scholarly journals Morphology and Physics of Supernova Remnants

1992 ◽  
Vol 9 ◽  
pp. 223-228 ◽  
Author(s):  
B. Aschenbach
Keyword(s):  
Survey Data ◽  
Supernova Remnants ◽  
Supernova Remnant ◽  
Thermal Pressure ◽  
X Ray ◽  
Cygnus Loop ◽  
Sky Survey ◽  
Pressure Equilibrium ◽  
Spectrally Resolved

AbstractSpectrally resolved X-ray images of the Cygnus Loop and the Vela supernova remnant have been obtained during the ROSAT all sky survey. The remnants show highly filamentary brightness distributions. Temperatures between 1·106 K and 10·106 K have been measured. Both remnants show significant deviation from thermal pressure equilibrium. The highest pressure excursions of up to a factor of 50 are associated with the X-ray brightest filaments. Pressure variations are expected for very recently shocked clouds, on a smaller scale though. In a limited search of the all sky survey data 14 extended objects have been found, which have tentatively been identified as previously unknown supernova remnants. A total number of ~ 60 new remnants are expected from the analysis of the full sky.

Studies of the X-ray emission from supernova remnants

1974 ◽  
Vol 340 (1623) ◽  
pp. 423-437
Keyword(s):  
Supernova Remnants ◽  
Column Density ◽  
Supernova Remnant ◽  
Crab Nebula ◽  
Lower Intensity ◽  
X Ray ◽  
Cassiopeia A ◽  
Cygnus Loop ◽  
A Value ◽  
The Crab Nebula

Supernova remnants are now recognized as a class of soft X-ray emitting-objects. The evolution of a remnant’s X-ray emission is discussed and a number of possible X-ray emission mechanisms are described. The spectrum of the Crab Nebula has been studied with Copernicus. The data have been used to derive a value of the gas column density of the interstellar medium. The X-ray structure and spectrum of the remnant Cassiopeia. A have been investigated and the results are presented. A high resolution X-ray map of the Puppis A supernova remnant has been obtained and the interpretation of the X-ray structure is discussed. X-ray emission has been detected from the pulsar PSR 08 33-45. This observation is compared with data obtained from the Uhuru satellite in order to derive the gas column density to the source. Weak soft X-ray emission has been detected from the Cygnus Loop in the regions expected but a t a lower intensity – a search for regions of higher intensity is continuing. A programme to identify known radio remnants as X-ray emitters is in progress and the results obtained so far are reported.

Some recent observations of supernova remnants emitting X-rays

1979 ◽  
Vol 366 (1726) ◽  
pp. 311-327
Keyword(s):  
Supernova Remnants ◽  
Supernova Remnant ◽  
X Rays ◽  
Coronal Line ◽  
Crystal Spectrometer ◽  
X Ray ◽  
Cygnus Loop ◽  
The Galaxy ◽  
Two Distinct Temperatures ◽  
Line Observation

There are currently believed to be 13 X-ray sources which can be fairly confidently identified with galactic supernova remnants. All of these sources are thought to be at reasonably small distances, thus supporting the view that absorption in the interstellar medium prevents us from seeing the more distant galactic remnants with the level of sensitivity currently available from soft X-ray instrumentation. Of the older remnants, the Cygnus Loop and Puppis-A are discussed in the light of recent observations. Several mapping experiments show that the Cygnus Loop exhibits a shell-like structure in X-rays, though with considerable fine structure. From these experiments, it is still not clear how uniform is the temperature over the X-ray emitting region. In addition, results from a crystal spectrometer are described which imply that the temperature may be higher than had been previously determined from proportional counter observations. Results from observations of Puppis-A are presented. These imply that two distinct temperatures exist in this source. It is argued that this may represent the interaction of the expanding shock front with a relatively dense interstellar cloud. The sources W44 and γ -Cygni supernova remnant are discussed and it is suggested that these may now be regarded as members of the class of confirmed X-ray emitting supernova remnants. Finally, an optical coronal line observation of the remnant N49 in the L. M. C. is considered, and it is suggested that this source is a likely candidate to be detected as the first X-ray emitting supernova remnant outside the galaxy.

Supernova Remnant Searches at Molonglo

1984 ◽  
Vol 5 (4) ◽  
pp. 537-540 ◽  
Author(s):  
A. J. Turtle ◽  
B. Y. Mills
Keyword(s):  
Supernova Remnants ◽  
Supernova Remnant ◽  
Magellanic Clouds ◽  
Radio Observations ◽  
X Ray

A catalogue of 38 supernova remnants (SNRs) identified in the Large and Small Magellanic Clouds from X-ray, optical and radio observations has recently been presented by Mills et al. (1984). One important consideration is the completeness of this catalogue and of the Galactic catalogues with which it is compared. These are currently being investigated.

scholarly journals Fermi-LAT and WMAP observations of the supernova remnant Puppis A

2013 ◽  
Vol 9 (S296) ◽  
pp. 295-299
Author(s):  
Marie-Hélène Grondin ◽  
John W. Hewitt ◽  
Marianne Lemoine-Goumard ◽  
Thierry Reposeur ◽  
Keyword(s):  
Supernova Remnants ◽  
Supernova Remnant ◽  
Gamma Ray ◽  
High Energy ◽  
Radio Spectrum ◽  
Wilkinson Microwave Anisotropy Probe ◽  
Large Area ◽  
X Ray ◽  
Inverse Compton Scattering ◽  
Γ Ray

