Localizing gravitational wave sources with optical telescopes and combining electromagnetic and gravitational wave data

TL;DR

This paper explores how combining electromagnetic observations with gravitational wave data enhances source localization and parameter estimation for neutron star mergers, facilitating more effective multi-messenger astronomy.

Contribution

It introduces a framework for integrating EM and GW data to improve localization and analysis of neutron star binary events, with preliminary results from the BlackGEM telescope array.

Findings

EM data improves GW parameter estimation accuracy

GW localization aids EM follow-up strategies

BlackGEM array shows promise for optical follow-up of GW events

Abstract

Neutron star binaries, which are among the most promising sources for the direct detection of gravitational waves (GW) by ground based detectors, are also potential electromagnetic (EM) emitters. Gravitational waves will provide a new window to observe these events and hopefully give us glimpses of new astrophysics. In this paper, we discuss how EM information of these events can considerably improve GW parameter estimation both in terms of accuracy and computational power requirement. And then in return how GW sky localization can help EM astronomers in follow-up studies of sources which did not yield any prompt emission. We discuss how both EM source information and GW source localization can be used in a framework of multi-messenger astronomy. We illustrate how the large error regions in GW sky localizations can be handled in conducting optical astronomy in the advance detector era. We show some preliminary results in the context of an array of optical telescopes called BlackGEM, dedicated for optical follow-up of GW triggers, that is being constructed in La Silla, Chile and is expected to operate concurrent to the advanced GW detectors.