produces magnetic fields in the shocked region between the bubble and interstellar medium (ISM), even if magnetic fields are absent initially. We have performed a series of two-dimensional magnetohydrodynamic simulations with the Biermann term and estimate the amplitude and total energy of the produced magnetic fields. We find that magnetic fields with amplitude $10^{-14}-10^{-17}$ G are generated inside the bubble, though the amount of magnetic fields generated depend on specific values of initial conditions. This corresponds to magnetic fields of $10^{28}-10^{31}$ ergs per each supernova remnant, which is strong enough to be the seed magnetic field for a galactic and/or interstellar dynamo.

  12. Biermann Mechanism in Primordial Supernova Remnant and Seed Magnetic Fields

    E-print Network

    Hidekazu Hanayama; Keitaro Takahashi; Kei Kotake; Masamune Oguri; Kiyotomo Ichiki; Hiroshi Ohno

    2005-07-11

    We study generation of magnetic fields by the Biermann mechanism in the pair-instability supernovae explosions of first stars. The Biermann mechanism produces magnetic fields in the shocked region between the bubble and interstellar medium (ISM), even if magnetic fields are absent initially. We perform a series of two-dimensional magnetohydrodynamic simulations with the Biermann term and estimate the amplitude and total energy of the produced magnetic fields. We find that magnetic fields with amplitude $10^{-14}-10^{-17}$ G are generated inside the bubble, though the amount of magnetic fields generated depend on specific values of initial conditions. This corresponds to magnetic fields of $10^{28}-10^{31}$ erg per each supernova remnant, which is strong enough to be the seed magnetic field for galactic and/or interstellar dynamo.

  13. Gamma-ray Emission from Crushed Clouds in Supernova Remnants

    E-print Network

    Uchiyama, Yasunobu; Funk, Stefan; Tajima, Hiroyasu; Tanaka, Takaaki

    2010-01-01

    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 neutral pions 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.

  14. 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) K? 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.

  15. Gamma-ray Emission from Crushed Clouds in Supernova Remnants

    NASA Astrophysics Data System (ADS)

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

    2010-11-01

    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 blast wave 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 ?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.

  16. 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~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.

  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. Relativistic MHD simulations of pulsar bow-shock nebulae

    Microsoft Academic Search

    N. Bucciantini; E. Amato; L. Del Zanna

    2005-01-01

    Pulsar bow-shock nebulae are a class of pulsar wind nebulae (PWNe) that form when the pulsar wind is confined by the ram pressure of the ambient medium, and are usually associated with old pulsars, that have already emerged from the progenitor Supernova Remnant (SNR). Until a few years ago these nebulae were mainly observed as Halpha sources; recently, also non-thermal

  19. 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.

  20. Toward Connecting Core-Collapse Supernova Explosions with Observations of their Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Handy, Timothy; Plewa, Tomasz; Odrzywolek, Andrzej

    2014-03-01

    We study the process of collapse of a massive star and the following explosion process until the formation of a young supernova remnant in a single simulation. These new models are critically evaluated against a database of core-collapse supernovae (ccSNe) explosion models obtained with a standard supernova code. We develop a multiphysics hydrocode capable of accounting for physics from before collapse occurs until the supernova remnant phase. This enables ccSNe studies with a single code without the need of remapping or transferring data between multiple codes. The code uses a new algorithm to account for the effects of neutrino-matter interaction in the collapsing stellar core. The algorithm uses ray-casting in three dimensions and enables performing collapse and explosion simulations on AMR meshes, including non-radial discretizations. Heating due to radioactive decay, and magnetization of the ejecta are included in the model. The asymmetry of the explosion continues to play a role well beyond the shock breakout phase. In particular, the lateral momentum deposited in the process of shock revival helps shape the supernova ejecta. Another important contributing factor shaping the ejecta is due to radioactive decay of nucleosynthetic products of the explosion.

  1. 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.

  2. CORRELATION OF SUPERNOVA REMNANT MASERS AND GAMMA-RAY SOURCES

    SciTech Connect

    Hewitt, John W. [NASA Goddard Space Flight Center, Mail Stop 662.0, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States); Yusef-Zadeh, Farhad [Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States); Wardle, Mark [Department of Physics and Engineering, Macquarie University, Sydney, NSW 2109 (Australia)

    2009-12-01

    Supernova remnants (SNRs) interacting with molecular clouds are potentially exciting systems in which to detect evidence of cosmic ray acceleration. Prominent gamma-ray emission is produced via the decay of neutral pions when cosmic rays encounter nearby dense clouds. In many of the SNRs coincident with gamma-ray sources, the presence of OH (1720 MHz) masers is used to identify interaction with dense gas and to provide a kinematic distance to the system. In this Letter we use statistical tests to demonstrate that there is a correlation between these masers and a class of GeV- to TeV-energy gamma-ray sources coincident with interacting remnants. For pion decay the gamma-ray luminosity provides a direct estimate of the local cosmic ray density. We find the cosmic ray density is enhanced by one to two orders of magnitude over the local solar value, comparable to X-ray-induced ionization in these remnants. The inferred ionization rates are sufficient to explain non-equilibrium chemistry in the post-shock gas, where high columns of hydroxyl are observed.

  3. Dynamical evolution of supernova remnants breaking through molecular clouds

    E-print Network

    Cho, Wankee; Koo, Bon-Chul

    2015-01-01

    We carry out three-dimensional hydrodynamic simulations of the supernova remnants (SNRs) produced inside molecular clouds (MCs) near their surface using the HLL code (Harten et al. 1983). 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 onedimensional simulations. Moreover, we produce synthetic X-ray surface brightness in order to research the center-bri...

  4. 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).

  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. A Broadband X-Ray Study of the Supernova Remnant 3C 397

    E-print Network

    S. Safi-Harb; R. Petre; K. A. Arnaud; J. W. Keohane; K. J. Borkowski; K. K. Dyer; S. P. Reynolds; J. P. Hughes

    2000-07-25

    We present an X-ray study of the radio bright supernova remnant (SNR) 3C 397 with ROSAT, ASCA, and RXTE. A central X-ray spot seen with the ROSAT High-Resolution Imager hints at the presence of a pulsar-powered component, and gives this SNR a composite X-ray morphology. Combined ROSAT and ASCA imaging show that the remnant is highly asymmetric, with its hard X-ray emission peaking at the western lobe. The spectrum of 3C 397 is heavily absorbed, and dominated by thermal emission with emission lines evident from Mg, Si, S, Ar and Fe. Single-component models fail to describe the spectrum, and at least two components are required. We use a set of non-equilibrium ionization (NEI) models (Borkowski et al. in preparation). The temperatures from the soft and hard components are 0.2 keV and 1.6 keV respectively. The corresponding ionization time-scales $n_0 t$ ($n_0$ being the pre-shock hydrogen density) are 6 $\\times 10^{12}$ cm$^{-3}$ s and 6 $\\times$ 10$^{10}$ cm$^{-3}$ s, respectively. The spectrum obtained with the Proportional Counter Array (PCA) of RXTE is contaminated by emission from the Galactic ridge, with only $\\sim$ 15% of the count rate originating from 3C 397 in the 5-15 keV range. The PCA spectrum allowed us to confirm the thermal nature of the hard X-ray emission. A third component originating from a pulsar-driven component is possible, but the contamination of the source signal by the Galactic ridge did not allow us to find pulsations from any hidden pulsar. We discuss the X-ray spectrum in the light of two scenarios: a young ejecta-dominated remnant of a core-collapse SN, and a middle-aged SNR expanding in a dense ISM. Spatially resolved spectroscopy (with CHANDRA and XMM) is needed to differentiate between the two scenarios, and address the nature of the mysterious radio-quiet X-ray hot spot.

  7. Second Epoch Hubble Space Telescope Imaging of Kepler's Supernova Remnant

    NASA Astrophysics Data System (ADS)

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

    2015-01-01

    We have obtained new HST/WFC3 images of Kepler's supernova remnant in H-alpha (F656N) and [N II] (F658N) emission line filters. The bright radiative shocks in dense clumps are detected in both filters, while non-radiative shocks are seen as faint filaments only in the H-alpha image. Most of these Balmer filaments lie around the periphery of the remnant where the blast wave encounters partially neutral interstellar gas. We compare the new images with HST/ACS images taken nearly 10 years previously, and find that these filaments tracing the forward shock have moved 0.6"-0.9" between the two epochs. Assuming a distance of 4 kpc to the remnant, these proper motions correspond to shock velocities of 1160-1740 km/s, which are consistent with the published values, 1550-2000 km/s (e.g. Blair et al. 1991, ApJ 366, 484). We also find a few Balmer filaments with highly non-radial proper motions. In one particularly interesting case in the projected interior of the remnant, SE of the center, the shock appears to have wrapped around a sharp density enhancement and moved about 0.3" in the period between the observations.The images allow us to study the evolution of the shock around an ejecta knot, which is punching through the remnant boundary in the northwest. The forward shock, visible as an arcuate Balmer filament, has moved about 1". At the trailing edges, the system of radiative knots formed by Rayleigh-Taylor instabilities have undergone significant changes - some knots have disappeared, new ones have appeared, and many have changed in brightness. Elsewhere in the remnant we find changes in the relative intensities of many small, bright knots over the 10 year baseline, indicating the short radiative lifetimes of these features.This work has been supported in part by grant HST-GO-12885 to the Universities Space Research Association.

  8. 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.

  9. 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.

  10. Since the discovery of pulsars in the 1960's and their subsequent identi cation as rapidly rotating neutron stars (for which the 1974

    E-print Network

    Crawford III, Fronefield

    . Such an object is called a pulsar. The Crab pulsar, located in the Crab supernova remnant which was formed in the supernova explosion seen in 1054 A.D. by Chinese astronomers, is the youngest known pulsar and is considered; in brightness steeply with increasing radiation frequency. However, in some cases (such as the Crab pulsar, men

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

    SciTech Connect

    Williams, Brian J.; Hewitt, John W.; Petre, Robert [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Borkowski, Kazimierz J.; Alwin Mao, S.; Reynolds, Stephen P.; Blondin, John M. [Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States); Ghavamian, Parviz, E-mail: brian.j.williams@nasa.gov [Department of Physics, Astronomy, and Geosciences, Towson University, Towson, MD 21252 (United States)

    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.

  12. Learning about the Spider from its Web: Studying the Neutron Star and Supernova Remnant in G328.4+0.2

    NASA Astrophysics Data System (ADS)

    Gelfand, J.; Gaensler, B.; Slane, P.; Patnaude, D.; Hughes, J.; Camilo, F.

    In this poster we present new radio and X-ray observation of G328 4 0 2 a Galactic non-thermal radio source which is either a pulsar wind nebula PWN or a composite supernova remnant SNR Combining the results from these observations with the prediction made by a simple hydrodynamical model for the evolution of a PWN inside a SNR we are able to constrain the evolutionary stage and age of this system as well as the initial period of the neutron star powering the PWN and the explosion energy and ejecta mass of the progenitor supernova explosion

  13. 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.

  14. Phosphorus in the Young Supernova Remnant Cassiopeia A

    E-print Network

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

    2013-01-01

    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.

  15. NON-MAXWELLIAN Halpha PROFILES IN TYCHO'S SUPERNOVA REMNANT

    SciTech Connect

    Raymond, John C. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Winkler, P. Frank [Department of Physics, Middlebury College, Middlebury, VT 05753 (United States); Blair, William P. [Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218 (United States); Lee, Jae-Joon; Park, Sangwook, E-mail: jraymond@cfa.harvard.ed, E-mail: winkler@middlebury.ed, E-mail: wpb@pha.jhu.ed, E-mail: lee.j.joon@gmail.co, E-mail: park@astro.psu.ed [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States)

    2010-04-01

    The broad components of the Halpha lines in most non-radiative shocks can be fit with single-Gaussian components. We have obtained a high-quality spectrum of a position in Tycho's supernova remnant with the MMT and Blue Channel Spectrograph which shows, for the first time, that a single Gaussian does not provide an acceptable fit. This implies that a single temperature Maxwellian particle velocity distribution cannot produce the emission. Possible alternative explanations are explored, including multiple shocks along the line of sight, a pickup ion contribution, a non-thermal tail (Kappa distribution), emission from a precursor in a cosmic ray modified shock, or turbulence. An Hubble Space Telescope image shows a bright knot that might account for a low temperature contribution, and all the possibilities probably contribute at some level. We discuss the implications of each explanation for the shock parameters and physics of collisionless shocks, but cannot conclusively rule out any of them.

  16. 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

  17. Slow Diffusion of Cosmic-Rays around a Supernova Remnant

    E-print Network

    Fujita, Yutaka; Takahara, Fumio

    2010-01-01

    We study the escape of cosmic-ray protons accelerated at a supernova remnant (SNR). We are interested in their propagation in 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 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.

  18. Grain destruction in a supernova remnant shock wave

    SciTech Connect

    Raymond, John C.; Gaetz, Terrance J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Ghavamian, Parviz [Department of Physics, Astronomy and Geosciences, Towson University, Towson, MD 21252 (United States); Williams, Brian J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Blair, William P. [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Borkowski, Kazimierz J. [Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States); Sankrit, Ravi, E-mail: jraymond@cfa.harvard.edu [SOFIA Science Center, NASA Ames Research Center, M/S 232-12, Moffett Field, CA 94035 (United States)

    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 ?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 ?m 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.

  19. 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.

  20. Dynamics of Supernova Remnants with Ejecta and Circumstellar Bubbles

    NASA Astrophysics Data System (ADS)

    Blondin, M. J.; Featherstone, N.; Borkowski, J. K.; Reynolds, P. S.

    2001-09-01

    Progenitors of core-collapse supernovae (SNe) blow bubbles in the ambient medium and sweep it into shells with their powerful stellar winds. After the explosion, SN ejecta initially collide with the stellar wind, then with the wind-blown bubble, and finally with a dense wind-swept shell. This collision is particularly energetic for SNe whose progenitors lost most of their outer envelopes just prior to explosion: the brightest galactic supernova remnant (SNR), Cas A, is a prime example of such an interaction with the circumstellar medium (CSM). The SN ejecta are far from being smooth for such remnants, because of vigorous turbulence and mixing of heavy-element ejecta immediately after the explosion and subsequent growth of Ni-Fe bubbles powered by the radioactive decay. We study the interaction of ``bubbly'' SN ejecta with a CSM bubble and a swept CSM shell, using hydrodynamical simulations in 2 and 3 dimensions with the VH-1 hydrocode. We compare our simulations with analytic self-similar (Chevalier & Liang 1989) solutions and with our previous simulations of interaction of bubbly ejecta with a uniform ambient medium. When compared with these simulations, the impact of bubbly ejecta with the shell results in a more vigorous turbulence and mixing. Dense and cool ejecta at the boundaries of adjacent bubbles may penetrate the shell, leading to plume-like and ring-like features. We examine whether such an interaction is responsible for the observed morphology of Cas A as seen by the Chandra X-ray Observatory and the Hubble Space Telescope, and for the different expansion rates seen at X-ray and radio wavelengths.

  1. Dust Cooling in Supernova Remnants in the Large Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Seok, Ji Yeon; Koo, Bon-Chul; Hirashita, Hiroyuki

    2015-07-01

    The infrared-to-X-ray (IRX) flux ratio traces the relative importance of dust cooling to gas cooling in astrophysical plasma such as supernova remnants (SNRs). We derive IRX ratios of SNRs in the LMC using Spitzer and Chandra SNR survey data and compare them with those of Galactic SNRs. IRX ratios of all the SNRs in the sample are found to be moderately greater than unity, indicating that dust grains are a more efficient coolant than gas although gas cooling may not be negligible. The IRX ratios of the LMC SNRs are systematically lower than those of the Galactic SNRs. As both dust cooling and gas cooling pertain to the properties of the interstellar medium, the lower IRX ratios of the LMC SNRs may reflect the characteristics of the LMC, and the lower dust-to-gas ratio (a quarter of the Galactic value) is likely to be the most significant factor. The observed IRX ratios are compared with theoretical predictions that yield IRX ratios an order of magnitude larger. This discrepancy may originate from the dearth of dust in the remnants due to either the local variation of the dust abundance in the preshock medium with respect to the canonical abundance or the dust destruction in the postshock medium. The non-equilibrium ionization cooling of hot gas, in particular for young SNRs, may also cause the discrepancy. Finally, we discuss implications for the dominant cooling mechanism of SNRs in low-metallicity galaxies.

  2. The Optical Spectrum of the SN 1006 Supernova Remnant Revisited

    E-print Network

    Parviz Ghavamian; P. Frank Winkler; John C. Raymond; Knox S. Long

    2002-02-26

    We present the deepest optical spectrum acquired to date of Balmer-dominated shocks in the NW rim of SN 1006. We detect the broad and narrow components of H-alpha, H-beta and H-gamma and report the first detection of the He I 6678 emission line in this supernova remnant. We may have detected, at the 1.5-sigma level, faint He II 4686 emission. We measure a full width half maximum of 2290 +/- 80 km/s in the broad component H-alpha line, with broad-to-narrow flux ratios of 0.84^+(0.03)_(-0.01) and 0.93^(+0.18)_(-0.16) in H-alpha and H-beta, respectively. To match these observations, our nonradiative shock models require a low degree of electron-proton equilibration at the shock front, T_e/T_p ~ 70%) preshock He, respectively. We conclude that the high H ionization fraction cannot be explained by either photoionization from the reverse shock or relic ionization from EUV photons released in the 1006 A.D. supernova. The most plausible explanation appears to be photoionization from the Galactic Lyman continuum.

  3. 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.

  4. Multifrequency Studies of Bright Radio Supernova Remnants. III. X-Ray and Radio Observations of 3C 397

    E-print Network

    K. K. Dyer; S. P. Reynolds

    1999-06-19

    Radio-bright, presumably young supernova remnants offer the opportunity of studying strong-shock physics and the nature of the interaction of ejected material with the surrounding medium. We use VLA and ROSAT images of the radio-bright supernova remnant 3C 397 (G41.1--0.3) to examine the shock structure in both thermal X-ray emission and nonthermal radio emission. The unusual rectangular morphology can be seen in VLA maps at 20 and 6 cm wavelength at a resolution of 6", and in ROSAT HRI images. The X-ray images resemble the radio strongly, except for a small, possibly un resolved X-ray hot spot near the center. There is no variation in the X-ray hardness ratio from ROSAT Position Sensitive Proportional Counter data across the remnant, suggesting that at least between 0.4 and 2 keV, the interior emission is not different in character from that in the bright shell regions. Thus 3C 397 is not a member of the ``thermal composite'' or ``mixed-morphology'' class (Rho 1998). The remnant is unpolarized at 20 cm, and has a mean fractional polarization of 1.5% +/- 0.1% at 6 cm. The polarized flux, and polarized fraction, peak inside the remnant at a location not coincident with either an internal maximum in total-intensity radio emission, or with the X-ray hot spot. Spectral-index maps between 6 and 20 cm do not show any systematic differences associated with interior emission; there appears to be no ``plerionic'' or pulsar-driven component in 3C 397 at least as normally characterized by high polarization and a flat radio spectrum. Spectral-index values spread about the mean by about 0.2, a result consistent with previous work. We make calculations of the upstream electron diffusion coefficient and the mean density. Finally, we speculate on possible mechanisms producing the X-ray hot spot.

  5. High Spatial Resolution Infrared Imaging and Spectroscopy of the Supernova Remnant IC443

    Microsoft Academic Search

    M. J. Richter; J. R. Graham; G. S. Wright

    1993-01-01

    We present high spatial resolution infrared imaging and long slit spectra of the molecular shock in the supernova remnant IC443. The 1--0 S(1) line of H_2 at 2.122 microns has been imaged at an angular resolution of 0.7'' over an area of 50'' x 65'' in the vicinity of the peak emission near the southeast edge of the supernova remnant.

  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. Fermi-LAT Observation of Supernova Remnant S147

    SciTech Connect

    Katsuta, J.; Uchiyama, Y.; Tanaka, T.; /SLAC /KIPAC, Menlo Park; Tajima, H.; /SLAC /KIPAC, Menlo Park /Nagoya U., Solar-Terrestrial Environ. Lab.; Bechtol, K.; Funk, S.; Lande, J.; /SLAC /KIPAC, Menlo Park; Ballet, J.; /AIM, Saclay; Hanabata, Y.; /Hiroshima U.; Lemoine-Goumard, M.; /CENBG, Gradignan; 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.

  8. DUST IN A TYPE Ia SUPERNOVA PROGENITOR: SPITZER SPECTROSCOPY OF KEPLER'S SUPERNOVA REMNANT

    SciTech Connect

    Williams, Brian J.; Borkowski, Kazimierz J.; Reynolds, Stephen P. [Physics Department, North Carolina State University, Raleigh, NC 27695-8202 (United States); Ghavamian, Parviz [Department of Physics, Astronomy, and Geosciences, Towson University, Towson, MD 21252 (United States); Blair, William P. [Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218-2686 (United States); Long, Knox S. [STScI, 3700 San Martin Dr., Baltimore, MD 21218 (United States); Sankrit, Ravi, E-mail: brian.j.williams@nasa.gov [SOFIA/USRA, NASA Ames Research Center, M/S N211-3, Moffett Field, CA 94035 (United States)

    2012-08-10

    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 {mu}m infrared (IR) spectra of the remnant, obtained with the Spitzer Space Telescope, dominated by emission from warm dust. Broad spectral features at 10 and 18 {mu}m, consistent with various silicate particles, are seen throughout. These silicates were likely formed in the stellar outflow from the progenitor system during the asymptotic giant branch 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 Infrared Spectrograph and Infrared Array Camera 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{sup -1}) 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{sup -1}) into moderate density material (n{sub 0} {approx} 50-250 cm{sup -3}) 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.

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

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

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

  10. New constraints on chemical abundances of the shocked plasma in the supernova remnant IC443

    Microsoft Academic Search

    Eleonora Troja; Fabrizio Bocchino; Marco Miceli; Fabio Reale

    2008-01-01

    The X-ray emission of shocked plasma inside supernova remants (SNRs) interacting with molecular clouds is an excellent tool to reveal the details of the environment and how it affects the remnant evolution. In this contribution, we review the results we have obtained on IC 443, the prototype of an interacting SNR. We have developed a self-consistent model for the remnant

  11. 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.

  12. Supernova Remnant W49B and Its Environment

    NASA Astrophysics Data System (ADS)

    Zhu, H.; Tian, W. W.; Zuo, P.

    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 H2 (0,0) S(0)-S(7) from the SNR-molecular cloud interaction. The H2 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-3 and a temperature of ~104 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 × 10-4 M ? and a 45 ± 4 K warm dust component with a mass of 6.4 ± 3.2 M ?. 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 ?m 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-1.

  13. 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.

  14. 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.

  15. Anomalous Radio Quiet Zones in X-ray Bright Young Supernova Remnants G54.1+0.3 and 3C58

    NASA Astrophysics Data System (ADS)

    Chen, J. Z.; Massenburg, S. J.; Wolpert, G. A.; Keohane, J. W.; Olbert, C. M.; Clearfield, C. R.

    2002-12-01

    We present analyses of the young, Crab-like supernova remnants (SNRs) G54.1+0.3 and 3C58 in the X-ray and radio wavelength regions using public data from the Chandra X-Ray Observatory and the Very Large Array. By overlaying the X-ray and radio images, we discover similar anomalous radio quiet point sources in each object that are slightly offset from the X-ray pulsar ( 5'' and 10' for G54.1+0.3 and 3C58 respectively). The radio quiet sources are likely not coincident with the X-ray pulsars due to the unrealistically large kick velocities that the pulsars would have to possess. To explain this radio offset, we discuss simple physical models, several of which appear promising, but all of which have significant weaknesses.

  16. Supernova remnant masers: Shock interactions with molecular clouds

    NASA Astrophysics Data System (ADS)

    Hewitt, John William

    Maser emission from the 1720-MHz transition of hydroxyl(OH) has identified shock interactions in 10% of all supernova remnants(SNRs). Such maser-emitting SNRs are also bright in molecular line emission. Though somewhat rare, SNRs interacting with dense molecular clouds are an important class in which to study cosmic ray acceleration, SNR evolution, and effects on the energetics and chemistry of the interstellar medium. To study molecular shocks via a multiwavelength approach, the VLA, GBT, Spitzer Space Telescope have been used in the following ways: (i) With the GBT widespread OH(1720 MHz) emission and absorption in other OH lines is observed across the interaction site. Observations of all four ground-state transitions at 1720, 1667/5 and 1612 MHz allows us to model OH excitation, yielding the temperature, density and OH abundance in the post-shock gas. Maser emission is found to have a higher flux density with the GBT than with high-resolution VLA observations for 10 of 15 observed remnants, suggesting maser emission is present on large spatial scales. (ii) Sensitive VLA observations of select SNRs (W44, IC 443, Kes 69, 3C 391, G357.7+0.3) reveal the nature of enhanced 1720 MHz emission. Numerous weak compact masers as well as diffuse extended emission are detected tracing the shock-front. Zeeman splitting of masers permits the post-shock magnetic field strength and the line of sight field direction to be directly measured. (iii) Rotational lines of molecular hydrogen are detected at the position of several masers with Spitzer IRS spectroscopy between 5 and 35 mm. Excitation of the hydrogen lines requires the passage of a C-type shock through dense molecular gas, in agreement with the conditions derived from OH excitation. The presence of bright ionic lines requires multiple shocks present at the interaction site. (iv) A new survey for SNR-masers has identified four new interacting SNRs within 10 degrees of the Galactic Center. Maser-emitting SNRs are found to be preferentially distributed in the inner Galaxy, and preferentially associated with gamma-ray sources. To date, nine remnants with TeV or GeV-energy coincidences also harbor OH(1720 MHz) masers, making this signpost of interaction a potential signpost of cosmic-ray acceleration as well. The enhanced local cosmic ray density is a viable mechanism to produce the high columns of OH which are observed in these sources.

  17. Ejecta and Interstellar Dust in Magellanic Clouds Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Borkowski, Kazimierz; Blair, William; Ghavamian, Parviz; Hendrick, Sean; Long, Knox; Raymond, John; Reynolds, Stephen; Sankrit, Ravi; Smith, Chris; Winkler, Frank

    2004-09-01

    Stellar explosions govern the interstellar dust lifecycle. In the early Universe, supernovae (SN) injected the first heavy elements into the interstellar medium (ISM). A significant fraction of ejecta was dust. Dust is destroyed today in supernova remnant's (SNR) blast waves. Our current understanding of both formation of dust in SNe and destruction of dust in blast waves is poorly understood. We propose to observe a complete sample of SNRs in Magellanic Clouds (MCs) with the Spitzer Space Telescope (SST) in order to dramatically advance our knowledge of these processes. Heavy-element ejecta have been detected in more than one third of all SNRs in MCs, mostly in X-rays. Dust within these ejecta is collisionally heated by electrons and ions, and reradiates the absorbed energy in the far-IR. We propose deep MIPS and IRAC imaging of all MC SNRs with heavy-element ejecta in order to detect and study ejecta dust. We will determine dust temperature, dust mass, and its spatial distribution within ejecta. We will also detect dust in the ISM swept by SNR blast waves. This dust is destroyed by sputtering in hot X-ray emitting plasmas. We will learn about dust destruction by measuring the dust/gas mass ratio behind blast waves through a combined IR-X-ray analysis. Sputtering preferentially destroys small dust grains, modifying the grain size distribution. This strongly affects thermal dust emission in the IRAC bands which is produced by small grains. We will learn about the destruction of small grains by observing spatial variations of IRAC band ratios behind blast waves. An unbiased survey of all SNRs in MCs is necessary for understanding of dust destruction. We propose 24 micron MIPS imaging of all MC SNRs, and 70 micron MIPS imaging of X-ray bright SNRs. The proposed MIPS and IRAC imaging of MC SNRs will provide us with unique information about ejecta dust in a large sample of SNRs and about destruction of the ISM dust.

  18. Dust Cooling in Supernova Remnants in the Large Magellanic Cloud

    E-print Network

    Seok, Ji Yeon; Hirashita, Hiroyuki

    2015-01-01

    The infrared-to-X-ray (IRX) flux ratio traces the relative importance of dust cooling to gas cooling in astrophysical plasma such as supernova remnants (SNRs). We derive IRX ratios of SNRs in the LMC using Spitzer and Chandra SNR survey data and compare them with those of Galactic SNRs. IRX ratios of all the SNRs in the sample are found to be moderately greater than unity, indicating that dust grains are a more efficient coolant than gas although gas cooling may not be negligible. The IRX ratios of the LMC SNRs are systematically lower than those of the Galactic SNRs. As both dust cooling and gas cooling pertain to the properties of the interstellar medium, the lower IRX ratios of the LMC SNRs may reflect the characteristics of the LMC, and the lower dust-to- gas ratio (a quarter of the Galactic value) is likely to be the most significant factor. The observed IRX ratios are compared with theoretical predictions that yield IRX ratios an order of magnitude larger. This discrepancy may originate from the dearth ...

  19. Spectrum of cosmic rays, produced in supernova remnants

    E-print Network

    E. G. Berezhko; H. J. Voelk

    2007-04-13

    Nonlinear kinetic theory of cosmic ray (CR) acceleration in supernova remnants is employed to calculate CR spectra. The magnetic field in SNRs is assumed to be significantly amplified by the efficiently accelerating nuclear CR component. It is shown that the calculated CR spectra agree in a satisfactory way with the existing measurements up to the energy $10^{17}$ eV. The power law spectrum of protons extends up to the energy $3\\times 10^{15}$ eV with a subsequent exponential cutoff. It gives a natural explanation for the observed knee in the Galactic CR spectrum. The maximum energy of the accelerated nuclei is proportional to their charge number $Z$. Therefore the break in the Galactic CR spectrum is the result of the contribution of progressively heavier species in the overall CR spectrum so that at $10^{17}$ eV the CR spectrum is dominated by iron group nuclei. It is shown that this component plus a suitably chosen extragalactic CR component can give a consistent description for the entire Galactic CR spectrum.

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

    SciTech Connect

    Xing, Yi; Wang, Zhongxiang [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030 (China); Zhang, Xiao; Chen, Yang [Department Astronomy, Nanjing University, 22 Hankou Road, Nanjing 210093 (China)

    2014-02-01

    We report on the results from our ?-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 (10? 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 ?-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.

  1. Understanding the Balmer Bubble in the Vela Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Chinn, Brian; Smith, C.; Points, S.; Heathcote, S.

    2014-01-01

    We present imaging and spectroscopic data and analysis of the Balmer-dominated filament that is ahead of the eastern edge of the radiative shock of Bullet C in the Vela Supernova Remnant. This filament was discovered in 2002 by Carlin & Smith(2002), and was suggested to be a non-radiative shock. Images of the filament were taken using H? and R band filters on the SMARTS 0.9m telescope at CTIO. These images were then compared to images taken in 2006 using the MOSAIC II imager on the Blanco Telescope at CTIO, in an attempt to detect proper motion of the filament. Comparison over the 7 year baseline failed to show proper motion of the filament. From this result, we are able to place an upper limit of ~270 km/s on the velocity of the Balmer-dominated filament. We also obtained moderate resolution spectra of the Balmer-dominated filament and the radiative shock using the Goodman Spectrograph at SOAR Telescope. Spectroscopic analysis of the Balmer-dominated filament failed to detect a broad component of the H? emission line, which would be expected for a high velocity non-radiative shock.

  2. Searching for Compact Objects in Supernova Remnants:. Initial Results

    NASA Astrophysics Data System (ADS)

    Kaplan, D. L.; Kulkarni, S. R.; Frail, D. A.; Gaensler, B. M.; Slane, P. O.; Gotthelf, E. V.

    2004-08-01

    Most astronomers now accept that stars more massive than about 9 M? explode as supernovae and leave stellar remnants, either neutron stars or black holes. However, less than half of the SNRs within 5 kpc have identified central sources. Here, we discuss a systematic effort to search for compact central sources in the remaining 23 SNRs of this distance limited sample. As the first part of this survey, we are able to state with some confidence that there are no associated central sources down to a level of one tenth of that of the Cas A central source, LX ? 1031 ergs s-1, in four SNRs (G093.3+6.9, G315.4-2.3, G084.2+0.8, and G127.1+0.5). We compare our limits with cooling curves for neutron stars and find that any putative neutron stars in these SNRs must be cooling faster than that expected for traditional 1.35 M? neutron stars.

  3. Searching for Compact Objects in Supernova Remnants: Initial Results

    NASA Astrophysics Data System (ADS)

    Kaplan, D. L.; Kulkarni, S. R.; Frail, D. A.; Gaensler, B. M.; Slane, P. O.; Gotthelf, E. V.

    Most astronomers now accept that stars more massive than about 9 Msun explode as supernovae and leave stellar remnants, either neutron stars or black holes. However, less than half of the SNRs within 5 kpc have identified central sources. Here, we discuss a systematic effort to search for compact central sources in the remaining 23 SNRs of this distance-limited sample. As the first part of this survey, we are able to state with some confidence that there are no associated central sources down to a level of one tenth of that of the Cas A central source, LX < 1e31 ergs/s, in four SNRs (G093.3+6.9, G315.4-2.3, G084.2+0.8, and G127.1+0.5). We compare our limits with cooling curves for neutron stars and find that any putative neutron stars in these SNRs must be cooling faster than expected for traditional 1.35 Msun neutron stars.

  4. Supernova remnant W49B and its environment

    E-print Network

    Zhu, H; Zuo, P

    2014-01-01

    We study Gamma-ray supernova remnant W49B and its environment using recent radio and infrared data. {\\it Spitzer} IRS low resolution data of W49B shows shocked excitation lines of H$_{2}$ (0,0) S(0)-S(7) from the SNR-molecular cloud interaction. The H$_2$ gas is composed of two components with temperature of $\\sim$260 K and $\\sim$1060 K respectively. Various spectral lines from atomic and ionic particles are detected towards W49B. We suggest the ionic phase has an electron density of $\\sim$500 cm${}^{-3}$ and a temperature of $\\sim$${10^4}$ K by the spectral line diagnoses. The mid- and far-infrared data from {\\it MSX}, {\\it Spitzer} and {\\it Herschel} reveals a 151 $\\pm$ 20 K hot dust component with a mass of 7.5 $\\pm$ 6.6 $\\times$ ${10}^{-4} {\\Msol}$ and a 45 $\\pm$ 4 K warm dust component with a mass of 6.4 $\\pm$ 3.2 ${\\Msol}$. 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 HI absorp...

  5. Supernova remnants as cosmic ray accelerators. SNR IC 443

    E-print Network

    B. Hnatyk; O. Petruk

    1999-02-10

    We examine the hypothesis that some supernova remnants (SNRs) may be responsible for some unidentified gamma-ray sources detected by EGRET instrument aboard the Compton Gamma Ray Observatory. If this is the case, gamma-rays are produced via pion production and decay from direct inelastic collisions of accelerated by SNR shock wave ultrarelativistic protons with target protons of the interstellar medium. We develop a 3-D hydrodynamical model of SNR IC 443 as a possible cosmic gamma-ray source 2EG J0618+2234. The derived parameters of IC 443: the explosion energy E_o=2.7*10^{50} erg, the initial hydrogen number density n(0)=0.21 cm^{-3}, the mean radius R=9.6 pc and the age t=4500 yr result in too low gamma-ray flux, mainly because of the low explosion energy. Therefore, we investigate in detail the hydrodynamics of IC 443 interaction with a nearby massive molecular cloud and show that the reverse shock wave considerably increases the cosmic ray density in the interaction region. Meantime, the Rayleigh-Taylor instability of contact discontinuity between the SNR and the cloud provides an effective mixing of the containing cosmic ray plasma and the cloud material. We show that the resulting gamma-ray flux is consistent with the observational data.

  6. Particle acceleration and nonthermal emission in supernova remnant Cas A

    NASA Astrophysics Data System (ADS)

    Zirakashvili, Vladimir; Aharonian, Felix; Yang, Rui-Zhi.; Ona-Wilhelmi, Emma; Tuffs, Richard

    The processes responsible for the broad-band radiation of the young supernova remnant Cas A are explored. Electrons, protons and the oxygen ions accelerated by forward and reverse shocks are included in the numerical calculations. We show that the available multi-wavelength observations in the radio, X-ray and gamma-ray bands can be best explained by invoking particle acceleration by both forward and reversed shocks. Although the TeV gamma-ray observations can be interpreted by interactions of both accelerated electrons and protons/ions, the measurements by Fermi LAT at energies below 1 GeV give a tentative preference to the hadronic origin of gamma-rays. Then, the acceleration efficiency in this source, despite the previous claims, should be very high; 25 % of the explosion energy (or approximately 3* 10(50) erg) should already be converted to cosmic rays, mainly by the forward shock. At the same time, the model calculations do not provide extension of the maximum energy of accelerated protons beyond 100 TeV.

  7. Iron and dust in the supernova remnant IC443

    NASA Astrophysics Data System (ADS)

    Kokusho, T.; Nagayama, T.; Kaneda, H.; Ishihara, D.; Lee, H. G.; Onaka, T.

    We observed the supernova remnant IC 443 with the IRSF 1.4-m telescope, using the narrow-band filters tuned for the [Fe II] 1.257, 1.644 µ m, Pa? , and H2 1-0 S(1) lines. Comparing these results with the intensities of thermal emission from the warm dust associated with IC 443, derived by AKARI and Spitzer images, we find that the [Fe II] emission is enhanced relative to the dust emission in the central region of IC 443. The Pa? emission is also detected in the regions where the [Fe II] emission is bright. In contrast, the H2 emission is limb-brightened in the southern ridge. We also derived the highly-ionized Fe line intensity map from the data obtained by Suzaku. From these results, we have investigated the origin of the [Fe II] emission, which is difficult to be explained simply by considering the lifetime of 0.1-µ m silicate dust grains against sputtering destruction and the time for Fe to reach an ionization equilibrium in the hot plasma of IC 443.

