The combined detection of a binary neutron-star merger in both gravitational waves (GWs) and electromagnetic (EM) radiation spanning the entire spectrum -- GW170817 / AT2017gfo / GRB170817A -- marks a breakthrough in the field of multi-messenger astronomy. Between the plethora of modeling and observations, the rich synergy that exists among the available data sets creates a unique opportunity to constrain the binary parameters, the equation of state of supranuclear density matter, and the physical processes at work during the kilonova and gamma-ray burst. We report, for the first time, Bayesian parameter estimation combining information from GW170817, AT2017gfo, GRB170817 to obtain truly multi-messenger constraints on the tidal deformability Λ~∈[302,860], total binary mass M∈[2.722,2.751]M⊙, the radius of a 1.4 solar mass neutron star R∈[11.3,13.5]km (with additional 0.2km systematic uncertainty), and an upper bound on the mass ratio of q≤1.27, all at 90% confidence. Our joint novel analysis makes use of new phenomenological descriptions of the dynamical ejecta, debris disk mass, and remnant black hole properties, all derived from a large suite of numerical relativity simulations.
@article{arxiv.1812.04803,
title = {Multi-messenger Bayesian parameter inference of a binary neutron-star merger},
author = {Michael W. Coughlin and Tim Dietrich and Ben Margalit and Brian D. Metzger},
journal= {arXiv preprint arXiv:1812.04803},
year = {2021}
}