Gravitational waves and neutrino emission from the merger of binary neutron stars

TL;DR

This paper presents the first full general relativity simulations of binary neutron star mergers with a finite-temperature EOS and neutrino cooling, revealing long-lived hypermassive neutron stars, their neutrino emissions, and gravitational wave signals.

Contribution

It introduces the first numerical simulations of neutron star mergers incorporating both a finite-temperature EOS and neutrino cooling in full general relativity.

Findings

Long-lived hypermassive neutron stars form for total mass below 3.0 solar masses.

Neutrino luminosity from HMNS is approximately 3-8 x 10^{53} ergs/s.

Gravitational wave amplitude is 4-6 x 10^{-22} at 2.1-2.5 kHz for 100 Mpc distance.

Abstract

Numerical simulations for the merger of binary neutron stars are performed in full general relativity incorporating a finite-temperature (Shen's) equation of state (EOS) and neutrino cooling for the first time. It is found that for this stiff EOS, a hypermassive neutron star (HMNS) with a long lifetime ($\gg 10$ ms) is the outcome for the total mass $\alt 3.0M_{\odot}$. It is shown that the typical total neutrino luminosity of the HMNS is $\sim 3$--$8\times 10^{53}$ ergs/s and the effective amplitude of gravitational waves from the HMNS is 4--$6 \times 10^{-22}$ at $f=2.1$--2.5 kHz for a source distance of 100 Mpc. We also present the neutrino luminosity curve when a black hole is formed for the first time.