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 \tilde { \Lambda } \in [ 302 , 860 ] , total binary mass M \in [ 2.722 , 2.751 ] M _ { \odot } , the radius of a 1.4 solar mass neutron star R \in [ 11.3 , 13.5 ] km ( with additional 0.2 km systematic uncertainty ) , and an upper bound on the mass ratio of q \leq 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 .