Gravitational-wave luminosity of binary neutron stars mergers

TL;DR

This paper analyzes the gravitational-wave luminosity and energy radiated by binary neutron star mergers using numerical simulations, revealing universal relations and constraints on remnant properties.

Contribution

It provides a comprehensive empirical analysis of gravitational-wave emission in neutron star mergers, establishing universal relations and constraints on remnant characteristics.

Findings

Peak luminosity depends on mass ratio and tidal parameters.

Prompt collapse yields highest peak luminosity.

Mergers forming neutron star remnants radiate most energy per unit mass.

Abstract

We study the gravitational-wave peak luminosity and radiated energy of quasicircular neutron star mergers using a large sample of numerical relativity simulations with different binary parameters and input physics. The peak luminosity for all the binaries can be described in terms of the mass ratio and of the leading-order post-Newtonian tidal parameter solely. The mergers resulting in a prompt collapse to black hole have largest peak luminosities. However, the largest amount of energy per unit mass is radiated by mergers that produce a hypermassive neutron star or a massive neutron star remnant. We quantify the gravitational-wave luminosity of binary neutron star merger events, and set upper limits on the radiated energy and the remnant angular momentum from these events. We find that there is an empirical universal relation connecting the total gravitational radiation and the angular momentum of the remnant. Our results constrain the final spin of the remnant black-hole and also indicate that stable neutron star remnant forms with super-Keplerian angular momentum.