A Late-Time Galaxy-Targeted Search for the Radio Counterpart of GW190814

Understand

GW190814 was a compact object binary coalescence detected in gravitational waves by Advanced LIGO and Advanced Virgo that garnered exceptional community interest due to its excellent localization and the uncertain nature of the binary's lighter-mass component (either the heaviest known neutron star, or the lightest known black hole).

• Despite extensive follow up observations, no electromagnetic counterpart has been identified.
• Here we present new radio observations of 75 galaxies within the localization volume at $\Delta t\approx 35-266$ days post-merger.
• Our observations cover $\sim32$% of the total stellar luminosity in the final localization volume and extend to later timescales than previously-reported searches, allowing us to place the deepest constraints to date on the existence of a radio afterglow from a highly off-axis relativistic jet launched during the merger (assuming that the merger occurred within the observed area).