Distinguishing types of compact-object binaries using the gravitational-wave signatures of their mergers

TL;DR

This paper evaluates how well gravitational-wave signals from different types of compact-object binaries can be distinguished, demonstrating that with enough detections, three subpopulations can be accurately identified and their rates measured.

Contribution

It provides a detailed analysis of the distinguishability of binary neutron stars, neutron-star black-hole binaries, and binary black holes using gravitational-wave data, including population predictions and measurement estimates.

Findings

Binary neutron stars and black-hole--neutron-star binaries can be distinguished.

With a few tens of detections, all three subpopulations can be identified.

Respective merger rates can be accurately measured.

Abstract

We analyze the distinguishability of populations of coalescing binary neutron stars, neutron-star black-hole binaries, and binary black holes, whose gravitational-wave signatures are expected to be observed by the advanced network of ground-based interferometers LIGO and Virgo. We consider population-synthesis predictions for plausible merging binary distributions in mass space, along with measurement accuracy estimates from the main gravitational-wave parameter-estimation pipeline. We find that for our model compact-object binary mass distribution, we can always distinguish binary neutron stars and black-hole--neutron-star binaries, but not necessarily black-hole--neutron-star binaries and binary black holes; however, with a few tens of detections, we can accurately identify the three subpopulations and measure their respective rates.