  8. On the existence of "radio thermally active" Galactic supernova remnants

    E-print Network

    Onic, D; Arbutina, B; Leahy, D

    2012-01-01

    In this paper, we investigate the possibility of significant production of thermal bremsstrahlung radiation at radio continuum frequencies that could be linked to some Galactic supernova remnants (SNRs). The main targets for this investigation are SNRs expanding in high density environments. There are several indicators of radio thermal bremsstrahlung radiation from SNRs, such as a flattening at higher frequencies and thermal absorption at lower frequencies intrinsic to an SNR. In this work we discuss the radio continuum properties of 3 SNRs that are the best candidates for testing our hypothesis of significant thermal emission. In the case of SNRs IC443 and 3C391, thermal absorption has been previously detected. For IC443, the contribution of thermal emission at 1 GHz, from our model fit is 3-57%. It is similar to the estimate obtained from the thermal absorption properties (10-40% at 1 GHz). In the case of the 3C391 the conclusions are not so clear. The results from our model fit (thermal emission contribut...

  9. Hydrodynamic Simulation of Supernova Remnants Including Efficient Particle Acceleration

    E-print Network

    Donald C. Ellison; Anne Decourchelle; Jean Ballet

    2003-08-19

    A number of supernova remnants (SNRs) show nonthermal X-rays assumed to be synchrotron emission from shock accelerated TeV electrons. The existence of these TeV electrons strongly suggests that the shocks in SNRs are sources of galactic cosmic rays (CRs). In addition, there is convincing evidence from broad-band studies of individual SNRs and elsewhere that the particle acceleration process in SNRs can be efficient and nonlinear. If SNR shocks are efficient particle accelerators, the production of CRs impacts the thermal properties of the shock heated, X-ray emitting gas and the SNR evolution. We report on a technique that couples nonlinear diffusive shock acceleration, including the backreaction of the accelerated particles on the structure of the forward and reverse shocks, with a hydrodynamic simulation of SNR evolution. Compared to models which ignore CRs, the most important hydrodynamical effects of placing a significant fraction of shock energy into CRs are larger shock compression ratios and lower temperatures in the shocked gas. We compare our results, which use an approximate description of the acceleration process, with a more complete model where the full CR transport equations are solved (i.e., Berezhko et al., 2002), and find excellent agreement for the CR spectrum summed over the SNR lifetime and the evolving shock compression ratio. The importance of the coupling between particle acceleration and SNR dynamics for the interpretation of broad-band continuum and thermal X-ray observations is discussed.

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

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

    The supernova remnant Kes 17 (SNR G304.6+0.1) is one of a few but growing number of remnants detected across the electromagnetic spectrum. In this paper, we analyze recent radio, X-ray, and ?-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.

  11. G354.4+0.0: the youngest Galactic supernova remnant?

    NASA Astrophysics Data System (ADS)

    Vink, Jacco

    2013-10-01

    Although the supernova rate in the Milky Way is thought to be 3 per century, only two supernova remnants younger than 400 yr are known, Cas A and G1.9+0.4. Both these sources are X-ray synchrotron emitters, and in both these sources freshly synthesized, radio-active Ti-44 has been detected. This year a new, small (1.6 arcmin) shell-type supernova remnant was discovered, G354.4+0.0, which is a good candidate to be the youngest supernova remnant in the Galaxy. We propose to observe G354.4+0.0 both with XMM-Newton, for detailed imaging spectroscopy, and with NuStar for characterizing the potential synchrotron emission and search for line emission caused by the decay of Ti-44 at 68 keV and 78 keV.

  12. The Cosmic Ray Yield Of Supernova Remnants IC 443 And Puppis A

    NASA Astrophysics Data System (ADS)

    Hewitt, John W.

    2011-01-01

    Supernovae have long been thought responsible for accelerating Galactic cosmic rays. Recent observations with the Fermi Gamma-ray Space Telescope clearly identify GeV energy emission towards several supernova remnants. Combining data from radio to gamma-rays, we assemble the broadband spectral energy distribution of IC 443 and Puppis A, supernova remnants which are interacting with molecular clouds and have spatially extended gamma-ray emission. We account for strong infrared emission from shock heated dust which contributes significantly to inverse Compton gamma-ray emission. Spectral breaks are detected at both radio and gamma-ray wavelengths, placing constraints on the underlying relativistic particle distribution responsible for nonthermal emission. We discuss the implications of our results for the yield of cosmic rays accelerated during the evolution of supernova remnants.

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

    NASA Astrophysics Data System (ADS)

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

    2008-07-01

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

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

    NASA Astrophysics Data System (ADS)

    Dwek, Eli

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

  15. Supernova 1987A Interpreted through the SLIP Pulsar Model

    NASA Astrophysics Data System (ADS)

    Middleditch, John

    2010-01-01

    The model of pulsar emission through superluminally induced polarization currents (SLIP) predicts that pulsations produced by such currents, induced by a rotating, magnetized body at many light cylinder radii, as would be the case for a neutron star born within any star of >1.5 solar masses, will drive pulsations close to the axis of rotation. Such highly collimated pulsations (<= 1 in 10,000), and the similarly collimated jets of particles which it drove, including 1e-6 solar masses with velocities of up to 0.95 c, were responsible for the features of its very early light curve (days 3 - 20), the "Mystery Spot," observed slightly later (days 30 - 50 and >), and later, in less collimated form, the bipolarity of SN 1987A itself. The pulsations and jet interacted with circumstellar material (CM), to produce features observed in the very early light curve which correspond to: 1) the entry of the pulsed beam into the CM; 2) the entry of the 0.95 c particles into the CM; 3) the exit of the pulsed beam from the CM (with contributions in the B and I bands -- the same as later inferred/observed for its 2.14 ms pulsations); and 4) the exit of the fastest particles from the CM. Because of the energy requirements of the jet in these early stages, the spindown required of its pulsar could exceed 1e-5 Hz/s at a rotation rate of 500 Hz. There is no reason to suggest that this mechanism is not universally applicable to all SNe with gaseous remnants remaining, and thus SN 1987A is the Rosetta Stone for 99% of SNe, gamma-ray bursts, and millisecond pulsars. This work was supported in part by the Department of Energy through the Los Alamos Directed Research Grant DR20080085.

  16. IRS Spectroscopy of Shocked Molecular Gas in Supernova Remnants: Probing the Interaction of a Supernova with a Molecular Cloud

    Microsoft Academic Search

    David Neufeld; Edwin Bergin; David Hollenbach; Michael Kaufman; Gary Melnick; Ronald Snell

    2004-01-01

    We propose to carry out Spitzer\\/IRS observations of the interaction of a supernova with a molecular cloud. Using the Short-Lo, Short-Hi, and Long-Hi modes of IRS, we will perform spectral-line mapping over the entire IRS bandpass (5.3 - 37 micron) of a roughly 1 x 1 arcmin region in each of four supernova remnants: IC443 (clump C), 3C391, W28, and

  17. Discovery of the supernova remnant G351.0-5.4

    NASA Astrophysics Data System (ADS)

    de Gasperin, F.; Evoli, C.; Brüggen, M.; Hektor, A.; Cardillo, M.; Thorman, P.; Dawson, W. A.; Morrison, C. B.

    2014-08-01

    While searching the NRAO VLA Sky Survey (NVSS) for diffuse radio emission, we have serendipitously discovered extended radio emission close to the Galactic plane. The radio morphology suggests the presence of a previously unknown Galactic supernova remnant. An unclassified ?-ray source detected by EGRET (3EG J1744-3934) is present in the same location and may stem from the interaction between high-speed particles escaping the remnant and the surrounding interstellar medium. Our aim is to confirm the presence of a previously unknown supernova remnant and to determine a possible association with the ?-ray emission 3EG J1744-3934. We have conducted optical and radio follow-ups of the target using the Dark Energy Camera (DECam) on the Blanco telescope at Cerro Tololo Inter-American Observatory (CTIO) and the Giant Meterwave Radio Telescope (GMRT). We then combined these data with archival radio and ?-ray observations. While we detected the extended emission in four different radio bands (325, 1400, 2417, and 4850 MHz), no optical counterpart has been identified. Given its morphology and brightness, it is likely that the radio emission is caused by an old supernova remnant no longer visible in the optical band. Although an unclassified EGRET source is co-located with the supernova remnant, Fermi-LAT data do not show a significant ?-ray excess that is correlated with the radio emission. However, in the radial distribution of the ?-ray events, a spatially extended feature is related to supernova remnant at a confidence level of ~1.5?. We classify the newly discovered extended emission in the radio band as the old remnant of a previously unknown Galactic supernova: SNR G351.0-5.4. FITS files of Figs. 1 and 5 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/568/A107

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

    SciTech Connect

    Arendt, Richard G. [CRESST, University of Maryland, Baltimore County, Baltimore, MD 21250 (United States); Dwek, Eli; Kober, Gladys [NASA Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States); Rho, Jeonghee [SETI Institute, 189 Bernardo Avenue, Mountain View, CA 94043 (United States); Hwang, Una, E-mail: Richard.G.Arendt@nasa.gov [NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States)

    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 ?m), and broad-band Herschel PACS imaging (70, 100, and 160 ?m), 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 ?m 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 ?}.

  19. STAR FORMATION ASSOCIATED WITH THE SUPERNOVA REMNANT IC443

    SciTech Connect

    Xu Jinlong; Wang Junjie [National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Miller, Martin, E-mail: xujl@bao.ac.cn [Institute of Physics, University of Cologne, Cologne 50937 (Germany)

    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.

  20. On the Existence of "Radio Thermally Active" Galactic Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Oni?, D.; Uroševi?, D.; Arbutina, B.; Leahy, D.

    2012-09-01

    In this paper, we investigate the possibility of significant production of thermal bremsstrahlung radiation at radio continuum frequencies that could be linked to some Galactic supernova remnants (SNRs). The main targets for this investigation are SNRs expanding in high-density environments. There are several indicators of radio thermal bremsstrahlung radiation from SNRs, such as a flattening at higher frequencies and thermal absorption at lower frequencies intrinsic to an SNR. In this work, we discuss the radio continuum properties of three SNRs that are the best candidates for testing our hypothesis of significant thermal emission. In the case of SNRs IC 443 and 3C 391, thermal absorption has been previously detected. For IC 443, the contribution of thermal emission at 1 GHz, from our model fit is 3%-57%. It is similar to the estimate obtained from the thermal absorption properties (10%-40% at 1 GHz). In the case of the 3C 391 the conclusions are not so clear. The results from our model fit (thermal emission contribution of 10%-25% at 1 GHz) and results obtained from the low-frequency absorption (thermal contribution of 0.15%-7% at 1 GHz) do not overlap. For the SNR 3C 396 we suggest that if previously detected thermal absorption could be intrinsic to the SNR then the thermal emission (<47% at 1 GHz from our model fit) could be significant enough to shape the radio continuum spectrum at high frequencies. Polarization observations for these SNRs can constrain the strength of a thermal component. Reliable observations at low frequencies (<100 MHz) are needed as well as more data at high radio frequencies (>1 GHz), in order to make stronger conclusions about the existence of "radio thermally active" SNRs.

  1. Star Formation Associated with the Supernova Remnant IC443

    NASA Astrophysics Data System (ADS)

    Xu, Jin-Long; Wang, Jun-Jie; 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 × 103 M sun. The integrated CO line intensity ratio (R_{I_CO(3-2)/I_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_{I_CO(3-2)/I_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.

  2. ROSAT observations of the supernova remnant 3C 400.2

    NASA Technical Reports Server (NTRS)

    Saken, Jon M.; Long, K. S.; Blair, W. P.; Winkler, P. F.

    1995-01-01

    We have used the ROSAT point source proportional counter (PSPC) to examine the X-ray emission from 3C 400.2, a supernova remnant (SNR) which is a member of a class of remnants with limb-brightened radio and centrally condensed X-ray morphologies. The X-ray emission fills the radio shell and is characterized by an interior peak in the northwest region of the remnant. Otherwise, the surface brightness has a relatively smooth distribution. The X-ray peak is not correlated with any radio features or with the observed optical filaments. The PSPC X-ray spectrum is not well fitted by a power-law model but can be described in terms of thermal emission from a hot plasma with solar abundances. The only point source along the line of sight to the SNR is associated with a bright foreground F8 star. Thus the X-ray emission from 3C 400.2 is unlikely to be due to synchrotron radiation from an active pulsar. If the emission arises from a thermal plasma and the absorbing column along the line of sight to 3C 400.2 is 7.8 x 10(exp 21)sq cm, then the temperature of the plasma is 0.27 keV, and the 0.4-2.4 keV X-ray luminosity is 1.3 x 10(exp 36) ergs/s for an assumed distance of 6 kpc. An X-ray hardness ratio map shows a slight increase in the hardness of the emission in the regions of the remnant with a higher X-ray surface brightness. Assuming uniform absorption across the remnant, this increase implies the temperature is approximately 1.5 times greater in the high surface brightness regions of SNR. The relatively uniform spectrum and the anticorrelation between X-ray and radio features seems to rule out the possibility that 3C 400.2 is actually two overlapping or interacting SNRs. The morphology of 3C 400.2 can be explained in terms of a multiphase interstellar medium (ISM) in which the primary shock is expanding into an ISM studded with dense cloudlets, if the clouds are evaporated or disrupted on a timescale which is long compared to the age of the SNR. It may also be possible to explain the emission in terms of the interaction of the SNR with a massive wind-driven shell, although the existing models for the evolution of A SNR in this environment suggest that the H-alpha luminosity should be much larger than the X-ray luminosity, which is not observed. We cannot completely rule out the possibility that 3C 400.2's appearance as a centrally peaked X-ray SNR is the result of an interaction between the remnant and a cloud along the line of sight, although this seems unlikely.

  3. Asymmetric Supernovae, Pulsars, Magnetars, and Gamma-Ray Bursts

    E-print Network

    J. Craig Wheeler; Insu Yi; Peter Hoeflich; Lifan Wang

    2000-03-09

    We outline the possible physical processes, associated timescales, and energetics that could lead to the production of pulsars, jets, asymmetric supernovae, and weak gamma-ray bursts in routine circumstances and to a magnetar and perhaps stronger gamma-ray burst in more extreme circumstances in the collapse of the bare core of a massive star. The production of a LeBlanc-Wilson MHD jet could provide an asymmetric supernova and result in a weak gamma-ray burst when the jet accelerates down the stellar density gradient of a hydrogen-poor photosphere. The matter-dominated jet would be formed promptly, but requires 5 to 10 s to reach the surface of the progenitor of a Type Ib/c supernova. During this time, the newly-born neutron star could contract, spin up, and wind up field lines or turn on an alpha-Omega dynamo. In addition, the light cylinder will contract from a radius large compared to the Alfven radius to a size comparable to that of the neutron star. This will disrupt the structure of any organized dipole field and promote the generation of ultrarelativistic MHD waves (UMHDW) at high density and Large Amplitude Electromagnetic Waves (LAEMW) at low density. The generation of the these waves would be delayed by the cooling time of the neutron star about 5 to 10 seconds, but the propagation time is short so the UMHDW could arrive at the surface at about the same time as the matter jet. In the density gradient of the star and the matter jet, the intense flux of UMHDW and LAEMW could drive shocks, generate pions by proton-proton collision, or create electron/positron pairs depending on the circumstances. The UMHDW and LAEMW could influence the dynamics of the explosion and might also tend to flow out the rotation axis to produce a collimated gamma-ray burst.

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

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

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

  5. 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.

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

    E-print Network

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

    2012-01-01

    Recent X-ray observations of the supernova remnant IC443 interacting with molecular clouds have shown the presence of a new population of hard X-ray sources related to the remnant itself, which has been interpreted in terms of fast ejecta fragment propagating inside the dense environment. Prompted by these studies, we have obtained a deep {\\sl XMM-Newton} observation of the supernova remnant (SNR) Kes 69, which also shows signs of shock-cloud interaction. We report on the detection of 18 hard X-ray sources in the field of Kes 69, a significant excess of the expected galactic source population in the field, spatially correlated with CO emission from the cloud in the remnant environment. The spectra of 3 of the 18 sources can be described as hard power laws with photon index IC443) and cataclysmic variables. While most of the observati...

  7. 18. Supernova remnants and the origin of cosmic rays 18.1 High-energy emission from SNR

    E-print Network

    Pohl, Martin Karl Wilhelm

    18. Supernova remnants and the origin of cosmic rays 18.1 High-energy emission from SNR We have already mentioned supernova remnants as possible sources of cosmic rays, and indeed synchrotron emission rays, then the cosmic-ray density in and near the SNR should be very high, so one should be able to see

  8. Thermal X-ray emission of the remnants of ashperical Supernova explosions

    E-print Network

    O. Petruk

    2001-03-26

    Evolution of adiabatic remnants of an aspherical supernova explosion in uniform medium are considered. Thermal X-ray emission of such remnants are investigated. It is shown that integral thermal X-ray characteristics (X-ray luminosity and spectrum) of the objects do not allow us to reveal the assymetry in the explosion because these characteristics are close to their Sedov counterparts. Surface distribution of X-ray emission is sensitive to anisotropy of the explosion and nonuniformity of the interstellar medium.

  9. The Distances to the Supernova Remnants IC443 and MSH11-61A

    Microsoft Academic Search

    John R. Dickel

    1973-01-01

    21-cm line absorption measurements in the direction of the supernova ; remnant 1C443 suggest that it probably lies at a distance greater than 2.2 kpc ; and may be unassociated with an extended H II region to the east of the SNR. The ; remnant MSH11-61A is probably at a distance of about 3.5 kpc but the H II region

  10. Point-Like and Extended X-Ray Sources in the Supernova Remnant IC443

    Microsoft Academic Search

    Fabrizio Bocchino; Andrei M. Bykov

    2005-01-01

    We present the results we have obtained on the non-thermal hard X-ray emission from IC443, a supernova remnant interacting with molecular cloud (MC), from the initial discovery with BeppoSAX\\/PDS to the most recent results with XMM\\/Newton. This remnant has been detected up to EGRET bandwidth, and we have resolved part of the hard emission as 1) a plerion nebula with

  11. 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.

  12. The proper motion of the Vela pulsar

    Microsoft Academic Search

    M. Bailes; J. E. Reynolds; R. N. Manchester; M. J. Kesteven; R. P. Norris; Epping CSIRO

    1989-01-01

    The proper motion of the Vela pulsar using the Parkes-Tidbinbilla Interferometer has been measured over a 2 yr period and obtain a value of 49 + or - 5 mas\\/yr at a position angle 305 deg. This proper motion implies that the pulsar was not born at the geometric center of the Vela supernova remnant nor at the peak of

  13. Detecting X-ray Synchrotron Emission in Supernova Remnants: Implications for Abundances and Cosmic Rays

    E-print Network

    Kristy K. Dyer; Stephen P. Reynolds; Kazik J. Borkowski; Robert Petre

    2000-11-30

    The 10^51 ergs released in a supernova have far reaching consequences in the galaxy, determining elemental abundances, accelerating cosmic rays, and affecting the makeup of the interstellar medium. Recently the spectra of several supernova remnants have been found to be dominated by nonthermal emission. Separating the thermal and nonthermal components is important not only for the understanding of cosmic-ray acceleration and shock microphysics properties but for accurate assessment of the temperatures and line strengths. New models designed to model spatially resolved synchrotron X-rays from type Ia supernovae can contribute to the understanding of both the thermal physics (dynamics, abundances) and nonthermal physics (shock acceleration, magnetic-field amplification) of supernova remnants. I will describe model fits to SN 1006, emphasizing the physical constraints that can be placed on SNRs, abundances, and the cosmic-ray acceleration process.

  14. High-Velocity H I Gas in Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Koo, Bon-Chul

    1993-05-01

    Using the Hat Creek 85 foot telescope, we had carried out a survey of H I 21 cm emission lines toward all 103 known northern supernova remnants (SNRs) in order to find rapidly expanding SNR shells (Koo & Heiles 1991). We detected 15 SNRs that have associated high-velocity (HV) H I gas, most of which are quite likely the gas accelerated by the SN blast wave. Although the large beam-size (FWHM~ 30') of the 85 foot telescope prevented us to see the structure of the HV H I gas, the H I mass distribution in line-of-sight velocity suggested clumpy shell structures in several SNRs. In order to resolve the structure of the HV H I gas, we have been carrying out high-resolution H I 21 cm line observations using the Arecibo telescope and the VLA. We report preliminary results on two SNRs, CTB 80 and W51. In CTB 80, the VLA observations revealed fast moving H I clumps, which have a dense (n_H ~ 100 cm(-3) ) core surrounded by a relatively diffuse envelope. The clumps are small, 3 pc to 5 pc, and have velocities between +40 km s(-1) and +80 km s(-1) with respect to the systematic velocity of CTB 80. The clumps have relatively large momentum per unit volume, which implies that they have been swept-up at an early stage of the SNR evolution. By analyzing the Arecibo data, we found that the interstellar medium around CTB 80 is far from being uniform and homogeneous, which explains the peculiar morphology of CTB 80 in infrared and radio continuum. In W51, HV H I gas moving up to v_LSR>+150 km s(-1) has been detected. The H I distribution is elongated along the northwest-southeast direction, and the peak is very close to an X-ray bright region. We discuss the implications of our results in relation to the X-ray and the radio continuum morphology of W51. This work was supported in part by NON DIRECTED RESEARCH FUND, Korea Research Foundation, 1992.

  15. Updated Radio Sigma-D Relation for Galactic Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Pavlovic, M. Z.; Dobardzic, A.; Vukotic, B.; Urosevic, D.

    2014-12-01

    We present the updated empirical radio surface-brightness-to-diameter (Sigma - D) relation for supernova remnants (SNRs) in our Galaxy. Our original calibration sample of Galactic SNRs with independently determined distances (Pavlovic et al. 2013, hereafter Paper I) is reconsidered and updated with data which became available in the past two years. The orthogonal fitting procedure and probability-density-function-based (PDF) method are applied to the calibration sample in the log Sigma - log D plane. Non-standard orthogonal regression keeps the Sigma-D and D-Sigma relations invariant within estimated uncertainties. Our previous Monte Carlo simulations verified that the slopes of the empirical Sigma-D relation should be determined by using the orthogonal regression, because of its good performances for data sets with severe scatter. The updated calibration sample contains 65 shell SNRs. 6 new Galactic SNRs are added to the sample from Paper I, one is omitted and distances are changed for 10 SNRs. The slope derived is here slightly steeper (? ? 5.2) than the Sigma-D slope in Paper I (? ? 4.8). The PDF method relies on data points density maps which can provide more reliable calibrations that preserve more information contained in the calibration sample. We estimate distances to five new faint Galactic SNRs discovered for the first time by Canadian Galactic Plane Survey, and obtained distances of 2.3, 4.0, 1.3, 2.9 and 4.7 kiloparsecs for G108.5+11.0, G128.5+2.6, G149.5+3.2, G150.8+3.8 and G160.1-1.1, respectively. The updated empirical relation is used to estimate distances of 160 shell Galactic SNRs and new results change their distance scales up to 15 per cent, compared to the results from Paper I. The PDF calculation can provide even few times higher or lower values in comparison with the orthogonal fit, as it uses a totally different approach. However, on average, this difference is 32, 24 and 18 per cent for mode, median and mean distances.

  16. The Shock Structure of Supernova Remnant IC443

    NASA Technical Reports Server (NTRS)

    Haas, Michael R.; Higdon, S. J. U.; Burton, M. G.; Hollenbach, D. J.; Fonda, Mark (Technical Monitor)

    2003-01-01

    We present and discuss ISO observations of IC443, a supernova remnant interacting with a molecular cloud. An SWS spectrum centered on molecular hydrogen clump R10E (RA(2000) = 6 17 7.6, Decl(2000) = 22 25 34.6) is dominated by strong [SiII] (34 microns) emission and the pure rotational transitions of molecular hydrogen ranging from 0-0 S(1) to 0-0 S(13). Fits to these H$-2$ lines imply a large column (approx. 7E19 cm$ {-2)$) of warm (T approx. 700 K) gas and an ortho/para ratio for hydrogen near 3. LWS Fabry-Perot spectra of [OI] (63 microns) and [CII] (158 microns) at positions R10E and C (RA(2000) = 6 17 42.8, Decl(2000) = 22 21 38.1) find broad (approx. 75 km/s), blue-shifted (-40 km/s) line profiles; their similarity strongly suggests a common, shock-generated origin for these two lines. The surprisingly large [CII]/[OI] ratio (approx. 0.1 to 0.2) confirms previous observations with the Kuiper Airborne Observatory. These [CII] and [OI] line intensities, the [SiII] intensity (above), and LWS grating measurements of OH (119 microns) and [OI] (145 microns) are all readily fit by a single, fast J-shock model. Although the [OI] (63) emission can alternatively be produced by a slow C-shock, this ensemble of lines can not be produced by such a shock and provides strong evidence for the existence of a J-shock. A 24-arcmin strip map shows that this far-infrared line emission is spatially correlated with the H$-2$ 1-0 S(1) emission, which most likely arises in an associated C-shock. In addition to this spatially correlated shock emission, the strip map identifies extended [CII] and [OI] emission with a significantly larger line ratio (approx. 0.6); this 'background' component is compared with current J-shock, C-shock, photo-dissociation region (PDR), and X-ray dissociation region (XDR) models in an effort to explain its origin.

  17. 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

  18. Investigation of Supernova Remnant Shocks in the Vela-Puppis Region

    NASA Technical Reports Server (NTRS)

    Sankrit, Ravi

    2005-01-01

    Overview: We observed supernova remnant (SNR) shocks at four locations in the Vela- Puppis region. The targets were a bright X-ray knot in the center of the remnant, Knot D on the eastern limb of the remnant, a region overlapping the Puppis A SNR and a region within Vela overlapping the edge of the SNR Rx10852.0-4622. The aim of the observations was to characterize the properties of the shocks and identify separate kinematic components of the emission. The first round of analysis of these data produced significant interesting results as outlined below. Further analyses, in conjunction with other datasets, are planned.

  19. The Nature of the Ultraluminous Oxygen-Rich Supernova Remnant in NGC 4449

    E-print Network

    Milisavljevic, Dan

    2007-01-01

    Optical images and spectra both ground-based and taken by the Hubble Space Telescope (HST) of the young, luminous O-rich supernova remnant in the irregular galaxy NGC 4449 are presented. HST images of the remnant and its local region were taken with the ACS/WFC using filters F435W, F555W, F814W (B, V, and I, respectively), F502N ([O III]), F658N (Halpha + [N II]), F660N ([N II]) and F550M (line-free continuum). These images show an unresolved remnant (FWHM blue-shifted emission line...

  20. Observation of Supernova Remnant IC 443 with the Fermi Large Area Telescope

    NASA Astrophysics Data System (ADS)

    Abdo, A. A.; Ackermann, M.; Ajello, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B. M.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Burnett, T. H.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Casandjian, J. M.; Cecchi, C.; Çelik, Ö.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Cillis, A. N.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Cominsky, L. R.; Conrad, J.; Cutini, S.; Dermer, C. D.; de Angelis, A.; de Palma, F.; Silva, E. do Couto e.; Drell, P. S.; Drlica-Wagner, A.; Dubois, R.; Dumora, D.; Farnier, C.; Favuzzi, C.; Fegan, S. J.; Focke, W. B.; Fortin, P.; Frailis, M.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giavitto, G.; Giebels, B.; Giglietto, N.; Giordano, F.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grondin, M.-H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hanabata, Y.; Harding, A. K.; Hayashida, M.; Hughes, R. E.; Jackson, M. S.; Jóhannesson, G.; Johnson, A. S.; 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.; Lee, S.-H.; Lemoine-Goumard, M.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Makeev, A.; Mazziotta, M. N.; Meurer, C.; Michelson, P. F.; Mitthumsiri, W.; Moiseev, A. A.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nakamori, T.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Orlando, E.; Ormes, J. F.; Ozaki, M.; Paneque, D.; Panetta, J. H.; Parent, D.; Pelassa, V.; Pepe, M.; Pesce-Rollins, M.; Piron, F.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Reposeur, T.; Rochester, L. S.; Rodriguez, A. Y.; Romani, R. W.; Roth, M.; Ryde, F.; Sadrozinski, H. F.-W.; Sanchez, D.; Sander, A.; Saz Parkinson, P. M.; Scargle, J. D.; Sgrò, C.; Siskind, E. J.; Smith, D. A.; Smith, P. D.; Spandre, G.; Spinelli, P.; Strickman, M. S.; Strong, A. W.; Suson, D. J.; Tajima, H.; Takahashi, H.; Takahashi, T.; Tanaka, T.; Thayer, J. B.; Thayer, J. G.; Thompson, D. J.; Tibaldo, L.; Torres, D. F.; Tosti, G.; Tramacere, A.; Uchiyama, Y.; Usher, T. L.; Van Etten, A.; Vasileiou, V.; Venter, C.; Vilchez, N.; Vitale, V.; Waite, A. P.; Wang, P.; Winer, B. L.; Wood, K. S.; Ylinen, T.; Ziegler, M.

    2010-03-01

    We report observation of the supernova remnant (SNR) IC 443 (G189.1+3.0) with the Fermi Gamma-ray Space Telescope Large Area Telescope (LAT) in the energy band between 200 MeV and 50 GeV. IC 443 is a shell-type SNR with mixed morphology located off the outer Galactic plane where high-energy emission has been detected in the X-ray, GeV and TeV gamma-ray bands. Past observations suggest IC 443 has been interacting with surrounding interstellar matter. Proximity between dense shocked molecular clouds and GeV-TeV gamma-ray emission regions detected by EGRET, MAGIC, and VERITAS suggests an interpretation that cosmic-ray (CR) particles are accelerated by the SNR. With the high gamma-ray statistics and broad energy coverage provided by the LAT, we accurately characterize the gamma-ray emission produced by the CRs accelerated at IC 443. The emission region is extended in the energy band with ?68 = 0fdg27 ± 0fdg01(stat) ± 0fdg03(sys) for an assumed two-dimensional Gaussian profile and overlaps almost completely with the extended source region of VERITAS. Its centroid is displaced significantly from the known pulsar wind nebula (PWN) which suggests the PWN is not the major contributor in the present energy band. The observed spectrum changes its power-law slope continuously and continues smoothly to the MAGIC and VERITAS data points. The combined gamma-ray spectrum (200 MeV

  1. X-ray Spectroscopy of Potential Small Magellanic Cloud Type Ia Supernova Remnants and Their Environments

    NASA Astrophysics Data System (ADS)

    Roper, Q.; McEntaffer, R. L.; DeRoo, C.; Filipovic, M.; Wong, G. F.; Crawford, E. J.

    2015-04-01

    We examine three supernova remnants in the SMC, IKT 5 (supernova remnant (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 Type Ia SNRs. We detect potential point sources that may be members of the progenitor systems of both DEM S 128 and IKT 5, which could suggest these could be Fe-rich core-collapse remnants.

  2. Measuring the Magnetic Fields of Central Compact Objects in Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Halpern, Jules

    2008-09-01

    X-ray timing studies of two X-ray pulsars in SNRs have detected no braking of their rotation, implying upper limits of 3E11 G on their surface dipole fields, well below those of ordinary young pulsars. We proposed that weak B-fields related to slow natal spin may be the physical basis of the class of Central Compact Objects (CCOs), including the unseen pulsar in SN 1987A. This proposal leverages existing timing data on CCO pulsars to determine if they are spinning down and, if so, to measure their magnetic fields by obtaining coherent timing solutions linking all previous data. Fields as small as 1E10 G can be measured in this way. Alternatively, accretion of supernova debris through a fallback disk may be occurring, which would be detectable as torque noise.

  3. Measuring the Magnetic Fields of Central Compact Objects in Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Halpern, Jules

    2007-10-01

    X-ray timing studies of two X-ray pulsars in SNRs have detected no braking of their rotation, implying upper limits of 3E11 G on their surface dipole fields, well below those of ordinary young pulsars. We proposed that weak B-fields related to slow natal spin may be the physical basis of the class of Central Compact Objects (CCOs), including the unseen pulsar in SN 1987A. This proposal leverages existing timing data on CCO pulsars to determine if they are spinning down and, if so, to measure their magnetic fields by obtaining coherent timing solutions linking all previous data. Fields as small as 1E10 G can be measured in this way. Alternatively, accretion of supernova debris through a fallback disk may be occurring, which would be detectable as torque noise.

  4. A Spitzer Space Telescope Infrared Survey of Supernova Remnants in the Inner Galaxy

    E-print Network

    William T. Reach; Jeonghee Rho; Achim Tappe; Thomas G. Pannuti; Crystal L. Brogan; Edward B. Churchwell; Marilyn R. Meade; Brian Babler; Remy Indebetouw; Barbara A. Whitney

    2005-10-20

    Using Infrared Array Camera (IRAC) images at 3.6, 4.5, 5.8, and 8 microns from the GLIMPSE Legacy science program on the Spitzer Space Telescope, we searched for infrared counterparts to the 95 known supernova remnants that are located within galactic longitudes 65>|l|>10 degrees and latitudes |b|<1 degree. Eighteen infrared counterparts were detected. Many other supernova remnants could have significant infrared emission but are in portions of the Milky Way too confused to allow separation from bright HII regions and pervasive mid-infrared emission from atomic and molecular clouds along the line of sight. Infrared emission from supernova remnants originates from synchrotron emission, shock-heated dust, atomic fine-structure lines, and molecular lines. The detected remnants are G11.2-0.3, Kes 69, G22.7-0.2, 3C 391, W 44, 3C 396, 3C 397, W 49B, G54.4-0.3, Kes 17, Kes 20A, RCW 103, G344.7-0.1, G346.6-0.2, CTB 37A, G348.5-0.0, and G349.7+0.2. The infrared colors suggest emission from molecular lines (9 remnants), fine-structure lines (3), and PAH (4), or a combination; some remnants feature multiple colors in different regions. None of the remnants are dominated by synchrotron radiation at mid-infrared wavelengths. The IRAC-detected sample emphasizes remnants interacting with relatively dense gas, for which most of the shock cooling occurs through molecular or ionic lines in the mid-infrared.

  5. 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.

  6. Discovery of X-rays from the composite supernova remnant G0.9+0.1 with the BeppoSAX satellite

    E-print Network

    S. Mereghetti; L. Sidoli; G. L. Israel

    1997-10-29

    Using the BeppoSAX satellite we have obtained the first secure X-ray detection of the supernova remnant G0.9+0.1. The 1-10 keV spectrum can be described with an absorbed power law with photon index 3 and N_H = 3 times 10^{23} cm^2. The high column density supports a distance similar to that of the Galactic Center. The X-ray emission, with a luminosity L_x = 10^{35} d_{10kpc}^{2} erg/s, coincides with the central radio core, confirming the composite nature of this remnant. Though a search for periodic pulsations gave a negative result, the observed X-rays are probably related to the presence of a young radio pulsar at the center of G0.9+0.1.

  7. Molecular emission in the IC443 Supernova Remnant

    Microsoft Academic Search

    A. Gusdorf; R. Gusten; Y. Yuan; D. Neufeld

    2011-01-01

    Supernovae are an important source of energy input to the interstellar medium. They send shock waves that propagate through and interact with the Interstellar Medium. These shock waves originally create large cavities filled with hot ionized material. At some point, supernova-driven shock waves become radiative, emitting strong line emissions, initially at optical and ultraviolet wavelengths, that are widely observed from

  8. 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 K? 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? 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? 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.

  9. FERMI -LAT OBSERVATIONS AND A BROADBAND STUDY OF SUPERNOVA REMNANT CTB 109

    E-print Network

    Castro, Daniel

    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 ?-ray emission coincident with CTB 109, using 37 ...

  10. Cosmic ray acceleration in supernova remnants and the FERMI\\/PAMELA data

    Microsoft Academic Search

    Markus Ahlers; Philipp Mertsch; Subir Sarkar

    2009-01-01

    We discuss recent observations of high energy cosmic ray positrons and electrons in the context of hadronic interactions in supernova remnants (SNRs), the suspected accelerators of galactic cosmic rays. Diffusive shock acceleration can harden the energy spectrum of secondary positrons relative to that of the primary protons and electrons and thus explain the rise in the positron fraction observed by

  11. A New Sigma -D Relation and Its Application to the Galactic Supernova Remnant Distribution

    Microsoft Academic Search

    Gary L. Case; Dipen Bhattacharya

    1998-01-01

    Technological advances in radio telescopes and X-ray instruments over the last 20 years have greatly increased the number of known supernova remnants (SNRs) and have led to a better determination of their properties. In particular, more SNRs now have reasonably determined distances. However, many of these distances were determined kinematically using old rotation curves (based on R&sun; = 10 kpc

  12. Possible optical counterparts to the X-ray point source in the supernova remnant CTB 80

    Microsoft Academic Search

    W. P. Blair; R. E. Schild

    1985-01-01

    A three color CCD image of the central region of the supernova remnant CTB 80 is presented, along with astrometry and photometry of many stars in the field. The color image does not show evidence of heavy or variable dust absorption in the surrounding region. Using an Einstein High Resolution Imager position for the central X-ray point source, two possible

  13. Shocked Molecular Gas in the Supernova Remnant IC443: Models with an Enhanced Ionization Rate

    Microsoft Academic Search

    G. F. Mitchell

    1988-01-01

    IC 443 is the only supernova remnant which we know to be interacting with interstellar molecular gas. The purpose of the present work is to see whether shock models are consistent with recent molecular observations and to assess the effects of an increased cosmic ray ionization rate on molecular abundances. New calculations of molecular abundances behind shocks have been carried

  14. Influence of Cosmic-ray Acceleration Processes on the Observable Properties of Supernova Remnant Models.

    NASA Astrophysics Data System (ADS)

    Kosenko, Daria; Blinnikov, Sergey

    We present numerical models for supernova remnant evolution, performed with a hydro-dynamical code SUPREMNA. The code accounts for electron thermal conduction, electron and ion tem-perature equilibration and includes self-consistent calculations of time-dependent ionization processes in the shocked plasma. In this study we present an additional modification of the package: introduction of cosmic-ray acceleration processes. We employ two-fluid approxima-tion, which allows us to take into account self-consistently thermal energy losses to relativistic particles. We investigate the influence of the relevant parameters on the dynamical and phys-ical properties of the modeled remnants and on the corresponding simulated X-ray spectra. We compare the properties of the models with the observed features of some young supernova remnants such as Tycho and SN1006.