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

scholarly journals High Resolution X-ray Spectra of Supernova Remnants

1983 ◽  
Vol 101 ◽  
pp. 205-211
Author(s):  
C. R. Canizares ◽  
P. F. Winkler ◽  
T. H. Markert ◽  
C. Berg
Keyword(s):  
Supernova Remnants ◽  
Abundance Ratio ◽  
Ionization Equilibrium ◽  
X Ray ◽  
Cygnus Loop ◽  
Doppler Shifts ◽  
Wide Range ◽  
Cas A ◽  
Einstein Observatory ◽  
Tycho’S Snr

We review results obtained with the Focal Plane Crystal Spectrometer (FPCS) on the Einstein Observatory. Clear evidence is found for departures from ionization equilibrium in the interior of Puppis A. This comes from the observed weakness of the forbidden lines relative to the resonance lines for the He - like triplets of O VII and Ne IX. However, it is shown that this departure from equilibrium does not alter our conclusion, based on previous FPCS results, that O and Ne are overabundant relative to Fe. The spectrum of N132D shows strong O VIII emission and very weak Fe emission, suggesting an even greater O/Fe abundance enhancement than in Puppis A. In the Cygnus Loop, the O to Ne abundance ratio is approximately solar; we have no information about Fe. The O VII triplet shows clear evidence for departures from ionization equilibrium in the Cygnus Loop. The spectrum of Tycho's SNR contains lines from ionization stages of Fe XVII through Fe XXIII and XXIV, indicating that a wide range of ionization conditions are present. Cas A and Kepler's SNR show relatively less emission from the higher ionization stages. For Tycho, we measured the strength of the strong Si XIII lines, and we find that a many-fold overabundance of Si relative to Fe is required regardless of the equilibrium state of the emitting plasma (confirming the Solid State Spectrometer results). On a separate topic, the completed analysis of X-ray Doppler shifts in Cas A suggests that the emitting material is concentrated in a ring that is inclined to the line of sight and is expanding at ~5000 km s−1.

scholarly journals Heating of the Interstellar Medium by Supernova Remnants

1983 ◽  
Vol 101 ◽  
pp. 385-392
Author(s):  
Donald P. Cox
Keyword(s):  
Interstellar Medium ◽  
Supernova Remnants ◽  
Supernova Remnant ◽  
Low Density ◽  
The Sun ◽  
X Ray ◽  
Interstellar Material ◽  
X Ray Background

We observe the heating of interstellar material in young supernova remnants (SNR). In addition, when analyzing the soft X-ray background we find evidence for large isolated regions of apparently hot, low density material. These, we infer, may have been heated by supernovae. One such region seems to surround the Sun. This has been modeled as a supernova remnant viewed from within. The most reasonable parameters are ambient density no ~ 0.004 cm−3, radius of about 100 pc, age just over 105 years (Cox and Anderson 1982).

scholarly journals Detailed X-ray Observations of the Cygnus Loop

1983 ◽  
Vol 101 ◽  
pp. 253-260
Author(s):  
W. H.-M. Ku ◽  
K. Long ◽  
R. Pisarski ◽  
M. Vartanian
Keyword(s):  
High Resolution ◽  
Proportional Counter ◽  
Supernova Remnant ◽  
Sounding Rocket ◽  
Loop Structure ◽  
High Quality ◽  
Radio Structure ◽  
X Ray ◽  
Cygnus Loop ◽  
Spatially Resolved

High quality X-ray spectral and imaging observations of the Cygnus Loop have been obtained with three different instruments. The High Resolution Imager (HRI) on the Einstein Observatory was used to obtain arcsecond resolution images of select bright regions in the Cygnus Loop which permit detailed comparisons between the X-ray, optical, and radio structure of the Loop. The Imaging Proportional Counter (IPC) on the Einstein Observatory was used to obtain an arcminute resolution map of essentially the full Loop structure. Finally, an Imaging Gas Scintillation Proportional Counter (IGSPC), carried aloft by a sounding rocket last fall, obtained modest resolution, spatially resolved spectrophotometry of the Cygnus Loop. An X-ray map of the Loop in the energy of the 0 VIII line was obtained. These data combine to yield a very powerful probe of the abundance, temperature, and density distribution of material in the supernova remnant, and in the interstellar medium.

scholarly journals Erratum: Properties of the X-ray-brightest Abell-type clusters of galaxies (XBACs) from ROSAT All-Sky Survey data -- I. The sample

1996 ◽  
Vol 283 (3) ◽  
pp. 1103-1104 ◽  
Author(s):  
H. Ebeling ◽  
W. Voges ◽  
H. Bohringer ◽  
A. C. Edge ◽  
J. P. Huchra ◽  
...  
Keyword(s):  
Survey Data ◽  
Clusters Of Galaxies ◽  
X Ray ◽  
Sky Survey

scholarly journals A VO study of SDSS AGNs with X-ray emission from ROSAT-PSPC pointed observations

2006 ◽  
Vol 2 (14) ◽  
pp. 581-581
Author(s):  
Robert J. Hanisch ◽  
Anatoly A. Suchkov ◽  
Timothy M. Heckman ◽  
Wolfgang H. Voges
Keyword(s):  
Survey Data ◽  
Sloan Digital Sky Survey ◽  
Radio Sources ◽  
X Ray ◽  
Sky Survey ◽  
Data Release

We use VO facilities to study AGNs with X-ray emission. We present a sample of 1744 of Type 1 AGNs from the Sloan Digital Sky Survey Data Release 4 (SDSS DR4) spectroscopic catalog with X-ray counterparts in the White-Giommi-Angelini catalogue (WGACAT) of ROSAT-pspc pointed observations. Of 1744 X-ray sources, 1410 (80.9%) are new AGN identifications. Of 4,574 SDSS DR4 AGNs for which we found radio matches in the catalogue of radio sources from the Faint Images of the Radio Sky at Twenty (FIRST) cm survey, 224 turned up in our sample of SDSS X-ray AGN.

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