Optimising gravitational waves follow-up using galaxies stellar mass

TL;DR

This paper introduces a new galaxy-targeting strategy for gravitational wave follow-up that prioritizes galaxies by stellar mass, improving the identification of host galaxies in electromagnetic observations.

Contribution

The paper develops a novel galaxy ranking method combining 3D localization and stellar mass, demonstrated with GW170817, and provides a publicly available catalog and ranking tool.

Findings

NGC4993 ranked first for GW170817 using the new method

Crossmatched GLADE and AllWISE catalogs with 93% efficiency

Stellar mass-based ranking improves follow-up targeting

Abstract

We present a new strategy to optimise the electromagnetic follow-up of gravitational wave triggers. This method is based on the widely used galaxy targeting approach where we add the stellar mass of galaxies in order to prioritise the more massive galaxies. We crossmatched the GLADE galaxy catalog with the AllWISE catalog up to 400Mpc with an efficiency of $\sim$93\%, and derived stellar masses using a stellar-to-mass ratio using the WISE1 band luminosity. We developed a new grade to rank galaxies combining their 3D localisation probability associated to the gravitational wave event with the new stellar mass information. The efficiency of this new approach is illustrated with the GW170817 event, which shows that its host galaxy, NGC4993, is ranked at the first place using this new method. The catalog, named Mangrove, is publicly available and the ranking of galaxies is automatically provided through a dedicated web site for each gravitational wave event.