  15. A search for OH 6 GHz maser emission towards southern supernova remnants

    E-print Network

    Korinne E. McDonnell; Alan E. Vaughan; Mark Wardle

    2007-04-18

    OH masers at 1720 MHz have proven to be excellent indicators of interactions between supernova remnants and molecular clouds. Recent calculations suggest that the 6049 MHz OH maser line is excited for higher column densities than for the 1720 MHz line. It is therefore a potentially valuable indicator of remnant-cloud interaction. We present preliminary results of a survey using the Parkes Methanol Multibeam receiver for 6049 MHz and 6035/6030 MHz OH masers towards 36 supernova remnants and 4 fields in the Large and Small Magellanic Clouds. While no 6049 MHz masers have been found, three new sites of 6035 and 6030 MHz OH maser emission have been discovered in star-forming regions.

  16. An Integral View of Balmer-dominated Shocks in Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Nikoli?, Sladjana; van de Ven, Glenn; Heng, Kevin; Kupko, Daniel; Lopez Aguerri, Jose Alfonso; Méndez-Abreu, Jairo; Serra, Joan Font; Beckman, John

    2014-01-01

    We present integral-field spectroscopic observations with the VIMOS-IFU at the VLT of fast (2000-3000 kms-1) Balmer-dominated shocks surrounding the northwestern rim of the remnant of supernova 1006. The high spatial and spectral resolution of the instrument enable us to show that the physical characteristics of the shocks exhibit a strong spatial variation over few atomic scale lengths across 133 sky locations. Our results point to the presence of a population of non-thermal protons (10-100 keV) which might well be the seed particles for generating high-energy cosmic rays. We also present observations of Tycho's supernova remnant taken with the narrow-band tunable filter imager OSIRIS at the GTC and the Fabry-Perot interferometer GHaFaS at the WHT to resolve respectively the broad and narrow H? lines across a large part of the remnant.

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

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

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

  18. Near-Infrared Study of Iron Knots in Cassiopeia A Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Lee, Yong-Hyun; Koo, Bon-Chul; Moon, Dae-Sik; Burton, Michael G.

    2014-01-01

    We present the results of near-infrared (NIR) imaging and spectroscopic observations of the Galactic supernova remnant Cassiopeia A (Cas A). Applying the method of Principal Component Analysis to our broadband NIR spectra, we identify a total of 61 NIR emission knots of Cas A and classify them into three groups of distinct spectral characteristics: Helium-rich, Sulfur-rich, and Iron-rich groups. The first and second groups are of the circumstellar and supernova ejecta origin, respectively. The third group, which has enhanced iron emission, is of particular interests since it shows intermediate characteristics between the former two groups. We suggest that the Iron-rich group is knots of swept-up circumstellar medium around the contact discontinuity in Cas A and/or supernova ejecta from deep layers of its progenitor star which have recently encountered a reverse shock in the remnant.

  19. How Do The Properties of Light Help Us To Study Supernovae and Their Remnants?

    NSDL National Science Digital Library

    This resource describes special properties of light that can help us to understand objects that are millions and billions of light years away. Students explore some of these properties and how they can use them to understand our universe. They will understand that superheated material created by the supernova explosion gives off X-rays and gamma-rays. They will find the answers to questions such as what electromagnetic (EM) radiation is and what units are used to characterize it. They also learn that it pays to make multiple observations of astronomical objects, since they emit light of different energies, that supernovae remnants can give off visible light, ultraviolet light, radio waves and X-rays, and that each observation of a supernovae remnant can give us different information about it. The site also includes a student exercise and links to more information.

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

    SciTech Connect

    Heinz, S.; Sell, P. [Department of Astronomy, University of Wisconsin-Madison, Madison, WI 53706 (United States); Fender, R. P. [Sub-department of Astrophysics, University of Oxford, Oxford OX1 3RH (United Kingdom); Jonker, P. G. [SRON, Netherlands Institute for Space Research, 3584-CA, Utrecht (Netherlands); Brandt, W. N. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Calvelo-Santos, D. E. [Department of Physics and Astronomy, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Tzioumis, A. K. [Australia Telescope National Facility, CSIRO, Epping, NSW 1710 (Australia); Nowak, M. A.; Schulz, N. S. [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Wijnands, R.; Van der Klis, M., E-mail: heinzs@astro.wisc.edu [Astronomical Institute "Anton Pannekoek," University of Amsterdam, 1090-GE Amsterdam (Netherlands)

    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.

  1. VERITAS Studies of the Supernova Remnants Cas A and IC 443

    NASA Astrophysics Data System (ADS)

    Humensky, T. B.

    2008-12-01

    VERITAS observed the supernova remnants Cassiopeia A (Cas A) and IC 443 during 2007, resulting in strong TeV detections of both sources. Cas A is a young remnant, and bright in both the radio and nonthermal X-rays, both tracers of cosmic-ray electrons. IC 443 is a middle-aged composite remnant interacting with a molecular cloud; the molecular cloud provides an enhanced density of target material for hadronic cosmic rays to produce TeV gamma rays via pion decay. The TeV morphology-point-like for Cas A and extended for IC 443-will be discussed in the context of existing multiwavelength data on the remnants.

  2. The Vela Pulsar and Its Synchrotron Nebula

    Microsoft Academic Search

    D. J. Helfand; E. V. Gotthelf; J. P. Halpern

    2000-01-01

    We present high-resolution Chandra X-ray observations of PSR0833-45, the 89 ms pulsar associated with the Vela supernova remnant. We have acquired two observations of the pulsar separated by one month to search for morphological changes in the pulsar and its environment following an extreme glitch in its rotation frequency. We find a well-resolved nebula with a morphology remarkably similar to

  3. Investigation of the Progenitors of the Type Ia Supernovae Associated with the LMC Supernova Remnants 0505-67.9 and 0509-68.7

    NASA Astrophysics Data System (ADS)

    Pagnotta, Ashley; Schaefer, Bradley E.

    2015-01-01

    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.

  4. Anisotropic Thermal Conduction in Supernova Remnants: Relevance to Hot Gas Filling Factors in the Magnetized ISM

    E-print Network

    David A. Tilley; Dinshaw S. Balsara

    2006-04-05

    We explore the importance of anisotropic thermal conduction in the evolution of supernova remnants via numerical simulations. The mean temperature of the bubble of hot gas is decreased by a factor of ~3 compared to simulations without thermal conduction, together with an increase in the mean density of hot gas by a similar factor. Thus, thermal conduction greatly reduces the volume of hot gas produced over the life of the remnant. This underscores the importance of thermal conduction in estimating the hot gas filling fraction and emissivities in high-stage ions in Galactic and proto-galactic ISMs.

  5. Search for Gamma-Ray Emission from the Supernova Remnant IC 443 with the MAGIC Telescope

    NASA Astrophysics Data System (ADS)

    García López, R. J.

    2009-05-01

    TeV observations of Supernova remnants (SNRs) and, in particular, of SNRs which appear to be physically related to EGRET sources are a prime target for the MAGIC telescope. MAGIC's spatial resolution and sensitivity can probe the main mechanism responsible for producing high energy photons in the SNR neighbourhood. Based on a recent systematical analysis of the molecular environment of the vicinity of all SNR-EGRET source pairs, the IC 443 remnant was chosen for observations with MAGIC. We briefly describe the observational strategy which provided the detection of a new very-high energy gamma-ray source: MAGIC J0616+225.

  6. A ROSAT observation of the supernova remnant Kes 79

    NASA Technical Reports Server (NTRS)

    Seward, F. D.; Velusamy, T.

    1995-01-01

    Kes 79 was observed with the ROSAT Position Sensitive Proportional Counter (PSPC) and High Resolution Imager (HRI). Some X-ray emission comes from a faint outer region, well correlated with the outer shell. Most emission is from a bright diffuse inner region where there are also bright radio filaments. The X-ray spectrum is fitted with a thermal model with temperature 1.3 keV. Variations in spectra from different regions arew small. There is no X-ray evidence for an internal neutron star. Remnant characteristics are derived using a simple blast-wave model. The observed X-ray absorption is less than expected. It is possible that the remnant is closer than the published distance of 10 kpc.

  7. Imagine the Universe: Radioactive Decay in Supernova Remnants

    NSDL National Science Digital Library

    This site explains how supernovae can be detected and studied by measuring the decay of radioactive elements in the material ejected from them. It is part of the Goddard Space Flight Center's "Imagine the Universe" website, created by GSFC's Laboratory for High Energy Astrophysics. It includes text, remotely sensed imagery, and links to other topics related to high energy astrophysics.

  8. Shock Interactions in the Supernova Remnant IC443

    Microsoft Academic Search

    Una Hwang

    2007-01-01

    We propose two ACIS-I observations to obtain high-quality spectra and images of the bright northeast region of the supernova IC 443. We aim to identify coherent shock structures in conjunction with optical images, and to perform spatially resolved spectroscopy and spectral imaging. The northeast region of IC 443 is interacting with diffuse interstellar medium, atomic and molecular clouds at its

  9. MOLECULAR ENVIRONMENT AND THERMAL X-RAY SPECTROSCOPY OF THE SEMICIRCULAR YOUNG COMPOSITE SUPERNOVA REMNANT 3C 396

    E-print Network

    Su, Yang

    We have investigated the molecular environment of the semicircular composite supernova remnant (SNR) 3C 396 and performed a Chandra spatially resolved thermal X-ray spectroscopic study of this young SNR. With our CO ...

  10. Expanding Ejecta in the Core-Collapse Supernova Remnant G292.0+1.8, Cas A’s Older Cousin

    NASA Astrophysics Data System (ADS)

    Twelker, Karl; Reith, C. N.; Winkler, P. F.; Long, K. S.

    2006-12-01

    G292.0+1.8 is an oxygen-rich supernova remnant (SNR)--a member of the same exclusive family as Cas A. It is the only Galactic SNR which displays all the features expected in the young remnant of a core-collapse supernova: optical (and X-ray) emission from fragments of metal-rich ejecta, an active pulsar and associated pulsar-wind nebula, and evidence for interaction of a blast wave with circumstellar wind material. We report here measurements of proper motions of the ejecta-dominated filaments, based on CCD images in the [O III] 5007 Å line taken from the CTIO 0.9m telescope at epochs from 1999 through 2006. We also use additional images from as early as 1986 for the central region of this 8-arcmin-diameter remnant. Matched narrow-band continuum images at most epochs aid in removing the myriad stars that litter the crowded field, making small, faint filaments of ejecta more apparent. We use a two-dimensional cross-correlation technique to measure the shifts for dozens of individual filaments between multiple epoch pairs. The fastest, most outlying filaments display proper motions as large as 0.15 arcsec/yr. Preliminary results appear consistent with undecelerated expansion from a common center, and suggest a kinematic age slightly younger than the 3000-3400 yr inferred by Ghavamian et al. (2005, ApJ, 635, 365) from Fabry-Perot measurements of the radial velocities for many of the ejecta filaments in G292. This work is partially supported by the National Science Foundation through grant AST-0307613.

  11. Modelling of the Galactic Distribution of Titanium-44 Emitting Young Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Dufour, Francois

    Following the lone detection of the Galactic supernova remnant Cas A by gamma-ray detectors aboard CGRO and hard X-ray detectors aboard INTEGRAL in the nuclear lines of the 44Ti decay chain, The et al, 2006, argued that these surveys should have detected several sources, given models for the yield of 44Ti and an estimate of the Galactic supernova rate. In this thesis, this result is revisited by exploring the effect of various newer yield models of Type II supernovae, which include yields that differ by approximately an order of magnitude. We also consider several estimates of the Galactic supernova rate, which also differ by an order of magnitude, and various models for the Galactic distribution of massive stars. We find that the lone detection of Cas A is in fact consistent with a large number of reasonable models. We find that in order to detect a significant number of previously unknown remnants in a survey for 44Ti and thus constrain supernova models, a sensitivity to fluxes of less than 1E-7 photon per square cm per second within an absolute Galactic latitude of less than 5 degrees is required.

  12. Discovery of TeV Gamma Rays from SN 1006: Further Evidence for the Supernova Remnant Origin of Cosmic Rays

    Microsoft Academic Search

    T. Tanimori; Y. Hayami; S. Kamei; S. A. Dazeley; P. G. Edwards; S. Gunji; S. Hara; T. Hara; J. Holder; A. Kawachi; T. Kifune; R. Kita; T. Konishi; A. Masaike; Y. Matsubara; T. Matsuoka; Y. Mizumoto; M. Mori; M. Moriya; H. Muraishi; Y. Muraki; T. Naito; K. Nishijima; S. Oda; S. Ogio; J. R. Patterson; M. D. Roberts; G. P. Rowell; K. Sakurazawa; T. Sako; Y. Sato; R. Susukita; A. Suzuki; R. Suzuki; T. Tamura; G. J. Thornton; S. Yanagita; T. Yoshida; T. Yoshikoshi

    1998-01-01

    In this Letter we report the discovery of TeV gamma-ray emission from a supernova remnant made with the CANGAROO 3.8 m telescope. TeV gamma rays were detected at the sky position and extension coincident with the northeast rim of shell-type supernova remnant (SNR) SN 1006 (Type Ia). SN 1006 has been a most likely candidate for an extended TeV gamma-ray

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

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1975-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

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

  15. 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.

  16. Evidence for shock acceleration of high-energy electrons in the supernova remnant SN1006

    NASA Astrophysics Data System (ADS)

    Koyama, K.; Petre, R.; Gotthelf, E. V.; Hwang, U.; Matsuura, M.; Ozaki, M.; Holt, S. S.

    1995-11-01

    HIGH-ENERGY cosmic rays (relativistic heavy nuclei) play an important role in heating interstellar matter in the Milky Way1,2, and they affect chemical abundances through collisions with atoms in the interstellar gas2. Although it has long been thought that these cosmic rays arise from supernovae3,4, direct evidence for such an association has been lacking. Here we report X-ray observations of the remnant of supernova 1006, made by the ASCA satellite, which indicate that emission from the edges of the remnant shell is dominated by radiation from electrons accelerated to energies of ˜ 100 TeV within the shock front. Ions in the shell are likely to have been accelerated to similar energies, thus giving rise to very-high-energy cosmic rays.

  17. Thermal and non-thermal contributions to the X-ray spectrum of Large Magellanic Cloud supernova remnants

    Microsoft Academic Search

    Sean Patrick Hendrick

    2003-01-01

    The study of supernovae and the expanding remnants that form after the explosion is important to understanding star formation and the distribution of elements in the interstellar medium (ISM). This work examines the X-ray spectrum of 14 LMC remnants: three new Chandra observations, and eleven archival ASCA observations. The plasma that is responsible for the X-ray emission is heated by

  18. XMM-Newton observations of the thermal X-ray emitting plasma in the supernova remnant IC443

    Microsoft Academic Search

    E. Troja; F. Bocchino; F. Reale

    2006-01-01

    We present a spatially resolved analysis of XMM-Newton observations of the Galactic supernova remnant SNR IC443 and a comparison with results obtained at other wavelengths This remnant is a classical example of SNR interacting with ambient molecular clouds MCs and it has been considered a member of the mixed morphology class Our data unveil for the first time a partial

  19. 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.

  20. Computer simulations of cosmic-ray diffusion near supernova remnant shock waves

    Microsoft Academic Search

    C. E. Max; A. L. Zachary; J. Arons

    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

  1. Observation of Supernova Remnant IC 443 with the Fermi Large Area Telescope

    Microsoft Academic Search

    A. A. Abdo; M. Ackermann; M. Ajello; L. Baldini; J. Ballet; G. Barbiellini; D. Bastieri; B. M. Baughman; K. Bechtol; R. Bellazzini; B. Berenji; R. D. Blandford; E. D. Bloom; E. Bonamente; A. W. Borgland; J. Bregeon; A. Brez; M. Brigida; P. Bruel; T. H. Burnett; S. Buson; G. A. Caliandro; R. A. Cameron; P. A. Caraveo; J. M. Casandjian; C. Cecchi; Ö. Çelik; A. Chekhtman; C. C. Cheung; J. Chiang; A. N. Cillis; S. Ciprini; R. Claus; J. Cohen-Tanugi; L. R. Cominsky; J. Conrad; S. Cutini; C. D. Dermer; A. de Angelis; F. de Palma; E. do Couto e. Silva; P. S. Drell; A. Drlica-Wagner; R. Dubois; D. Dumora; C. Farnier; C. Favuzzi; S. J. Fegan; W. B. Focke; P. Fortin; M. Frailis; Y. Fukazawa; S. Funk; P. Fusco; F. Gargano; D. Gasparrini; N. Gehrels; S. Germani; G. Giavitto; B. Giebels; N. Giglietto; F. Giordano; T. Glanzman; G. Godfrey; I. A. Grenier; M.-H. Grondin; J. E. Grove; L. Guillemot; S. Guiriec; Y. Hanabata; A. K. Harding; M. Hayashida; R. E. Hughes; M. S. Jackson; G. Jóhannesson; A. S. Johnson; T. J. Johnson; W. N. Johnson; T. Kamae; H. Katagiri; J. Kataoka; N. Kawai; M. Kerr; J. Knödlseder; M. L. Kocian; M. Kuss; J. Lande; L. Latronico; S.-H. Lee; M. Lemoine-Goumard; F. Longo; F. Loparco; B. Lott; M. N. Lovellette; P. Lubrano; G. M. Madejski; A. Makeev; M. N. Mazziotta; C. Meurer; P. F. Michelson; W. Mitthumsiri; A. A. Moiseev; C. Monte; M. E. Monzani; A. Morselli; I. V. Moskalenko; S. Murgia; T. Nakamori; P. L. Nolan; J. P. Norris; E. Nuss; T. Ohsugi; E. Orlando; J. F. Ormes; M. Ozaki; D. Paneque; J. H. Panetta; D. Parent; V. Pelassa; M. Pepe; M. Pesce-Rollins; F. Piron; T. A. Porter; S. Rainò; R. Rando; M. Razzano; A. Reimer; O. Reimer; T. Reposeur; L. S. Rochester; A. Y. Rodriguez; R. W. Romani; M. Roth; F. Ryde; H. F.-W. Sadrozinski; D. Sanchez; A. Sander; P. M. Saz Parkinson; J. D. Scargle; C. Sgrò; E. J. Siskind; D. A. Smith; P. D. Smith; G. Spandre; P. Spinelli; M. S. Strickman; A. W. Strong; D. J. Suson; H. Tajima; H. Takahashi; T. Takahashi; T. Tanaka; J. B. Thayer; J. G. Thayer; D. J. Thompson; L. Tibaldo; D. F. Torres; G. Tosti; A. Tramacere; Y. Uchiyama; T. L. Usher; A. Van Etten; V. Vasileiou; C. Venter; N. Vilchez; V. Vitale; A. P. Waite; P. Wang; B. L. Winer; K. S. Wood; T. Ylinen; M. Ziegler

    2010-01-01

    We report observation of the supernova remnant (SNR) IC 443 (G189.1+3.0) with the Fermi Gamma-ray Space Telescope Large Area Telescope (LAT) in the energy band between 200 MeV and 50 GeV. IC 443 is a shell-type SNR with mixed morphology located off the outer Galactic plane where high-energy emission has been detected in the X-ray, GeV and TeV gamma-ray bands.

  2. 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.

  3. Discovery of Resolved X-ray\\/radio\\/optical Supernova Remnants in M31

    Microsoft Academic Search

    A. K. H. Kong; M. R. Garcia; L. O. Sjouwerman; B. F. Williams; F. A. Primini; J. R. Dickel

    2003-01-01

    Chandra observations of M31 allow the first spatially resolved X-ray image of a supernova remnant (SNR) in an external spiral galaxy. CXOM31 J004327.7+411829 is a slightly elongated ring-shaped object with a diameter of 11'' (42 pc). In addition, the X-ray image hints that the chemical composition of the SNR is spatially dependent. The age of the SNR is estimated to

  4. The Most Likely Sources of High-Energy Cosmic-Ray Electrons in Supernova Remnants

    Microsoft Academic Search

    T. Kobayashi; Y. Komori; K. Yoshida; J. Nishimura

    2004-01-01

    Evidence of nonthermal X-ray emission and TeV gamma rays from supernova remnants (SNRs) have strengthened the hypothesis that primary Galactic cosmic-ray electrons are accelerated in SNRs. High-energy electrons lose energy via synchrotron and inverse Compton processes during propagation in the Galaxy. Because of these radiative losses, TeV electrons liberated from SNRs at distances larger than ~1 kpc, or times older

  5. Thermal X-Ray Emission and Cosmic-Ray Production in Young Supernova Remnants

    Microsoft Academic Search

    Anne Decourchelle; Donald C. Ellison; Jean Ballet

    2000-01-01

    We have developed a simple model to investigate the modifications of the hydrodynamics and nonequilibrium ionization X-ray emission in young supernova remnants due to nonlinear particle acceleration. In nonlinear, diffusive shock acceleration, the heating of the gas to X-ray-emitting temperatures is strongly coupled to the acceleration of cosmic-ray ions. If the acceleration is efficient and a significant fraction of the

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

    E-print Network

    Enomoto, R; Yoshida, T; Tanimori, T

    2008-01-01

    Kepler's supernova, discovered in October 1604, 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 Cherenkov 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.

  7. G54.1 + 0.3 - A new Crab-like supernova remnant

    NASA Technical Reports Server (NTRS)

    Velusamy, T.; Becker, R. H.

    1988-01-01

    High-resolution multifrequency observations with the VLA and OSRT of the small-diameter flat-spectrum radio source G54.1 + 0.3 are presented. The filled-center brightness distribution, strong polarization at 6 cm, and flat radio spectrum (alpha of about -0.13) from 0.327 to 5 GHz confirm that G54.1 + 0.3 is a Crab-like supernova remnant.

  8. G54. 1 + 0. 3 - a new Crab-like supernova remnant

    SciTech Connect

    Velusamy, T.; Becker, R.H.

    1988-04-01

    High-resolution multifrequency observations with the VLA and OSRT of the small-diameter flat-spectrum radio source G54.1 + 0.3 are presented. The filled-center brightness distribution, strong polarization at 6 cm, and flat radio spectrum (alpha of about -0.13) from 0.327 to 5 GHz confirm that G54.1 + 0.3 is a Crab-like supernova remnant. 22 references.

  9. Spitzer spectral line mapping of supernova remnants: I. Basic data and principal component analysis

    Microsoft Academic Search

    David A. Neufeld; David J. Hollenbach; Michael J. Kaufman; Ronald L. Snell; Gary J. Melnick; Edwin A. Bergin; Paule Sonnentrucker

    2007-01-01

    We report the results of spectroscopic mapping observations carried out\\u000atoward small (1 x 1 arcmin) regions within the supernova remnants W44, W28,\\u000aIC443, and 3C391 using the Infrared Spectrograph of the Spitzer Space\\u000aTelescope. These observations, covering the 5.2 - 37 micron spectral region,\\u000ahave led to the detection of a total of 15 fine structure transitions of Ne+,

  10. TeV Gamma Rays and Cosmic-Ray Acceleration in Supernova Remnants

    Microsoft Academic Search

    James H. Buckley

    1998-01-01

    If supernova remnants (SNRs) are the site of cosmic-ray acceleration, the associated nuclear interactions should result in an observable flux of pi^0-decay gamma-rays for the nearest SNRs. Measurements of the TeV gamma-ray flux from nearby, radio-bright SNRs have been made with the Whipple imaging air Cherenkov telescope but reveal no significant emission (Buckley et al. 1998). Three of these SNRs

  11. 2 MASS Near-Infrared Imaging of the Supernova Remnant IC443

    Microsoft Academic Search

    J. Rho; S. van Dyk; T. Jarrett; R. Cutri; W. Reach

    1999-01-01

    We present near-infrared imaging of IC443, covering the entire supernova remnant (50' diameter) from The Two Micron All Sky Survey (2MASS). 2MASS imaging is taken simultaneously in the J (1.25mu m), H (1.65mu m) and K_s (2.17mu m) bands using a 1.3 m telescope with a three-channel camera. The images have 3.5'' spatial resolution with a pixel size of 1''.

  12. 2 MASS Near-Infared Imaging of the Supernova Remnant IC443

    Microsoft Academic Search

    Jeonghee Rho; Schuyler van Dyk; T. Jarrett; C. Roc; W. T. Reach

    1999-01-01

    We present near-infrared imaging of IC443, covering the entire supernova remnant (50' diameter) from The Two Micron All Sky Survey (2MASS). 2MASS imaging is taken simultaneously in the J (1.25 microns), H (1.65 microns) and K_s (2.17 microns) bands using a 1.3 m telescope with a three-channel camera. The images have 3.5'' spatial resolution with a pixel size of 1''.

  13. ISOCAM spectro-imaging of the H2 rotational lines in the supernova remnant IC443

    Microsoft Academic Search

    D. Cesarsky; P. Cox; G. Pineau des Forets; E. F. van Dishoeck; F. Boulanger; C. M. Wright

    1999-01-01

    We report spectro-imaging observations of the bright western ridge of the\\u000asupernova remnant IC 443 obtained with the ISOCAM circular variable filter\\u000a(CVF) on board the Infrared Space Observatory (ISO). This ridge corresponds to\\u000aa location where the interaction between the blast wave of the supernova and\\u000aambient molecular gas is amongst the strongest. The CVF data show that the

  14. The Sizes of OH (1720 MHz) Supernova Remnant Masers: MERLIN and VLBA Observations of IC443

    Microsoft Academic Search

    Ian M. Hoffman; W. M. Goss; C. L. Brogan; M. J Claussen; A. M. S. Richards

    2002-01-01

    MERLIN and VLBA observations of the 1720 MHz maser emission from the OH\\u000amolecule in the supernova remnant IC443 are presented. Based on MERLIN data\\u000awith a resolution of 160 mas, the deconvolved sizes of the maser sources are in\\u000athe range 90 to 180 mas (135 to 270 AU). The 12 mas resolution VLBA images show\\u000acompact cores with

  15. Diffuse neutrinos from extragalactic supernova remnants: Dominating the 100 TeV IceCube flux

    NASA Astrophysics Data System (ADS)

    Chakraborty, Sovan; Izaguirre, Ignacio

    2015-05-01

    IceCube has measured a diffuse astrophysical flux of TeV-PeV neutrinos. The most plausible sources are unique high energy cosmic ray accelerators like hypernova remnants (HNRs) and remnants from gamma ray bursts in star-burst galaxies, which can produce primary cosmic rays with the required energies and abundance. In this case, however, ordinary supernova remnants (SNRs), which are far more abundant than HNRs, produce a comparable or larger neutrino flux in the ranges up to 100-150 TeV energies, implying a spectral break in the IceCube signal around these energies. The SNRs contribution in the diffuse flux up to these hundred TeV energies provides a natural baseline and then constrains the expected PeV flux.

  16. New radio observations of the composite supernova remnant G29.7-0.3

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    The galactic supernova remnant G29.7-0.3, recently identified as a new member of the class of composite remnants, has been imaged with the VLA at three wavelengths: 2, 6, and 20 cm. Two spectrally distinct components, a flat-spectrum core surrounded by a shell with alpha of about -0.7, suggested by early observations, have been confirmed. Neutral hydrogen absorption measurements of these two components confirm their physical association and place the remnant at a distance of about 21 kpc. A radio polarization map of the Crab-like core and results of an examination of existing X-ray data for evidence of emission from the shell component are also presented. A comparison of the radio and X-ray properties of G29.7-0.3 and other composite SNRs concludes the report.

  17. 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.

  18. The 7Li/6Li Isotope Ratio near the Supernova Remnant IC 443

    NASA Astrophysics Data System (ADS)

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

    2012-05-01

    We present an analysis of 7Li/6Li isotope ratios along four sight lines that probe diffuse molecular gas near the supernova remnant IC 443. Recent gamma-ray observations have revealed the presence of shock-accelerated cosmic rays interacting with the molecular cloud surrounding the remnant. Our results indicate that the 7Li/6Li ratio is lower in regions more strongly affected by these interactions, a sign of recent Li production by cosmic rays. We find that 7Li/6Li ?7 toward HD 254755, which is located just outside the visible edge of IC 443, while 7Li/6Li ?3 along the line of sight to HD 43582, which probes the interior region of the supernova remnant. No evidence of 7Li synthesis by neutrino-induced spallation is found in material presumably contaminated by the ejecta of a core-collapse supernova. The lack of a neutrino signature in the 7Li/6Li ratios near IC 443 is consistent with recent models of Galactic chemical evolution, which suggest that the ?-process plays only a minor role in Li production. Based on observations obtained with the Hobby-Eberly Telescope, which is a joint project of the University of Texas at Austin, the Pennsylvania State University, Stanford University, Ludwig-Maximilians-Universität München, and Georg-August-Universität Göttingen.

  19. Maximum Energies of Shock-accelerated Electrons in Young Shell Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Reynolds, Stephen P.; Keohane, Jonathan W.

    1999-11-01

    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 Emax, 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 Emax 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 Emax 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 ?G, no object could reach 1000 TeV, and only one, Kes 73, has an upper limit on Emax above 100 TeV. All the other remnants have limits at or below 80 TeV. Emax 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 Emax 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.

  20. On the origin of strong magnetic fields in young supernova remnants

    E-print Network

    Jun, B I; Jun, Byung Il; Norman, Michael L

    1996-01-01

    Young supernova remnants such as Tycho generally exhibit a bright circular clumpy shell in both radio and X-ray emission. For several young remnants, various arguments suggest that the magnetic field is larger than can be explained by compression of a few \\mu G ambient magnetic field by the shock wave. Radio polarization studies reveal a net radial orientation of magnetic fields in the shell which cannot be explained by the simple compression either. We model Rayleigh-Taylor instability at the interface of the ejecta and the shocked ambient medium to explain these observations. We have performed multidimensional MHD simulations of the instability in the shell of a Type-I supernova remnant for the first time utilizing a moving grid technique which allows us to follow the growth of the instability and its effect on the local magnetic field in detail. We find that the evolution of the instability is very sensitive to the deceleration of the ejecta and the evolutionary stage of the remnant. As the reverse shock e...

  1. 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.

  2. A Bow Shock Nebula Around a Compact X-Ray Source in the Supernova Remnant IC443

    E-print Network

    C. M. Olbert; C. R. Clearfield; N. E. Williams; J. W. Keohane; D. A. Frail

    2001-03-16

    We present spectra and high resolution images of the hard X-ray feature along the southern edge of the supernova remnant IC443. Data from the Chandra X-ray Observatory reveal a comet-shaped nebula of hard emission, which contains a softer point source at its apex. We also present 20cm, 6cm, and 3.5cm images from the Very Large Array that clearly show the cometary nebula. Based on the radio and X-ray morphology and spectrum, and the radio polarization properties, we argue that this object is a synchrotron nebula powered by the compact source that is physically associated with IC443. The spectrum of the soft point source is adequately but not uniquely fit by a black body model (kT=0.71 +/- 0.08 keV, L=(6.5 +/- 0.9) * 10^31 erg/s). The cometary morphology of the nebula is the result of the supersonic motion of the neutron star (V_NS=250 +/- 50 km/s), which causes the relativistic wind of the pulsar to terminate in a bow shock and trail behind as a synchrotron tail. This velocity is consistent with an age of 30,000 years for the SNR and its associated neutron star.

  3. A Bow Shock Nebula Around a Compact X-Ray Source in the Supernova Remnant IC443

    E-print Network

    Olbert, C M; Williams, N E; Keohane, J W; Frail, D A

    2001-01-01

    We present spectra and high resolution images of the hard X-ray feature along the southern edge of the supernova remnant IC443. Data from the Chandra X-ray Observatory reveal a comet-shaped nebula of hard emission, which contains a softer point source at its apex. We also present 20cm, 6cm, and 3.5cm images from the Very Large Array that clearly show the cometary nebula. Based on the radio and X-ray morphology and spectrum, and the radio polarization properties, we argue that this object is a synchrotron nebula powered by the compact source that is physically associated with IC443. The spectrum of the soft point source is adequately but not uniquely fit by a black body model (kT=0.71 +/- 0.08 keV, L=(6.5 +/- 0.9) * 10^31 erg/s). The cometary morphology of the nebula is the result of the supersonic motion of the neutron star (V_NS=250 +/- 50 km/s), which causes the relativistic wind of the pulsar to terminate in a bow shock and trail behind as a synchrotron tail. This velocity is consistent with an age of 30,0...

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

    NASA Astrophysics Data System (ADS)

    Vink, Jacco

    2009-05-01

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

  5. Microphysics of shock acceleration from observations of X-ray synchrotron emission from supernova remnants

    NASA Astrophysics Data System (ADS)

    Reynolds, S.

    Several supernova remnants are known to show X-ray synchrotron emission, from electron distributions that are the rolling-off tail of the distributions responsible for radio emission. These electron populations are presumably produced in the remnant blast wave (or reverse shock, if one is still present) by diffusive shock acceleration. Simple models have been used to confirm the synchrotron interpretation. However, new Chandra and XMM-Newton observations have allowed the comparison of data and models at a much higher degree of detail. Model parameters now include both macroscopic quantities (remnant age, shock speed and shock history, mean magneticfield strength) and microphysical parameters (magnitude and energy-dependence of the electron diffusion coefficient, shock obliquity angle between the upstream magnetic field and shock normal, ionization fraction). These models make both spectral and morphological predictions. As more remnants are found in which synchrotron Xray emission is likely to be important, a better understanding of the process is essential for the correct interpretation of either the thermal or the nonthermal emission. I shall describe the current status of synchrotron modeling from SNR blast waves, focusing on the dependence on the microphysical parameters, and shall describe the constraints provided by observations of SN 1006, RCW 86, and other remnants.

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

    SciTech Connect

    Di Stefano, R. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Kilic, Mukremin, E-mail: rd@cfa.harvard.edu, E-mail: kilic@ou.edu [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 West Brooks Street, Norman, OK 73019 (United States)

    2012-11-01

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

  7. The Absence of Ex-companions in Type Ia Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Di Stefano, R.; Kilic, Mukremin

    2012-11-01

    Type Ia supernovae (SNe Ia) play important roles in our study of the expansion and acceleration of the universe, but because we do not know the exact nature or natures of the progenitors, there is a systematic uncertainty that must be resolved if SNe Ia are to become more precise cosmic probes. No progenitor system has ever been identified either in the pre- or post-explosion images of a Ia event. There have been recent claims for and against the detection of ex-companion stars in several SNe Ia remnants. These studies, however, usually ignore the angular momentum gain of the progenitor white dwarf (WD), which leads to a spin-up phase and a subsequent spin-down phase before explosion. For spin-down timescales greater than 105 years, the donor star could be too dim to detect by the time of explosion. Here we revisit the current limits on ex-companion stars to SNR 0509-67.5, a 400-year-old remnant in the Large Magellanic Cloud. If the effects of possible angular momentum gain on the WD are included, a wide range of single-degenerate progenitor models are allowed for this remnant. We demonstrate that the current absence of evidence for ex-companion stars in this remnant, as well as other SNe Ia remnants, does not necessarily provide the evidence of absence for ex-companions. We discuss potential ways to identify such ex-companion stars through deep imaging observations.

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

    SciTech Connect

    Crawford, E. J.; Filipovi?, M. D. [University of Western Sydney (Australia); McEntaffer, R. L.; Brantseg, T.; Heitritter, K.; Roper, Q. [Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 (United States); Haberl, F. [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstraße, D-85748 Garching (Germany); Uroševi?, D., E-mail: e.crawford@uws.edu.au [Department of Astronomy, Faculty of Mathematics, University of Belgrade, Studentski trg 16, 11000 Belgrade (Serbia)

    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 ? = 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 ? = –0.59 ± 0.09, we find that an equipartition magnetic field for the remnant is ?90 ?G, 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%.

  9. Shock and Awe: Measuring the Expansion of the Shock Front of Supernova Remnant SN1006

    NASA Astrophysics Data System (ADS)

    Dills, Sidney; McKinney, L.; Moffett, D. A.; Reynoso, E.

    2014-01-01

    We have determined the expansion of the supernova remnant (SNR) of SN1006 over a seven-year period, using data collected in 2003 and 2010. The data was calibrated and imaged using Miriad and CASA programming before we stacked the two images to accurately assess the expansion rate. Our data was collected from the Very Large Array (VLA) in New Mexico and Australian Telescope Compact Array (ATCA). The 2003 epoch observations were conducted at the ATCA and the VLA. The 2010 epoch observations were conducted only at the ATCA. We processed the data using the Miriad and CASA software packages, which allowed us to perform calibration and imaging of radio interferometer visibility data. We deconvolved the raw images using CLEAN and MAXEN (maximum entropy deconvolution) to remove spurious side lobes, resulting in epoch images with a synthesized beamwidth of 6.0 arcseconds per beam. We used the 2010 image as a template to align the 2003 image and to match resolution. A difference image formed from the two epoch images reveals an obvious expansion of the SNR. We measured the expansion rate at nine points along the shell of the remnant. We found that the expansion rate varied across the remnant’s shell. The greatest amount of expansion measured was 5.71 arcseconds over seven years, which for a distance of 2.2 kpc, has the remnant moving at 8,500 km/s. The average expansion measured across the shell was 4.25 arcseconds over seven years.

