Predictions for the rates of compact binary coalescences observable by ground-based gravitational-wave detectors

TLDR

Astrophysical estimates of compact‑binary coalescence rates remain uncertain due to unknown model parameters and assumptions. This work provides an up‑to‑date, comprehensive summary of the rates for all types of compact binary coalescence sources detectable by LIGO and Virgo. The authors convert these astrophysical coalescence rates into expected detection rates using data from the LIGO S5 and Virgo VSR2 science runs and projected sensitivities of the Advanced detectors. They estimate a binary neutron‑star coalescence rate of about 100 per Myr per Milky Way Equivalent Galaxy (range 1–1000) and predict detection rates of 0.02 per year for Initial LIGO‑Virgo (0.0002–0.2) and 40 per year for Advanced LIGO‑Virgo (0.4–400).

Abstract

We present an up-to-date, comprehensive summary of the rates for all types of compact binary coalescence sources detectable by the Initial and Advanced versions of the ground-based gravitational-wave detectors LIGO and Virgo. Astrophysical estimates for compact-binary coalescence rates depend on a number of assumptions and unknown model parameters, and are still uncertain. The most confident among these estimates are the rate predictions for coalescing binary neutron stars which are based on extrapolations from observed binary pulsars in our Galaxy. These yield a likely coalescence rate of 100 per Myr per Milky Way Equivalent Galaxy (MWEG), although the rate could plausibly range from 1 per Myr per MWEG to 1000 per Myr per MWEG. We convert coalescence rates into detection rates based on data from the LIGO S5 and Virgo VSR2 science runs and projected sensitivities for our Advanced detectors. Using the detector sensitivities derived from these data, we find a likely detection rate of 0.02 per year for Initial LIGO-Virgo interferometers, with a plausible range between 0.0002 and 0.2 per year. The likely binary neutron-star detection rate for the Advanced LIGO-Virgo network increases to 40 events per year, with a range between 0.4 and 400 per year.