Determining Progenitors of Young Supernova Remnants from Their Fe K-Shell Emission
Abstract
Young Supernova Remnants (SNRs) retain crucial information about their explosion and nucleosynthesis mechanisms. However, interactions with the surrounding circumstellar and interstellar medium can conceal these data and so it is not unusual that even the basic progenitor type (i.e., Ia or core-collapse) of a remnant remains controversial. Here we propose a new method to discriminate the progenitors solely using the Fe K-shell X-ray spectrum. We systematically analyzed Suzaku and Chandra observations of young ejecta-dominated SNRs to determine the intensity and centroid of the Fe-K emission lines. We found that the Fe ejecta in Type Ia SNRs are commonly less ionized than those in core-collapse SNRs. It was found, moreover, that luminosity and centroid of the Fe-K emission are well correlated among each group of Type Ia or core-collapse remnants, and that the more luminous remnants tend to be more highly ionized. These results may reflect the pre-explosion density of the remnants. Evidence of overionization was observed only in core-collapse SNRs, implying their origin to be related to interaction with stellar wind material. Our method can potentially be utilized in systematic studies of extragalactic SNRs with future missions, such as AXSIO, that have high-resolution imaging and spectroscopic capabilities. This will help study, for example, the supernova rate in different ISM environments.
- Publication:
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AAS/High Energy Astrophysics Division #13
- Pub Date:
- April 2013
- Bibcode:
- 2013HEAD...1340008Y