  10. Dust sputtering by Reverse Shocks in Supernova Remnants

    E-print Network

    Biman B. nath; Tanmoy Laskar; J. Michael Shull

    2008-04-22

    We consider sputtering of dust grains, believed to be formed in cooling supernovae ejecta, under the influence of reverse shocks. In the regime of self-similar evolution of reverse shocks, we can follow the evolution of ejecta density and temperature analytically as a function of time in different parts of the ejecta, and calculate the sputtering rate of graphite and silicate grains embedded in the ejecta as they encounter the reverse shock. Through analytic (1D) calculations, we find that a fraction of dust mass ($ 1\\hbox{--}20$% for silicates and %$\\le 5$% for graphites) can be sputtered by reverse shocks, the fraction varying with the grain size distribution and the steepness of the density profile of the ejecta mass. It is expected that many more grains will get sputtered in the region between the forward and reverse shocks, so that our analytical results provide a lower limit to the destroyed fraction of dust mass.

  11. Nature versus Nurture: The Origin of Soft Gamma-Ray Repeaters and Anomalous X-Ray Pulsars

    Microsoft Academic Search

    D. Marsden; R. E. Lingenfelter; R. E. Rothschild; J. C. Higdon

    2001-01-01

    Soft gamma-ray repeaters (SGRs) and anomalous X-ray pulsars (AXPs) are young and radio-quiet X-ray pulsars that have been rapidly spun-down to slow spin periods clustered in the range 5-12 s. Most of these unusual pulsars also appear to be associated with supernova shell remnants (SNRs) with typical ages less than 30 kyr. By examining the sizes of these remnants versus

  12. 3-D Model of Broadband Emission from Supernova Remnants Undergoing Non-linear Diffusive Shock Acceleration

    SciTech Connect

    Lee, Shiu-Hang; Kamae, Tuneyoshi; Ellison, Donald C.

    2008-07-02

    We present a 3-dimensional model of supernova remnants (SNRs) where the hydrodynamical evolution of the remnant is modeled consistently with nonlinear diffusive shock acceleration occurring at the outer blast wave. The model includes particle escape and diffusion outside of the forward shock, and particle interactions with arbitrary distributions of external ambient material, such as molecular clouds. We include synchrotron emission and cooling, bremsstrahlung radiation, neutral pion production, inverse-Compton (IC), and Coulomb energy-loss. Boardband spectra have been calculated for typical parameters including dense regions of gas external to a 1000 year old SNR. In this paper, we describe the details of our model but do not attempt a detailed fit to any specific remnant. We also do not include magnetic field amplification (MFA), even though this effect may be important in some young remnants. In this first presentation of the model we don't attempt a detailed fit to any specific remnant. Our aim is to develop a flexible platform, which can be generalized to include effects such as MFA, and which can be easily adapted to various SNR environments, including Type Ia SNRs, which explode in a constant density medium, and Type II SNRs, which explode in a pre-supernova wind. When applied to a specific SNR, our model will predict cosmic-ray spectra and multi-wavelength morphology in projected images for instruments with varying spatial and spectral resolutions. We show examples of these spectra and images and emphasize the importance of measurements in the hard X-ray, GeV, and TeV gamma-ray bands for investigating key ingredients in the acceleration mechanism, and for deducing whether or not TeV emission is produced by IC from electrons or pion-decay from protons.

  13. 3-D Model of Broadband Emission from Supernova Remnants Undergoing Non-linear Diffusive Shock Acceleration

    E-print Network

    Shiu-Hang Lee; Tsuneyoshi Kamae; Donald C. Ellison

    2008-06-25

    We present a 3-dimensional model of supernova remnants (SNRs) where the hydrodynamical evolution of the remnant is modeled consistently with nonlinear diffusive shock acceleration occuring at the outer blast wave. The model includes particle escape and diffusion outside of the forward shock, and particle interactions with arbitrary distributions of external ambient material, such as molecular clouds. We include synchrotron emission and cooling, bremsstrahlung radiation, neutral pion production, inverse-Compton (IC), and Coulomb energy-loss. Boardband spectra have been calculated for typical parameters including dense regions of gas external to a 1000 year old SNR. In this paper, we describe the details of our model but do not attempt a detailed fit to any specific remnant. We also do not include magnetic field amplification (MFA), even though this effect may be important in some young remnants. In this first presentation of the model we don't attempt a detailed fit to any specific remnant. Our aim is to develop a flexible platform, which can be generalized to include effects such as MFA, and which can be easily adapted to various SNR environments, including Type Ia SNRs, which explode in a constant density medium, and Type II SNRs, which explode in a pre-supernova wind. When applied to a specific SNR, our model will predict cosmic-ray spectra and multi-wavelength morphology in projected images for instruments with varying spatial and spectral resolutions. We show examples of these spectra and images and emphasize the importance of measurements in the hard X-ray, GeV, and TeV gamma-ray bands for investigating key ingredients in the acceleration mechanism, and for deducing whether or not TeV emission is produced by IC from electrons or neutral pions from protons.

  14. Failed supernovae explain the compact remnant mass function

    SciTech Connect

    Kochanek, C. S. [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210, USAAND (United States); Center for Cosmology and AstroParticle Physics, The Ohio State University, 191 W. Woodruff Avenue, Columbus, OH 43210 (United States)

    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. Investigations of supernovae and supernova remnants in the era of SKA

    E-print Network

    Wang, Lingzhi; Zhu, Hui; Tian, Wenwu; Wang, Xiaofeng

    2015-01-01

    Two main physical mechanisms are used to explain supernova explosions: thermonuclear explosion of a white dwarf(Type Ia) and core collapse of a massive star (Type II and Type Ib/Ic). Type Ia supernovae serve as distance indicators that led to the discovery of the accelerating expansion of the Universe. The exact nature of their progenitor systems however remain unclear. Radio emission from the interaction between the explosion shock front and its surrounding CSM or ISM provides an important probe into the progenitor star's last evolutionary stage. No radio emission has yet been detected from Type Ia supernovae by current telescopes. The SKA will hopefully detect radio emission from Type Ia supernovae due to its much better sensitivity and resolution. There is a 'supernovae rate problem' for the core collapse supernovae because the optically dim ones are missed due to being intrinsically faint and/or due to dust obscuration. A number of dust-enshrouded optically hidden supernovae should be discovered via SKA1-...

  16. 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.

  17. 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. [Department of Physics and Astronomy, Rutgers, State University of New Jersey, Piscataway, NJ 08854 (United States); Badenes, Carles [School of Physics and Astronomy, Tel-Aviv University, Tel-Aviv 69978 (Israel); Fesen, Robert [Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755 (United States); Ghavamian, Parviz [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Moffett, David [Department of Physics, Furman University, Greenville, SC 29613 (United States); Plucinksy, Paul P.; Slane, Patrick [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Rakowski, Cara E. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Reynoso, Estela M. [Instituto de Astronomia y Fisica del Espacio, Buenos Aires (Argentina)

    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.

  18. Simulating anisotropic thermal conduction in supernova remnants - II. Implications for the interstellar medium

    NASA Astrophysics Data System (ADS)

    Balsara, Dinshaw S.; Bendinelli, Anthony J.; Tilley, David A.; Massari, Andrew R.; Howk, J. Christopher

    2008-05-01

    We present a large number of 2.5D simulations of supernova remnants expanding into interstellar media having a range of densities, temperatures and magnetic field strengths. The simulations include equilibrium cooling and anisotropic, flux-limited thermal conduction along magnetic field lines. The volume of hot gas produced during the remnant's evolution is shown to be strongly influenced by the inclusion of thermal conduction, supporting prior results by Slavin & Cox and Tilley & Balsara. The magnetic field has also been shown to play an extremely important role in reheating the gas at later epochs when the hot gas bubble collapses on itself. Low-density, strongly magnetized runs show the greatest effect of this reheating. The four-volumes and three-areas of gas with characteristic temperatures that cause it to emit in OVI, OVII and OVIII have also been catalogued and their dependence on interstellar parameters has been documented. The results reveal the importance of magnetic tension forces as well as the anisotropic thermal conduction along field lines for the production of these ions. Simulated luminosities and linewidths of OVI, OVII and OVIII as well as their dosages have been catalogued. Simulated linewidths of radioactive species, 26Al and 60Fe, ejected by supernovae have also been catalogued and found to be less than 200 km s-1 for most of the remnants' evolution. These results enable us to understand why INTEGRAL has thus far been unable to detect very large linewidths for these radioactive species in certain star-forming regions.

  19. 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.

  20. 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]:H? 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.

  1. THE CHANDRA ACIS SURVEY OF M33: X-RAY, OPTICAL, AND RADIO PROPERTIES OF THE SUPERNOVA REMNANTS

    SciTech Connect

    Long, Knox S.; Ghavamian, Parviz [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Blair, William P.; Kuntz, Kip D. [The Henry A. Rowland Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218 (United States); Winkler, P. Frank; McNeil, Emily K. [Department of Physics, Middlebury College, Middlebury, VT 05753 (United States); Becker, Robert H. [Department of Physics, University of California, 1 Shields Avenue, Davis, CA 95616 (United States); Gaetz, Terrance J.; Kirshner, Robert P.; Plucinsky, Paul P.; Tuellmann, Ralph [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Helfand, David J.; Saul, Destry [Columbia Astrophysics Laboratory, 550 W. 120th Street, New York, NY 10027 (United States); Hughes, John P. [Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Pannuti, Thomas G. [Department of Earth and Space Sciences, Space Science Center, 235 Martindale Drive, Morehead State University, Morehead, KY 40351 (United States); Williams, Benjamin [Astronomy Department, University of Washington, Seattle, WA 98195 (United States)], E-mail: long@stsci.edu, E-mail: wpb@pha.jhu.edu, E-mail: winkler@middlebury.edu

    2010-04-01

    M33 contains a large number of emission nebulae identified as supernova remnants (SNRs) based on the high [S II]:H{alpha} ratios characteristic of shocked gas. Using Chandra data from the ChASeM33 survey with a 0.35-2 keV sensitivity of {approx}2 x 10{sup 34} erg s{sup -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 {approx}4 x 10{sup 35} erg s{sup -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.

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

    E-print Network

    H. E. S. S. Collaboration; :; F. Aharonian

    2004-11-18

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

  3. EXPANSION OF THE YOUNGEST GALACTIC SUPERNOVA REMNANT G1.9+0.3

    SciTech Connect

    Carlton, Ashley K. [Department of Physics, Wake Forest University, Winston-Salem, NC 27109 (United States); Borkowski, Kazimierz J.; Reynolds, Stephen P. [Department of Physics, North Carolina State University, Raleigh, NC 27695-8202 (United States); Hwang, Una; Petre, Robert [NASA/GSFC, Code 660, Greenbelt, MD 20771 (United States); Green, David A. [Cavendish Laboratory, 19 J.J. Thomson Ave., Cambridge CB3 0HE (United Kingdom); Krishnamurthy, Kalyani; Willett, Rebecca, E-mail: carlak7@wfu.edu [Electrical and Computer Engineering, Duke University, Durham, NC 27708 (United States)

    2011-08-10

    We present a measurement of the expansion and brightening of G1.9 + 0.3, the youngest Galactic supernova remnant (SNR), comparing Chandra X-ray images obtained in 2007 and 2009. A simple uniform-expansion model describes the data well, giving an expansion rate of 0.642% {+-} 0.049% yr{sup -1} and a flux increase of 1.7% {+-} 1.0% yr{sup -1}. Without deceleration, the remnant age would then be 156 {+-} 11 yr, consistent with earlier results. Since deceleration must have occurred, this age is an upper limit; we estimate an age of about 110 yr or an explosion date of about 1900. The flux increase is comparable to reported increases at radio wavelengths. G1.9+0.3 is the only Galactic SNR increasing in flux, with implications for the physics of electron acceleration in shock waves.

  4. 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.

  5. 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.

  6. Electron Heating, Magnetic Field Amplification, and Cosmic Ray Precursor Length at Supernova Remnant Shocks

    NASA Astrophysics Data System (ADS)

    Laming, J. M.; Hwang, U.; Ghavamian, P.; Rakowski, C. E.

    2014-01-01

    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 provides 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 may be quenched either by nonresonant or resonant channels. In the former case, the cosmic rays become magnetized and amplification saturates at higher magnetic fields. The precursor can extend out to 10^17 - 10^18 cm and is potentially resolvable in Galactic supernova remnants. If the saturation occurs instead by resonant channels, the cosmic rays are scattered by turbulence and the precursor length will likely be too small to be resolvable with current instruments. 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 ? and shock velocity v_s is ? /v_s. In the nonresonantly saturated case, the precursor length declines less quickly with increasing v_s. Where precursor length proportional to 1/v_s gives constant electron heating, as observed for instance by Ghavamian et al. and van Adelsberg et al., this increased precursor length would be expected to lead to higher electron temperatures at faster supernova remnant shocks than studied by these previous works as an indirect observation of the shock precursor. Existing results and new data analysis of SN 1006 and Cas A suggests some observational support for this idea. Work supported by NASA ADAP program and by basic research funds of the Office of Naval Research.

  7. Magnetic Shaping of Supernova Remnant Bubbles: Effects on Estimates of Interstellar Porosity

    NASA Astrophysics Data System (ADS)

    Norman, M. L.

    1996-05-01

    The relative amounts of cold, warm and hot phases in the Galactic ISM continues to be the focus of intense observational and theoretical studies. The production and fate of hot gas primarily from supernova explosions requires numerical simulations of increasing sophistication. We have embarked on a systematic program to incorporate magnetic fields, heat conduction, radiative cooling, cosmic rays, and turbulent motions into multidimensional models of supernova remnant and superbubble evolution. Here we present results of 2D numerical MHD simulations of the late (> 5 Myr) evolution of an isolated supernova remnant in a warm diffuse medium threaded by a uniform magnetic field. We follow the complete evolution of the remnant through collapse of the hot bubble as it radiates away its thermal energy. The effects of heat conduction are included through the incorporation of a new implicit algorithm in the ZEUS-2D code which we describe. The parameters adopted are identical to those used by Slavin and Cox (ApJ, 392, 131, 1992): Eo=5 x 10(50) erg, no=0.2 cm(-3) , To=10(4) K, Bo=5 mu G. Our results generalize the spherically symmetric models of Slavin and Cox (1992) to 2D axisymmetry. Magnetic stresses collimate the hot bubble into a prolate ``hot sausage" aligned with the magnetic field by 1 Myr. Thereafter the axis ratio of the sausage increases superlinearly with time as the bubble collapses radially but continues to expand axially with approximately the ambient magnetosonic speed. Magnetic pressure prevents the shell from collapsing due to radiative losses everywhere except at the polar caps. We compute the four-volume of the hot bubble for various choices of heat conduction and compare these results with the spherically symmetric models.

  8. Evidence of a Curved Cosmic-Ray Electron Spectrum in the Supernova Remnant SN 1006

    NASA Astrophysics Data System (ADS)

    Allen, Glenn E.; Houck, J. C.; Sturner, S. J.

    2003-07-01

    We present the results of a joint spectral analysis of Chandra ACIS X-ray data, some radio data and the CANGAROO gamma-ray data for the eastern rim of the supernova remnant SN 1006. The results provide strong evidence that the shape of the GeV to TeV electron spectrum is curved as has been predicted. The best-fit values of the "maximum" energy of the electrons and the strength of the magnetic field are = 25+10 TeV and b= 10+8 µG, respectively. -7 -5

  9. 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.

  10. Emissions from supernova remnants in the presence of small-scale random magnetic fields

    NASA Astrophysics Data System (ADS)

    Yoshida, T.; Yanagita, S.; Kifune, T.

    We study non-thermal emissions by relativistic electrons from supernova remnants(SNRs) in the presence of small-scale random and large-scale regular magnetic fields. We extend our pure jitter and inverse Compton emission models (Ogasawara et al. 2006) and construct the emission models with regular magnetic fields. We apply them to the multi-wavelength data of TeV gamma-ray sources SNRs RX J1713.7-3946 (G347.3-0.5) and RX J0852.0-4622 (G266.6-1.2). The physical fit parameters of random and regular magnetic fields are discussed.

  11. Molecular and Ionic shocks in the Supernova Remnant 3C391

    Microsoft Academic Search

    William T. Reach; Jeonghee Rho; T. H. Jarrett; Pierre-Olivier Lagage

    2001-01-01

    New observations of the supernova remnant 3C391 are in the H2 2.12 micron and\\u000a[Fe II] 1.64 micron narrow-band filters at the Palomar 200-inch telescope, and\\u000ain the 5-15 micron CVF on ISOCAM. Shocked H2 emission was detected from the\\u000aregion 3C391:BML, where broad millimeter CO and CS lines had previously been\\u000adetected. A new H2 clump was confirmed to

  12. New Models for X-Ray Synchrotron Radiation from the Remnant of Supernova 1006 AD

    E-print Network

    K. K. Dyer; S. P. Reynolds; K. J. Borkowski

    2000-01-13

    Galactic cosmic rays up to energies of around 10^15 eV are assumed to originate in supernova remnants (SNRs). The shock wave of a young SNR like SN 1006 AD can accelerate electrons to energies greater than 1 TeV, where they can produce synchrotron radiation in the X-ray band. A new model (SRESC) designed to model synchrotron X-rays from Type Ia supernovae can constrain values for the magnetic-field strength and electron scattering properties, with implications for the acceleration of the unseen ions which dominate the cosmic-ray energetics. New observations by ASCA, ROSAT, and RXTE have provided enormously improved data, which now extend to higher X-ray energies. These data allow much firmer constraints. We will describe model fits to these new data on SN 1006 AD, emphasizing the physical constraints that can be placed on SNRs and on the cosmic-ray acceleration process.

  13. A Catalog of Outer Ejecta Knots in the Cassiopeia A Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Hammell, Molly C.; Fesen, Robert A.

    2008-11-01

    Hubble Space Telescope images of the core-collapse supernova remnant Cassiopeia A are used to identify high-velocity knots of ejecta located outside the remnant's main emission shell of expanding debris. These ejecta fragments are found near or ahead of the remnant's forward shock front and mostly lie from 120" to 300" in radial distance from the remnant's center of expansion. Filter flux ratios when correlated with published spectra show that these knots can be divided into three emission classes: (1) knots dominated by [N II] ??6548, 6583 emissions, (2) knots dominated by [O II] ??7319, 7330 emissions, and (3) knots displaying filter flux ratios suggestive of [S II], [O II], and [Ar III] ?7135 emission line strengths similar to the ``fast-moving knots'' (FMKs) found in the remnant's bright main shell. Of 1825 knots identified, 444 are strong [N II] emission knots, 192 are strong [O II] emission knots, and 1189 are FMK-like knots. In terms of location around the remnant, 972, 207, and 646 knots are found in the remnant's northeast jet, southwest jet, and non-jet regions, respectively. Assuming a distance of 3.4 kpc, derived knot transverse velocities based on proper motion measurements spanning a 9 month interval indicate maximum transverse expansion velocities for these three knot classes of 14,500, 13,500, and 11,500 km s-1, respectively. We present a catalog of these outlying ejecta clumps comprising finding charts, epoch 2004.2 knot positions, proper motions, photometric filter fluxes, and estimated knot emission type, along with cross-references to previous knot identifications and data. This compilation represents a nearly tenfold increase in the number of outlying, high-velocity ejecta knots identified around the Cassiopeia A remnant. Based 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 No. NAS5-26555.

  14. An X-ray study of five supernova remnants in the Carina spiral arm

    NASA Technical Reports Server (NTRS)

    Hwang, Una; Markert, Thomas H.

    1994-01-01

    The ROSAT Position Sensitive Proportional Counter (PSPC) is used to perform an exploratory study of four fields in the Carina spiral arm containing five radio supernova remnants, only one of which has previously been studied in X-rays. We present upper limits for the detection in X-rays of G298.5 - 0.3, G298.6 - 0.0, and G299.0+0.2, and report a 4 sigma detection of G296.8-0.3. In addition, we present detailed spatial and spectral analysis of the bright X-ray remnant G296.1-0.7, which has previously been studied by both the Einstein IPC and EXOSAT LE/CMA. We detect relatively slight, but statistically significant, variations in the spectrum across the remnant via spatially resolved spectral fits and a study of the spatial variation of hardness ratios. In general, the spectrum is characteristic of a thermal plasma with kT about 0.2 keV and N(sub H) about 1.5 x 10(exp 21/sq. cm). The total X-ray emitting mass is estimated to be about 250 solar mass for an optically estimated distance of 4 kpc to the remnant. At this distance, the linear dimensions of the remnant are roughly 35 - 50 pc, implying an age on the order of 20,000 yr. Assuming that X-ray and radio brightnesses are related by SIGMA(sub R) proportional to SIGMA(exp 0.69)(sub X) and that the four radio remnants have X-ray spectral characteristics similar to G296.1-0.7, we find that the column densities to these sources must be several times 10(exp 22)/sq cm in order to explain their low X-ray count rates. This column density is considerably in excess of the X-ray fitted column density to G296.1-0.7, but is comparable to the total column densities in H I measured via the 21 cm line in the directions to all five remnants. This implies that G296.1 - 0.7 is at a significantly smaller distance than the other remnants.

  15. New approximate analytical method for calculating a point explosion in an inhomogeneous medium and its application to modeling X-ray radiation from three-dimensional supernova remnants.

    NASA Astrophysics Data System (ADS)

    Gnatyk, B. I.; Petruk, O. L.

    1996-01-01

    The authors investigate the adiabatic stage in the evolution of supernova remnants in a medium with a large-scale density gradient. They propose a new approximate analytical method for calculating the hydrodynamical model of a asymmetric point explosion in an arbitrary inhomogeneous medium. The method is used to study the evolution of the shape and X-ray characteristics of nonspherical supernova remnants.

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

    NASA Astrophysics Data System (ADS)

    Uchiyama, Yasunobu

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

  17. Limits on the Number of Galactic Young Supernova Remnants Emitting in the Decay Lines of 44Ti

    NASA Astrophysics Data System (ADS)

    Dufour, François; Kaspi, Victoria M.

    2013-09-01

    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 44Ti. Specifically, we consider the distribution of the supernova progenitors, the supernova rate in the Galaxy, the ratios of supernova types, the Galactic production of 44Ti, and the 44Ti yield from supernovae of different types to derive credible bounds on the expected number of detectable remnants. We find that, within 1? uncertainty, the Galaxy should contain an average of 5.1^{+2.4}_{-2.0} remnants detectable to a survey with a 44Ti decay line flux limit of 10-5 photons cm-2 s-1, with a probability of detecting a single remnant of 2.7^{+10.0}_{-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 44Ti 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 44Ti, 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 44Ti decay flux of 10-7 photons cm-2 s-1.

  18. Fermi-Lat Discovery of GeV Gamma-Ray Emission from the Young Supernova Remnant Cassiopeia A

    Microsoft Academic Search

    A. A. Abdo; M. Ackermann; M. Ajello; A. Allafort; L. Baldini; J. Ballet; G. Barbiellini; M. G. Baring; D. Bastieri; B. M. Baughman; K. Bechtol; R. Bellazzini; B. Berenji; R. D. Blandford; E. D. Bloom; E. Bonamente; A. W. Borgland; J. Bregeon; A. Brez; M. Brigida; P. Bruel; R. Buehler; T. H. Burnett; G. Busetto; G. A. Caliandro; R. A. Cameron; P. A. Caraveo; J. M. Casandjian; C. Cecchi; Ö. Çelik; E. Charles; S. Chaty; A. Chekhtman; C. C. Cheung; J. Chiang; A. N. Cillis; S. Ciprini; R. Claus; J. Cohen-Tanugi; J. Conrad; S. Corbel; F. de Palma; S. W. Digel; M. Dormody; E. do Couto e. Silva; P. S. Drell; R. Dubois; D. Dumora; Y. Edmonds; C. Farnier; C. Favuzzi; S. J. Fegan; E. C. Ferrara; W. B. Focke; P. Fortin; M. Frailis; Y. Fukazawa; S. Funk; P. Fusco; F. Gargano; D. Gasparrini; N. Gehrels; S. Germani; G. Giavitto; N. Giglietto; F. Giordano; T. Glanzman; G. Godfrey; I. A. Grenier; M.-H. Grondin; J. E. Grove; L. Guillemot; S. Guiriec; Y. Hanabata; E. Hays; A. K. Harding; M. Hayashida; D. Horan; R. E. Hughes; M. S. Jackson; A. S. Johnson; T. J. Johnson; W. N. Johnson; T. Kamae; H. Katagiri; J. Kataoka; N. Kawai; M. Kerr; J. Knödlseder; M. Kuss; J. Lande; L. Latronico; M. Lemoine-Goumard; F. Longo; F. Loparco; B. Lott; M. N. Lovellette; P. Lubrano; A. Makeev; M. N. Mazziotta; C. Meurer; P. F. Michelson; W. Mitthumsiri; T. Mizuno; C. Monte; M. E. Monzani; A. Morselli; I. V. Moskalenko; S. Murgia; T. Nakamori; P. L. Nolan; J. P. Norris; E. Nuss; T. Ohsugi; A. Okumura; N. Omodei; E. Orlando; J. F. Ormes; D. Paneque; J. H. Panetta; V. Pelassa; M. Pepe; M. Pesce-Rollins; F. Piron; M. Pohl; T. A. Porter; S. Rainò; R. Rando; A. Reimer; O. Reimer; T. Reposeur; S. Ritz; A. Y. Rodriguez; R. W. Romani; M. Roth; H. F.-W. Sadrozinski; A. Sander; P. M. Saz Parkinson; J. D. Scargle; C. Sgrò; E. J. Siskind; D. A. Smith; P. D. Smith; P. Spinelli; M. S. Strickman; D. J. Suson; H. Tajima; T. Takahashi; T. Tanaka; J. B. Thayer; J. G. Thayer; D. J. Thompson; S. E. Thorsett; L. Tibaldo; O. Tibolla; D. F. Torres; G. Tosti; A. Tramacere; Y. Uchiyama; T. L. Usher; A. Van Etten; V. Vasileiou; C. Venter; N. Vilchez; V. Vitale; A. P. Waite; P. Wang; B. L. Winer; K. S. Wood; R. Yamazaki; T. Ylinen; M. Ziegler

    2010-01-01

    We report on the first detection of GeV high-energy gamma-ray emission from a young supernova remnant (SNR) with the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope. These observations reveal a source with no discernible spatial extension detected at a significance level of 12.2sigma above 500 MeV at a location that is consistent with the position of the remnant

  19. The acceleration of cosmic-ray protons in the supernova remnant RX J1713.7-3946

    Microsoft Academic Search

    R. Enomoto; T. Tanimori; T. Naito; T. Yoshida; S. Yanagita; M. Mori; P. G. Edwards; A. Asahara; G. V. Bicknell; S. Gunji; S. Hara; T. Hara; S. Hayashi; C. Itoh; S. Kabuki; F. Kajino; H. Katagiri; J. Kataoka; A. Kawachi; T. Kifune; H. Kubo; J. Kushida; S. Maeda; A. Maeshiro; Y. Matsubara; Y. Mizumoto; M. Moriya; H. Muraishi; Y. Muraki; T. Nakase; K. Nishijima; M. Ohishi; K. Okumura; J. R. Patterson; K. Sakurazawa; R. Suzuki; D. L. Swaby; K. Takano; T. Takano; F. Tokanai; K. Tsuchiya; H. Tsunoo; K. Uruma; A. Watanabe; T. Yoshikoshi

    2002-01-01

    Protons with energies up to ~1015eV are the main component of cosmic rays, but evidence for the specific locations where they could have been accelerated to these energies has been lacking. Electrons are known to be accelerated to cosmic-ray energies in supernova remnants, and the shock waves associated with such remnants, when they hit the surrounding interstellar medium, could also

  20. Supernova outbursts and the formation of relativistic objects. II

    Microsoft Academic Search

    O. Kh. Guseinov; F. K. Kazumov; V. I. Lazarev; A. V. Osipchuk

    1973-01-01

    A genetic relationship between a pulsar and a supenova remnant may be ; considered persuasive only if they are <30 pc apart. Just two pairs satisfy this ; criterion: P0531--Crab and P0833---Vela: in these cases the components also agree ; in age. The scarcity of pairs suggests that supernova remnants disperse quite ; rapidly (in approx equal 4.10⁴ yr); thus

  1. Polarization Observations of 1720 MHz OH Masers toward the Three Supernova Remnants W28, W44, and IC443

    E-print Network

    Claussen, M J; Goss, W M; Gaume, R A

    1997-01-01

    (abridged) - We present arcsecond resolution observations from the VLA of the satellite line of the hydroxyl molecule (OH) at 1720.53 MHz toward three Galactic supernova remnants: W28, W44 and IC443. All of our observations are consistent with a model in which the OH(1720 MHz) is collisionally excited by H2 molecules in the postshock gas heated by a non-dissociative shock. Supernova remnants with OH(1720 MHz) maser emission may be promising candidates to conduct high energy searches for the sites of cosmic ray acceleration.

  2. Polarization Observations of 1720 MHz OH Masers toward the Three Supernova Remnants W28, W44, and IC443

    E-print Network

    M. J Claussen; D. A. Frail; W. M. Goss; R. A. Gaume

    1997-06-06

    (abridged) - We present arcsecond resolution observations from the VLA of the satellite line of the hydroxyl molecule (OH) at 1720.53 MHz toward three Galactic supernova remnants: W28, W44 and IC443. All of our observations are consistent with a model in which the OH(1720 MHz) is collisionally excited by H2 molecules in the postshock gas heated by a non-dissociative shock. Supernova remnants with OH(1720 MHz) maser emission may be promising candidates to conduct high energy searches for the sites of cosmic ray acceleration.

  3. Fermi LAT Observations of the Supernova Remnant W28 (G6.4-0.1)

    E-print Network

    Abdo, A A

    2010-01-01

    We present detailed analysis of the two gamma-ray sources,1FGL J1801.3-2322c and 1FGL J1800.5-2359c,that have been found toward the supernova remnant(SNR) W28 with the Large Area Telescope(LAT) on board the Fermi Gamma-ray Space Telescope.1FGL J1801.3-2322c is found to be an extended source within the boundary of SNR W28,and to extensively overlap with the TeV gamma-ray source HESS J1801-233,which is associated with a dense molecular cloud interacting with the supernova remnant.The gamma-ray spectrum measured with LAT from 0.2--100 GeV can be described by a broken power-law function with a break of ~1GeV,and photon indices of 2.09$\\pm$0.08(stat)$\\pm$0.28(sys) below the break and 2.74$\\pm$0.06(stat)$\\pm$0.09(sys) above the break.Given the clear association between HESS J1801-233 and the shocked molecular cloud and a smoothly connected spectrum in the GeV--TeV band,we consider the origin of the gamma-ray emission in both GeV and TeV ranges to be the interaction between particles accelerated in the SNR and the m...

  4. 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.

  5. The Compact Central Object in the Supernova Remnant G266.2-1.2

    E-print Network

    Oleg Kargaltsev; George G. Pavlov; Divas Sanwal; Gordon P. Garmire

    2002-07-27

    We observed the compact central object CXOU J085201.4--461753 in the supernova remnant G266.2--1.2 (RX J0852.0--4622) with the Chandra ACIS detector in timing mode. The spectrum of this object can be described by a blackbody model with the temperature kT=404 eV and radius of the emitting region R=0.28 km, at a distance of 1 kpc. Power-law and thermal plasma models do not fit the source spectrum. The spectrum shows a marginally significant feature at 1.68 keV. Search for periodicity yields two candidate periods, about 301 ms and 33 ms, both significant at a 2.1 sigma level; the corresponding pulsed fractions are 13% and 9%, respectively. We find no evidence for long-term variability of the source flux, nor do we find extended emission around the central object. We suggest that CXOU J085201.4--461753 is similar to CXOU J232327.9+584842, the central source of the supernova remnant Cas A. It could be either a neutron star with a low or regular magnetic field, slowly accreting from a fossil disk, or, more likely, an isolated neutron star with a superstrong magnetic field. In either case, a conservative upper limit on surface temperature of a 10 km radius neutron star is about 90 eV, which suggests accelerated cooling for a reasonable age of a few thousand years.

  6. How precisely neutrino emission from supernova remnants can be constrained by gamma ray observations?

    E-print Network

    F. L. Villante; F. Vissani

    2008-07-25

    We propose a conceptually and computationally simple method to evaluate the neutrinos emitted by supernova remnants using the observed gamma-ray spectrum. The proposed method does not require any preliminary parametrization of the gamma ray flux; the gamma ray data can be used as an input. In this way, we are able to propagate easily the observational errors and to understand how well the neutrino flux and the signal in neutrino telescopes can be constrained by gamma-ray data. We discuss the various possible sources of theoretical and systematical uncertainties (e.g., neutrino oscillation parameters, hadronic modeling, etc.), obtaining an estimate of the accuracy of our calculation. Furthermore, we apply our approach to the supernova remnant RX J1713.7-3946, showing that neutrino emission is very-well constrained by the H.E.S.S. gamma-ray data: indeed, the accuracy of our prediction is limited by theoretical uncertainties. Neutrinos from RX J1713.7-3946 can be detected with an exposure of the order km^2 year, provided that the detection threshold in future neutrino telescopes will be equal to about 1 TeV.

  7. AKARI AND BLAST OBSERVATIONS OF THE CASSIOPEIA A SUPERNOVA REMNANT AND SURROUNDING INTERSTELLAR MEDIUM

    SciTech Connect

    Sibthorpe, B. [UK Astronomy Technology Centre, Royal Observatory Edinburgh, Blackford Hill, Edinburgh, EH9 3HJ (United Kingdom); Ade, P. A. R.; Griffin, M.; Hargrave, P. C.; Mauskopf, P. [Department of Physics and Astronomy, Cardiff University, 5 The Parade, Cardiff, CF24 3AA (United Kingdom); Bock, J. J. [Jet Propulsion Laboratory, Pasadena, CA 91109-8099 (United States); Chapin, E. L.; Halpern, M.; Marsden, G. [Department of Physics and Astronomy, 6224 Agricultural Road, University of British Columbia, Vancouver, BC V6T 1Z1 (Canada); Devlin, M. J.; Dicker, S.; Klein, J. [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Gundersen, J. O. [Department of Physics, University of Miami, 1320 Campo Sano Drive, Coral Gables, FL 33146 (United States); Hughes, D. H. [Instituto Nacional de Astrofisica, Optica y Electronica, Luis Enrique Erro 1, Tonantzintla, Puebla 72840 (Mexico); Jeong, W.-S. [Korea Astronomy and Space Science Institute, 61-1, Hwaam-dong, Yuseong-gu, Daejeon 305-348 (Korea, Republic of); Kaneda, H. [Department of Astrophysics, Nagoya University, Chikusa-ku, Nagoya 464-8602 (Japan); Koo, B.-C.; Lee, H.-G. [Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Martin, P. G. [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Toronto, ON M5S 3H8 (Canada); Moon, D.-S., E-mail: bruce.sibthorpe@stfc.ac.u [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada)

    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.

  8. Constraining the Flux of Low-Energy Cosmic Rays Accelerated by the Supernova Remnant IC 443

    NASA Astrophysics Data System (ADS)

    Indriolo, Nick; Blake, Geoffrey A.; Goto, Miwa; Usuda, Tomonori; Geballe, Thomas R.; Oka, Takeshi; McCall, Benjamin J.

    2010-06-01

    It has long been theorized that supernova remnants (SNR) accelerate the majority of Galactic cosmic rays. Observations in the ?-ray, X-ray, and radio regimes support this theory, at least for cosmic rays with energies above a few GeV. However, there is no direct evidence that SNRs accelerate cosmic rays in the MeV--GeV range. These low-energy cosmic rays are of great importance, as they are the primary means by which H_2 is ionized in the interstellar medium. Collisions between H_2^+ and H_2 will rapidly form H_3^+, a molecule which can then be observed to infer the ionization rate of H_2. Using the Subaru and Keck telescopes, we have searched for H_3^+ absorption in sight lines which probe molecular material known to be interacting with the SNR IC 443. By computing the ionization rate of H_2 in these sight lines, we constrain the flux of low-energy cosmic rays generated by this particular supernova remnant.

  9. Molecular and Ionic shocks in the Supernova Remnant 3C391

    E-print Network

    Reach, W T; Jarrett, T H; Lagage, P O; Reach, William T.; Rho, Jeonghee; Lagage, Pierre-Olivier

    2001-01-01

    New observations of the supernova remnant 3C391 are in the H2 2.12 micron and [Fe II] 1.64 micron narrow-band filters at the Palomar 200-inch telescope, and in the 5-15 micron CVF on ISOCAM. Shocked H2 emission was detected from the region 3C391:BML, where broad millimeter CO and CS lines had previously been detected. A new H2 clump was confirmed to have broad CO emission, demonstrating that the near-infrared H2 images can trace previously undetected molecular shocks. The [Fe II] emission has a significantly different distribution, being brightest in the bright radio bar, at the interface between the supernova remnant and the giant molecular cloud, and following filaments in the radio shell. The near-infrared [Fe II] and the mid-infrared 12-18 micron filter images are the first images to reveal the radiative shell of 3C391. The mid-infrared spectrum is dominated by bright ionic lines and H2 S(2) through S(7). There are no aromatic hydrocarbons associated with the shocks, nor is their any mid-infrared continuu...

