Accuracy of inference on the physics of binary evolution from gravitational-wave observations

TL;DR

This paper assesses how gravitational-wave observations of merging binary black holes can precisely constrain uncertain aspects of massive star binary evolution physics, using Fisher analysis on simulated populations.

Contribution

It demonstrates that gravitational-wave data can significantly narrow down key binary evolution parameters with about 1000 observations, providing new insights into stellar physics.

Findings

1000 observations constrain model parameters to a few percent

Gravitational-wave data can strongly constrain stellar evolution physics

Rapid binary population synthesis effectively models the black hole population

Abstract

The properties of the population of merging binary black holes encode some of the uncertain physics of the evolution of massive stars in binaries. The binary black hole merger rate and chirp mass distribution are being measured by ground-based gravitational-wave detectors. We consider isolated binary evolution and explore how accurately the physical model can be constrained with such observations by applying the Fisher information matrix to the merging black hole population simulated with the rapid binary population synthesis code COMPAS. We investigate variations in four COMPAS parameters: common envelope efficiency, kick velocity dispersion, and mass loss rates during the luminous blue variable and Wolf--Rayet stellar evolutionary phases. We find that 1000 observations would constrain these model parameters to a fractional accuracy of a few percent. Given the empirically determined binary black hole merger rate, we can expect gravitational-wave observations alone to place strong constraints on the physics of stellar and binary evolution within a few years.