Thermal X‐Ray Emission from Shocked Ejecta in Type Ia Supernova Remnants. II. Parameters Affecting the Spectrum

The supernova remnants left behind by Type Ia supernovae provide an excellentopportunity for the study of these enigmatic objects. In a previous work, weshowed that it is possible to use the X-ray spectra of young Type Ia supernovaremnants to explore the physics of Type Ia supernovae and identify the relevantmechanism underlying these explosions. Our simulation technique is based onhydrodynamic and nonequilibrium ionization calculations of the interaction of agrid of Type Ia explosion models with the surrounding ambient medium, coupledto an X-ray spectral code. In this work we explore the influence of two keyparameters on the shape of the X-ray spectrum of the ejecta: the density of theambient medium around the supernova progenitor and the efficiency ofcollisionless electron heating at the reverse shock. We also discuss theperformance of recent 3D simulations of Type Ia SN explosions in the context ofthe X-ray spectra of young SNRs. We find a better agreement with theobservations for Type Ia supernova models with stratified ejecta than for 3Ddeflagration models with well mixed ejecta. We conclude that our grid of TypeIa supernova remnant models can improve our understanding of these objects andtheir relationship to the supernovae that originated them.Comment: Accepted for publication in Ap