Electromagnetic Counterparts to Gravitational Wave Sources

Speaker:

Charlie Kilpatrick, postdoctoral scholar, University of California Santa Clara

Description:

On August 17, 2017, the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo detected a gravitational wave signal, GW170817, from a binary neutron star merger. 11 hours later, my team, the One-Meter Two-Hemispheres (1M2H) collaboration, used the 1-m Swope telescope at Las Campanas Observatory in Chile to discover that event's optical counterpart, a kilonova powered by the radioactive decay of r-process species synthesized in the merger. In this talk, I will describe the planning and search strategies that led to this discovery as well as our continuing analysis of SSS17a. I will describe new constraints on the synthesis of the heaviest, so-called third peak r- process species in the kilonova, implying neutron star mergers are the source of most lanthanides and actinides in the Universe. Finally, LIGO and Virgo have been conducting their third observing run (O3) since April, 2019, with several new neutron star mergers reported. I will describe new techniques used by the 1M2H collaboration to quickly discover candidate counterparts and identify their nature. Although no new electromagnetic counterparts have been verified, limits from the non-detection of counterparts place strong constraints on the total energy and ejecta mass in neutron star mergers.