Gravitational-Wave Research Seminar

The binary neutron star (BNS) merger GW170817 was accompanied by radiation across the EM spectrum. The thermal kilonova emission, which arose from the r-process nucleosynthesis and lasted for a few weeks post-merger, gave insight into the mass and composition of the Newtonian ejecta. The non-thermal afterglow emission, which was monitored extensively at radio wavelengths and lasted for almost two years, probed the energetics and morphology of the relativistic ejecta. Importantly, radio VLBI observations of GW170817 revealed superluminal motion of a compact radio source. These observational data, together with state-of-the-art hydrodynamical simulations, gave credence to an energetic and narrowly-collimated jet, provided a direct observational link between BNS mergers and short GRBs, and facilitated a precise measurement of the Hubble's constant (through the "standard siren" technique). Although a unique event, GW170817 represents only an initial exploration of a rich scientific landscape. In the final part of my talk, I will discuss how the EM counterparts of future LIGO/Virgo GW events (BNS and NSBH mergers) will further our understanding of binary stellar evolution, physics of jet launching, r-process chemical enrichment and NS equation of state.