Optical and near-infrared observations of SN 2013dx associated with GRB 130702A

We present optical and near-infrared (NIR) light curves and optical spectra of SN 2013dx, associated with the nearby (redshift 0.145) gamma-ray burst GRB 130702A. The prompt isotropic gamma-ray energy released from GRB 130702A is measured to be E_(yiso)=6.4_(-1.0)^(+1.3) x 10^(50) erg (1 keV to 10 MeV in the rest frame), placing it intermediate between low-luminosity GRBs like GRB 980425/SN 1998bw and the broader cosmological population. We compare the observed g'r'i'z' light curves of SN 2013dx to a SN 1998bw template, finding that SN 2013dx evolves ~20% faster (steeper rise time), with a comparable peak luminosity. Spectroscopically, SN 2013dx resembles other broad-lined SNe Ic, both associated with (SN 2006aj and SN 1998bw) and lacking (SN 1997ef, SN 2007I, and SN 2010ah) gamma-ray emission, with photospheric velocities around peak of ~ 21,000 km s^(−1). We construct a quasi-bolometric g'r'i'z'yJ) light curve for SN 2013dx, only the fifth GRB-associated SN with extensive NIR coverage and the third with a bolometric light curve extending beyond Δt > 40 days. Together with the measured photospheric velocity, we derive basic explosion parameters using simple analytic models. We infer a ^(56)Ni mass of M_(Ni)= 0.37 ± 0.01 M_☉, an ejecta mass of M_(ej) = 3.1 ± 0.1 M_☉, and a kinetic energy of E_K = 8.2 ± 0.43 x 10^(51) erg (statistical uncertainties only), consistent with previous GRB-associated supernovae. When considering the ensemble population of GRB-associated supernovae, we find no correlation between the mass of synthesized 56Ni and high-energy properties, despite clear predictions from numerical simulations that M_(Ni) should correlate with the degree of asymmetry. On the other hand, M_(Ni) clearly correlates with the kinetic energy of the supernova ejecta across a wide range of core-collapse events.