Prospect of Studying Hard X- and Gamma-Rays from Type Ia Supernovae

TL;DR

This study uses multi-dimensional radiation transfer simulations to evaluate the detectability of hard X-ray and gamma-ray emissions from Type Ia supernovae, predicting future observatories' capabilities to observe these signals and constrain explosion models.

Contribution

It provides the first detailed predictions of gamma-ray and X-ray signals from Type Ia supernovae for current and upcoming observatories, enhancing understanding of supernova explosion mechanisms.

Findings

Current gamma-ray non-detection limits 56Ni mass to a0a0 1.0 Msun.

NuStar and ASTRO-H can detect SNe Ia up to 15-25 Mpc.

Next-generation missions like GRIPS could observe SNe Ia up to 35 Mpc.

Abstract

We perform multi-dimensional, time-dependent radiation transfer simulations for hard X-ray and gamma-ray emissions, following radioactive decays of 56Ni and 56Co, for two-dimensional delayed detonation models of Type Ia supernovae (SNe Ia). The synthetic spectra and light curves are compared with the sensitivities of current and future observatories for an exposure time of 10^6 seconds. The non-detection of the gamma-ray signal from SN 2011fe at 6.4 Mpc by SPI on board INTEGRAL places an upper limit for the mass of 56Ni of \lesssim 1.0 Msun, independently from observations in any other wavelengths. Signals from the newly formed radioactive species have not been convincingly measured yet from any SN Ia, but the future X-ray and gamma-ray missions are expected to deepen the observable horizon to provide the high energy emission data for a significant SN Ia sample. We predict that the hard X-ray detectors on board NuStar (launched in 2012) or ASTRO-H (scheduled for launch in 2014) will reach to SNe Ia at \sim15 Mpc, i.e., one SN every few years. Furthermore, according to the present results, the soft gamma-ray detector on board ASTRO-H will be able to detect the 158 keV line emission up to \sim25 Mpc, i.e., a few SNe Ia per year. Proposed next generation gamma-ray missions, e.g., GRIPS, could reach to SNe Ia at \sim20 - 35 Mpc by MeV observations. Those would provide new diagnostics and strong constraints on explosion models, detecting rather directly the main energy source of supernova light.