Discovery of the nearby long, soft GRB 100316D with an associated
  supernova
  We report the Swift discovery of nearby long, soft gamma-ray burst GRB
100316D, and the subsequent unveiling of its low redshift host galaxy and
associated supernova. We derive the redshift of the event to be z = 0.0591 +/-
0.0001 and provide accurate astrometry for the GRB-SN. We study the extremely
unusual prompt emission with time-resolved gamma-ray to X-ray spectroscopy, and
find that the spectrum is best modelled with a thermal component in addition to
a synchrotron emission component with a low peak energy. The X-ray light curve
has a remarkably shallow decay out to at least 800 s. The host is a bright,
blue galaxy with a highly disturbed morphology and we use Gemini South, VLT and
HST observations to measure some of the basic host galaxy properties. We
compare and contrast the X-ray emission and host galaxy of GRB 100316D to a
subsample of GRB-SNe. GRB 100316D is unlike the majority of GRB-SNe in its
X-ray evolution, but resembles rather GRB 060218, and we find that these two
events have remarkably similar high energy prompt emission properties.
Comparison of the host galaxies of GRB-SNe demonstrates, however, that there is
a great diversity in the environments in which GRB-SNe can be found. GRB
100316D is an important addition to the currently sparse sample of
spectroscopically confirmed GRB-SNe, from which a better understanding of long
GRB progenitors and the GRB--SN connection can be gleaned.
