Speaker
Description
Identifying the electromagnetic counterparts to gravitational wave sources is vital to enabling the myriad of investigations possible with multi-messenger astronomy. However, locating faint, fast-varying transients in large sky localisations, given the intrinsic uncertainty in their detailed properties, is challenging. Here we investigate the expected gravitational wave localisations for a sample of merger-induced gamma-ray bursts within the horizon of gravitational-wave detectors during the observing run, O5 (2027+), and determine for which events counterparts could have been detected by various sky searches based only on the gravitational wave localisation (e.g., assuming no additional location constraints from gamma-ray detections). We do this by constructing synthetic skymaps for each event, assuming they arise from either a binary neutron star or a neutron star-black hole merger, and then simulating follow-up searches for these skymaps. Thereafter, by comparing the known counterpart brightness at the time different surveys would have observed, we assess which counterparts would have been detected by searches with the available instrumentation. We further discuss the challenges of correctly identifying these sources as their counterpart and how prospects may improve in observing run O5, thanks to both improved gravitational wave localisations and follow-up capabilities. We also make recommendations for future follow-up campaigns using the insights gained from this study.