  10. Time-Dependent Diffusive Shock Acceleration in Slow Supernova Remnant Shocks

    NASA Astrophysics Data System (ADS)

    Xiaping, Tang; Chevalier, Roger

    2015-01-01

    Recent gamma ray observations show that middle aged supernova remnants interacting with molecular clouds can be sources of both GeV and TeV emission. Models involving re-acceleration of pre-existing cosmic rays in the ambient medium and direct interaction between supernova remnant and molecular clouds have been proposed to explain the observed gamma ray emission. For the re-acceleration process, standard DSA theory in the test particle limit produces a steady state particle spectrum that is too flat compared to observations, which suggests that the high energy part of the observed spectrum has not yet reached a steady state. We derive a time dependent DSA solution in the test particle limit for situations involving re-acceleration of pre-existing cosmic rays in the preshock medium. Simple estimates with our time dependent DSA solution plus a molecular cloud interaction model can reproduce the overall shape of the spectra of IC 443 and W44 from GeV to TeV energies through pure ?^0-decay emission.We allow for a power law momentum dependence of the diffusion coefficient, finding that a power law index of 0.5 is favored.

  11. Observation of Supernova Remnant IC443 with the Fermi Large Area Telescope

    E-print Network

    Abdo, A A

    2010-01-01

    We report observation of the supernova remnant IC443 (G189.1+3.0) with the Fermi Gamma-ray Space Telescope Large Area Telescope (LAT) in the energy band between 200MeV and 50GeV. IC443 is a shell-type supernova remnant with mixed morphology located off the outer Galactic plane where high-energy emission has been detected in the X-ray, GeV and TeV gamma-ray bands. Past observations suggest IC443 has been interacting with surrounding interstellar matter. Proximity between dense shocked molecular clouds and GeV-TeV gamma-ray emission regions detected by EGRET, MAGIC and VERITAS suggests an interpretation that cosmic-ray (CR) particles are accelerated by the SNR. With the high gamma-ray statistics and broad energy coverage provided by the LAT, we accurately characterize the gamma-ray emission produced by the CRs accelerated at IC443. The emission region is extended in the energy band with theta_68 = 0.27 deg +/- 0.01 deg (stat) +/- 0.03 deg (sys) for an assumed 2-dimensional Gaussian profile and overlaps almost c...

  12. Giant-scale supernova remnants - The role of differential galactic rotation and the formation of molecular clouds

    NASA Astrophysics Data System (ADS)

    Tenorio-Tagle, G.; Palous, J.

    1987-11-01

    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 Nopacity = 1021Z_sun;/Z cm-2 (Franco and Cox, 1986) and thus form molecular clouds. The resultant clouds have masses larger than 105M_sun;, 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.

  13. 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.

  14. 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.

  15. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2012-05-01

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

  17. 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.

  18. Optical and Far-UV Spectroscopy of Knot D in the Vela Supernova Remnant

    E-print Network

    Ravi Sankrit; William P. Blair; John C. Raymond

    2003-02-13

    We present spectra of optical filaments associated with the X-ray knot D in the Vela supernova remnant. It has been suggested that Knot D is formed by a bullet of supernova ejecta, that it is a break-out of the shock front of the Vela SNR, and also that it is an outflow from the recently discovered remnant RXJ0852.0-4622. We find that Knot D is a bow shock propagating into an interstellar cloud with normal abundances and typical cloud densities (n_H ~ 4-11 cm^-3). Optical longslit spectra show that the [S II] 6716,6731 to Halpha line ratio is greater than unity, proving that the optical filaments are shock excited. The analysis of far-ultraviolet spectra obtained with the Hopkins Ultraviolet Telescope and with the Far Ultraviolet Spectroscopic Explorer (FUSE) LWRS aperture show that slower shocks (~100 km s^-1) produce most of the low ionization lines such as O III] 1662, while faster shocks (~180 km s^-1) produce the O VI 1032,1038 and other high ionization lines. C III and O VI lines are also detected in the FUSE MDRS aperture, which was located on an X-ray bright region away from the optical filaments. The lines have two velocity components consistent with ~150 km s^-1 shocks on the near and far sides of the knot. The driving pressure in the X-ray knot, P/k ~ 1.8E+7 cm^-3 K, is derived from the shock properties. This is over an order of magnitude larger than the characteristic X-ray pressure in the Vela SNR. The velocity distribution of the emission and the overpressure support the idea that Knot D is a bow shock around a bullet or cloud that originated near the center of the Vela remnant.

  19. 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 [Department of Physics and Astronomy, University of Manitoba, Winnipeg MB R3T 2N2 (Canada); Slane, Patrick O. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Gotthelf, E. V., E-mail: harsha@physics.umanitoba.ca, E-mail: samar@physics.umanitoba.ca, E-mail: slane@cfa.harvard.edu, E-mail: eric@astro.columbia.edu [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States)

    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.

  20. Spatially-resolved Thermal Continuum Absorption against the Supernova Remnant W49B

    E-print Network

    C. K. Lacey; T. Joseph W. Lazio; Namir E. Kassim; N. Duric; D. S. Briggs; K. K. Dyer

    2001-05-25

    We present sub-arcminute resolution imaging of the Galactic supernova remnant W49B at 74 MHz (25") and 327 MHz (6"), the former being the lowest frequency at which the source has been resolved. While the 327 MHz image shows a shell-like morphology similar to that seen at higher frequencies, the 74 MHz image is considerably different, with the southwest region of the remnant almost completely attenuated. The implied 74 MHz optical depth (~ 1.6) is much higher than the intrinsic absorption levels seen inside two other relatively young remnants, Cas A and the Crab Nebula, nor are natural variations in the relativistic electron energy spectra expected at such levels. The geometry of the absorption is also inconsistent with intrinsic absorption. We attribute the absorption to extrinsic free-free absorption by a intervening cloud of thermal electrons. Its presence has already been inferred from the low-frequency turnover in the integrated continuum spectrum and from the detection of radio recombination lines toward the remnant. Our observations confirm the basic conclusions of those measurements, and our observations have resolved the absorber into a complex of classical HII regions surrounded either partially or fully by low-density HII gas. We identify this low-density gas as an extended HII region envelope (EHE), whose statistical properties were inferred from low resolution meter- and centimeter-wavelength recombination line observations. Comparison of our radio images with HI and H_2CO observations show that the intervening thermal gas is likely associated with neutral and molecular material as well.

  1. EVOLUTION OF THE RADIO REMNANT OF SUPERNOVA 1987A: MORPHOLOGICAL CHANGES FROM DAY 7000

    SciTech Connect

    Ng, C.-Y. [Department of Physics, The University of Hong Kong, Pokfulam Road (Hong Kong); Zanardo, G.; Potter, T. M.; Staveley-Smith, L. [International Centre for Radio Astronomy Research (ICRAR), The University of Western Australia, Crawley, WA 6009 (Australia); Gaensler, B. M. [Australian Research Council, Centre of Excellence for All-sky Astrophysics (CAASTRO) (Australia); Manchester, R. N.; Tzioumis, A. K., E-mail: ncy@bohr.physics.hku.hk [CSIRO Astronomy and Space Science, Australia Telescope National Facility, Marsfield, NSW 1710 (Australia)

    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. Evolution of Supernova Remnants Expanding out of the Dense Circumstellar Matter into the Rarefied Interstellar Medium

    E-print Network

    Shimizu, Takafumi; Koyama, Katsuji

    2011-01-01

    We carry out 3D-hydrodynamical calculations for the interaction of expanding supernova ejecta with the dense circumstellar matter (CSM) and the rarefied interstellar medium (ISM) outside. The CSM is composed of the stellar wind matter from the progenitor in its pre-supernova phase, and assumed to be axially symmetric: more matter around the equator than in the polar direction driven by rotation of the progenitor. Because of high density of the CSM, the ionization state of the shock-heated ejecta quickly becomes equilibrium with the electron temperature. When the blast wave breaks out of the CSM into the rarefied ISM, the shocked ejecta cools rapidly due to adiabatic expansion, and hence an over-ionized/recombining plasma would be left. The ejecta is reheated by the second reverse shock due to the interaction with the ISM. We calculate the emission measure of the supernova remnant (SNR) along the line of sight, and find that the over-ionized plasma appears to be bar-like with wings in the edge-on (equatorial v...

  3. Spectroscopic Detection of Carbon Monoxide in the Young Supernova Remnant Cassiopeia A

    NASA Astrophysics Data System (ADS)

    Rho, J.; Onaka, T.; Cami, J.; Reach, W. T.

    2012-03-01

    We report the detection of carbon monoxide (CO) emission from the young supernova remnant Cassiopeia A (Cas A) at wavelengths corresponding to the fundamental vibrational mode at 4.65 ?m. We obtained AKARI Infrared Camera spectra toward four positions which unambiguously reveal the broad characteristic CO ro-vibrational band profile. The observed positions include unshocked ejecta at the center, indicating that CO molecules form in the ejecta at an early phase. We extracted a dozen spectra across Cas A along the long 1' slits and compared these to simple CO emission models in local thermodynamic equilibrium to obtain first-order estimates of the excitation temperatures and CO masses involved. Our observations suggest that significant amounts of carbon may have been locked up in CO since the explosion 330 years ago. Surprisingly, CO has not been efficiently destroyed by reactions with ionized He or the energetic electrons created by the decay of the radiative nuclei. Our CO detection thus implies that less carbon is available to form carbonaceous dust in supernovae than is currently thought and that molecular gas could lock up a significant amount of heavy elements in supernova ejecta.

  4. The Expansion Asymmetry and Age of the Cassiopeia A Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Fesen, Robert A.; Hammell, Molly C.; Morse, Jon; Chevalier, Roger A.; Borkowski, Kazimierz J.; Dopita, Michael A.; Gerardy, Christopher L.; Lawrence, Stephen S.; Raymond, John C.; van den Bergh, Sidney

    2006-07-01

    HST images of the young supernova remnant Cas A are used to explore the expansion and spatial distribution of its highest velocity debris. ACS WFC images taken in 2004 March and December with Sloan F625W, F775W, and F850LP filters were used to identify 1825 high-velocity, outlying ejecta knots through measured proper motions of 0.35"-0.90" yr-1, corresponding to Vtrans=5500-14,500 km s-1 assuming d=3.4 kpc. The distribution of derived transverse expansion velocities for these ejecta knots shows a striking bipolar asymmetry with the highest velocity knots (Vtrans>=10,500 km s-1) confined to nearly opposing northeast and southwest ``jets'' at P.A.=45deg-70deg and 230°-270°, respectively. The jets have about the same maximum expansion velocity of ~=14,000 km s-1 and appear kinematically and chemically distinct in that they are the remnant's only S-rich ejecta with expansion velocities above the 10,000-11,000 km s-1 exhibited by outer nitrogen-rich ejecta, which otherwise represent the remnant's highest velocity debris. In addition, we find significant gaps in the spatial distribution of outlying ejecta in directions that are approximately perpendicular to the jets (P.A.=145deg-200deg and 335°-350°). The remnant's central X-ray point source lies some 7" to the southeast of the estimated expansion center (P.A.=169deg+/-8.4d) indicating a projected motion toward the middle of the broad southern ejecta knot gap. Extrapolations of measured 9 month proper motions for all 1825 outer ejecta knots and a selected subsample of 72 bright and compact knots suggest explosion dates (assuming no knot deceleration) of 1662+/-27 and 1672+/-18, respectively. We find some evidence for nonuniform deceleration in different directions around the remnant and find 126 knots located along the northwestern limb among the least decelerated ejecta, suggesting a convergence date of 1681+/-19. A remnant age of around 325 yr would imply a ~=350 km s-1 transverse velocity for the central X-ray point source. Based 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 (AURA), Inc., under NASA contract NAS5-26555.

  5. 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.

  6. 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.

  7. MEASURING DUST PRODUCTION IN THE SMALL MAGELLANIC CLOUD CORE-COLLAPSE SUPERNOVA REMNANT 1E 0102.2-7219

    SciTech Connect

    Sandstrom, Karin M. [Astronomy Department, 601 Campbell Hall, University of California, Berkeley, CA 94720 (United States); Bolatto, Alberto D. [Department of Astronomy and Laboratory for Millimeter-wave Astronomy, University of Maryland, College Park, MD 20742 (United States); Stanimirovic, Snezana [Department of Astronomy, University of Wisconsin, Madison, WI 53706 (United States); Van Loon, Jacco Th. [Astrophysics Group, Lennard-Jones Laboratories, Keele University, Staffordshire ST5 5BG (United Kingdom); Smith, J. D. T. [Ritter Astrophysical Research Center, University of Toledo, OH 43603 (United States)], E-mail: karin@astro.berkeley.edu

    2009-05-10

    We present mid-infrared spectral mapping observations of the core-collapse supernova remnant 1E 0102.2-7219 in the Small Magellanic Cloud using the InfraRed Spectrograph on the Spitzer Space Telescope. The remnant shows emission from fine structure transitions of neon and oxygen as well as continuum emission from dust. Comparison of the mid-IR dust emission with observations at X-ray, radio, and optical wavelengths shows that the dust is associated with the supernova ejecta and is thus newly formed in the remnant. The spectrum of the newly formed dust is well reproduced by a model that includes 3 x 10{sup -3} M {sub sun} of amorphous carbon dust at 70 K and 2 x 10{sup -5} M {sub sun} of Mg{sub 2}SiO{sub 4} (forsterite) at 145 K. Our observations place a lower limit on the amount of dust in the remnant since we are not sensitive to the cold dust in the unshocked ejecta. We compare our results to observations of other core-collapse supernovae and remnants, particularly Cas A where very similar spectral mapping observations have been carried out. We observe a factor of {approx}10 less dust in E 0102 than seen in Cas A, although the amounts of amorphous carbon and forsterite are comparable. Finally, we present evidence suggesting that the grain size distribution of the newly formed dust in E 0102 has been altered by the hot plasma behind the reverse shock.

  8. Gamma-Ray Emission from the Shell of Supernova Remnant W44 Revealed by the Fermi LAT

    Microsoft Academic Search

    A. A. Abdo; M. Ackermann; M. Ajello; L. Baldini; J. Ballet; G. Barbiellini; M. G. Baring; D. Bastieri; B. M. Baughman; K. Bechtol; R. Bellazzini; B. Berenji; R. D. Blandford; E. D. Bloom; E. Bonamente; A. W. Borgland; J. Bregeon; A. Brez; M. Brigida; P. Bruel; T. H. Burnett; S. Buson; G. A. Caliandro; R. A. Cameron; P. A. Caraveo; J. M. Casandjian; C. Cecchi; Ö. Çelik; A. Chekhtman; C. C. Cheung; J. Chiang; S. Ciprini; R. Claus; I. Cognard; J. Cohen-Tanugi; L. R. Cominsky; J. Conrad; S. Cutini; C. D. Dermer; A. de Angelis; F. de Palma; S. W. Digel; E. do Couto e Silva; P. S. Drell; R. Dubois; D. Dumora; C. Espinoza; C. Farnier; C. Favuzzi; S. J. Fegan; W. B. Focke; P. Fortin; M. Frailis; Y. Fukazawa; S. Funk; P. Fusco; F. Gargano; D. Gasparrini; N. Gehrels; S. Germani; G. Giavitto; B. Giebels; N. Giglietto; F. Giordano; T. Glanzman; G. Godfrey; I. A. Grenier; M.-H. Grondin; J. E. Grove; L. Guillemot; S. Guiriec; Y. Hanabata; A. K. Harding; M. Hayashida; E. Hays; R. E. Hughes; M. S. Jackson; G. Jóhannesson; A. S. Johnson; T. J. Johnson; W. N. Johnson; T. Kamae; H. Katagiri; J. Kataoka; J. Katsuta; N. Kawai; M. Kerr; J. Knödlseder; M. L. Kocian; M. Kramer; M. Kuss; J. Lande; L. Latronico; M. Lemoine-Goumard; F. Loparco; B. Lott; M. N. Lovellette; P. Lubrano; A. G. Lyne; G. M. Madejski; A. Makeev; M. N. Mazziotta; J. E. McEnery; C. Meurer; P. F. Michelson; W. Mitthumsiri; T. Mizuno; C. Monte; M. E. Monzani; A. Morselli; I. V. Moskalenko; S. Murgia; T. Nakamori; P. L. Nolan; J. P. Norris; A. Noutsos; E. Nuss; T. Ohsugi; N. Omodei; E. Orlando; J. F. Ormes; D. Paneque; D. Parent; V. Pelassa; M. Pesce-Rollins; F. Piron; T. A. Porter; S. Rainò; R. Rando; M. Razzano; A. Reimer; O. Reimer; T. Reposeur; L. S. Rochester; A. Y. Rodriguez; R. W. Romani; M. Roth; F. Ryde; H. F.-W. Sadrozinski; D. Sanchez; A. Sander; P. M. Saz Parkinson; J. D. Scargle; C. Sgrò; E. J. Siskind; D. A. Smith; P. D. Smith; G. Spandre; P. Spinelli; B. W. Stappers; F. W. Stecker; M. S. Strickman; D. J. Suson; H. Takahashi; T. Takahashi; T. Tanaka; J. B. Thayer; J. G. Thayer; G. Theureau; D. J. Thompson; L. Tibaldo; O. Tibolla; D. F. Torres; G. Tosti; A. Tramacere; Y. Uchiyama; T. L. Usher; V. Vasileiou; C. Venter; N. Vilchez; V. Vitale; A. P. Waite; P. Wang; B. L. Winer; K. S. Wood; R. Yamazaki; T. Ylinen; M. Ziegler

    2010-01-01

    Recent observations of supernova remnants (SNRs) hint that they accelerate cosmic rays to energies close to ~1015 electron volts. However, the nature of the particles that produce the emission remains ambiguous. We report observations of SNR W44 with the Fermi Large Area Telescope at energies between 2 × 108 electron volts and 3 ×1011 electron volts. The detection of a

  9. Molecular and Ionic shocks in the Supernova Remnant 3C391

    E-print Network

    William T. Reach; Jeonghee Rho; T. H. Jarrett; Pierre-Olivier Lagage

    2001-08-09

    New observations of the supernova remnant 3C391 are in the H2 2.12 micron and [Fe II] 1.64 micron narrow-band filters at the Palomar 200-inch telescope, and in the 5-15 micron CVF on ISOCAM. Shocked H2 emission was detected from the region 3C391:BML, where broad millimeter CO and CS lines had previously been detected. A new H2 clump was confirmed to have broad CO emission, demonstrating that the near-infrared H2 images can trace previously undetected molecular shocks. The [Fe II] emission has a significantly different distribution, being brightest in the bright radio bar, at the interface between the supernova remnant and the giant molecular cloud, and following filaments in the radio shell. The near-infrared [Fe II] and the mid-infrared 12-18 micron filter images are the first images to reveal the radiative shell of 3C391. The mid-infrared spectrum is dominated by bright ionic lines and H2 S(2) through S(7). There are no aromatic hydrocarbons associated with the shocks, nor is their any mid-infrared continuum, suggesting that macromolecules and very small grains are destroyed. Comparing 3C391 to the better-studied IC443, both remnants have molecular- and ionic-dominated regions; for 3C391, the ionic-dominated region is the interface into the giant molecular cloud, showing that the main bodies of giant molecular clouds contain significant regions with densities 100 to 1000/cm^3 and a small filling factor with higher-density. The molecular shocked region resolves into 16 clumps of H2 emission, with some fainter diffuse emission but with no associated near-infrared continuum sources. One of the clumps is coincident with a previously-detected OH 1720 MHz maser. These clumps are interpreted as a cluster of pre-stellar, dense molecular cores that are presently being shocked by the supernova blast wave.

  10. 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

  11. 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

  12. 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.

  13. A Cr-K emission line survey in young supernova remnants with Chandra

    E-print Network

    X. J. Yang; H. Tsunemi; F. J. Lu; L. Chen

    2008-10-26

    We performed a Cr-K emission line survey in young supernova remnants (SNRs) with the Chandra archival data. Our sample includes W49B, Cas A, Tycho and Kepler. We confirmed the existence of the Cr line in W49B and discovered this emission line in the other three SNRs. The line center energies, equivalent widths (EWs) and fluxes of the Cr lines are given. The Cr in Cas A is in a high ionization state while that in Tycho and Kepler is in a much lower one. We find a good positive correlation between Cr and Fe line center energies, suggesting a common origin of Cr and Fe in the nucleosynthesis, which is consistent with the theoretical predictions. We propose that the EW ratio between Cr and Fe can be used as a supplementary constraint on the progenitors' properties and the explosion mechanism.

  14. Detection of the Characteristic Pion-Decay Signature in Supernova Remnants

    E-print Network

    :,; 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; Çelik, Ö; 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; Silva, E do Couto 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; 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; 10.1126/science.1231160

    2013-01-01

    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.

  15. 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. [Department of Physics and Astronomy, University of New Mexico, MSC07 4220, Albuquerque, NM 87131 (United States); Sjouwerman, L. O.; Frail, D. A.; Claussen, M. J., E-mail: ylva@unm.edu [National Radio Astronomy Observatory, P.O. Box 0, Lopezville Road 1001, Socorro, NM 87801 (United States)

    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.

  16. XMM and Chandra Spectroscopy of the Brightest Supernova Remnants in M33

    NASA Astrophysics Data System (ADS)

    Plucinsky, Paul

    2014-08-01

    We present a spectral analysis of the X-ray brightest Supernova Remnants (SNRs) in the nearby, spiral galaxy M33 from our deep XMM-Newton survey (see poster by Garofali et al. this conference) that complements our previous survey with Chandra (ChASeM33). We have simultaneously fit the XMM and Chandra spectra to constrain the temperature and abundances. We do not find any young (t<1,000 yr) SNRs that could be analogs of Cas A or the Crab, but we find several SNRs older than 1,000 yr that show evidence of enhanced abundances. The X-ray detected SNRs appear to occur preferentially in regions with a higher than average density of the Interstellar Medium. We present the first detailed spectral analysis of the third most luminous X-ray SNR in M33 that was outside the ChASeM33 survey area.

  17. On cosmic ray acceleration in supernova remnants and the FERMI/PAMELA data

    E-print Network

    Markus Ahlers; Philipp Mertsch; Subir Sarkar

    2009-12-08

    We discuss recent observations of high energy cosmic ray positrons and electrons in the context of hadronic interactions in supernova remnants, the suspected accelerators of galactic cosmic rays. Diffusive shock acceleration can harden the energy spectrum of secondary positrons relative to that of the primary protons (and electrons) and thus explain the rise in the positron fraction observed by PAMELA above 10 GeV. We normalize the hadronic interaction rate by holding pion decay to be responsible for the gamma-rays detected by HESS from some SNRs. By simulating the spatial and temporal distribution of SNRs in the Galaxy according to their known statistics, we are able to then fit the electron (plus positron) energy spectrum measured by Fermi. It appears that IceCube has good prospects for detecting the hadronic neutrino fluxes expected from nearby SNRs.

  18. On cosmic ray acceleration in supernova remnants and the FERMI/PAMELA data

    E-print Network

    Ahlers, Markus; Sarkar, Subir

    2009-01-01

    We discuss recent observations of high energy cosmic ray positrons and electrons in the context of hadronic interactions in supernova remnants, the suspected accelerators of galactic cosmic rays. Diffusive shock acceleration can harden the energy spectrum of secondary positrons relative to that of the primary protons (and electrons) and thus explain the rise in the positron fraction observed by PAMELA above 10 GeV. We normalize the hadronic interaction rate by holding pion decay to be responsible for the gamma-rays detected by HESS from some SNRs. By simulating the spatial and temporal distribution of SNRs in the Galaxy according to their known statistics, we are able to then fit the electron (plus positron) energy spectrum measured by Fermi. It appears that IceCube has good prospects for detecting the hadronic neutrino fluxes expected from nearby SNRs.

  19. Cosmic ray acceleration in supernova remnants and the FERMI/PAMELA data

    SciTech Connect

    Ahlers, Markus; Mertsch, Philipp; Sarkar, Subir [Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford OX1 3NP (United Kingdom)

    2009-12-15

    We discuss recent observations of high energy cosmic ray positrons and electrons in the context of hadronic interactions in supernova remnants (SNRs), the suspected accelerators of galactic cosmic rays. Diffusive shock acceleration can harden the energy spectrum of secondary positrons relative to that of the primary protons and electrons and thus explain the rise in the positron fraction observed by PAMELA above 10 GeV. We normalize the hadronic interaction rate by holding pion decay to be responsible for the gamma rays detected by HESS from some SNRs. By simulating the spatial and temporal distribution of SNRs in the Galaxy according to their known statistics, we are able to then fit the electron (plus positron) energy spectrum measured by Fermi. It appears that IceCube has good prospects for detecting the hadronic neutrino fluxes expected from nearby SNRs.

  20. Cosmic ray acceleration in supernova remnants and the FERMI/PAMELA data

    NASA Astrophysics Data System (ADS)

    Ahlers, Markus; Mertsch, Philipp; Sarkar, Subir

    2009-12-01

    We discuss recent observations of high energy cosmic ray positrons and electrons in the context of hadronic interactions in supernova remnants (SNRs), the suspected accelerators of galactic cosmic rays. Diffusive shock acceleration can harden the energy spectrum of secondary positrons relative to that of the primary protons and electrons and thus explain the rise in the positron fraction observed by PAMELA above 10 GeV. We normalize the hadronic interaction rate by holding pion decay to be responsible for the gamma rays detected by HESS from some SNRs. By simulating the spatial and temporal distribution of SNRs in the Galaxy according to their known statistics, we are able to then fit the electron (plus positron) energy spectrum measured by Fermi. It appears that IceCube has good prospects for detecting the hadronic neutrino fluxes expected from nearby SNRs.

  1. A possible explanation of photon emission from supernova remnants by jitter radiation

    NASA Astrophysics Data System (ADS)

    Ogasawara, T.; Yoshida, T.; Yanagita, S.; Kifune, T.

    2007-06-01

    We investigate a possibility that non-thermal X-ray emission in a supernova remnant(SNR) is produced by jitter radiation, which is the analogue of synchrotron radiation in small-scale random magnetic fields. We can fit the multi-wavelength data of SNRs RX J1713.7-3946 (G347.3-0.5) and RX J0852.0-4622 (G266.6-1.2) by constructing pure jitter and inverse Compton (IC) emission models. We find that the physical fit parameters of random magnetic fields take values of several tens of ?G strength and of the order of ˜107 cm correlation length. These properties of random magnetic fields in collisionless shock of SNRs are discussed.

  2. Acceleration of cosmic rays by young core-collapse supernova remnants

    E-print Network

    Telezhinsky, I; Pohl, M

    2012-01-01

    Context. Supernova Remnants (SNRs) are thought to be the primary candidates for the sources of Galactic cosmic rays. According to Diffusive Shock Acceleration theory, SNR shocks produce a power-law spectrum with index s = 2, perhaps non-linearly modified to harder spectra at high energy. Observations of SNRs often indicate particle spectra that are softer than that and show features not expected from classical theory. Known drawbacks of the standard approach are the assumption that SNRs evolve in a uniform environment, and that the reverse shock does not accelerate particles. Relaxing those assumptions increases the complexity of the problem, because one needs reliable hydrodynamical data for the plasma flow as well as good estimates for the magnetic field at the reverse shock. Aims. We show that these two factors are especially important when modeling young core-collapse SNRs that evolve in a complicated circumstellar medium shaped by the winds of progenitor stars. Methods. We use high-resolution numerical s...

  3. Model for Synchrotron Emission from Shell Supernova Remnants in Nonuniform Interstellar Medium and Nonuniform Magnetic Field

    E-print Network

    O. Petruk

    2002-06-27

    Possibility to model the high energy synchrotron emission (in X- and gamma-rays) from supernova remnants is an important task for modern astronomy and astrophysics, because it may be responsible for the nonthermal X-rays and TeV gamma-rays observed recently from a number of SNRs. This emission allows as to look in the processes of particle acceleration on SNR shocks and generation of cosmic rays. In this paper, a model for the synchrotron emission from shell SNR in nonuniform interstellar medium and nonuniform magnetic field is presented. This model is a generalization of the model of Reynolds and Chevalier developed for a spherical SNR in the uniform medium and uniform magnetic field. The model will be used for studies on the thermal and nonthermal X-ray images and spectra from nonspherical SNRs in different interstellar magnetic field configurations.

  4. Alfven Wave Amplification and Self-Containment of Cosmic-Rays Escaping from a Supernova Remnant

    E-print Network

    Fujita, Yutaka; Ohira, Yutaka; Iwasaki, Kazunari

    2011-01-01

    We study the escape of cosmic-ray (CR) protons accelerated at a supernova remnant (SNR) by numerically solving a diffusion-convection equation from the vicinity of the shock front to the region far away from the front. We consider the amplifications of Alfven waves generated by the escaping CR particles and their effects on CR escape into interstellar medium (ISM). We find that the amplification of the waves significantly delays the escape of the particles even far away from the shock front (on a scale of the SNR). This means that the energy spectrum of CR particles measured through gamma-ray observations at molecular clouds around SNRs is seriously affected by the particle scattering by the waves.

  5. VizieR Online Data Catalog: NGC 3000 candidate supernova remnants (Millar+, 2012)

    NASA Astrophysics Data System (ADS)

    Millar, W. C.; White, G. L.; Filipovic, M. D.

    2012-11-01

    We present the results of a study of observational and identification techniques used for surveys and spectroscopy of candidate supernova remnants (SNRs) in the Sculptor Group galaxy NGC300. The goal of this study was to investigate the reliability of using [Sii]:H?>=0.4 in optical SNR surveys and spectra as an identifying feature of extra-galactic SNRs (egSNRs), and also to investigate the effectiveness of the observing techniques (which are hampered by seeing conditions and telescope pointing errors) using this criterion in egSNR surveys and spectrographs. This study is based on original observations of these objects and archival data obtained from the Hubble Space Telescope which contained images of some of the candidate SNRs in NGC300. We found that the reliability of spectral techniques may be questionable and very high-resolution images may be needed to confirm a valid identification of some egSNRs. (2 data files).

  6. Detection of the Characteristic Pion-Decay Signature in Supernova Remnants

    NASA Astrophysics Data System (ADS)

    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.; Çelik, Ö.; 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.

    2013-02-01

    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.

  7. SUBARU HIGH-RESOLUTION SPECTROSCOPY OF STAR G IN THE TYCHO SUPERNOVA REMNANT

    SciTech Connect

    Kerzendorf, Wolfgang E.; Schmidt, Brian P.; Yong, David [Research School of Astronomy and Astrophysics, Mount Stromlo Observatory, Cotter Road, Weston Creek, ACT 2611 (Australia); Asplund, M. [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Strasse 1, Postfach 1317, D-85748 Garching (Germany); Nomoto, Ken'ichi [Institute for the Physics and Mathematics of the Universe, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8568 (Japan); Podsiadlowski, Ph. [Department of Astrophysics, University of Oxford, Oxford, OX1 3RH (United Kingdom); Frebel, Anna [McDonald Observatory, University of Texas, 1 University Station C1402, Austin, TX 78712-0259 (United States); Fesen, Robert A. [Department of Physics and Astronomy, 6127 Wilder Laboratory, Dartmouth College, Hanover, NH 03755 (United States)], E-mail: wkerzend@mso.anu.edu.au, E-mail: brian@mso.anu.edu.au, E-mail: yong@mso.anu.edu.au, E-mail: nomoto@astron.s.u-tokyo.ac.jp, E-mail: podsi@astro.ox.ac.uk, E-mail: anna@astro.as.utexas.edu, E-mail: fesen@snr.dartmouth.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.

  8. X-ray study of the supernova remnant G337.2-0.7

    NASA Astrophysics Data System (ADS)

    Takata, Akihiro; Nobukawa, Masayoshi; Uchida, Hiroyuki; Tsuru, Takeshi Go; Tanaka, Takaaki; Koyama, Katsuji

    2015-06-01

    This paper reports on the Suzaku result of the Galactic supernova remnant (SNR) G337.2-0.7. The X-ray spectrum is well explained by three components in ionizing phase. One is a plasma with a low temperature kT = 0.70_{-0.03}^{+0.02}keV, solar abundances, and an ionization parameter n_et = 5.7^{+0.7}_{-0.4}× 10^{11}s cm-3. The second is a middle-temperature plasma with kT = 1.54^{+0.13}_{-0.02}keV and high metal abundances in a highly ionized state of n_et = 3.6^{+0.2}_{-0.5}× 10^{11}s cm-3, and the third is a high-temperature plasma with kT = 3.1^{+0.2}_{-0.1}keV and high metal abundances in a low-ionized state of n_et=2.1^{+0.4}_{-0.2}× 10^{10}s cm-3. The high metal-abundance plasmas are likely to be of an ejecta origin, while the solar abundance plasma would be of an interstellar-gas origin. The abundance pattern and mass of the ejecta confirm that G337.2-0.7 is a remnant of a Type Ia supernova (SN). The derived Fe mass of ejecta MFe = 0.025-0.039 M? is far smaller than that expected from any Type Ia model, suggesting that most Fe has not yet been heated by the reverse shock. The ejecta has enhanced distribution in the northeastern region compared to the central region, and therefore the SN explosion or SNR evolution would be asymmetric.

  9. X-ray observations of supernova remnant G54.1+0.3: X-ray spectrum and the discovery of an X-ray jet

    E-print Network

    F. J. Lu; B. Aschenbach; L. M. Song

    2000-05-24

    We present in this paper analyses of the $ROSAT$ PSPC and $ASCA$ SIS and GIS observations of the Crab-like supernova remnant (SNR) G54.1+0.3. Its spectrum obtained by $ROSAT$ PSPC favors a power law model with a photon index of -0.8$^{+0.8}_{-2.0}$, absorbed energy flux in 0.1-2.4 keV of 1.0$\\times 10^{-12}$ erg cm$^{-2}$ s$^{-1}$, and absorption column density of 12.3$^{+8.0}_{-3.2}\\times 10^{21}$ cm$^{-2}$. $ASCA$ SIS observation shows that its spectrum can also be best fitted with power law model. The fitted parameters are, photon index -1.9$^{+0.1}_{-0.2}$, absorbed energy flux in 0.7-2.1 keV 6.5$\\times10^{-13}$ erg cm$^{-2}$ s$^{-1}$, and column density 17.9$^{+2.8}_{-2.5}\\times 10^{21}$ cm$^{-2}$. The high absorption column density indicates a distance similar to the radius of the galaxy. The 0.1-2.4 keV X-ray luminosity of G54.1+0.3 is 3.2$\\times10^{33}$$d_{10}^2$ erg s$^{-1}$, where $d_{10}$ is the distance in 10 kpc. With an image restoration method we have obtained high spatial resolution X-ray image of the remnant, which clearly shows an X-ray jet pointing to the northeast with a length about 40$\\arcsec$ from the center of the nebula. Its X-ray luminosity in 0.1-2.4 keV is about 5.1$\\times10^{32}$$d_{10}^2$ erg s$^{-1}$. The X-ray jet is consistent with the radio extension to the northeast in both direction and position. We propose that the X-ray jet is connected with the pulsar assumed to exist in the remnant.

  10. Radio-Continuum Emission from the Young Galactic Supernova Remnant G1.9+0.3

    NASA Astrophysics Data System (ADS)

    De Horta, A. Y.; Filipovic, M. D.; Crawford, E. J.; Stootman, F. H.; Pannuti, T. G.; Bozzetto, L. M.; Collier, J. D.; Sommer, E. R.; Kosakowski, A. R.

    2014-12-01

    We present an analysis of a new Australia Telescope Compact Array (ATCA) radio-continuum observation of supernova remnant (SNR) G1.9+0.3, which at an age of ˜181±25 years is the youngest known in the Galaxy. We analysed all available radio-continuum observations at 6-cm from the ATCA and Very Large Array. Using this data we estimate an expansion rate for G1.9+0.3 of 0.563±0.078 percent per year between 1984 and 2009. We note that in the 1980's G1.9+0.3 expanded somewhat slower (0.484 percent per year) than more recently (0.641 percent per year). We estimate that the average spectral index between 20-cm and 6-cm, across the entire SNR is ?=-0.72±0.26 which is typical for younger SNRs. At 6-cm, we detect an average of 6 percent fractionally polarised radio emission with a peak of 17±3 percent. The polarised emission follows the contours of the strongest of X-ray emission. Using the new equipartition formula we estimate a magnetic field strength of B?273~? G, which to date, is one of the highest magnetic field strength found for any SNR and consistent with G1.9+0.3 being a very young remnant.

  11. FERMI-LAT AND WMAP OBSERVATIONS OF THE PUPPIS A SUPERNOVA REMNANT

    SciTech Connect

    Hewitt, J. W. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Grondin, M.-H. [Max-Planck-Institut fuer Kernphysik, D-69029 Heidelberg (Germany); Lemoine-Goumard, M.; Reposeur, T. [Centre d'Etudes Nucleaires de Bordeaux-Gradignan, Universite Bordeaux 1, CNRS/IN2p3, F-33175 Gradignan (France); Ballet, J. [Laboratoire AIM, CEA-IRFU/CNRS/Universite Paris Diderot, Service d'Astrophysique, CEA Saclay, F-91191 Gif sur Yvette (France); Tanaka, T., E-mail: john.w.hewitt@nasa.gov, E-mail: marie-helene.grondin@mpi-hd.mpg.de, E-mail: lemoine@cenbg.in2p3.fr [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States)

    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.

  12. FERMI-LAT OBSERVATIONS AND A BROADBAND STUDY OF SUPERNOVA REMNANT CTB 109

    SciTech Connect

    Castro, Daniel [MIT-Kavli Center for Astrophysics and Space Research, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Slane, Patrick; Patnaude, Daniel J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Ellison, Donald C. [Physics Department, North Carolina State University, Box 8202, Raleigh, NC 27695 (United States)

    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.

