Abstract
X-ray spectra from the JAXA satellite Suzaku showed supernova remnant (SNR) 3C 397 to be rich in iron- group elements (IGEs), including iron, nickel, manganese, and chromium. Comparisons of the measured global abundances of these iron group elements against those obtained from numerical simulations indicated that the remnant is very likely to be the product of a near-Chandrasekhar-mass (near-MCh) type Ia supernova (SN Ia) explosion. In a recent follow-up observation from the ESA satellite XMM-Newton, clumps of neutron-rich isotopes such as chromium and titanium were discovered in the outer regions of the ejecta. To probe the detonation mechanism and progenitor of 3C 397 in more detail using the recent XMM-Newton data, we created hydrodynamical models, varying the central density and composition of the progenitor white dwarf, and the detonation mechanism. From our suite of models, a high central density model with pure deflagration shows a substantial amount of neutronizated mass in the ejecta with clumps rich in chromium, and a subluminous SN Ia event. In contrast, our high-density deflagration-to-detonation transition (DDT) model shows a homogeneous distribution of highly neutronized yields in the ejecta, and produces a normal brightness SN Ia. In this research I am presenting the implications of these findings both for the progenitor and explosion mechanism of 3C 397, as well as the for the broader class of SNe Ia.