A search for kilonova radio flares in a sample of Swift/BAT short GRBs

Following the discovery of the remarkable binary neutron star merger GW170817 by the LIGO and Virgo collaborations, much research has been conducted to uncover the nature of its post-merger remnant. GW170817 was accompanied by a gamma-ray burst (GRB), an optical kilonova, and a radio-to-X-ray-emitting structured jet. Several theoretical scenarios predict that, once the jet emission fades sufficiently, the kilonova ejecta itself may power a late-time radio flare associated with the fastest ejecta tail. This late-time radio emission can reveal important information on the nature of the post-merger remnant (neutron star versus black hole) and can be used as a tool to find nearby, GW170817-like neutron star mergers years after they have occurred. In this context, I will present the results, now published in ApJ, of an observing campaign carried out with the Jansky VLA aimed at determining whether short GRBs in the Swift/BAT sample lacking accurate localization, ones with no detected afterglow, could have originated from events like GW170817.