A Late-time Radio Search for Highly Off-axis Jets from PTF Broad-lined Ic Supernovae in GRB-like Host Galaxy Environments

Abstract

Hydrogen/Helium-poor stripped-envelope core-collapse supernovae with broad lines (SNe Ic-bl) almost always accompany the nearby ($z<0.3$) jetted relativistic explosions known as long duration gamma-ray bursts (GRBs). However, the majority of SNe Ic-bl have no detected GRB counterpart. At least some of these SNe should harbor off-axis jets, whose afterglow may become detectable at late times, particularly at radio wavelengths. Here, we present Karl G. Jansky Very Large Array radio observations (rest frame times of $\sim 3$-$4\times 10^3$ days post SN discovery) of a sample of 14 SNe Ic-bl discovered by the Palomar Transient Factory (PTF) that have been demonstrated to originate from the same host environments as the SNe Ic-bl associated with nearby GRBs. Of the 14 SNe, we identify three that are radio detected, one of which (PTF10tqv, $z=0.0795$) is consistent with an off-axis jet with energy similar to classical GRBs ($\sim 10^{51}$-$10^{51.7}$erg). Using recently developed synchrotron radiation code, we find that for our 11 non-detections, which are among the deepest limits obtained for Ic-bl, we rule out an off-axis jet with an energy of $\gtrsim 10^{51}\mathrm{erg}$ in circumburst densities of $\gtrsim 10^{-1}{\mathrm{cm}}^{-3}$. We predict that well-spaced monitoring of newly discovered SNe Ic-bl from $\sim 10$days to $\sim 10$years (rest frame) to luminosities of $\sim 10^{27}{\mathrm{erg}\mathrm{s}}^{-1}{\mathrm{Hz}}^{-1}$ will constrain the existence of highly off-axis jets ($\gtrsim 60^{\circ }$) with classical GRB energies. The VLA Sky Survey will probe jets that are $\lesssim 60^{\circ }$ off-axis, whereas the Deep Synpotic Array 2000 will probe jets out to $\sim 90^{\circ }$ off-axis, demonstrating the importance of utilizing radio surveys to supplement targeted observations.

20 pages, 8 figures, accepted