Population of Merging Compact Binaries Inferred Using Gravitational Waves through GWTC-3
Journal Articles
Overview
Research
Identity
Additional Document Info
View All
Overview
abstract
We report on the population properties of compact binary mergers inferred
from gravitational-wave observations of these systems during the first three
LIGO-Virgo observing runs. The Gravitational-Wave Transient Catalog 3 contains
signals consistent with three classes of binary mergers: binary black hole,
binary neutron star, and neutron star-black hole mergers. We infer the binary
neutron star merger rate to be between 10 and 1700 Gpc$^{-3} yr$^{-1}$ and the
neutron star-black hole merger rate to be between 7.8 and 140 Gpc$^{-3}
yr$^{-1}$, assuming a constant rate density in the comoving frame and taking
the union of 90% credible intervals for methods used in this work. We infer the
binary black hole merger rate, allowing for evolution with redshift, to be
between 17.9 and 44 Gpc$^{-3}$ yr$^{-1}$ at a fiducial redshift (z=0.2). The
rate of binary black hole mergers is observed to increase with redshift at a
rate proportional to $(1+z)^\kappa$ with $\kappa=2.9^{+1.7}_{-1.8}$ for
$z\lesssim1$. Using both binary neutron star and neutron star-black hole
binaries, we obtain a broad, relatively flat neutron star mass distribution
extending from $1.2^{+0.1}_{-0.2}$ to $2.0^{+0.3}_{-0.3}\,M_\odot$. We
confidently determine that the merger rate as a function of mass sharply
declines after the expected maximum neutron star mass, but cannot yet confirm
or rule out the existence of a lower mass gap between neutron stars and black
holes. We also find the binary black hole mass distribution has localized over-
and underdensities relative to a power-law distribution, with peaks emerging at
chirp masses of $8.3^{+0.3}_{-0.5}$ and $27.9^{+1.9}_{-1.8}\,M_\odot$. While we
continue to find that the mass distribution of a binary's more massive
component strongly decreases as a function of primary mass, we observe no
evidence of a strongly suppressed merger rate above approximately $60\,M_\odot$
[abridged]