  13. Spatially Resolved Low Frequency VLA observations of the Supernova Remnant 3C 391

    E-print Network

    C. L. Brogan; T. J. Lazio; N. E. Kassim; K. K. Dyer

    2005-03-02

    We present VLA images of the supernova remnant (SNR) 3C~391 at 74, 330, and 1465 MHz. This remnant has been known for some time to exhibit a turnover in its integrated radio continuum spectrum at frequencies < 100 MHz, indicative of free-free absorption from thermal ionized gas along the line of sight. For the first time, our data reveal the spatially resolved morphology of the low frequency free-free absorption with a resolution of ~70 arcsec. Contrary to the expectation that such absorption arises from unrelated low density HII regions (or their envelopes) along the line of sight, these data suggest that in this case the absorbing medium is directly linked to the SNR itself. 3C~391 has been shown in a number of recent papers to be interacting with a molecular cloud. Indeed, it exhibits a number of signposts of SNR/molecular cloud shocks including OH (1720 MHz) masers and broad molecular emission lines. Comparison of the regions of strongest 74 MHz absorption with existing X-ray, IR, and molecular data suggests that the free-free absorption originates from the SNR/molecular cloud shock boundaries due to ionized gas created from the passage of a J-type shock with a speed of ~100 km/s. This makes only the second SNR for which such (extrinsic) spatially resolved absorption has been measured, and the only one for which the absorption is thought to arise from a SNR/molecular cloud interface region.

  14. A "Missing" Supernova Remnant revealed by the 21-cm Line of Atomic Hydrogen

    E-print Network

    Koo, B C; Salter, C J

    2006-01-01

    Although some 20--30,000 supernova remnants (SNRs) are expected to exist in the Milky Way, only about 230 are presently known. This implies that most SNRs are ``missing''. Recently, we proposed that small ($\\simlt 1^\\circ$), faint, high-velocity features seen in large-scale 21-cm line surveys of atomic hydrogen ({\\sc Hi}) in the Galactic plane could be examples of such {\\it missing} old SNRs. Here we report on high-resolution \\schi observations of one such candidate, FVW 190.2+1.1, which is revealed to be a rapidly expanding ($\\sim 80$ \\kms) shell. The parameters of this shell seem only consistent with FVW 190.2+1.1 being the remnant of a SN explosion that occurred in the outermost fringes of the Galaxy some $\\sim 3\\times 10^5$ yr ago. This shell is not seen in any other wave band suggesting that it represents the oldest type of SNR, that which is essentially invisible except via its \\schi line emission. FVW 190.2+1.1 is one of a hundred "forbidden-velocity wings" (FVWs) recently identified in the Galactic pl...

  15. A "Missing" Supernova Remnant revealed by the 21-cm Line of Atomic Hydrogen

    E-print Network

    B-C Koo; J-h Kang; C. J. Salter

    2006-04-09

    Although some 20--30,000 supernova remnants (SNRs) are expected to exist in the Milky Way, only about 230 are presently known. This implies that most SNRs are ``missing''. Recently, we proposed that small ($\\simlt 1^\\circ$), faint, high-velocity features seen in large-scale 21-cm line surveys of atomic hydrogen ({\\sc Hi}) in the Galactic plane could be examples of such {\\it missing} old SNRs. Here we report on high-resolution \\schi observations of one such candidate, FVW 190.2+1.1, which is revealed to be a rapidly expanding ($\\sim 80$ \\kms) shell. The parameters of this shell seem only consistent with FVW 190.2+1.1 being the remnant of a SN explosion that occurred in the outermost fringes of the Galaxy some $\\sim 3\\times 10^5$ yr ago. This shell is not seen in any other wave band suggesting that it represents the oldest type of SNR, that which is essentially invisible except via its \\schi line emission. FVW 190.2+1.1 is one of a hundred "forbidden-velocity wings" (FVWs) recently identified in the Galactic plane, and our discovery suggests that many of these are likely to be among the oldest SNRs. We discuss the possible link between FVWs and fast-moving atomic clouds in the Galaxy.

  16. IUE spectra and optical imaging of the oxygen-rich supernova remnant N132D

    NASA Technical Reports Server (NTRS)

    Blair, William P.; Raymond, John C.; Long, Knox S.

    1994-01-01

    We present new optical Charge Coupled Devices (CCD) interference filter imagery and International Ultraviolet Explorer (IUE) spectroscopy for the oxygen-rich supernova remnant N132D in the Large Magellanic Cloud. The optical images show a wealth of structure, and comparison with an archival Einstein High Resolution Imager (HRI) X-ray image shows that a few optical features have X-ray counter-parts, but in general there is little correlation between X-ray and optical features. The IUE spectra at two positions show strong lines of carbon and oxygen, with lines of neon, magnesium, silicon, and helium also present and variable in relative intensities. We use optical data for N132D from Dopita & Tuohy (1984) with our UV observations to compare with shock models (both with and without thermal conduction) and X-ray photoionization model calculations. While none of the model fits is entirely satisfactory, the generally weak UV emission relative to optical disagrees with the general character of shock model predictions and indicates that photoionization is the dominant excitation mechanism for the UV/optical emission. This conclusion is similar to what was found for E0102 - 7219, the oxygen-rich remnant in the Small Magellanic Cloud. We derive rough abundances for the emitting material in N132D, compare to stellar nucleosynthesis models, and discuss the implications for its precursor. A precursor near 20 solar mass is consistent with the data.

  17. VERITAS observations of supernova remnants for studies of cosmic ray acceleration

    NASA Astrophysics Data System (ADS)

    Park, Nahee

    Supernova remnants (SNRs) have been suggested as the main sites for acceleration of cosmic rays (CRs) with energies up to the knee region ( 10(15) eV). Gamma-ray emission from SNRs can provide a unique window to observe the cosmic ray acceleration and to test existing acceleration models in these objects. The Very Energetic Radiation Imaging Telescope Array System (VERITAS) is an array of atmospheric Cherenkov telescopes that measures gamma rays with energies higher than 100 GeV. Located in Arizona, USA, VERITAS has observed several SNRs in the northern hemisphere since the beginning of operations in 2007. These include two young SNRs of different types (Cassiopeia A and Tycho), as well as middle- to old-aged remnants with nearby target material such as molecular clouds. Gamma-ray data from different types of SNRs in different evolutionary stages are important to study SNRs as CR accelerators. Here we present a summary of VERITAS results on Galactic SNRs including Tycho, and discuss what these observations have taught us.

  18. Frequency dependence of the evolution of the radio emission of the supernova remnant Cas A

    NASA Astrophysics Data System (ADS)

    Vinyaikin, E. N.

    2014-09-01

    Many-year measurements of the radio flux of the young supernova remnant Cassiopeia A relative to the radio galaxy Cygnus A were continued at 290 and 151.5 MHz. The new data are used together with previously published observations carried out at decameter, meter, centimeter, and millimeter wavelengths to derive the frequency dependence of the secular variation of the radio flux density of Cas A: . The observed slowing of the secular variations with decreasing frequency at decameter wavelengths can be explained by a decrease in the optical depth of a remnant HII zone around Cas A with time due to recombination of hydrogen atoms. The new derived frequency dependence for the rate of the secular decrease, absolute and relative measurements of the radio flux density of Cas A carried out over the last 25 years, and the absolute spectrum of Cyg A are used to construct the spectrum of Cas A in the range 5-250 000 MHz predicted for epoch 2015.5.

  19. The properties of non-thermal X-ray filaments in young supernova remnants

    NASA Astrophysics Data System (ADS)

    Rettig, R.; Pohl, M.

    2012-09-01

    Context. Young supernova remnants (SNRs) exhibit narrow filaments of non-thermal X-ray emission whose widths can be limited either by electron energy losses or damping of the magnetic field. Aims: We want to investigate whether or not different models of these filaments can be observationally tested. Methods: Using observational parameters of four historical remnants, we calculated the filament profiles and compared the spectra of the filaments with those of the total non-thermal emission. For that purpose, we solved a one-dimensional stationary transport equation for the isotropic differential number density of the electrons. Results: We find that the difference between the spectra of filament and total non-thermal emission above 1 keV is more pronounced in the damping model than in the energy-loss model. Conclusions: A considerable damping of the magnetic field can result in an observable difference between the spectra of filament and total non-thermal emission, thus potentially permitting an observational discrimination between the energy-loss model and the damping model of the X-ray filaments.

  20. 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.

  1. Possible Detection of the Stellar Donor or Remnant for the Type Iax Supernova 2008ha

    E-print Network

    Foley, Ryan J; Jha, Saurabh W; Bildsten, Lars; Fong, Wen-fai; Narayan, Gautham; Rest, Armin; Stritzinger, Maximilian D

    2014-01-01

    Type Iax supernovae (SNe Iax) are thermonuclear explosions that are related to SNe Ia, but are physically distinct. The most important differences are that SNe Iax have significantly lower luminosity (1% - 50% that of typical SNe Ia), lower ejecta mass (~0.1 - 0.5 M_sun), and may leave a bound remnant. The most extreme SN Iax is SN 2008ha, which peaked at M_V = -14.2 mag, about 5 mag below that of typical SNe Ia. Here, we present Hubble Space Telescope (HST) images of UGC 12682, the host galaxy of SN 2008ha, taken 4.1 years after the peak brightness of SN 2008ha. In these deep, high-resolution images, we detect a source coincident (0.86 HST pixels; 0.043"; 1.1 sigma) with the position of SN 2008ha with M_F814W = -5.4 mag. We determine that this source is unlikely to be a chance coincidence, but that scenario cannot be completely ruled out. If this source is directly related to SN 2008ha, it is either the luminous bound remnant of the progenitor white dwarf or its companion star. The source is consistent with ...

  2. G33. 6 + 0. 1 - A shell type supernova remnant with unusual structure

    SciTech Connect

    Velusamy, T.; Becker, R.H.; Seward, F.D. (Tata Inst. of Fundamental Research, Udhagamandalan (India) California Univ., Davis (United States) Lawrence Livermore National Lab., Livermore (United States) Smithsonian Astrophysical Observatory, Cambridge, MA (United States))

    1991-08-01

    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 {minus}0.6 to {minus}0.75) is consistent with that of shell type remnants, the bright filamentary emission along the 'inner ring' has relatively flatter spectrum (alpha about {minus}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. 20 refs.

  3. 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.

  4. DISCOVERY OF TeV GAMMA-RAY EMISSION FROM TYCHO'S SUPERNOVA REMNANT

    SciTech Connect

    Acciari, V. A.; Benbow, W. [Fred Lawrence Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, Amado, AZ 85645 (United States); Aliu, E.; Errando, M. [Department of Physics and Astronomy, Barnard College, Columbia University, NY 10027 (United States); Arlen, T. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Aune, T. [Santa Cruz Institute for Particle Physics and Department of Physics, University of California, Santa Cruz, CA 95064 (United States); Beilicke, M.; Buckley, J. H.; Bugaev, V.; Dickherber, R. [Department of Physics, Washington University, St. Louis, MO 63130 (United States); Bradbury, S. M. [School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT (United Kingdom); Byrum, K. [Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439 (United States); Cannon, A.; Collins-Hughes, E. [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Cesarini, A. [School of Physics, National University of Ireland Galway, University Road, Galway (Ireland); Ciupik, L. [Astronomy Department, Adler Planetarium and Astronomy Museum, Chicago, IL 60605 (United States); Cui, W.; Finley, J. P. [Department of Physics, Purdue University, West Lafayette, IN 47907 (United States); Duke, C. [Department of Physics, Grinnell College, Grinnell, IA 50112-1690 (United States); Finnegan, G., E-mail: dbsaxon@udel.edu, E-mail: wakely@uchicago.edu [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States)

    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.

  5. Nonthermal Emission from Middle-aged Supernova Remnants Interacting with Molecular Clouds

    NASA Astrophysics Data System (ADS)

    Tang, Y. Y.; Fang, J.; Zhang, L.

    2011-09-01

    Supernova remnants (SNRs) interacting with dense molecular clouds (MCs) are proven to be bright ?-ray emitters by recent observations in the GeV-TeV band. We theoretically investigate the multiband radiative properties of the four middle-aged SNRs IC443, W51C, W28, and W44 with a time-dependent injection model. In the model, part of the SNR shell transports into a dense MC, with the other part of the shell evolving in a relatively tenuous interstellar medium. We find a broken power law with a break energy of ~3-40 GeV that must be imposed to reproduce the observed multiwavelength spectra for the four remnants. The results indicate that the observed ?-ray spectra can be reproduced as a p-p interaction of the high-energy protons injected by the shell interacting with the MC with the dense matter, whereas the radio emission is produced via synchrotron radiation of the injected electrons from the other part of the shell for the four middle-aged SNRs.

  6. NONTHERMAL EMISSION FROM MIDDLE-AGED SUPERNOVA REMNANTS INTERACTING WITH MOLECULAR CLOUDS

    SciTech Connect

    Tang, Y. Y.; Fang, J.; Zhang, L., E-mail: lizhang@ynu.edu.cn [Department of Physics, Yunnan University, Kunming 650091 (China)

    2011-09-20

    Supernova remnants (SNRs) interacting with dense molecular clouds (MCs) are proven to be bright {gamma}-ray emitters by recent observations in the GeV-TeV band. We theoretically investigate the multiband radiative properties of the four middle-aged SNRs IC443, W51C, W28, and W44 with a time-dependent injection model. In the model, part of the SNR shell transports into a dense MC, with the other part of the shell evolving in a relatively tenuous interstellar medium. We find a broken power law with a break energy of {approx}3-40 GeV that must be imposed to reproduce the observed multiwavelength spectra for the four remnants. The results indicate that the observed {gamma}-ray spectra can be reproduced as a p-p interaction of the high-energy protons injected by the shell interacting with the MC with the dense matter, whereas the radio emission is produced via synchrotron radiation of the injected electrons from the other part of the shell for the four middle-aged SNRs.

  7. MOLECULAR ENVIRONMENT AND AN X-RAY SPECTROSCOPY OF SUPERNOVA REMNANT KESTEVEN 78

    SciTech Connect

    Zhou Ping; Chen Yang [Department of Astronomy, Nanjing University, Nanjing 210093 (China)

    2011-12-10

    We investigate the molecular environment of the Galactic supernova remnant (SNR) Kesteven 78 and perform an XMM-Newton X-ray spectroscopic study for the northeastern edge of the remnant. SNR Kes 78 is found to interact with the molecular clouds (MCs) at a systemic local standard of rest velocity of 81 km s{sup -1}. At around this velocity, the SNR appears to contact a long molecular strip in the northeast and a large cloud in the east as revealed in the {sup 13}CO line, which may be responsible for the radio brightness peak and the OH maser, respectively. The {sup 12}CO-line bright region morphologically matches the eastern bright radio shell in general, and the SNR is consistent in extent with a CO cavity. Broadened {sup 12}CO-line profiles discerned in the eastern maser region and the western clumpy molecular arc and the elevated {sup 12}CO (J = 2-1)/(J = 1-0) ratios along the SNR boundary may be signatures of shock perturbation in the molecular gas. The SNR-MC association places the SNR at a kinematic distance of 4.8 kpc. The X-rays arising from the northeastern radio shell are emitted by underionized hot ({approx}1.5 keV), low-density ({approx}0.1 cm{sup -3}) plasma with solar abundance, and the plasma may be of intercloud origin. The age of the remnant is inferred to be about 6 kyr. The size of the molecular cavity in Kes 78 implies an initial mass around 22 M{sub Sun} for the progenitor.

  8. Cr-K Emission Line as a Constraint on the Progenitor Properties of Supernova Remnants

    E-print Network

    Yang, X J; Lu, F J; Li, Aigen; Xiang, F Y; Xiao, H P; Zhong, J X

    2013-01-01

    We perform a survey of the Cr, Mn and Fe-K emission lines in young supernova remnants (SNRs) with the Japanese X-ray astronomy satellite {\\sl Suzaku}. The Cr and/or Mn emission lines are detected in 3C\\,397 and 0519-69.0 for the first time. We also confirm the detection of these lines in Kepler, W49B, N103B and Cas A. We derive the line parameters (i.e., the line centroid energy, flux and equivalent width [EW]) for these six sources and perform a correlation analysis for the line center energies of Cr, Mn and Fe. Also included in the correlation analysis are Tycho and G344.7-0.1 for which the Cr, Mn and Fe-K line parameters were available in the literature through {\\sl Suzaku} observations. We find that the line center energies of Cr correlates very well with that of Fe and that of Mn. This confirms our previous findings that the Cr, Mn and Fe are spatially co-located, share a similar ionization state, and have a common origin in the supernova nucleo-synthesis. We find that the ratio of the EW of the Cr emiss...

  9. Infrared-Excess Stellar Objects in the Supernova Remnant G54.1+0.3

    NASA Astrophysics Data System (ADS)

    Koo, Bon-Chul

    2012-01-01

    We propose COMICS N- and Q-band imaging observations of infrared-excess stellar objects in G54.1+0.3. G54.1+0.3 is a young supernova remnant (SNR) which has recently attracted considerable interest by its associated infrared (IR) loop and embedded stellar sources discovered by AKARI and Spitzer infrared space telescopes. Two scenarios have been proposed for the relation between the stellar sources with IR excess and the SNR: (i) the stellar sources are young massive stellar objects whose formation was triggered by the progenitor of the SNR, and the IR-excess emission is from their circumstellar material, (ii) the stellar sources are massive stars in a cluster to which the progenitor of the SNR belonged, and the IR-excess emission is from the supernova ejecta dusts. The COMICS silicate filter sets provide sufficient sensitivity and spectral resolution to derive the exact shape of spectra, which together with the Q-band photometry will reveal the nature of dusts in this intriguing object. We also propose [Ne II] and Q-band imaging observations of the brightest compact source in the IR loop to investigate the spatial correlation between the SN ejecta and dusts, which is essential to understand the nature of this compact source.

  10. MOLECULAR CLOUDS AS A PROBE OF COSMIC-RAY ACCELERATION IN A SUPERNOVA REMNANT

    SciTech Connect

    Fujita, Yutaka; Ohira, Yutaka; Tanaka, Shuta J.; Takahara, Fumio [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043 (Japan)

    2009-12-20

    We study cosmic-ray acceleration in a supernova remnant (SNR) and the escape from it. We model nonthermal particle and photon spectra for the hidden SNR in the open cluster Westerlund 2, and the old-age mixed-morphology SNR W 28. We assume that the SNR shock propagates in a low-density cavity, which is created and heated through the activities of the progenitor stars and/or previous supernova explosions. We indicate that the diffusion coefficient for cosmic rays around the SNRs is less than approx1% of that away from them. We compare our predictions with the gamma-ray spectra of molecular clouds illuminated by the cosmic rays (Fermi and H.E.S.S.). We found that the spectral indices of the particles are approx2.3. This may be because the particles were accelerated at the end of the Sedov phase, and because energy-dependent escape and propagation of particles did not much affect the spectrum.

  11. Supernova Remnants Interacting with Molecular Clouds: X-Ray and Gamma-Ray Signatures

    NASA Astrophysics Data System (ADS)

    Slane, Patrick; Bykov, Andrei; Ellison, Donald C.; Dubner, Gloria; Castro, Daniel

    2015-05-01

    The giant molecular clouds (MCs) found in the Milky Way and similar galaxies play a crucial role in the evolution of these systems. The supernova explosions that mark the death of massive stars in these regions often lead to interactions between the supernova remnants (SNRs) and the clouds. These interactions have a profound effect on our understanding of SNRs. Shocks in SNRs should be capable of accelerating particles to cosmic ray (CR) energies with efficiencies high enough to power Galactic CRs. X-ray and ?-ray studies have established the presence of relativistic electrons and protons in some SNRs and provided strong evidence for diffusive shock acceleration as the primary acceleration mechanism, including strongly amplified magnetic fields, temperature and ionization effects on the shock-heated plasmas, and modifications to the dynamical evolution of some systems. Because protons dominate the overall energetics of the CRs, it is crucial to understand this hadronic component even though electrons are much more efficient radiators and it can be difficult to identify the hadronic component. However, near MCs the densities are sufficiently high to allow the ?-ray emission to be dominated by protons. Thus, these interaction sites provide some of our best opportunities to constrain the overall energetics of these particle accelerators. Here we summarize some key properties of interactions between SNRs and MCs, with an emphasis on recent X-ray and ?-ray studies that are providing important constraints on our understanding of cosmic rays in our Galaxy.

  12. SPITZER OBSERVATIONS OF DUST DESTRUCTION IN THE PUPPIS A SUPERNOVA REMNANT

    SciTech Connect

    Arendt, Richard G. [CRESST, University of Maryland-Baltimore County, Baltimore, MD 21250 (United States); Dwek, Eli [NASA Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States); Blair, William P.; Hwang, Una [Henry A. Rowland Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Ghavamian, Parviz; Long, Knox S. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Petre, Robert [NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States); Rho, Jeonghee [Spitzer Science Center, MS 220-6, California Institute of Technology, Pasadena, CA 91125 (United States); Winkler, P. Frank, E-mail: Richard.G.Arendt@nasa.go [Department of Physics, Middlebury College, Middlebury, VT 05753 (United States)

    2010-12-10

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

  13. ISOCAM spectro-imaging of the H2 rotational lines in the supernova remnant IC443

    E-print Network

    D. Cesarsky; P. Cox; G. Pineau des Forets; E. F. van Dishoeck; F. Boulanger; C. M. Wright

    1999-06-24

    We report spectro-imaging observations of the bright western ridge of the supernova remnant IC 443 obtained with the ISOCAM circular variable filter (CVF) on board the Infrared Space Observatory (ISO). This ridge corresponds to a location where the interaction between the blast wave of the supernova and ambient molecular gas is amongst the strongest. The CVF data show that the 5 to 14 micron spectrum is dominated by the pure rotational lines of molecular hydrogen (v = 0--0, S(2) to S(8) transitions). At all positions along the ridge, the H2 rotational lines are very strong with typical line fluxes of 10^{-4} to 10^{-3} erg/sec/cm2/sr. We compare the data to a new time-dependent shock model; the rotational line fluxes in IC 443 are reproduced within factors of 2 for evolutionary times between 1,000 and 2,000 years with a shock velocity of 30 km/sec and a pre-shock density of 10^4 /cm3.

  14. ISOCAM spectro-imaging of the $H_{2}$ rotational lines in the supernova remnant IC443

    E-print Network

    Cesarsky, D A; Pineau des Forêts, G; Van Dishoeck, E F; Boulanger, F; Wright, C M

    1999-01-01

    We report spectro-imaging observations of the bright western ridge of the supernova remnant IC 443 obtained with the ISOCAM circular variable filter (CVF) on board the Infrared Space Observatory (ISO). This ridge corresponds to a location where the interaction between the blast wave of the supernova and ambient molecular gas is amongst the strongest. The CVF data show that the 5 to 14 micron spectrum is dominated by the pure rotational lines of molecular hydrogen (v = 0--0, S(2) to S(8) transitions). At all positions along the ridge, the H2 rotational lines are very strong with typical line fluxes of 10^{-4} to 10^{-3} erg/sec/cm2/sr. We compare the data to a new time-dependent shock model; the rotational line fluxes in IC 443 are reproduced within factors of 2 for evolutionary times between 1,000 and 2,000 years with a shock velocity of 30 km/sec and a pre-shock density of 10^4 /cm3.

  15. A Study of the Non-Thermal X-Ray Emission of Shell-Type Supernova Remnants

    NASA Technical Reports Server (NTRS)

    Allen, Glenn E.

    2002-01-01

    The term of the second year of the award is the period from March 15, 2001 to March 14, 2002. As was the specified goal of the second year, we analyzed the spatial and spectral X-ray data for several young supernova remnants. I published a paper about an analysis of the ROSAT, ASCA, and RXTE data for the supernova remnant SN 1006. A copy of this paper is enclosed. As described in the paper, we believe that we accurately modeled the nonthermal X-ray emission from the remnant. The results of this analysis are used to infer properties about the cosmic rays accelerated in the remnant and to argue that the strength of the magnetic field in the remnant is considerably larger than the value of about 10 micro G reported elsewhere. The results were presented at the August 2001 International Cosmic Ray Conference in Hamburg, German),. I began analyzing new Chandra X-ray data for SN 1006. This analysis will yield the first measure of the strength of the magnetic field in the remnant for the first time. Preliminary results support our previous conclusion that the magnetic field strength in the remnant is much larger than 10 micro G. The field strength seems to be about the strength expected based on an equipartition calculation. The result supports recent models that describe the how the shock structure is influenced by the efficient acceleration of cosmic rays. This work will be presented at the April 2002 High Energy Astrophysics Division meeting in Albuquerque and published this summer. A copy of the abstract for the talk is enclosed. I began studying new Chandra X-ray data for the supernova remnant Cas A. The results of this work show that the forward shock is a region where cosmic-ray electrons are accelerated, which is consistent with theoretical expectations. The work was presented at the September 2001 Two Years of Science with Chandra symposium in Washington, DC. A copy of the poster paper is enclosed. Dr. Thomas Pannuti, whose research work is supported by the award, analyzed ROSAT, ASCA, and RXTE data for the supernova remnant G347.3-0.5. The results show for the first time that thermal X-ray emission is produced in the remnant. As expected, the thermal emission is consistent with a model in which the remnant is expanding into a very low density environment. The results also provide an accurate description of the nonthermal emission from the remnant. Dr. Pannuti presented this work at several conferences. A copy of the paper for the proceedings of the August 2001 Neutron Stars in Supernova Remnants symposium in enclosed. The work will be submitted to the Astrophysical Journal in the next few months.

  16. The structure of TeV-bright shell-type supernova remnants

    NASA Astrophysics Data System (ADS)

    Yang, Chuyuan; Liu, Siming; Fang, Jun; Li, Hui

    2015-01-01

    Aims: Two-dimensional magnetohydrodynamic (MHD) simulations are used to model the emission properties of TeV-bright shell-type supernova remnants (SNRs) and to explore their nature. Methods: In the leptonic scenario for the TeV emission, the ?-ray emission is produced via inverse Compton scattering of background soft photons by high-energy electrons accelerated by the shocks of the SNRs. In a previous paper, we showed that since the energy densities of the cosmic microwave background radiation and that of the IR/optical background photons are much higher than that of the photons produced by the same high-energy electrons via the synchrotron process, the observed correlation between X-ray and TeV brightness of SNR RX J1713.7-3946 can be readily explained with the assumption that the energy density of relativistic electrons is proportional to that of the magnetic field. The TeV emissivity is therefore proportional to the magnetic field energy density and MHD simulations can be used to model the TeV structure of such remnants directly. Two-dimensional MHD simulations for SNRs are then performed under the assumption that the ambient interstellar medium is turbulent with the magnetic field and density fluctuations, following a Kolmogorov-like power-law spectrum. Results: (1) As expected, these simulations confirm early 1D and 2D modelings of these sources, namely the hydrodynamical evolution of the shock waves and amplification of magnetic field by Rayleigh-Taylor convective flows and by shocks propagating in a turbulent medium; (2) we reproduce rather complex morphological structure for ?-rays, for example, the bright thin rim and significant asymmetry, suggesting intrinsic variations of the source morphology not related to the structure of the progenitor and environment; and (3) the observed radial profile of several remnants are well reproduced with an ambient medium density of 0.1-1 cm-3. An even lower ambient density leads to a sharper drop of the TeV brightness with radius than what is observed near the outer edge of these remnants. Conclusions: In a turbulent background medium, we can reproduce the observed characteristics of several shell-type TeV SNRs with reasonable parameters except for a higher ambient density than that inferred from X-ray observations.

  17. A 20 Year Radio Light Curve for the Young Supernova Remnant G1.9+0.3

    E-print Network

    T. Murphy; B. M. Gaensler; S. Chatterjee

    2008-06-11

    The radio source G1.9+0.3 has recently been identified as the youngest known Galactic supernova remnant, with a putative age of ~100 years. We present a radio light curve for G1.9+0.3 based on 25 epochs of observation with the Molonglo Observatory Synthesis Telescope, spanning 20 years from 1988 to 2007. These observations are all at the same frequency (843 MHz) and comparable resolutions (43" x 91" or 43" x 95") and cover one fifth of the estimated lifetime of the supernova remnant. We find that the flux density has increased at a rate of 1.22 +0.24/-0.16 per cent per year over the last two decades, suggesting that G1.9+0.3 is undergoing a period of magnetic field amplification.

  18. Elemental abundances of the supernova remnant G292.0+1.8: Evidence for a massive progenitor

    NASA Technical Reports Server (NTRS)

    Hughes, John P.; Singh, K. P.

    1994-01-01

    We present a comprehensive nonequilibrium ionization (NEI) analysis of X-ray spectral data from the Einstein Observatory and EXOSAT for the supernova remnant G292.0+1.8. The spectra are well described by a single-temperature, single-timescale NEI model with kT = 1.64(sub -0.19)(sup +0.29) keV and n(sub e)t = (5.55(sub -1.12)(sup +1.2) x 10(exp 10)s/cu cm, which establishes that this remnant is indeed young and in the ionizing phase of evolution of its X-ray spectrum. We determine the abundances of the elements O, Ne, Mg, Si, S, Ar, and Fe and examine their variation over the allowed range of column density, kT, and n(sub e)t. Numerical calculations of the nucleosynthesis expected for a 25 solar mass progenitor agree best with the fitted abundances; in fact the minimum rms percent difference between this model and the derived abundances is only 15%. From the fitted emission measure and a simple geometric model of the remnant we estimate the mass of X-ray-emitting plasma to be 9.3(sub -6.2)(sup +1.19) solar mass, for an assumed distance of 4.8 +/- 1.6 kpc. Additional errors on this mass estimate, from clumping of the ejecta, for example, may be substantial. No evidence was found for a difference in the thermodynamic state of the plasma as a function of elemental composition based on analysis of the individual ionization timescales of the various species. In this sense then, G292.0+1.8 resembles the remnant Cas A (another product of a massive star supernova), while it is different from the remnants of SN 1572 (Tycho) and SN 1006, both of which are believed to be from Type Ia supernovae.

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

    Microsoft Academic Search

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

    1999-01-01

    Recent 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

  20. Hard-X-ray emission lines from the decay of 44Ti in the remnant of supernova 1987A.

    PubMed

    Grebenev, S A; Lutovinov, A A; Tsygankov, S S; Winkler, C

    2012-10-18

    It is assumed that the radioactive decay of (44)Ti powers the infrared, optical and ultraviolet emission of supernova remnants after the complete decay of (56)Co and (57)Co (the isotopes that dominated the energy balance during the first three to four years after the explosion) until the beginning of active interaction of the ejecta with the surrounding matter. Simulations show that the initial mass of (44)Ti synthesized in core-collapse supernovae is (0.02-2.5)?×?10(-4) solar masses (M circled dot). Hard X-rays and ?-rays from the decay of this (44)Ti have been unambiguously observed from Cassiopeia A only, leading to the suggestion that values of the initial mass of (44)Ti near the upper bound of the predictions occur only in exceptional cases. For the remnant of supernova 1987A, an upper limit to the initial mass of (44)Ti of <10(-3) M circled dot has been obtained from direct X-ray observations, and an estimate of (1-2)?×?10(-4) M circled dot has been made from infrared light curves and ultraviolet spectra by complex and model-dependent computations. Here we report observations of hard X-rays from the remnant of supernova 1987A in the narrow band containing two direct-escape lines of (44)Ti at 67.9 and 78.4?keV. The measured line fluxes imply that this decay provided sufficient energy to power the remnant at late times. We estimate that the initial mass of (44)Ti was (3.1?±?0.8)?×?10(-4), which is near the upper bound of theoretical predictions. PMID:23075986

  1. An X-ray study of IC443 and the discovery of a new supernova remnant by ROSAT

    Microsoft Academic Search

    I. Asaoka; B. Aschenbach

    1994-01-01

    The supernova remnant IC443 and the surrounding field have been imaged for the first time in X-rays during the ROSAT all-sky survey. Radio and infrared observations had suggested that IC443 consists of three connected, partially incomplete sub-shells. Whereas two of the three sub-shells have been known in X-rays before, the full extent and the structure of the third sub-shell have

  2. Constraints on cosmic-ray origin from TeV gamma-ray observations of supernova remnants

    Microsoft Academic Search

    J. H. Buckley; C. W. Akerlof; D. A. Carter-Lewis; M. Catanese; M. F. Cawley; V. Connaughton; D. J. Fegan; J. P. Finley; J. A. Gaidos; A. M. Hillas; F. Krennrich; R. C. Lamb; R. W. Lessard; J. E. McEnery; G. Mohanty; J. Quinn; A. J. Rodgers; H. J. Rose; A. C. Rovero; M. S. Schubnell; G. Sembroski; R. Srinivasan; T. C. Weekes; J. Zweerink

    1998-01-01

    If supernova remnants (SNRs) are the site of cosmic-ray acceleration, the associated nuclear interactions should result in an observable flux of gamma -rays for the nearest SNRs. Measurements of the TeV gamma -ray flux from six nearby, radio-bright SNRs have been made with the Whipple Observatory imaging air \\\\v Cerenkov telescope over the period September 1993 to June 1996. No

  3. Evidence of a Curved Cosmic-Ray Electron Spectrum in the Supernova Remnant SN 1006

    NASA Astrophysics Data System (ADS)

    Allen, Glenn E.; Houck, J. C.; Sturner, S. J.

    2006-09-01

    A joint spectral analysis of Chandra ACIS X-ray data and MOST radio data was performed for thirteen small regions along the bright northeastern rim of the supernova remnant SN 1006. These data were fitted with a synchrotron radiation model. The nonthermal electron spectrum used to compute the photon emission spectra is the traditional exponentially cut-off power law with one notable difference. The power-law index is not a constant. It is a linear function of the logarithm of the momentum. This functional form enables us to show, for the first time, that the electron spectrum of SN 1006 seems to flatten with increasing energy. At 1 GeV (i.e. radio-synchrotron-emitting momenta), the power-law index is about 2.2. At 10 TeV (i.e. X-ray-synchrotron-emitting momenta), the index is about 2.0. This result is qualitatively consistent with theoretical models of the amount of curvature in the proton spectrum of the remnant and implies that cosmic rays are dynamically important instead of being "test" particles. The spectral analysis also provides a means of determining the critical frequency of the synchrotron spectrum associated with the highest energy electrons. The critical frequency seems to vary along the northeastern rim with a maximum value of 1.04e17 Hz. This value implies that the electron diffusion coefficient can be no larger than a factor of about 4-20 times the Bohm diffusion coefficient if the velocity of the forward shock is in the range 2300-5000 km/s. Since the coefficient is close to the Bohm limit, electrons are accelerated nearly as fast as possible in the regions where the critical frequency is about 1e17 Hz.

  4. Evidence of a Curved Synchrotron Spectrum in the Supernova Remnant SN 1006

    NASA Astrophysics Data System (ADS)

    Allen, G. E.; Houck, J. C.; Sturner, S. J.

    2008-08-01

    A joint spectral analysis of some Chandra ACIS X-ray data and Molonglo Observatory Synthesis Telescope radio data was performed for 13 small regions along the bright northeastern rim of the supernova remnant SN 1006. These data were fitted with a synchrotron radiation model. The nonthermal electron spectrum used to compute the photon emission spectra is the traditional exponentially cut off power law, with one notable difference: The power-law index is not a constant. It is a linear function of the logarithm of the momentum. This functional form enables us to show, for the first time, that the synchrotron spectrum of SN 1006 seems to flatten with increasing energy. The effective power-law index of the electron spectrum is 2.2 at 1 GeV (i.e., radio synchrotron-emitting momenta) and 2.0 at about 10 TeV (i.e., X-ray synchrotron-emitting momenta). This amount of change in the index is qualitatively consistent with theoretical models of the amount of curvature in the proton spectrum of the remnant. The evidence of spectral curvature implies that cosmic rays are dynamically important instead of being ``test'' particles. The spectral analysis also provides a means of determining the critical frequency of the synchrotron spectrum associated with the highest-energy electrons. The critical frequency seems to vary along the northeastern rim, with a maximum value of 1.1+1.0-0.5×1017 Hz. This value implies that the electron diffusion coefficient can be no larger than a factor of ~4.5-21 times the Bohm diffusion coefficient if the velocity of the forward shock is in the range 2300-5000 km s-1. Since the coefficient is close to the Bohm limit, electrons are accelerated nearly as fast as possible in the regions where the critical frequency is about 1017 Hz.

  5. The abundances of major elements in Cas A and Tycho supernova remnants

    NASA Technical Reports Server (NTRS)

    Gorenstein, P.

    1995-01-01

    The objective of this program was to map the abundances of major elements such as O, Si, S, and Fe in the supernova remnants, Tycho and Cas A. The approach was based upon using archival cosmic X-ray data from several space missions, notably, the Einstein Observatory, EXOSAT, ROSAT, BBSRT, and ASCA. Two of the missions, Einstein and ROSAT, had high resolution telescopes that provided excellent images, but no spectral information. Two missions with much poorer resolution telescopes, BBXRT and ASCA, gave good spectral information through pulse height of signals in their cooled solid state detector, but rather crude spatial information. Our goal was to extract spectral information from the combined analysis of the Einstein and ROSAT images of Cas A and Tycho and to verify or refine the spectral map by checking its agreement with the BBSRT or ASCA spectra results for larger regions. In particular, we note that the Einstein and ROSAT telescopes have different spectral responses. The Einstein bandwidth includes the 2-4 keV region which is absent from ROSAT. Hence, by forming linear combinations of the Einstein and ROSAT images, we are able to resolve the contributions of the 0.5-2 keV band from the 2-4 keV band. The former contains lines of O and Fe while the latter is dominated by Si and S. We correct for the expansion that has taken place in the remnants during the ten-year interval between the Einstein and ROSAT measurements, but we must assume that no significant spectral changes have occurred during that time. The analysis of the Tycho SNR was completed and the results have been published. A copy of the paper is included. The analysis of Cas A has proved to be more complicated. It is continuing with support from another program. Part of the problem may be due to difficulties in the aspect information which is needed to precisely register the ROSAT and Einstein images.

