Suzaku view of supernova remnants
Abstract
We present the spectral studies of thermal emissions from supernova remnants (SNRs) with the latest Japanese X-ray astronomy satellite Suzaku. In the X-ray spectrum from the southeast region of SN 1006, we robustly detected the K-shell emission from Fe, for the first time. Fe was found to be less ionized than the other lighter elements, such as Si and S. This fact strongly suggests that Fe has been heated by the reverse shock more recently than the other elements, consistent with a picture where the ejecta are stratified by composition with Fe in the interior. From the several other Type Ia SNRs, Tycho, Kepler, and N103B, Suzaku successfully detected emission lines of low-abundant elements, Cr, Mn, and/or Ni. A number ratio of Mn/Cr in Type Ia SNRs would especially be a good probe for an initial metallicity of the progenitor, because the product of Mn is sensitive to the neutron excess in the white dwarf. We finally report on the recent results concerning the middle-aged SNRs, IC 443 and W49B. We discovered strong free-bound emission from these SNRs, the firm evidences of peculiar recombining (overionized) plasma.
- Publication:
-
Memorie della Societa Astronomica Italiana
- Pub Date:
- 2010
- Bibcode:
- 2010MmSAI..81..382Y
- Keywords:
-
- ISM: Supernova Remnants;
- X-Rays: Spectra