Short Gamma-Ray Bursts and Gravitational Waves from Dynamically Formed Merging Binaries

TL;DR

This paper proposes a method to estimate gravitational wave event rates from merging binaries in globular clusters, linking short gamma-ray bursts to these events and analyzing their observational properties.

Contribution

It introduces a new approach to estimate GW event rates from dynamically formed binaries in globular clusters and connects SHBs with these mergers.

Findings

A significant fraction of SHBs occur at low redshifts.

The method constrains the luminosity function of SHBs.

Predicted GW event rate is enhanced by mergers in globular clusters.

Abstract

Merging binary systems consisting of two collapsed objects are among the most promising sources of high frequency gravitational wave, GW, signals for ground based interferometers. Double neutron star or black hole/neutron star mergers are also believed to give rise to short hard bursts, SHBs, a subclass of gamma ray bursts. SHBs might thus provide a powerful way to infer the merger rate of two-collapsed object binaries. Under the hypothesis that most SHBs originate from double neutron star or black hole/neutron star mergers, we outline here a method to estimate the incidence of merging events from dynamically formed binaries in globular clusters and infer the corresponding GW event rate that can be detected with Advanced LIGO/Virgo. In particular a sizeable fraction of detectable GW events is expected to be coincident with SHBs. The beaming and redshift distribution of SHBs are reassessed and their luminosity function constrained by using the results from recent SHBs observations. We confirm that a substantial fraction of SHBs goes off at low redshifts, where the merging of systems formed in globular clusters through dynamical interactions is expected.