Under the lens: black hole multi-messenger localization

by Laura Uronen (Chinese University of Hong Kong)

Tuesday 7 Jan 2025, 13:00 → 14:00 Europe/Brussels

Traditional lensing has been observed for well past a century now, with ever more stunning images of arced galaxies and duplicate supernovae from deeper and deeper parts of the Universe reaching our telescopes each year. Gravitational waves have, on their side, ushered in a new era of astronomy, and more importantly, a new brand of multi-messenger astronomy. Since both of these are natural consequences of Einstein’s theory of General Relativity, it is of course safe to assume that they go hand in hand. The proposed field of gravitational-wave lensing is, for now, still young and remains firmly planted in the theoretical domain for the moment. But it is only a question of time before a lensed gravitational wave is confirmed, and with it will come a swathe of multi-messenger science opportunities, and in particular open new multi-messenger applications in the case of dark binaries without a direct EM counterpart. This talk will aim to look at two burning questions of black hole physics: How do you find a black hole? And once found, what can we reveal about these elusive, extreme binaries? I will first present a brief overview of gravitational-wave lensing, specifically in the case of black holes, followed by the basics of dark binary multi-messenger localization and its applications. In particular, I will focus on two specific applications examining what these detections might tell us about black hole formation channels and source populations.