Prospects for gravitational-wave observations of neutron-star tidal disruption in neutron-star/black-hole binaries

TL;DR

This paper estimates the gravitational-wave frequency at neutron-star tidal disruption in NS/BH binaries, suggesting LIGO-II could measure neutron star radii and inform the equation of state from tidal disruption signals.

Contribution

It models neutron-star tidal disruption using a Newtonian ellipsoid approach and predicts the potential for gravitational-wave observations to determine neutron star radii.

Findings

LIGO-II could measure neutron star radius R to 15% accuracy at 140 Mpc.

The tidal disruption frequency f_td depends strongly on R.

Potential to extract neutron star equation of state information from gravitational waves.

Abstract

For an inspiraling neutron-star/black-hole binary (NS/BH), we estimate the gravity-wave frequency f_td at the onset of NS tidal disruption. We model the NS as a tidally distorted, homogeneous, Newtonian ellipsoid on a circular, equatorial geodesic around a Kerr BH. We find that f_td depends strongly on the NS radius R, and estimate that LIGO-II (ca. 2006-2008) might measure R to 15% precision at 140 Mpc (about 1 event/yr under current estimates). This suggests that LIGO-II might extract valuable information about the NS equation of state from tidal-disruption waves.