Gamma rays from a supernova of type Ia: SN2014J

TL;DR

This paper reports on gamma-ray observations of the nearby Type Ia supernova SN2014J, providing new insights into the radioactive decay processes powering the supernova's light and evolution.

Contribution

It presents the first gamma-ray measurements of SN2014J, offering novel observational data on radioactive decay in a Type Ia supernova.

Findings

Detection of gamma-ray lines from $^{56}$Ni decay

Measurement of gamma-ray line evolution over 5 months

Implications for supernova explosion models

Abstract

SN2014J is the closest supernova of type Ia that occured in the last 40 years. This provides an opportunity for unprecedented observational detail and coverage in many astronomical bands, which will help to better understand the still unknown astrophysics of these supernovae. For the first time, such an event occurs sufficiently nearby so that also gamma rays are able to contribute to such investigations. This is important, as the primary source of the supernova light is the radioactive energy from about 0.5 M$_\odot$ of $^{56}$Ni produced in the explosion, and the gamma rays associated with this decay make the supernova shine for months. The INTEGRAL gamma-ray observatory of ESA has followed the supernova emission for almost 5 months. The characteristic gamma ray lines from the $^{56}$Ni decay chain through $^{56}$Co to $^{56}$Fe have been measured. We discuss these observations, and the implications of the measured gamma-ray line characteristics as they evolve.