Constraints on Compact Binary Formation and Effective Gravitational Wave Likelihood Approximation

TL;DR

This paper develops a method to analyze the formation of compact binaries through isolated binary evolution, comparing synthetic predictions with observed gravitational-wave data to improve understanding of their astrophysical parameters.

Contribution

It introduces an efficient multi-dimensional likelihood analysis method for constraining binary formation parameters from gravitational-wave observations.

Findings

Consistent models with high stellar mass and angular momentum loss.

Demonstrated benefits of multi-parameter analysis for formation channels.

Identified potential biases in binary evolution modeling.

Abstract

Since the initial discovery of gravitational-waves from merging black holes, the LIGO Scientific Collaboration together with Virgo and KAGRA have published 90 gravitational-wave observations of compact binary mergers in the Gravitational-Wave Transient Catalog papers. In this work, we carry out an investigation of isolated binary evolution formation channel, comparing predictions of the gravitational-wave population from the StarTrack synthetic universe simulations to the observed population. We construct, apply, and provide parametric and non-parametric models for the likelihood function of the full set of astrophysical parameters of each event in the Gravitational-Wave Transient Catalogs, including truncated multivariate normal distributions normalized on a bounded interval, demonstrated in our prior work. We present our findings for the formation parameters for the isolated binary evolution formation channel for compact objects. Our preliminary results demonstrate the benefits of a multi-dimensional analysis which is sensitive to the interdependence of the predicted detection population on many formation parameters. Our essential contribution is therefore a method for carrying out such an analysis efficiently. We discuss potential sources of bias as we also present the properties of our best binary evolution models, which are consistent with unrestricted stellar mass loss due to winds, high mass and angular momentum loss to ejected portions of a common envelope, and substantial black hole supernova recoil kicks. We conclude with a discussion of the impact of these activities for gravitational-wave and multi-messenger astronomy.