X- and gamma-ray signatures of type Ia supernovae

In this paper, we investigate with a Monte Carlo code the hard X-ray continuum and γ-ray line emissions of various theoretical models of Type Ia supernova explosions. We describe the influence of the distributions of velocity, mass, ⁵⁶Ni, and heavy elements on the spectral and temporal evolution of the radiations, ultimately derived from the positrons and γ-ray lines of the ⁵⁶Ni → ⁵⁶Co → ⁵⁶Fe decay chain. We focus on the first 300-400 days of the explosion and derive the correspondence between the parameters of an explosion model and its hard photon signatures. The effect of mixing instabilities is also studied and estimates of the future detectability of the derived hard X- and γ-ray features are presented. We find that OSSE on the Gamma-Ray Observatory can detect both gamma-ray lines and the hard X-ray continuum from any Type Ia supernova within 10 Mpc of Earth.