  6. Discovering and Characterizing the Young Supernova Remnant Population in M101

    NASA Astrophysics Data System (ADS)

    Blair, William

    2013-10-01

    Young supernova remnants {SNRs}, especially ones like Cas A where heavy elements are still prominent, provide insights into SNe, the stars that produce them, and the galaxies where they reside. Here we propose to leverage and expand on existing Hubble ACS/WFC images of the iconic face-on spiral M101 by obtaining new [O III] data and [S II] images with WFC3 to identify and characterize the SNR population of M101. Deep H-alpha images of M101 already exist for 4 ACS fields, as does an extremely deep {1 Ms Chandra} X-ray study-important since many SNRs, including ALL of the known ejecta-dominated ones, are strong X-ray sources. While existing data have enabled exploration of SNRs previously identified from the ground, they do not allow identifications of new {and especially young} SNRs. We propose to observe these fields in [O III] {strongest line in ejecta-dominated SNRs} and [S II] {to provide the [S II]/H-alpha ratio diagnostic to distinguish SNRs from photoionized nebulae}, plus adding one new field in these lines plus H-alpha. For a modest time investment, all the optical and X-ray diagnostics will be in hand to explore what we expect to be a rich population of young SNRs in the complex inner regions of the galaxy where HST resolution is most needed. Furthermore, ACS images in BVI also exist for these fields, so we will use CMD fitting to constrain the progenitor masses for many of these as we did for the SN 1957D remnant in M83. We will compare to other galaxies, especially M83 where the young SNRs appear to have evolved quickly beyond the ejecta-dominated stage. M101 and M83 differ in mean abundances and star formation rate areal density, providing contrasting conditions.

  7. DIRECT EVIDENCE FOR HADRONIC COSMIC-RAY ACCELERATION IN THE SUPERNOVA REMNANT IC 443

    SciTech Connect

    Tavani, M.; Argan, A.; Cocco, V.; D'Ammando, F.; Costa, E.; De Paris, G.; Monte, E. Del; Donnarumma, I.; Evangelista, Y.; Feroci, M. [INAF/IASF-Roma, I-00133 Roma (Italy); Giuliani, A.; Chen, A. W.; Caraveo, P.; Contessi, T. [INAF/IASF-Milano, I-20133 Milano (Italy); Barbiellini, G. [Dipartimento di Fisica and INFN Trieste, I-34127 Trieste (Italy); Bulgarelli, A.; Cocco, G. Di; Fuschino, F. [INAF/IASF-Bologna, I-40129 Bologna (Italy); Cattaneo, P. W. [INFN-Pavia, I-27100 Pavia (Italy); Ferrari, A. [CIFS-Torino, I-10133 Torino (Italy)] (and others)

    2010-02-20

    The supernova remnant (SNR) IC 443 is an intermediate-age remnant well known for its radio, optical, X-ray, and gamma-ray energy emissions. In this Letter, we study the gamma-ray emission above 100 MeV from IC 443 as obtained by the AGILE satellite. A distinct pattern of diffuse emission in the energy range 100 MeV-3 GeV is detected across the SNR with its prominent maximum (source 'A') localized in the northeastern shell with a flux F=(47{+-}10)x10{sup -8} photons cm{sup -2}s{sup -1} above 100 MeV. This location is the site of the strongest shock interaction between the SNR blast wave and the dense circumstellar medium. Source 'A' is not coincident with the TeV source located 0.4 deg. away and associated with a dense molecular cloud complex in the SNR central region. From our observations, and from the lack of detectable diffuse TeV emission from its northeastern rim, we demonstrate that electrons cannot be the main emitters of gamma rays in the range 0.1-10 GeV at the site of the strongest SNR shock. The intensity, spectral characteristics, and location of the most prominent gamma-ray emission together with the absence of cospatial detectable TeV emission are consistent only with a hadronic model of cosmic-ray acceleration in the SNR. A high-density molecular cloud (cloud 'E') provides a remarkable 'target' for nucleonic interactions of accelerated hadrons; our results show enhanced gamma-ray production near the molecular cloud/shocked shell interaction site. IC 443 provides the first unambiguous evidence of cosmic-ray acceleration by SNRs.

  8. THE MAGELLAN/IMACS CATALOG OF OPTICAL SUPERNOVA REMNANT CANDIDATES IN M83

    SciTech Connect

    Blair, William P. [Henry A. Rowland Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218 (United States); Winkler, P. Frank [Department of Physics, Middlebury College, Middlebury, VT 05753 (United States); Long, Knox S., E-mail: wpb@pha.jhu.edu, E-mail: winkler@middlebury.edu, E-mail: long@stsci.edu [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

    2012-11-15

    We present a new optical imaging survey of supernova remnants (SNRs) in M83, using data obtained with the Magellan I 6.5 m telescope and IMACS instrument under conditions of excellent seeing. Using the criterion of strong [S II] emission relative to H{alpha}, we confirm all but three of the 71 SNR candidates listed in our previous survey, and expand the SNR candidate list to 225 objects, more than tripling the earlier sample. Comparing the optical survey with a new deep X-ray survey of M83 with Chandra, we find that 61 of these SNR candidates have X-ray counterparts. We also identify an additional list of 46 [O III]-selected nebulae for follow-up as potential ejecta-dominated remnants, seven of which have associated X-ray emission that makes them strong candidates. Some of the other [O III]-bright objects could also be normal interstellar medium (ISM) dominated SNRs with shocks fast enough to doubly ionize oxygen, but with H{alpha} and [S II] emission faint enough to have been missed. A few of these objects may also be H II regions with abnormally high [O III] emission compared with the majority of M83 H II regions, compact nebulae excited by young Wolf-Rayet stars, or even background active galactic nuclei. The SNR H{alpha} luminosity function in M83 is shifted by a factor of {approx}4.5 times higher than for M33 SNRs, indicative of a higher mean ISM density in M83. We describe the search technique used to identify the SNR candidates and provide basic information and finder charts for the objects.

  9. Direct Evidence for Hadronic Cosmic-Ray Acceleration in the Supernova Remnant IC 443

    NASA Astrophysics Data System (ADS)

    Tavani, M.; Giuliani, A.; Chen, A. W.; Argan, A.; Barbiellini, G.; Bulgarelli, A.; Caraveo, P.; Cattaneo, P. W.; Cocco, V.; Contessi, T.; D'Ammando, F.; Costa, E.; De Paris, G.; Del Monte, E.; Di Cocco, G.; Donnarumma, I.; Evangelista, Y.; Ferrari, A.; Feroci, M.; Fuschino, F.; Galli, M.; Gianotti, F.; Labanti, C.; Lapshov, I.; Lazzarotto, F.; Lipari, P.; Longo, F.; Marisaldi, M.; Mastropietro, M.; Mereghetti, S.; Morelli, E.; Moretti, E.; Morselli, A.; Pacciani, L.; Pellizzoni, A.; Perotti, F.; Piano, G.; Picozza, P.; Pilia, M.; Pucella, G.; Prest, M.; Rapisarda, M.; Rappoldi, A.; Scalise, E.; Rubini, A.; Sabatini, S.; Striani, E.; Soffitta, P.; Trifoglio, M.; Trois, A.; Vallazza, E.; Vercellone, S.; Vittorini, V.; Zambra, A.; Zanello, D.; Pittori, C.; Verrecchia, F.; Santolamazza, P.; Giommi, P.; Colafrancesco, S.; Antonelli, L. A.; Salotti, L.

    2010-02-01

    The supernova remnant (SNR) IC 443 is an intermediate-age remnant well known for its radio, optical, X-ray, and gamma-ray energy emissions. In this Letter, we study the gamma-ray emission above 100 MeV from IC 443 as obtained by the AGILE satellite. A distinct pattern of diffuse emission in the energy range 100 MeV-3 GeV is detected across the SNR with its prominent maximum (source "A") localized in the northeastern shell with a flux F = (47 ± 10) × 10^{-8} photons cm^{-2} s^{-1} above 100 MeV. This location is the site of the strongest shock interaction between the SNR blast wave and the dense circumstellar medium. Source "A" is not coincident with the TeV source located 0.4° away and associated with a dense molecular cloud complex in the SNR central region. From our observations, and from the lack of detectable diffuse TeV emission from its northeastern rim, we demonstrate that electrons cannot be the main emitters of gamma rays in the range 0.1-10 GeV at the site of the strongest SNR shock. The intensity, spectral characteristics, and location of the most prominent gamma-ray emission together with the absence of cospatial detectable TeV emission are consistent only with a hadronic model of cosmic-ray acceleration in the SNR. A high-density molecular cloud (cloud "E") provides a remarkable "target" for nucleonic interactions of accelerated hadrons; our results show enhanced gamma-ray production near the molecular cloud/shocked shell interaction site. IC 443 provides the first unambiguous evidence of cosmic-ray acceleration by SNRs.

  10. Three-dimensional Simulations of the Non-thermal Broadband Emission from Young Supernova Remnants Including Efficient Particle Acceleration

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

    Supernova remnants are believed to be major contributors to Galactic cosmic rays. In this paper, we explore how the non-thermal emission from young remnants can be used to probe the production of energetic particles at the shock (both protons and electrons). Our model couples hydrodynamic simulations of a supernova remnant with a kinetic treatment of particle acceleration. We include two important back-reaction loops upstream of the shock: energetic particles can (1) modify the flow structure and (2) amplify the magnetic field. As the latter process is not fully understood, we use different limit cases that encompass a wide range of possibilities. We follow the history of the shock dynamics and of the particle transport downstream of the shock, which allows us to compute the non-thermal emission from the remnant at any given age. We do this in three dimensions, in order to generate projected maps that can be compared with observations. We observe that completely different recipes for the magnetic field can lead to similar modifications of the shock structure, although to very different configurations of the field and particles. We show how this affects the emission patterns in different energy bands, from radio to X-rays and ?-rays. High magnetic fields (>100 ?G) directly impact the synchrotron emission from electrons, by restricting their emission to thin rims, and indirectly impact the inverse Compton emission from electrons and also the pion decay emission from protons, mostly by shifting their cut-off energies to respectively lower and higher energies.

  11. Three-dimensional simulations of the non-thermal broadband emission from young supernova remnants including efficient particle acceleration

    SciTech Connect

    Ferrand, Gilles; Safi-Harb, Samar [Department of Physics and Astronomy, University of Manitoba, Winnipeg, MB R3T 2N2 (Canada); Decourchelle, Anne, E-mail: gferrand@physics.umanitoba.ca, E-mail: samar@physics.umanitoba.ca, E-mail: anne.decourchelle@cea.fr [Laboratoire AIM (CEA/Irfu, CNRS/INSU, Université Paris VII), CEA Saclay, bât. 709, F-91191 Gif sur Yvette (France)

    2014-07-01

    Supernova remnants are believed to be major contributors to Galactic cosmic rays. In this paper, we explore how the non-thermal emission from young remnants can be used to probe the production of energetic particles at the shock (both protons and electrons). Our model couples hydrodynamic simulations of a supernova remnant with a kinetic treatment of particle acceleration. We include two important back-reaction loops upstream of the shock: energetic particles can (1) modify the flow structure and (2) amplify the magnetic field. As the latter process is not fully understood, we use different limit cases that encompass a wide range of possibilities. We follow the history of the shock dynamics and of the particle transport downstream of the shock, which allows us to compute the non-thermal emission from the remnant at any given age. We do this in three dimensions, in order to generate projected maps that can be compared with observations. We observe that completely different recipes for the magnetic field can lead to similar modifications of the shock structure, although to very different configurations of the field and particles. We show how this affects the emission patterns in different energy bands, from radio to X-rays and ?-rays. High magnetic fields (>100 ?G) directly impact the synchrotron emission from electrons, by restricting their emission to thin rims, and indirectly impact the inverse Compton emission from electrons and also the pion decay emission from protons, mostly by shifting their cut-off energies to respectively lower and higher energies.

  12. FERMI-LAT DISCOVERY OF GeV GAMMA-RAY EMISSION FROM THE YOUNG SUPERNOVA REMNANT CASSIOPEIA A

    SciTech Connect

    Abdo, A. A. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Ackermann, M.; Ajello, M.; Allafort, A.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Ballet, J. [Laboratoire AIM, CEA-IRFU/CNRS/Universite Paris Diderot, Service d'Astrophysique, CEA Saclay, 91191 Gif sur Yvette (France); Barbiellini, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Baring, M. G. [Department of Physics and Astronomy, Rice University, MS-108, P.O. Box 1892, Houston, TX 77251 (United States); Bastieri, D. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy); Baughman, B. M. [Department of Physics, Center for Cosmology and Astro-Particle Physics, The Ohio State University, Columbus, OH 43210 (United States); Bonamente, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06123 Perugia (Italy); Brigida, M. [Dipartimento di Fisica 'M. Merlin' dell'Universita e del Politecnico di Bari, I-70126 Bari (Italy)], E-mail: funk@slac.stanford.edu, E-mail: uchiyama@slac.stanford.edu (and others)

    2010-02-10

    We report on the first detection of GeV high-energy gamma-ray emission from a young supernova remnant (SNR) with the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope. These observations reveal a source with no discernible spatial extension detected at a significance level of 12.2{sigma} above 500 MeV at a location that is consistent with the position of the remnant of the supernova explosion that occurred around 1680 in the Cassiopeia constellation-Cassiopeia A (Cas A). The gamma-ray flux and spectral shape of the source are consistent with a scenario in which the gamma-ray emission originates from relativistic particles accelerated in the shell of this remnant. The total content of cosmic rays (electrons and protons) accelerated in Cas A can be estimated as W {sub CR} {approx_equal} (1-4) x 10{sup 49} erg thanks to the well-known density in the remnant assuming that the observed gamma ray originates in the SNR shell(s). The magnetic field in the radio-emitting plasma can be robustly constrained as B {>=} 0.1 mG, providing new evidence of the magnetic field amplification at the forward shock and the strong field in the shocked ejecta.0.

  13. Can we explain AMS-02 antiproton and positron excesses simultaneously by nearby supernovae without pulsars nor dark matter?

    E-print Network

    Kohri, Kazunori; Fujita, Yutaka; Yamazaki, Ryo

    2015-01-01

    We explain the excess of the antiproton fraction recently reported by the AMS-02 experiment by considering collisions between cosmic-ray protons accelerated by a local supernova remnant (SNR) and the surrounding dense cloud. The same "pp collisions" provide the right branching ratio to fit the observed positron excess simultaneously without a fine tuning. The supernova happened in relatively lower metalicity than the major cosmic-ray sources. The cutoff energy of electrons marks the supernova age of ~10^{5} years, while the antiproton excess may extend to higher energy. Both antiproton and positron fluxes are completely consistent with our predictions in Fujita, Kohri, Yamazaki and Ioka (2009).

  14. Spatially-resolved Spectroscopy of the IC443 Pulsar Wind Nebula and Environs

    NASA Astrophysics Data System (ADS)

    Swartz, Douglas A.; Weisskopf, M. C.; Zavlin, V.; Bucciantini, N.; Clarke, T. E.; Karovska, M.; Pavlov, G. G.; van der Horst, A.; Yukita, M.

    2013-04-01

    Deep Chandra ACIS observations of the region around the putative pulsar, CXO J061705.3+222127, in the supernova remnant IC443 confirm that (1) the spectrum and flux of the central object are consistent with a rotation-powered pulsar interpretation, (2) the non-thermal surrounding nebula is likely powered by a pulsar wind, and (3) the thermal-dominated spectrum at greater distances is consistent with emission from the supernova remnant. The observations further reveal, for the first time, a ring-like morphology surrounding the pulsar and a jet-like structure oriented roughly north-south across the ring and through the pulsar location. The cometary shape of the nebula, suggesting motion towards the southwest, appears to be subsonic; there is no evidence for a strong bow shock and the ring, presumably formed at a wind termination shock, is not distorted by motion through the ambient medium.

  15. Probing the Reverse Shock in an Oxygen-Rich Supernovae Remnant

    NASA Technical Reports Server (NTRS)

    Gaetz, Terrance (Principal Investigator); Sonneborn, George (Technical Monitor)

    2005-01-01

    The purpose of this investigation is to examine the O VI emission from the X-ray bright ring of the supernova remnant 1 E0102.2-729 in the small Magellanic cloud. Three pointings were positioned tangent to the ring, north (N), northeast (NE), and southeast (SE), to examine a range of X-ray emitting regions overlapping a range of optical [O III] nebulosity and to examine the velocity structure. One background pointing was also obtained, but it was contaminated by a star. The background levels in the pointings on the remnant were low enough that the background pointing was not required for the remaining analysis. The SE pointing was reobserved in August, 2004, in order to bring the total exposure up to the originally requested 15 ks. The archive notified us of the data's availability in mid September. Significant broad O VI 1032 and O VI 1038 emission was found, brightest in the NE and SE pointings. In the NE and SE pointings, the FWHM of the broad O VI component is approx.800-1000 km/s, while in the N pointing, the line is approx.1500 km/s wide. The O VI is redshifted in the N (approx.380 km/s) and NE (approx.60 km/s) but is blueshifted in the SE (approx. -160 km/s). These FUSE O VI velocity dispersions can be compared to the X-ray gas velocities inferred from Doppler distortions in the Chandra X-ray data as reported by Flanagan et al. 2004 (ApJ 605, 230). The bulk velocities in the X-ray bright ring of order +/- 1000 km/s, comparable to the velocity dispersion seen in the FUSE data. However, the X-ray data indicates a redshift of approx.1000 km/s in the SE, while the FUSE data show a blueshift of approx.160 km/s, underscoring the complex velocity structure in this remnant. The O VI fluxes estimated from the fits to the FUSE data were combined with X-ray (XMM- Newton) O VI1 and O VIII fluxes and compared with predictions from a plasma nonequilibrium ionization model in a "line-based" analysis. We found that the plasma departs significantly from collisional ionization equilibrium, particularly in the SE, and that the plasma excitation conditions vary among the pointings: the O plasma sees different conditions than the Ne and Mg plasmas.

  16. Cr-K Emission Line as a Constraint on the Progenitor Properties of Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Yang, X. J.; Tsunemi, H.; Lu, F. J.; Li, Aigen; Xiang, F. Y.; Xiao, H. P.; Zhong, J. X.

    2013-03-01

    We perform a survey of the Cr, Mn, and Fe-K emission lines in young supernova remnants (SNRs) with the Japanese X-ray astronomy satellite Suzaku. The Cr and/or Mn emission lines are detected in 3C 397 and 0519-69.0 for the first time. We also confirm the detection of these lines in Kepler, W49B, N103B, and Cas A. We derive the line parameters (i.e., the line centroid energy, flux, and equivalent width (EW)) for these six sources and perform a correlation analysis for the line center energies of Cr, Mn, and Fe. Also included in the correlation analysis are Tycho and G344.7-0.1 for which the Cr, Mn, and Fe-K line parameters were available in the literature through Suzaku observations. We find that the line center energies of Cr correlate very well with that of Fe and that of Mn. This confirms our previous findings that Cr, Mn, and Fe are spatially co-located, share a similar ionization state, and have a common origin in the supernova nucleosynthesis. We find that the ratio of the EW of the Cr emission line to that of Fe (\\gamma _Cr/Fe\\equiv EW(Cr)/EW(Fe)) provides useful constraints on the SNR progenitors and on the SN explosion mechanisms: for SNRs with ?Cr/Fe > 2%, a Type Ia origin is favored (e.g., N103B, G344.7-0.1, 3C 397, and 0519-69.0) for SNRs with ?Cr/Fe < 2%, they could be of either core-collapse origin or carbon-deflagration Ia origin.

  17. Cr-K EMISSION LINE AS A CONSTRAINT ON THE PROGENITOR PROPERTIES OF SUPERNOVA REMNANTS

    SciTech Connect

    Yang, X. J.; Xiang, F. Y.; Xiao, H. P.; Zhong, J. X. [Department of Physics, Xiangtan University, Xiangtan 411105 (China)] [Department of Physics, Xiangtan University, Xiangtan 411105 (China); Tsunemi, H. [Department of Earth and Space Science, Osaka University, Osaka 560-0043 (Japan)] [Department of Earth and Space Science, Osaka University, Osaka 560-0043 (Japan); Lu, F. J. [Key Laboratory for Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)] [Key Laboratory for Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Li, Aigen, E-mail: xjyang@xtu.edu.cn [Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211 (United States)] [Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211 (United States)

    2013-03-20

    We perform a survey of the Cr, Mn, and Fe-K emission lines in young supernova remnants (SNRs) with the Japanese X-ray astronomy satellite Suzaku. The Cr and/or Mn emission lines are detected in 3C 397 and 0519-69.0 for the first time. We also confirm the detection of these lines in Kepler, W49B, N103B, and Cas A. We derive the line parameters (i.e., the line centroid energy, flux, and equivalent width (EW)) for these six sources and perform a correlation analysis for the line center energies of Cr, Mn, and Fe. Also included in the correlation analysis are Tycho and G344.7-0.1 for which the Cr, Mn, and Fe-K line parameters were available in the literature through Suzaku observations. We find that the line center energies of Cr correlate very well with that of Fe and that of Mn. This confirms our previous findings that Cr, Mn, and Fe are spatially co-located, share a similar ionization state, and have a common origin in the supernova nucleosynthesis. We find that the ratio of the EW of the Cr emission line to that of Fe ({gamma}{sub Cr/Fe}{identical_to}EW(Cr)/EW(Fe)) provides useful constraints on the SNR progenitors and on the SN explosion mechanisms: for SNRs with {gamma}{sub Cr/Fe} > 2%, a Type Ia origin is favored (e.g., N103B, G344.7-0.1, 3C 397, and 0519-69.0); for SNRs with {gamma}{sub Cr/Fe} < 2%, they could be of either core-collapse origin or carbon-deflagration Ia origin.

  18. NONTHERMAL RADIATION FROM SUPERNOVA REMNANTS: EFFECTS OF MAGNETIC FIELD AMPLIFICATION AND PARTICLE ESCAPE

    SciTech Connect

    Kang, Hyesung [Department of Earth Sciences, Pusan National University, Pusan 609-735 (Korea, Republic of); Jones, T. W. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States); Edmon, Paul P., E-mail: kang@uju.es.pusan.ac.kr, E-mail: twj@msi.umn.edu, E-mail: pedmon@cfa.harvard.edu [Research Computing, Harvard University, Cambridge, MA 02138 (United States)

    2013-11-01

    We explore nonlinear effects of wave-particle interactions on the diffusive shock acceleration (DSA) process in Type Ia-like supernova remnant (SNR) blast waves by implementing phenomenological models for magnetic field amplification (MFA), Alfvénic drift, and particle escape in time-dependent numerical simulations of nonlinear DSA. For typical SNR parameters, the cosmic-ray (CR) protons can be accelerated to PeV energies only if the region of amplified field ahead of the shock is extensive enough to contain the diffusion lengths of the particles of interest. Even with the help of Alfvénic drift, it remains somewhat challenging to construct a nonlinear DSA model for SNRs in which of the order of 10% of the supernova explosion energy is converted into CR energy and the magnetic field is amplified by a factor of 10 or so in the shock precursor, while, at the same time, the energy spectrum of PeV protons is steeper than E {sup –2}. To explore the influence of these physical effects on observed SNR emission, we also compute the resulting radio-to-gamma-ray spectra. Nonthermal emission spectra, especially in X-ray and gamma-ray bands, depend on the time-dependent evolution of the CR injection process, MFA, and particle escape, as well as the shock dynamic evolution. This result comes from the fact that the high-energy end of the CR spectrum is composed of particles that are injected in the very early stages of the blast wave evolution. Thus, it is crucial to better understand the plasma wave-particle interactions associated with collisionless shocks in detailed modeling of nonthermal radiation from SNRs.

  19. Identification of Ambient Molecular Clouds Associated with Galactic Supernova Remnant IC 443

    NASA Astrophysics Data System (ADS)

    Lee, Jae-Joon; Koo, Bon-Chul; Snell, Ronald L.; Yun, Min S.; Heyer, Mark H.; Burton, Michael G.

    2012-04-01

    The Galactic supernova remnant (SNR) IC 443 is one of the most studied core-collapse SNRs for its interaction with molecular clouds. However, the ambient molecular clouds with which IC 443 is interacting have not been thoroughly studied and remain poorly understood. Using the Five College Radio Astronomy Observatory 14 m telescope, we obtained fully sampled maps of the ~1° × 1° region toward IC 443 in the 12CO J = 1-0 and HCO+ J = 1-0 lines. In addition to the previously known molecular clouds in the velocity range v LSR = -6 to -1 km s-1 (-3 km s-1 clouds), our observations reveal two new ambient molecular cloud components: small (~1') bright clouds in v LSR = -8 to -3 km s-1 (SCs) and diffuse clouds in v LSR = +3 to +10 km s-1 (+5 km s-1 clouds). Our data also reveal the detailed kinematics of the shocked molecular gas in IC 443 however, the focus of this paper is the physical relationship between the shocked clumps and the ambient cloud components. We find strong evidence that the SCs are associated with the shocked clumps. This is supported by the positional coincidence of the SCs with shocked clumps and other tracers of shocks. Furthermore, the kinematic features of some shocked clumps suggest that these are the ablated material from the SCs upon the impact of the SNR shock. The SCs are interpreted as dense cores of parental molecular clouds that survived the destruction by the pre-supernova evolution of the progenitor star or its nearby stars. We propose that the expanding SNR shock is now impacting some of the remaining cores and the gas is being ablated and accelerated, producing the shocked molecular gas. The morphology of the +5 km s-1 clouds suggests an association with IC 443. On the other hand, the -3 km s-1 clouds show no evidence for interaction.

  20. Pulsar-driven Jets in Supernovae, Gamma-ray Bursts, and SS 433

    NASA Astrophysics Data System (ADS)

    Middleditch, John

    2010-05-01

    The model of pulsar emission through superluminally induced polarization currents (SLIP) predicts that pulsations produced by such currents, induced at many light cylinder radii by a rotating, magnetized body, as would be the case for a neutron star born within any star of more than 1.4 solar masses, will drive pulsations close to the axis of rotation. In SN 1987A, such highly collimated (less than 1 in 10,000) 2.14 ms pulsations, and the similarly collimated jets of particles which they drove, including 1e-6 solar masses with velocities of up to 0.95 c, were responsible for the features of its very early light (days 3 - 20), its "Mystery Spot," observed slightly later (days 30 - 50 and after), and still later, in less collimated form, its bipolarity. SLIP also explains why the 2.14 ms pulsations were more or less consistently observed between years 5.0 and 6.5, and why they eventually disappeared after year 9.0. There is no reason to suggest that this mechanism is not universally applicable to all SNe with gaseous remnants remaining, and thus SN 1987A is the Rosetta Stone for 99% of SNe, gamma-ray bursts, and millisecond pulsars, and possibly SS 433. The axially driven pulsations enforce a toroidal geometry onto all early SNRs, rendering even Ia's unsuitable as standard candles. SLIP predicts that almost all pulsars with very sharp single pulses have been detected because the Earth is in a favored direction where their fluxes diminish only as 1/distance, and this has been verified in the laboratory as well as for the Parkes Multibeam Survey. SLIP also specifically predicts that gamma-ray-burst afterglows will be essentially 100% pulsed at 500 Hz in their proper frame. This work was supported in part by the Department of Energy through the Los Alamos Directed Research Grant DR20080085.

  1. Chandra Imaging and Spectroscopy of the Eastern XA Region of the Cygnus Loop Supernova Remnant

    NASA Astrophysics Data System (ADS)

    McEntaffer, R. L.; Brantseg, T.

    2011-04-01

    The XA region of the Cygnus Loop is a bright knot of X-ray emission on the eastern edge of the supernova remnant. The emission results from the interaction of the supernova blast wave with density enhancements at the edge of a precursor formed cavity. However, this interaction is complex given the irregular morphology of the cavity wall. To study the nature and origin of the X-ray emission, we use high spatial resolution images from Chandra. We extract spectra from these images to analyze the physical conditions of the plasma. Our goal is to probe the density of various regions to form a picture of the cavity wall and characterize the interaction between this supernova and the local interstellar medium. We find that a series of regions along the edge of the X-ray emission appears to trace out the location of the cavity wall. The best-fit plasma models result in two temperature component equilibrium models for each region. The low-temperature components have densities that are an order of magnitude higher than the high-temperature components. The high-density plasma may exist in the cavity wall where it equilibrates rapidly and cools efficiently. The low-density plasma is interior to the enhancement and heated further by a reverse shock from the wall. Calculations of shock velocities and timescales since shock heating are consistent with this interpretation. Furthermore, we find a bright knot of emission indicative of a discrete interaction of the blast wave with a high-density cloud in the cavity wall with a size scale ~0.1 pc. Aside from this, other extractions made interior to the X-ray edge are confused by line-of-sight projection of various components. Some of these regions show evidence of detecting the cavity wall but their location makes the interpretation difficult. In general, the softer plasmas are well fit at temperatures langkTrang~ 0.11 keV, with harder plasmas at temperatures of langkTrang~ 0.27 keV. All regions displayed consistent metal depletions most notably in N, O, and Ne at an average of 0.54, 0.55, and 0.36 times solar, respectively.

  2. Determination of acceleration mechanism characteristics directly and nonparametrically from observations: Application to supernova remnants

    NASA Astrophysics Data System (ADS)

    Petrosian, Vahé; Chen, Qingrong

    2014-05-01

    We have developed an inversion method for determination of the characteristics of the acceleration mechanism directly and nonparametrically from observations, in contrast to the usual forward fitting of parametric model variables to observations. In two recent papers [V. Petrosian and Q. Chen, Astrophys. J. 712, L131 (2010); Q. Chen and V. Petrosian, Astrophys. J. 777, 33 (2013)], we demonstrated the efficacy of this inversion method by its application to acceleration of electrons in solar flares based on stochastic acceleration by turbulence. Here we explore its application for determining the characteristics of shock acceleration in supernova remnants (SNRs) based on the electron spectra deduced from the observed nonthermal radiation from SNRs and the spectrum of the cosmic ray electrons observed near the Earth. These spectra are related by the process of escape of the electrons from SNRs and energy loss during their transport in the Galaxy. Thus, these observations allow us to determine spectral characteristics of the momentum and pitch angle diffusion coefficients, which play crucial roles in both direct acceleration by turbulence and in high Mach number shocks. Assuming that the average electron spectrum deduced from a few well-known SNRs is representative of those in the solar neighborhood, we find interesting discrepancies between our deduced forms for these coefficients and those expected from well-known wave-particle interactions. This may indicate that the standard assumptions made in the treatment of shock acceleration need revision. In particular, the escape of particles from SNRs may be more complex than generally assumed.

  3. The X-Ray Spectrum of the Supernova Remnant 1E 0102-72.3

    NASA Technical Reports Server (NTRS)

    Rasmussen, Andrew P.; Behar, Ehud; Kahn, Steven M.; denHerder, Jan Willem; vanderHeyden, Kurt

    1997-01-01

    In this letter we present the soft X-ray (5-35A) spectrum of the supernova remnant (SNR) IE 0102-72.3 in the Small Magellanic Cloud, acquired by the reflection grating spectrometer (RGS) aboard ESA's XMM-Newton Observatory. This extended-source X-ray spectrum of unprecedented spectral resolution (lambda/Delta(lambda) approx. 300) permits, for the first time, unabiguous identification and measurement of isolated emission lines and line complexes alike. The diagnostic power of performing spectroscopy using groups of emission lines from single ions is exemplified. In particular, the bright Lyman and helium series lines for light elements (C VI, O VII, O VIII, Ne IX, Ne X and possibly Mg XI & Mg XII) show peculiar ratios, where the values [1s - np] / [1s - (n + l)p] are systematically weaker than expected for electron impact excitation. These measured ratios resemble signatures of recombining or charge exchanging plasmas. We argue that charge exchange, given its large cross section and evidence for inhomogeneous media within the SNR, is a likely mechanism for the observed emission. Also. the well known temperature diagnostics G(T(sub e)) = (i + f)/r of helium- like triplets (O VII & Ne IX) indicate high temperatures, well above the maximum emission temperature T(sub m) for each ion, and consistent with a purely ionizing plasma. The density diagnostics R(n(sub e)) = f / i meanwhile, are consistent with the low density limit, as expected.

  4. HESS J1640-465 - an exceptionally luminous TeV ?-ray supernova remnant

    NASA Astrophysics Data System (ADS)

    Abramowski, A.; Aharonian, F.; Benkhali, F. Ait; Akhperjanian, A. G.; Angüner, E.; Anton, G.; Balenderan, S.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker Tjus, J.; Bernlöhr, K.; Birsin, E.; Bissaldi, E.; Biteau, J.; Böttcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P. M.; Chalme-Calvet, R.; Chaves, R. C. G.; Cheesebrough, A.; Chrétien, M.; Colafrancesco, S.; Cologna, G.; Conrad, J.; Couturier, C.; Cui, Y.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; Drury, L. O'C.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, K.; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Grondin, M.-H.; Grudzi?ska, M.; Häffner, S.; Hahn, J.; Harris, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung, I.; Kastendieck, M. A.; Katarzy?ski, K.; Katz, U.; Kaufmann, S.; Khélifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Klu?niak, W.; Kneiske, T.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Krayzel, F.; Krüger, P. P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Méhault, J.; Meintjes, P. J.; Menzler, U.; Meyer, M.; Moderski, R.; Mohamed, M.; Moulin, E.; Murach, T.; Naumann, C. L.; de Naurois, M.; Niemiec, J.; Nolan, S. J.; Oakes, L.; Ohm, S.; Wilhelmi, E. de Oña; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Arribas, M. Paz; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Poon, H.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Raue, M.; Reimer, A.; Reimer, O.; Renaud, M.; Reyes, R. de los; Rieger, F.; Rob, L.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schüssler, F.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sol, H.; Spengler, G.; Spies, F.; Stawarz, ?.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Szostek, A.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; van Soelen, B.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Völk, H. J.; Volpe, F.; Vorster, M.; Vuillaume, T.; Wagner, S. J.; Wagner, P.; Ward, M.; Weidinger, M.; Weitzel, Q.; White, R.; Wierzcholska, A.; Willmann, P.; Wörnlein, A.; Wouters, D.; Zabalza, V.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.

    2014-04-01

    The results of follow-up observations of the TeV ?-ray source HESS J1640-465 from 2004 to 2011 with the High Energy Stereoscopic System (HESS) are reported in this work. The spectrum is well described by an exponential cut-off power law with photon index ? = 2.11 ± 0.09stat ± 0.10sys, and a cut-off energy of E_c = 6.0^{+2.0}_{-1.2} TeV. The TeV emission is significantly extended and overlaps with the northwestern part of the shell of the SNR G338.3-0.0. The new HESS results, a re-analysis of archival XMM-Newton data and multiwavelength observations suggest that a significant part of the ?-ray emission from HESS J1640-465 originates in the supernova remnant shell. In a hadronic scenario, as suggested by the smooth connection of the GeV and TeV spectra, the product of total proton energy and mean target density could be as high as WpnH ˜ 4 × 1052(d/10kpc)2 erg cm-3.

  5. Supernova Remnant Kesteven 27: Interaction with A Neighbor HI Cloud Viewed by Fermi

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

    We report on the likely detection of ?-ray emission from the supernova remnant (SNR) Kesteven 27 (Kes 27). We analyze 5.7 yr Fermi Large Area Telescope data of the SNR region and find an unresolved source at a position consistent with the radio brightness peak and the X-ray knot of Kes 27, which is located in the eastern region of the SNR and caused by its interaction with a nearby Hi cloud. The source’s emission is best fit with a power-law spectrum with a photon index of 2.5 ± 0.1 and a >0.2 GeV luminosity of 5.8× {{10}34} erg s?1 assuming a distance of 4.3 kpc, as derived from radio observations of the nearby Hi cloud. Comparing the properties of the source with that of other SNRs that are known to be interacting with nearby high-density clouds, we discuss the origin of the source’s emission. The spectral energy distribution of the source can be described by a hadronic model that considers the interaction of energetic protons escaping from the shock front of Kes 27 with a high-density cloud.

  6. Far-infrared sources in the vicinity of the supernova remnant W28

    NASA Technical Reports Server (NTRS)

    Odenwald, S. F.; Shivanandan, K.; Fazio, G. G.; Mcbreen, B.; Campbell, M. F.; Moseley, H.; Rengarajan, T. N.

    1984-01-01

    The W28 supernova remnant molecular cloud complex has been surveyed in the 40-250 micron spectral range with a three-sigma sensitivity of 100-165 Jy per beam. Only two sources have been found. One, located near the center of the SNR, has a luminosity of 54,000 solar luminosities and can be identified with the thermal radio source G6.6-0.1. The energizing source is probably an O-type ZAMS star. The second source, which is near the boundary of the SNR at a sharp gradient of OH absorption, has a luminosity of 6000 solar luminosities and has no radio counterpart. It is best explained as a B1 ZAMS star or a pre-main sequence object presumably formed from the impact of an expanding SNR with a molecular cloud. No far-IR emission is observed at the position of the CO molecular cloud, which seems to have been impacted by the SNR.

  7. Two new supernova remnants in OB associations in the Large Magellanic Cloud

    NASA Technical Reports Server (NTRS)

    Smith, R. Chris; Chu, You-Hua; Mac Low, Mordecai-Mark; Oey, M. S.; Klein, Uli

    1994-01-01

    We discovered two extended x-ray sources in a Roentgen Satellite (ROSAT) Positron Sensitive Proportional Counter (PSPC) observation pointed at the H II region N9 in the Large Magellanic Cloud. These two sources are in the H II regions N4D and N9. The x-ray characteristics suggest that both might be supernova remnants (SNRs). Follow-up charge coupled device (CCD) images taken with interference filters show high (S II)/H-alpha ratios in the optical nebulae of these x-ray sources, confirming the presence of high velocity shocks commonly seen in SNRs. These two sources are also detected in the radio continuum at 8.55 and 4.75 GHz; both appear nonthermal compared to nearby H II regions. The confirmation of these two SNRs demonstrates that many SNRs in or near H II regions have been overlooked in previous surveys, and that the ROSAT x-ray survey combined with an optical CCD imaging survey of the Magellanic Clouds would provide the most effective way to uncover SNRs.

