On the use of galaxy catalogs in gravitational-wave parameter estimation

TL;DR

This paper explores incorporating galaxy catalog data into gravitational-wave event localization, demonstrating potential benefits for real events but limited improvements in simulations, highlighting the need for advanced sampling techniques.

Contribution

It evaluates a method to include galaxy catalog information in gravitational-wave parameter estimation, showing its effectiveness on real events and identifying areas for methodological improvements.

Findings

Successfully identified the true host galaxy for GW170817 with decreased localization area.

No significant improvement observed in simulated binary neutron star mergers.

Future sampling methods may enhance the method's effectiveness.

Abstract

A major challenge in gravitational-wave multi-messenger astrophysics is the imprecise localization of gravitational-wave compact binary mergers. We investigate the use of a method to include galaxy catalog information in performing parameter estimation of these events. We test its effectiveness with the gravitational-wave events GW170817, GW190425, and GW190814, as well as with simulated binary neutron star mergers. For GW170817, we recover the true host galaxy as the most probable galaxy after a straightforward mass reweighting, with significantly decreased localization area and volume. On the simulated sample, however, we do not find improvement compared to performing a simple galaxy catalog crossmatch with a regular gravitational wave localization. Future investigations into sampling methods may yield improvements that increase the viability of this method.