Tidal Deformabilities and Radii of Neutron Stars from the Observation of GW170817

Understand

We use gravitational-wave observations of the binary neutron star merger GW170817 to explore the tidal deformabilities and radii of neutron stars.

• We perform Bayesian parameter estimation with the source location and distance informed by electromagnetic observations.
• We also assume that the two stars have the same equation of state; we demonstrate that for stars with masses comparable to the component masses of GW170817, this is effectively implemented by assuming that the stars' dimensionless tidal deformabilities are determined by the binary's mass ratio $q$ by $\Lambda_1/\Lambda_2 = q^6$.
• We investigate different choices of prior on the component masses of the neutron stars.