  8. The Suzaku Key Project of the Kepler Supernova Remnant: A Status Report

    NASA Astrophysics Data System (ADS)

    Park, Sangwook; Badenes, C.; Hughes, J. P.; Slane, P. O.; Burrows, D. N.; Mori, K.

    2010-02-01

    The Kepler supernova remnant (SNR) is a historical (SN 1604) Type Ia SNR with a peculiar progenitor that exploded in the ambient medium modified by stellar winds. We detect atomic emission lines from trace ejecta elements Mn and Cr in the Kepler SNR using our initial 100 ks Suzaku observation. The detection of these low abundant metal species produced by incomplete Si-burning in the Type Ia SN provides a unique opportunity to reveal the progenitor's metallicity. We also detect K line emission from the Ni-rich ejecta which was produced in the nuclear statistical equilibrium at the deepest core of the progenitor. As the start of our Suzaku Key Project of the Kepler SNR to place a tight constraint on the progenitor's metallicity, we performed 220 ks background observations to reduce the systematic errors on the Mn and Cr line flux measurements. We report on the refined measurements of the Mn to Cr line flux ratio using our new background data. Our preliminary results suggest an enhanced metallicity (several times the Solar) for the Kepler SNR's progenitor. The completion of our Suzaku Key Project with the upcoming deep Kepler observation will be essential to pin down the suggested high metallicity of the progenitor by significantly reducing the large statistical uncertainties embedded in the current data.

  9. Study of TeV shell supernova remnants at gamma-ray energies

    E-print Network

    Acero, F; Renaud, M; Ballet, J; Hewitt, J W; Rousseau, R; Tanaka, T

    2015-01-01

    The breakthrough developments of Cherenkov telescopes in the last decade have led to angular resolution of 0.1{\\deg} and an unprecedented sensitivity. This has allowed the current generation of Cherenkov telescopes to discover a population of supernova remnants (SNRs) radiating in very-high-energy (VHE, E>100 GeV) gamma-rays. A number of those VHE SNRs exhibit a shell-type morphology spatially coincident with the shock front of the SNR. The members of this VHE shell SNR club are RX J1713.7-3946, Vela Jr, RCW 86, SN 1006, and HESS J1731-347. The latter two objects have been poorly studied in high-energy (HE, 0.1 5 sigma. With this Fermi analysis, we now have a complete view of the HE to VHE gamma-ray emission of TeV shell SNRs. All five sources have a hard HE photon index (electrons radiating from radio to VHE gamma-rays through synchrotron and inverse Compton processes. In addition when correcting for the distance,...

  10. Radio spectral characteristics of the supernova remnant Puppis A and nearby sources

    E-print Network

    Reynoso, E M

    2015-01-01

    This paper presents a new study of the spectral index distribution of the supernova remnant (SNR) Puppis A. The nature of field compact sources is also investigated according to the measured spectral indices. This work is based on new observations of Puppis A and its surroundings performed with the Australia Telescope Compact Array in two configurations using the Compact Array Broad-band Backend centered at 1.75 GHz. We find that the global spectral index of Puppis A is -0.563 +/- 0.013. Local variations have been detected, however this global index represents well the bulk of the SNR. At the SE, we found a pattern of parallel strips with a flat spectrum compatible with small-scale filaments, although not correlated in detail. The easternmost filament agrees with the idea that the SN shock front is interacting with an external cloud. There is no evidence of the previously suggested correlation between emissivity and spectral index. A number of compact features are proposed to be evolved clumps of ejecta based...

  11. XMMU J0541.8-6659, a new supernova remnant in the Large Magellanic Cloud

    E-print Network

    Grondin, M -H; Haberl, F; Pietsch, W; Crawford, E J; Filipovic, M D; Bozzetto, L M; Points, S; Smith, R C

    2012-01-01

    The high sensitivity of the XMM-Newton instrumentation offers the opportunity to study faint and extended sources in the Milky Way and nearby galaxies such as the Large Magellanic Cloud (LMC) in detail. The ROSAT PSPC survey of the LMC has revealed more than 700 X-ray sources, among which there are 46 supernova remnants (SNRs) and candidates. We have observed the field around one of the most promising SNR candidates in the ROSAT PSPC catalogue, labelled [HP99] 456 with XMM-Newton, to determine its nature. We investigated the XMM-Newton data along with new radio-continuum, near infrared and optical data. In particular, spectral and morphological studies of the X-ray and radio data were performed. The X-ray images obtained in different energy bands reveal two different structures. Below 1.0 keV the X-ray emission shows the shell-like morphology of an SNR with a diameter of ~73 pc, one of the largest known in the LMC. For its thermal spectrum we estimate an electron temperature of (0.49 +/- 0.12)keV assuming non...

  12. Non-thermal radiation from molecular clouds illuminated by cosmic rays from nearby supernova remnants

    E-print Network

    Stefano Gabici; Sabrina Casanova; Felix A. Aharonian

    2008-09-30

    Molecular clouds are expected to emit non-thermal radiation due to cosmic ray interactions in the dense magnetized gas. Such emission is amplified if a cloud is located close to an accelerator of cosmic rays and if cosmic rays can leave the accelerator and diffusively reach the cloud. We consider the situation in which a molecular cloud is located in the proximity of a supernova remnant which is accelerating cosmic rays and gradually releasing them into the interstellar medium. We calculate the multiwavelength spectrum from radio to gamma rays which emerges from the cloud as the result of cosmic ray interactions. The total energy output is dominated by the gamma ray emission, which can exceed the emission from other bands by an order of magnitude or more. This suggests that some of the unidentified TeV sources detected so far, with no obvious or very weak counterpart in other wavelengths, might be associated with clouds illuminated by cosmic rays coming from a nearby source.

  13. Fermi Large Area Telescope Observations of the Cygnus Loop Supernova Remnant

    SciTech Connect

    Katagiri, H.; /Ibaraki U., Mito; Tibaldo, L.; /INFN, Padua /Padua U. /Paris U., VI-VII; Ballet, J.; /Paris U., VI-VII; Giordano, F.; /Bari U. /Bari Polytechnic /INFN, Bari; Grenier, I.A.; /Paris U., VI-VII; Porter, T.A.; /Stanford U., HEPL /KIPAC, Menlo Park /SLAC; Roth, M.; /Washington U., Seattle; Tibolla, O.; /Wurzburg U.; Uchiyama, Y.; /Stanford U., HEPL /KIPAC, Menlo Park /SLAC; Yamazaki, R.; /Sagamihara, Aoyama Gakuin U.

    2011-11-08

    We present an analysis of the gamma-ray measurements by the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope in the region of the supernova remnant (SNR) Cygnus Loop (G74.0-8.5). We detect significant gamma-ray emission associated with the SNR in the energy band 0.2-100 GeV. The gamma-ray spectrum shows a break in the range 2-3 GeV. The gamma-ray luminosity is {approx} 1 x 10{sup 33} erg s{sup -1} between 1-100 GeV, much lower than those of other GeV-emitting SNRs. The morphology is best represented by a ring shape, with inner/outer radii 0{sup o}.7 {+-} 0{sup o}.1 and 1{sup o}.6 {+-} 0{sup o}.1. Given the association among X-ray rims, H{alpha} filaments and gamma-ray emission, we argue that gamma rays originate in interactions between particles accelerated in the SNR and interstellar gas or radiation fields adjacent to the shock regions. The decay of neutral pions produced in nucleon-nucleon interactions between accelerated hadrons and interstellar gas provides a reasonable explanation for the gamma-ray spectrum.

  14. Suzaku observation of supernova remnant G332.5-5.6

    E-print Network

    Zhu, H; Wu, D

    2015-01-01

    We analyze the Suzaku XIS data of the central region of supernova remnant G332.5-5.6. The X-ray data are well described by a single non-equilibrium ionization thermal model, {\\tt vnei}, with an absorbing hydrogen column density of 1.4$^{+0.4}_{-0.1}$ $\\times$ 10$^{21}$ cm$^{-2}$. The plasma is characterized by an electron temperature of 0.49$^{+0.08}_{-0.06}$ keV with subsolar abundances for O (0.58$^{+0.06}_{-0.05}$ solar value) and Fe (0.72$^{+0.06}_{-0.05}$ solar value) and slightly overabundance for Mg (1.23$^{+0.14}_{-0.14}$ solar value). It seems that the central X-ray emission originates from projection effect or evaporation of residual clouds inside G332.5-5.6. We estimate a distance of 3.0 $\\pm$ 0.8 kpc for G332.5-5.6 based on the extinction-distance relation. G332.5-5.6 has an age of 7 - 9 kyr.

  15. Class I Methanol (CH$_{3}$OH) Maser Conditions near Supernova Remnants

    E-print Network

    McEwen, Bridget C; Sjouwerman, Loránt O

    2014-01-01

    We present results from calculations of the physical conditions necessary for the occurrence of 36.169 ($4_{-1}-3_{0}\\, E$), 44.070 ($7_{0}-6_{1}\\,A^+$), 84.521 ($5_{-1}-4_{0}\\,E$), and 95.169 ($8_{0}-7_{1}\\,A^+$) GHz methanol (CH$_3$OH) maser emission lines near supernova remnants (SNRs), using the MOLPOP-CEP program. The calculations show that given a sufficient methanol abundance, methanol maser emission arises over a wide range of densities and temperatures, with optimal conditions at $n\\sim 10^4-10^6$ cm$^{-3}$ and $T>60$ K. The 36~GHz and 44~GHz transitions display more significant maser optical depths compared to the 84~GHz and 95~GHz transitions over the majority of physical conditions. It is also shown that line ratios are an important and applicable probe of the gas conditions. The line ratio changes are largely a result of the $E$-type transitions becoming quenched faster at increasing densities. The modeling results are discussed using recent observations of CH$_3$OH and hydroxyl (OH) masers near ...

  16. Violent evolution of supernova remnants as revealed by Chandra and XMM-Newton

    NASA Astrophysics Data System (ADS)

    Katsuda, S.; Tsunemi, H.

    Recent Chandra and XMM-Newton observations have directly revealed evolution of young supernova remnants (SNRs), i.e., expansions and year-scale spectral variations. We show that expansions can be used to infer basic parameters of SNRs such as the age, the distance, and the density: Vela Jr. turns out to be located gtrsim 750 pc away and 1000-3000 yr old, and the ambient density around the northeastern rim of SN1006 is found to be 0.085+0.055-0.035 cm-3. In addition, Chandra confirms a paradoxical difference in expansion rates for Cas A measured in the different wave bands. On the other hand, Chandra-based expansions for Kepler and Tycho are found to disagree with the previous ROSAT/Einstein-based expansions, but be consistent with radio expansions. Year-scale flickering of filaments is discovered in RX J1713.7-3946 and Cas A. It is considered to be possible evidence of extremely fast acceleration/cooling of relativistic electrons in a strongly amplified magnetic field to the level of mG-scale. Also, global flux decline and spectral steepening are found in Cas A, whereas no such spectral variations are detected in SN1006.

  17. Dust Destruction in a Nonradiative Shock in the Cygnus Loop Supernova Remnant

    SciTech Connect

    Sankrit, Ravi [SOFIA, NASA Ames Research Center, M/S 211-3, Moffett Field, CA 94041 (United States); Williams, Brian J.; Borkowski, Kazimierz J.; Reynolds, Stephen P. [North Carolina State University (United States); Raymond, John C.; Gaetz, Terrance J. [Smithsonian Astronomical Observatory (United States); Blair, William P. [Johns Hopkins University (United States); Ghavamian, Parviz; Long, Knox S. [STScI (United States)

    2009-11-11

    We present 24 {mu}m and 70 {mu}m images of a non-radiative shock in the Cygnus Loop supernova remnant, obtained with the Multiband Imaging Photometer on board the Spitzer Space Telescope. The observed emission is from dust grains heated in the post-shock region. The 70 {mu}m to 24 {mu}m flux ratio depends on the dust heating and the dust destruction rates, and thereby it is a sensitive tracer of the gas density and temperature in the shocked plasma. We model the dust emission and grain destruction in the post-shock flow, and find that the observed 70 {mu}m to 24 {mu}m flux ratios are produced for post-shock densities, n{sub H}{approx}2.0 cm{sup -3} and electron temperatures of about 0.20 keV. We find that about 35% of the dust has been destroyed in the shock, and that non-thermal sputtering (i.e. sputtering due to bulk motion of the grains relative to the gas) contributes significantly to the dust destruction.

  18. Soft X-ray Spectroscopy of the Cygnus Loop Supernova Remnant

    E-print Network

    Randall L. McEntaffer; Webster Cash

    2008-01-29

    The Cygnus X-ray Emission Spectroscopic Survey (CyXESS) sounding rocket payload was launched from White Sands Missile Range on 2006 November 20 and obtained a high resolution spectrum of the Cygnus Loop supernova remnant in the soft X-rays. The novel X-ray spectrograph incorporated a wire-grid collimator feeding an array of gratings in the extreme off-plane mount which ultimately dispersed the spectrum onto Gaseous Electron Multiplier (GEM) detectors. This instrument recorded 65 seconds of usable data between 43-49.5 \\AA in two prominent features. The first feature near 45 \\AA is dominated by the He-like triplet of \\ion{O}{7} in second order with contributions from \\ion{Mg}{10} and \\ion{Si}{9}-\\ion{Si}{12} in first order, while the second feature near 47.5 \\AA is first order \\ion{S}{9} and \\ion{S}{10}. Fits to the spectra give an equilibrium plasma at $\\log(T)=6.2$ ($kT_e=0.14$ keV) and near cosmic abundances. This is consistent with previous observations, which demonstrated that the soft x-ray emission from the Cygnus Loop is dominated by interactions between the initial blast wave with the walls of a precursor formed cavity surrounding the Cygnus Loop and that this interaction can be described using equilibrium conditions.

  19. Cooling neutron star in the Cassiopeia A supernova remnant: evidence for superfluidity in the core

    NASA Astrophysics Data System (ADS)

    Shternin, Peter S.; Yakovlev, Dmitry G.; Heinke, Craig O.; Ho, Wynn C. G.; Patnaude, Daniel J.

    2011-03-01

    According to recent results of Ho & Heinke, the Cassiopeia A supernova remnant contains a young (?330-yr-old) neutron star (NS) which has carbon atmosphere and shows notable decline of the effective surface temperature. We report a new (2010 November) Chandra observation which confirms the previously reported decline rate. The decline is naturally explained if neutrons have recently become superfluid (in triplet state) in the NS core, producing a splash of neutrino emission due to Cooper pair formation (CPF) process that currently accelerates the cooling. This scenario puts stringent constraints on poorly known properties of NS cores: on density dependence of the temperature Tcn(?) for the onset of neutron superfluidity [Tcn(?) should have a wide peak with maximum ? (7-9) × 108 K]; on the reduction factor q of CPF process by collective effects in superfluid matter (q > 0.4) and on the intensity of neutrino emission before the onset of neutron superfluidity (30-100 times weaker than the standard modified Urca process). This is serious evidence for nucleon superfluidity in NS cores that comes from observations of cooling NSs.

  20. H I ZEEMAN EXPERIMENTS OF SHOCKED ATOMIC GAS IN TWO SUPERNOVA REMNANTS INTERACTING WITH MOLECULAR CLOUDS

    SciTech Connect

    Koo, Bon-Chul [Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Heiles, Carl [Astronomy Department, University of California, Berkeley, CA 94720-3411 (United States); Stanimirovic, Snezana [Department of Astronomy, University of Wisconsin-Madison, Madison, WI 53706 (United States); Troland, Tom, E-mail: koo@astrohi.snu.ac.k [Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506 (United States)

    2010-07-15

    We have carried out observations of Zeeman splitting of the H I 21 cm emission line from shocked atomic gas in the supernova remnants (SNRs) IC 443 and W51C using the Arecibo telescope. The observed shocked atomic gas is expanding at {approx}100 km s{sup -1} and this is the first Zeeman experiment of such fast-moving, shocked atomic gas. The emission lines, however, are very broad and the systematic error due to baseline curvature hampers an accurate measurement of field strengths. We derive an upper limit of 100-150 {mu}G on the strength of the line-of-sight field component. These two SNRs are interacting with molecular clouds, but the derived upper limits are considerably smaller than the field strengths expected from a strongly shocked dense cloud. We discuss the implications and conclude that either the magnetic field within the telescope beam is mostly randomly oriented or the high-velocity H I emission is from a shocked interclump medium of relatively low density.

  1. Non-linear diffusive acceleration of heavy nuclei in supernova remnant shocks

    E-print Network

    D. Caprioli; P. Blasi; E. Amato

    2010-11-09

    We describe a semi-analytical approach to non-linear diffusive shock acceleration in the case in which nuclei other than protons are also accelerated. The structure of the shock is determined by the complex interplay of all nuclei, and in turn this shock structure determines the spectra of all components. The magnetic field amplification upstream is described as due to streaming instability of all nuclear species. The amplified magnetic field is then taken into account for its dynamical feedback on the shock structure as well as in terms of the induced modification of the velocity of the scattering centers that enters the particle transport equation. The spectra of accelerated particles are steep enough to be compared with observed cosmic ray spectra only if the magnetic field is sufficiently amplified and the scattering centers have high speed in the frame of the background plasma. We discuss the implications of this generalized approach on the structure of the knee in the all-particle cosmic ray spectrum, which we interpret as due to an increasingly heavier chemical composition above $10^{15}$eV. The effects of a non trivial chemical composition at the sources on the gamma ray emission from a supernova remnant when gamma rays are of hadronic origin are also discussed.

  2. GAMMA-RAY EMISSION FROM SUPERNOVA REMNANT INTERACTION WITH MOLECULAR CLUMPS

    NASA Astrophysics Data System (ADS)

    Tang, Xiaping; Chevalier, R.

    2014-01-01

    Observations of the middle-aged supernova remnants IC 443, W28, and W51C indicate that the brightnesses at GeV and TeV energies are correlated with each other and with regions of molecular clump interaction, but not with the radio synchrotron brightness. We suggest that the radio emission is primarily associated with a radiative shell in the interclump medium of a molecular cloud, while the Gamma-ray emission is primarily associated with the interaction of the radiative shell with molecular clumps. The shell interaction produces a high pressure region, so that the Gamma-ray luminosity can be approximately reproduced even if shock acceleration of particles is not efficient, provided that energetic particles are trapped in the cooling shell. In addition, the GeV through TeV emission can be produced in the interaction region if the trapping occurs to sufficiently high energies. Alternatively, diffusive acceleration may be efficient; in this case the observed GeV emission can be approximately reproduced, but not the TeV emission.

  3. The Fermi Bubbles as a Scaled-up Version of Supernova Remnants

    E-print Network

    Fujita, Yutaka; Yamazaki, Ryo

    2013-01-01

    In this study, we treat the Fermi bubbles as a scaled-up version of supernova remnants (SNRs). The bubbles are created through activities of the super-massive black hole (SMBH) or starbursts at the Galactic center (GC). Cosmic-rays (CRs) are accelerated at the forward shocks of the bubbles like SNRs, which means that we cannot decide whether the bubbles were created by the SMBH or starbursts from the radiation from the CRs. We follow the evolution of CR distribution by solving a diffusion-advection equation, considering the reduction of the diffusion coefficient by CR streaming. In this model, gamma-rays are created through hadronic interaction between CR protons and the gas in the Galactic halo. In the GeV band, we can well reproduce the observed flat distribution of gamma-ray surface brightness, because some amount of gas is left behind the shock. The edge of the bubbles is fairly sharp owing to the high gas density behind the shock and the reduction of the diffusion coefficient there. The latter also contr...

  4. Nonthermal Radiation of Young Supernova Remnants: The Case of CAS A

    NASA Astrophysics Data System (ADS)

    Zirakashvili, V. N.; Aharonian, F. A.; Yang, R.; Oña-Wilhelmi, E.; Tuffs, R. J.

    2014-04-01

    The processes responsible for the broadband radiation of the young supernova remnant Cas A are explored by using a new code that is designed for a detailed treatment of the diffusive shock acceleration of particles in the nonlinear regime. The model is based on spherically symmetric hydrodynamic equations complemented with transport equations for relativistic particles. Electrons, protons, and the oxygen ions accelerated by forward and reverse shocks are included in the numerical calculations. We show that the available multi-wavelength observations in the radio, X-ray, and gamma-ray bands can be best explained by invoking particle acceleration by both forward and reversed shocks. Although the TeV gamma-ray observations can be interpreted by interactions of both accelerated electrons and protons/ions, the measurements by Fermi Large Area Telescope at energies below 1 GeV give a tentative preference to the hadronic origin of gamma-rays. Then, the acceleration efficiency in this source, despite the previous claims, should be very high; 25% of the explosion energy (or approximately 3 × 1050 erg) should already be converted to cosmic rays, mainly by the forward shock. At the same time, the model calculations do not provide extension of the maximum energy of accelerated protons beyond 100 TeV. In this model, the acceleration of electrons is dominated by the reverse shock; the required 1048 erg can be achieved under the assumption that the injection of electrons (positrons) is supported by the radioactive decay of 44Ti.

  5. Multi-Frequency Study of Supernova Remnants and H II Regions in NGC300

    NASA Astrophysics Data System (ADS)

    Payne, J. L.; Filipovic, M. D.; Pannuti, T. G.; Jones, P. A.; Duric, N.; White, L.; Carpano, S.

    2005-04-01

    We present a multi-frequency study of supernova remnants (SNRs) and H2 regions in the nearby Sculptor Group Sd galaxy NGC300, based on new ATCA observations at the wavelengths of 13 and 20 cm, XMM-Newton observations, newly-processed ROSAT (PSPC/HRI; Read & Pietsch 2001) and VLA (20/6 cm) images of this galaxy. We have investigated the physical properties at the X-ray and radio wavelengths of the 28 optical SNRs found by Blair & Long (1997) and have expanded on the multi-wavelength work by Pannuti et al. (2000) on this same galaxy. From a total of 54 radio sources and 11 X-ray sources, we report 18 SNRs and five (5) SNR candidates (classified by spectral index alone) in NGC300. Five of these 18 SNRs are associated with reported optical SNRs and three have X-ray counterparts. An additional 12 radio SNRs are seen in the Blair & Long (1997) [S2] images. We also investigate luminosity function of our SNRs. Three background radio sources are confirmed and 12 other sources could represent additional background objects. Twenty two radio correlations with OB associations within NGC300 correspond to either H2 regions or SNRs making them a good tracer of SNRs near star-forming regions. Additionally, two of our radio sources coincide with potential globular clusters of NGC300 reported by Kim et al. (2002).

  6. The Nature of the Vela Supernova Remnant as Revealed by O VI and C IV Absorption

    NASA Technical Reports Server (NTRS)

    Lines, Nichols J.; Slavin, J.; Anderson, C.

    2001-01-01

    Highly ionized gas, in particular C IV and O VI, is produced in the interstellar medium in regions with hot (T approx. 10(exp 6) K) X-ray emitting gas and at the boundaries where hot gas and cooler (T approx. 10(exp 4) K) gas interact. Supernova remnant shocks produce most of the hot gas in the ISM and, if they are in the correct range of speeds, should produce observable quantities of C IV and O VI absorption. In turn, the column densities of these ions are potentially powerful diagnostics of the shock speed and interstellar environment in which the SNR is evolving. With the advent of FUSE, the power of this diagnostic technique is now available. We have FUSE data toward 8 stars behind the Vela SNR, and have developed a data reduction and analysis method that produces reasonably reliable O VI column densities, in spite of the complexities of the FUSE spectra in this region. In order to gain insight into the observational results, the Vela SNR evolution was modelled using Piecewise Parabolic Method numerical hydrodynamics code. The code is 1-D and incorporates non-equilibrium ionization, radiative cooling, thermal conduction and magnetic pressure.

  7. ?-rays from molecular clouds illuminated by accumulated diffusive protons - II. Interacting supernova remnants

    NASA Astrophysics Data System (ADS)

    Li, Hui; Chen, Yang

    2012-04-01

    Recent observations reveal that spectral breaks at ˜GeV are commonly present in Galactic ?-ray supernova remnants (SNRs) interacting with molecular clouds and that most of them have a spectral (E2dF/dE) 'platform' extending from the break to lower energies. In Paper I, we developed an accumulative diffusion model by considering an accumulation of the diffusive protons escaping from the shock front throughout the history of the SNR expansion. In this paper, we improve the model by incorporating the finite volume of molecular clouds, demonstrate the model dependence on particle diffusion parameters and cloud size, and apply it to nine interacting SNRs (W28, W41, W44, W49B, W51C, Cygnus Loop, IC443, CTB 37A and G349.7+0.2). This refined model naturally explains the GeV spectral breaks and, in particular, the 'platforms', together with available TeV data. We find that the index of the diffusion coefficient ? is in the range 0.5-0.7, similar to the Galactic averaged value, and the diffusion coefficient for cosmic rays around the SNRs is essentially two orders of magnitude lower than the Galactic average (?˜ 0.01), which is a good indication for the suppression of cosmic-ray diffusion near SNRs.

  8. Gamma-rays from molecular clouds illuminated by accumulated diffusive protons. II: interacting supernova remnants

    E-print Network

    Li, Hui

    2011-01-01

    Recent observations reveal that spectral breaks at ~ GeV are commonly present in Galactic gamma-ray supernova remnants (SNRs) interacting with molecular clouds and that most of them have a spectral ($E^2dF/dE$) "platform" extended from the break to lower energies. In paper I (Li & Chen 2010), we developed an accumulative diffusion model by considering an accumulation of the diffusive protons escaping from the shock front throughout the history of the SNR expansion. In this paper, we improve the model by incorporating finite-volume of MCs and apply it to nine interacting SNRs (W28, W41, W44, W49B, W51C, Cygnus Loop, IC443, CTB 37A, and G349.7+0.2). This refined model naturally explains the GeV spectral breaks and, especially, the "platform"s, together with available TeV data. We find that the diffusion coefficient for cosmic rays around the SNRs is essentially two orders of magnitude lower than the Galactic average, which is a good indication for the suppression of cosmic ray diffusion near SNRs.

  9. Recombining Plasma in the Gamma-Ray-emitting Mixed-morphology Supernova Remnant 3C 391

    NASA Astrophysics Data System (ADS)

    Ergin, T.; Sezer, A.; Saha, L.; Majumdar, P.; Chatterjee, A.; Bayirli, A.; Ercan, E. N.

    2014-07-01

    A group of middle-aged mixed-morphology (MM) supernova remnants (SNRs) interacting with molecular clouds (MCs) has been discovered to be strong GeV gamma-ray emitters by the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope (Fermi-LAT). The recent observations of the Suzaku X-ray satellite have revealed that some of these interacting gamma-ray-emitting SNRs, such as IC443, W49B, W44, and G359.1-0.5, have overionized plasmas. 3C 391 (G31.9+0.0) is another Galactic MM SNR interacting with MCs. It was observed in GeV gamma rays by Fermi-LAT as well as in the 0.3-10.0 keV X-ray band by Suzaku. In this work, 3C 391 was detected in GeV gamma rays with a significance of ~18? and we showed that the GeV emission is point-like in nature. The GeV gamma-ray spectrum was shown to be best explained by the decay of neutral pions assuming that the protons follow a broken power-law distribution. We revealed radiative recombination structures of silicon and sulfur from 3C 391 using Suzaku data. In this paper, we discuss the possible origin of this type of radiative plasma and hadronic gamma rays.

  10. X-ray and gamma-ray studies of particle acceleration in supernova remnants

    NASA Astrophysics Data System (ADS)

    Tanaka, Takaaki; Fermi LAT Collaboration

    2012-03-01

    Supernova remnants (SNRs) are prime candidates for acceleration sites of cosmic rays. In the last ~15 years, X-ray and TeV gamma-ray observations of SNRs indeed provided evidence that expanding SNR shells are able to accelerate charged particles up to TeV energies. Improved sensitivities of X-ray and TeV gamma-ray instruments enabled not only the detection of nonthermal radiation but also detailed spectral and morphological studies of SNRs. A new window for those studies has recently been opened by the Large Area Telescope (LAT) aboard the Fermi Gamma-ray Space Telescope, which is sensitive to gamma rays in the GeV band. Fermi LAT data put new constraints on emission mechanisms of young SNRs such as RX J1713.7-3946, and RX J0852.0-4622, which are known also as emitters of non-thermal X-rays and TeV gamma rays. Another important finding by the Fermi LAT is bright GeV emission from middle-aged SNRs interacting with molecular clouds, such as W44, W51C, and IC 443. We summarize recent X-ray and gamma-ray observations of non-thermal emission from SNRs. We also discuss possible scenarios to explain multi-wavelength spectra of SNRs.

  11. H I Zeeman Experiments of Shocked Atomic Gas in Two Supernova Remnants Interacting with Molecular Clouds

    NASA Astrophysics Data System (ADS)

    Koo, Bon-Chul; Heiles, Carl; Stanimirovi?, Snežana; Troland, Tom

    2010-07-01

    We have carried out observations of Zeeman splitting of the H I 21 cm emission line from shocked atomic gas in the supernova remnants (SNRs) IC 443 and W51C using the Arecibo telescope. The observed shocked atomic gas is expanding at ~100 km s-1 and this is the first Zeeman experiment of such fast-moving, shocked atomic gas. The emission lines, however, are very broad and the systematic error due to baseline curvature hampers an accurate measurement of field strengths. We derive an upper limit of 100-150 ?G on the strength of the line-of-sight field component. These two SNRs are interacting with molecular clouds, but the derived upper limits are considerably smaller than the field strengths expected from a strongly shocked dense cloud. We discuss the implications and conclude that either the magnetic field within the telescope beam is mostly randomly oriented or the high-velocity H I emission is from a shocked interclump medium of relatively low density.

  12. Gamma-rays from molecular clouds illuminated by cosmic rays escaping from interacting supernova remnants

    NASA Astrophysics Data System (ADS)

    Ohira, Yutaka; Murase, Kohta; Yamazaki, Ryo

    2011-01-01

    Recently, the gamma-ray telescopes AGILE and Fermi observed several middle-aged supernova remnants (SNRs) interacting with molecular clouds. It is likely that their gamma-rays arise from the decay of neutral pions produced by the inelastic collision between cosmic rays (CRs) and nucleons, which suggests that SNRs make the bulk of Galactic CRs. In this paper, we provide the analytical solution of the distribution of CRs that have escaped from a finite-size region, which naturally explains observed broken power-law spectra of the middle-aged SNRs. In addition, the typical value of the break energy of the gamma-ray spectrum, 1-10 GeV, is naturally explained from the fact that the stellar wind dynamics shows a separation between the molecular clouds and the explosion centre of about 10 pc. We find that the runaway-CR spectrum of the four middle-aged SNRs (W51C, W28, W44 and IC 443) interacting with molecular clouds could be the same, even though it leads to different gamma-ray spectra. This result is consistent with that of recent studies of Galactic CR propagation, and supports that SNRs are indeed the sources of Galactic CRs.

  13. Discovery of Strong Radiative Recombination Continua from the Supernova Remnant IC 443 with Suzaku

    NASA Astrophysics Data System (ADS)

    Yamaguchi, H.; Ozawa, M.; Koyama, K.; Masai, K.; Hiraga, J. S.; Ozaki, M.; Yonetoku, D.

    2009-11-01

    We present the Suzaku spectroscopic study of the Galactic middle-aged supernova remnant (SNR) IC 443. The X-ray spectrum in the 1.75-6.0 keV band is described by an optically thin thermal plasma with the electron temperature of ~0.6 keV and several additional Lyman lines. We robustly detect, for the first time, strong radiative recombination continua (RRC) of H-like Si and S around at 2.7 and 3.5 keV. The ionization temperatures of Si and S determined from the intensity ratios of the RRC to He-like K? lines are ~1.0 keV and ~1.2 keV, respectively. We thus find firm evidence for an extremely overionized (recombining) plasma. As the origin of the overionization, a thermal conduction scenario argued in previous work is not favored in our new results. We propose that the highly ionized gas was made at the initial phase of the SNR evolution in dense regions around a massive progenitor, and the low electron temperature is due to a rapid cooling by an adiabatic expansion.

  14. Recombining Plasma in the Gamma-ray Emitting Mixed-Morphology Supernova Remnant 3C 391

    E-print Network

    Ergin, Tülün; Saha, Lab; Majumdar, Pratik; Chatterjee, Anshu; Bay?rl?, Arif; Ercan, E Nihal

    2014-01-01

    A group of middle-aged mixed-morphology (MM) supernova remnants (SNRs) interacting with molecular clouds (MC) has been discovered as strong GeV gamma-ray emitters by Large Area Telescope on board Fermi Gamma Ray Space Telescope (Fermi-LAT). The recent observations of the Suzaku X-ray satellite have revealed that some of these interacting gamma-ray emitting SNRs, such as IC443, W49B, W44, and G359.1-0.5, have overionized plasmas. 3C 391 (G31.9+0.0) is another Galactic MM SNR interacting with MC. It was observed in GeV gamma rays by Fermi-LAT as well as in the 0.3 $-$ 10.0 keV X-ray band by Suzaku. In this work, 3C 391 was detected in GeV gamma rays with a significance of $\\sim$ 18 $\\sigma$ and we showed that the GeV emission is point-like in nature. The GeV gamma-ray spectrum was shown to be best explained by the decay of neutral pions assuming that the protons follow a broken power-law distribution. We revealed radiative recombination structures of silicon and sulfur from 3C 391 using Suzaku data. In this pap...

  15. Identification of Ambient Molecular Clouds Associated with Galactic Supernova Remnant IC443

    E-print Network

    Lee, Jae-Joon; Snell, Ronald L; Yun, Min S; Heyer, Mark H; Burton, Michael G

    2012-01-01

    The Galactic supernova remnant (SNR) IC443 is one of the most studied core-collapse SNRs for its interaction with molecular clouds. However, the ambient molecular clouds with which IC443 is interacting have not been thoroughly studied and remain poorly understood. Using Five College Radio Astronomy Observatory 14m telescope, we obtained fully sampled maps of ~ 1{\\deg} \\times 1{\\deg} region toward IC443 in the 12CO J=1-0 and HCO+ J=1-0 lines. In addition to the previously known molecular clouds in the velocity range v_lsr = -6 to -1 km/s (-3 km/s clouds), our observations reveal two new ambient molecular cloud components: small (~ 1') bright clouds in v_lsr = -8 to -3 km/s (SCs), and diffuse clouds in v_lsr = +3 to +10 km/s (+5 km/s clouds). Our data also reveal the detailed kinematics of the shocked molecular gas in IC443, however the focus of this paper is the physical relationship between the shocked clumps and the ambient cloud components. We find strong evidence that the SCs are associated with the shocke...

  16. Gamma-Ray Emission from Supernova Remnant Interactions with Molecular Clumps

    NASA Astrophysics Data System (ADS)

    Tang, Xiaping; Chevalier, Roger A.

    2014-04-01

    Observations of the middle-aged supernova remnants IC 443, W28, and W51C indicate that the brightnesses at GeV and TeV energies are correlated with each other and with regions of molecular clump interaction, but not with the radio synchrotron brightness. We suggest that the radio emission is primarily associated with a radiative shell in the interclump medium of a molecular cloud, while the ?-ray emission is primarily associated with the interaction of the radiative shell with molecular clumps. The shell interaction produces a high pressure region, so that the ?-ray luminosity can be approximately reproduced even if shock acceleration of particles is not efficient, provided that energetic particles are trapped in the cooling region. In this model, the spectral shape >~ 2 GeV is determined by the spectrum of cosmic ray protons. Models in which diffusive shock acceleration determines the spectrum tend to underproduce TeV emission because of the limiting particle energy that is attained.

  17. The Sizes of OH (1720 MHz) Supernova Remnant Masers MERLIN and VLBA Observations of IC443

    E-print Network

    Hoffman, I M; Brogan, C L; Claussen, M J; Richards, A M S; Hoffman, Ian M.

    2003-01-01

    MERLIN and VLBA observations of the 1720 MHz maser emission from the OH molecule in the supernova remnant IC443 are presented. Based on MERLIN data with a resolution of 160 mas, the deconvolved sizes of the maser sources are in the range 90 to 180 mas (135 to 270 AU). The 12 mas resolution VLBA images show compact cores with sizes in the range 15 to 55 mas. The maser brightness temperatures are (2-34)x10^6 K for the MERLIN sources and (5-19)x10^8 K for the VLBA cores, in agreement with theory. Unlike the Zeeman Stokes V profiles observed in other OH (1720 MHz) SNR masers, single-handed circular polarization line profiles are observed in IC443 on all angular scales from 1000 to 10 mas resolution. For one line component, the observed line width is 0.24+/-0.07 km/s, compared to an estimated Doppler width of 0.49 km/s. This discrepancy in line widths can be accounted for if the maser emission arises from an elongated ellipsoidal region of masing gas.

  18. Spitzer spectral line mapping of supernova remnants: I. Basic data and principal component analysis

    E-print Network

    Neufeld, David A; Kaufman, Michael J; Snell, Ronald L; Melnick, Gary J; Bergin, Edwin A; Sonnentrucker, Paule

    2007-01-01

    We report the results of spectroscopic mapping observations carried out toward small (1 x 1 arcmin) regions within the supernova remnants W44, W28, IC443, and 3C391 using the Infrared Spectrograph of the Spitzer Space Telescope. These observations, covering the 5.2 - 37 micron spectral region, have led to the detection of a total of 15 fine structure transitions of Ne+, Ne++, Si+, P+, S, S++, Cl+, Fe+, and Fe++; the S(0) - S(7) pure rotational lines of molecular hydrogen; and the R(3) and R(4) transitions of hydrogen deuteride. In addition to these 25 spectral lines, the 6.2, 7.7, 8.6, 11.3 and 12.6 micron PAH emission bands were also observed. Most of the detected line transitions have proven strong