The MUSE view of the host galaxy of GRB 100316D

: Izzo L, Thone CC, Schulze S, Mehner A, Flores H, Cano Z, Postigo AD, Kann DA, Amorin R, Anderson JP, Bauer FE, Bensch K, Christensen L, Covino S, Della Valle M, Fynbo JPU, Jakobsson P, Klose S, Kuncarayakti H, Leloudas G, Milvang-Jensen B, Moller P, Puech M, Rossi A, Sanchez-Ramirez R, Vergani SD

Publisher: OXFORD UNIV PRESS

: 2017

: Monthly Notices of the Royal Astronomical Society

: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

: MON NOT R ASTRON SOC

: 472

: 4

: 4480

: 4496

: 17

: 0035-8711

: 1365-2966

DOI: https://doi.org/10.1093/mnras/stx2244

The low distance, z = 0.0591, of GRB 100316D and its association with SN 2010bh represent two important motivations for studying this host galaxy and the GRB's immediate environment with the integral field spectrographs like Very Large Telescope/Multi-Unit Spectroscopic Explorer. Its large field of view allows us to create 2D maps of gas metallicity, ionization level and the star formation rate (SFR) distribution maps, as well as to investigate the presence of possible host companions. The host is a late-type dwarf irregular galaxy with multiple star-forming regions and an extended central region with signatures of on-going shock interactions. The gamma-ray burst (GRB) site is characterized by the lowest metallicity, the highest SFR and the youngest (similar to 20-30 Myr) stellar population in the galaxy, which suggest a GRB progenitor stellar population with masses up to 20-40 M-circle dot. We note that the GRB site has an offset of similar to 660 pc from the most luminous SF region in the host. The observed SF activity in this galaxy may have been triggered by a relatively recent gravitational encounter between the host and a small undetected (L-H alpha <= 10(36) erg s(-1)) companion.