SN 2013dx associated with GRB 130702A: A detailed photometric and spectroscopic monitoring and a study of the environment

Abstract

We aim at characterizing SN 2013dx, associated with GRB 130702A, and their environment, through ground-based observational campaigns in the optical-IR band. We infer a synthesized 56Ni mass of ∼0.2 M⊙, a photospheric velocity of the ejected material declining from ∼ 2.7 × 104 km s-1 at 8 rest frame days from the explosion, to ∼ 3.5× 103 km s-1 at 40 days, a kinetic energy of ∼ 35 × 1051 erg, an ejected mass of ∼ 7 M⊙ and a progenitor mass of ∼ 25-30 M⊙. We also find that the host belongs to a group of galaxies, an unprecedented finding for a GRB-associated SN and, to our knowledge, for long GRBs in general.