In this paper we use recent X-ray and radio observations of the ejecta-rich Galactic supernova remnant ( SNR ) G337.2 - 0.7 to determine properties of the supernova ( SN ) explosion that formed this source .
H i absorption measurements from the Australia Telescope Compact Array ( ATCA ) constrain the distance to G337.2 - 0.7 to lie between 2.0 \pm 0.5 and 9.3 \pm 0.3 kpc .
Combined with a clear radio image of the outer blast-wave , this distance allows us to estimate the dynamical age ( between 750 and 3500 years ) from the global X-ray spectrum obtained with the XMM - Newton and Chandra observatories .
The presence of ejecta is confirmed by the pattern of fitted relative abundances , which show Mg , Ar and Fe to be less enriched ( compared to solar ) than Si , S or Ca , and the ratio of Ca to Si to be 3.4 \pm 0.8 times the solar value ( under the assumption of a single electron temperature and single ionization timescale ) .
With the addition of a solar abundance component for emission from the blast-wave , these abundances ( with the exception of Fe ) resemble the ejecta of a Type Ia , rather than core-collapse , SN .
Comparing directly to models of the ejecta and blast-wave X-ray emission calculated by evolving realistic SN Ia explosions to the remnant stage allows us to deduce that one-dimensional delayed detonation and pulsed delayed detonation models can indeed reproduce the major features of the global spectrum .
In particular , stratification of the ejecta , with the Fe shocked most recently , is required to explain the lack of prominent Fe-K emission .