Measuring Neutron Star Radii with Gravitational Wave Detectors

Coalescing binary neutron stars (NS) are expected to be an important source of gravitational waves (GW) detectable by laser interferometers. We present here a simple method for determining the compactness ratio M/R of NS based on the observed deviation of the GW energy spectrum from point-mass behavior at the end of an inspiral event. Our method is based on the properties of quasi-equilibrium binary NS sequences and does not require the computation of the full GW signal h(t). Combined with the measurement of the NS masses from the GW signal during inspiral, the determination of M/R will allow very strong constraints to be placed on the equation of state of nuclear matter at high densities.