Astronomy and Astrophysics – Astrophysics
Scientific paper
2006-09-14
Astron.J.133:147-153,2007
Astronomy and Astrophysics
Astrophysics
9 pages, 8 figures, to be published in Astronomical Journal
Scientific paper
10.1086/509571
A comparison of X-ray observations of the Cassiopeia A supernova remnant taken in 2000, 2002, and 2004 with the Chandra ACIS-S3 reveals the presence of several small scale features (<= 10 arcsec) which exhibit significant intensity changes over a 4 year time frame. Here we report on the variability of six features, four of which show count rate increases from ~ 10% to over 90%, and two which show decreases of ~ 30% -- 40%. While extracted 1-4.5 keV X-ray spectra do not reveal gross changes in emission line strengths, spectral fits using non-equilibrium ionization, metal-rich plasma models indicate increased or decreased electron temperatures for features showing increasing or decreasing count rates, respectively. Based on the observed count rate changes and the assumption that the freely expanding ejecta has a velocity of ~ 5000 km/s at the reverse shock front, we estimate the unshocked ejecta to have spatial scale variations of 0.02 - 0.03 pc, which is consistent with the X-ray emitting ejecta belonging to a more diffuse component of the supernova ejecta than that seen in the optically emitting ejecta, which have spatial scales ~ 0.001 pc.
Fesen Robert A.
Patnaude Daniel J.
No associations
LandOfFree
Small-Scale X-ray Variability in the Cassiopeia A Supernova Remnant does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Small-Scale X-ray Variability in the Cassiopeia A Supernova Remnant, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Small-Scale X-ray Variability in the Cassiopeia A Supernova Remnant will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-537048