Discovery of a gamma-ray burst with an associated supernova

TL;DR

This paper reports the discovery of a nearby long gamma-ray burst with an associated supernova, analyzing its unusual prompt emission and host galaxy properties to enhance understanding of GRB progenitors.

Contribution

It presents the first detailed analysis of GRB 100316D and its supernova, including spectral features, host galaxy characteristics, and comparison with previous GRB-SN cases.

Findings

Detection of thermal component in prompt emission

Host galaxy is bright, blue, and disturbed

GRB 100316D adds to the limited sample of spectroscopically confirmed GRB-SNe

Abstract

We report the discovery of the nearby long, soft GRB 100316D, and the subsequent unveiling of its host galaxy and associated supernova. We study the extremely unusual prompt emission with time-resolved gamma-ray to X-ray spectroscopy and find that a thermal component in addition to the synchrotron spectrum is required. The host galaxy is a bright, blue galaxy with a highly disturbed morphology. From optical photometry and spectroscopy we provide an accurate astrometry and redshift, and derive the key host properties of star formation rate and stellar age. We compare our findings for this GRB-SN with the well known previous case of GRB 060218. GRB 100316D is an important addition to the current sparse sample of spectroscopically confirmed GRB-SNe, from which a better understanding of long GRB progenitors and the GRB-SN connection can be gleaned.