The expansion of Cassiopeia A as seen in X-rays
Abstract
We have for the first time measured the overall expansion rate of the supernova remnant Cas A as seen in X-rays using ROSAT and Einstein HRI images with time differences up to almost 17 years. The overall expansion timescale of Cas A is found to be 501 plusminus 15 yr. This is significantly shorter than the timescale based on high resolution radio data. Although the results clearly indicate that Cas A is not anymore in the free expansion phase,the discrepancy between the radio and X-ray timescales cannot be easily understood. Furthermore, the expansion rate is incompatible with that predicted by a self-similar model for a supernova remnant ploughing through the wind of its progenitor.
Cite
@article{arxiv.astro-ph/9806319,
title = {The expansion of Cassiopeia A as seen in X-rays},
author = {Jacco Vink and Hans Bloemen and Jelle Kaastra and Johan Bleeker},
journal= {arXiv preprint arXiv:astro-ph/9806319},
year = {2007}
}
Comments
7 pages; 4 figures. Accepted by Astronomy and Astrophysics (August 3, 1998). Major text changes have been made, mostly in section 4. For more information see http://www.sron.nl/~jaccov/casAexp/casa_exp.html