Can Ejecta‐dominated Supernova Remnants be Typed from Their X‐Ray Spectra? The Case of G337.2−0.7

In this paper we use recent X-ray and radio observations of the ejecta-richGalactic supernova remnant (SNR) G337.2-0.7 to determine properties of thesupernova (SN) explosion that formed this source. H I absorption measurementsfrom the Australia Telescope Compact Array (ATCA) constrain the distance toG337.2-0.7 to lie between 2.0 +/- 0.5 and 9.3 +/- 0.3 kpc. Combined with aclear radio image of the outer blast-wave, this distance allows us to estimatethe dynamical age (between 750 and 3500 years) from the global X-ray spectrumobtained with the XMM-Newton and Chandra observatories. The presence of ejectais confirmed by the pattern of fitted relative abundances, which show Mg, Arand Fe to be less enriched (compared to solar) than Si, S or Ca, and the ratioof Ca to Si to be 3.4 +/- 0.8 times the solar value (under the assumption of asingle electron temperature and single ionization timescale). With the additionof a solar abundance component for emission from the blast-wave, theseabundances (with the exception of Fe) resemble the ejecta of a Type Ia, ratherthan core-collapse, SN. Comparing directly to models of the ejecta andblast-wave X-ray emission calculated by evolving realistic SN Ia explosions tothe remnant stage allows us to deduce that one-dimensional delayed detonationand pulsed delayed detonation models can indeed reproduce the major features ofthe global spectrum. In particular, stratification of the ejecta, with the Feshocked most recently, is required to explain the lack of prominent Fe-Kemission.Comment: 21 pages emulateapj including 9 figures, 5 tables, accepted for publication in the Astrophysical Journa