Sign on

SAO/NASA ADS Astronomy Abstract Service

· Find Similar Abstracts (with default settings below)
· Electronic Refereed Journal Article (HTML)
· Full Refereed Journal Article (PDF/Postscript)
· arXiv e-print (arXiv:astro-ph/0107175)
· On-line Data
· References in the article
· Citations to the Article (25) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (8)
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
X-Ray Observations of the Supernova Remnant G21.5-0.9
Authors:
Safi-Harb, S.; Harrus, I. M.; Petre, R.; Pavlov, G. G.; Koptsevich, A. B.; Sanwal, D.
Affiliation:
AA(University of Manitoba, Winnipeg, MB R3T 2N2, Canada; ), AB(NASA Goddard Space Flight Center, Greenbelt, MD 20771; Universities Space Research Association.), AC(NASA Goddard Space Flight Center, Greenbelt, MD 20771), AD(Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802), AE(Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802; On leave from Ioffe Physical Technical Institute, St. Petersburg, Russia.), AF(Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802)
Publication:
The Astrophysical Journal, Volume 561, Issue 1, pp. 308-320. (ApJ Homepage)
Publication Date:
11/2001
Origin:
UCP
ApJ Keywords:
ISM: individual (G21.5-0.9), Stars: Neutron, ISM: Supernova Remnants, X-Rays: ISM
DOI:
10.1086/322978
Bibliographic Code:
2001ApJ...561..308S

Abstract

We present the analysis of archival X-ray observations of the supernova remnant (SNR) G21.5-0.9. Based on its morphology and spectral properties, G21.5-0.9 has been classified as a Crab-like SNR. For that reason, it was chosen as a Chandra calibration target. In their early analysis of part of these calibration data, Slane and coworkers discovered a low surface brightness, extended emission. They interpreted this component as the blast wave formed in the supernova explosion. XMM-Newton observations by Warwick and coworkers revealed the nonthermal nature of this emission, suggesting that it is instead an extension of the synchrotron nebula. In this paper, we revisit the Chandra analysis using new calibration data, improving the statistics by a factor of 2. We also include ROSAT and ASCA observations. Our analysis confirms the nonthermal nature of the extended emission. Advanced CCD Imaging Spectrometer images indicate that this component is not limb-brightened and that it shows knotty structures and a bright filament 2' north of the center. We find no evidence of line emission from any part of the remnant. We can reject a collisional equilibrium ionization thermal model at solar abundances and nonequilibrium ionization (NEI) models (such as a plane-parallel shock model with different ionization ages and constant temperature or an NEI model with a single ionization age and a constant temperature). The entire remnant is best fitted with a power-law model with a photon index steepening away from the center. The total unabsorbed flux FX(0.5-10 keV) is 1.1×10-10 ergs cm-2 s-1 with an 85% contribution from the 40" radius core. Timing analysis of the High-Resolution Camera data failed to detect any pulsations. We put a 16% upper limit on the pulsed fraction. We derive the physical parameters of the putative pulsar and compare them with those of other plerions (such as the Crab nebula and 3C 58).
Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)
   

Find Similar Abstracts:

Use: Authors
Title
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints