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:0803.3410)
· On-line Data
· References in the article
· Citations to the Article (14) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (2)
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
Fast Variability of Nonthermal X-Ray Emission in Cassiopeia A: Probing Electron Acceleration in Reverse-Shocked Ejecta
Authors:
Uchiyama, Yasunobu; Aharonian, Felix A.
Affiliation:
AA(Department of High Energy Astrophysics, ISAS/JAXA, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510, Japan; .), AB(Dublin Institute for Advanced Studies, 5 Merrion Square, Dublin 2, Ireland.; Max-Planck-Institut für Kernphysik, P.O. Box 103980, D69029 Heidelberg, Germany; .)
Publication:
The Astrophysical Journal, Volume 677, Issue 2, pp. L105-L108. (ApJL Homepage)
Publication Date:
04/2008
Origin:
UCP
ApJ Keywords:
Acceleration of Particles, ISM: Individual: Name: Cassiopeia A, Radiation Mechanisms: Nonthermal
DOI:
10.1086/588190
Bibliographic Code:
2008ApJ...677L.105U

Abstract

Recent discovery of the year-scale variability in the synchrotron X-ray emission of the supernova remnant (SNR) RX J1713.7-3946 has initiated our study of multiepoch X-ray images and spectra of the young SNR Cassiopeia A based on the Chandra archive data taken in 2000, 2002, and 2004. We have found year-scale time variations in the X-ray intensity for a number of X-ray filaments or knots associated with the reverse-shocked regions. The X-ray spectra of the variable filaments are characterized by a featureless continuum, and described by a power law with a photon index within 1.9-2.3. The upper limits on the iron K-line equivalent width are 110 eV, which favors a synchrotron origin of the X-ray emission. The characteristic variability timescale of 4 yr can be explained by the effects of fast synchrotron cooling and diffusive shock acceleration with a plausible magnetic field of 1 mG. The X-ray variability provides a new effective way of studying particle acceleration at supernova shocks.
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