Concurrent estimation of noise and compact-binary signal parameters in gravitational-wave data

TL;DR

This paper introduces a method to jointly estimate noise and binary parameters in gravitational-wave data, reducing bias from assuming perfect knowledge of noise properties, and finds current noise uncertainties are minor.

Contribution

It presents a novel joint estimation approach that marginalizes over noise uncertainties, improving parameter inference accuracy in gravitational-wave analysis.

Findings

Joint estimation agrees with traditional methods within measurement uncertainties.

Uncertainty in noise spectral density is subdominant at current sensitivities.

The method enables more robust parameter estimation by accounting for noise variability.

Abstract

Gravitational-wave parameter estimation for compact binary signals typically relies on sequential estimation of the properties of the detector Gaussian noise and of the binary parameters. This procedure assumes that the noise variance, expressed through its power spectral density, is perfectly known in advance. We assess the impact of this approximation on the estimated parameters by means of an analysis that simultaneously estimates the noise and compact binary parameters, thus allowing us to marginalize over uncertainty in the noise properties. We compare the traditional sequential estimation method and the new full marginalization method using events from the GWTC-3 catalog. We find that the recovered signals and inferred parameters agree to within their statistical measurement uncertainty. At current detector sensitivities, uncertainty about the noise power spectral density is a subdominant effect compared to other sources of uncertainty.