Enhancing gravitational wave astronomy with galaxy catalogues

TL;DR

This paper presents a Bayesian method leveraging galaxy catalogues to improve sky localization and inclination angle estimates in joint gravitational wave and electromagnetic observations, enhancing multi-messenger astronomy.

Contribution

It introduces a novel Bayesian framework that incorporates galaxy catalogues to refine source localization and inclination estimates in GW-EM multi-messenger observations.

Findings

Galaxy catalogue information reduces sky localization area.

Inclination angle estimation improves with galaxy data.

Top candidate galaxies have high posterior probabilities.

Abstract

Joint gravitational wave (GW) and electromagnetic (EM) observations, as a key research direction in multi-messenger astronomy, will provide deep insight into the astrophysics of a vast range of astronomical phenomena. Uncertainties in the source sky location estimate from gravitational wave observations mean follow-up observatories must scan large portions of the sky for a potential companion signal. A general frame of joint GW-EM observations is presented by a multi-messenger observational triangle. Using a Bayesian approach to multi-messenger astronomy, we investigate the use of galaxy catalogue and host galaxy information to reduce the sky region over which follow-up observatories must scan, as well as study its use for improving the inclination angle estimates for coalescing binary compact objects. We demonstrate our method using a simulated neutron stars inspiral signal injected into simulated Advanced detectors noise and estimate the injected signal sky location and inclination angle using the Gravitational Wave Galaxy Catalogue. In this case study, the top three candidates in rank have $72\%$, $15\%$ and $8\%$ posterior probability of being the host galaxy, receptively. The standard deviation of cosine inclination angle (0.001) of the neutron stars binary using gravitational wave-galaxy information is much smaller than that (0.02) using only gravitational wave posterior samples.