Joint Electromagnetic and Gravitational Wave Inference of Binary Neutron Star Merger GW170817 Using Forward-Modeling Ejecta Predictions

Neutron star mergers serve as astrophysical laboratories for studying nuclear matter in the most extreme temperature and density regimes. These mergers emit gravitational radiation up to and shortly after merger and electromagnetic radiation on timescale of days to weeks post-merger. By studying both types of radiation, we are able to place stronger constraints on the pre-merger binary parameters and the post-merger ejecta parameters which describe the subsequent electromagnetic radiation. We present a joint electromagnetic and gravitational wave inference for binary neutron star merger GW170817 and its associated kilonova AT2017gfo. In this talk, I will discuss how different assumptions for the mass ejected from these mergers, calculated as a function of the binary parameters, manifest in the resultant posterior distributions for these parameters.