Vanderbilt University

 

Supermassive black holes (SMBHs) with mass of a million to ten billion times the mass of the sun reside in the center of most galaxies. Additionally, galaxies merge frequently to form bigger, more massive galaxies. This naturally leads to galaxies with two SMBHs, which progressively move to smaller and smaller separations and form gravitationally bound binaries. Even though supermassive black hole binaries (SMBHBs) should be common, they remain a missing piece in the puzzle of galaxy formation. SMBHBs can be detected from their bright electromagnetic (EM) emission, the brightness of which changes periodically, or from their strong emission of gravitational waves (GWs). I will describe recent EM searches for SMBHBs that have revealed ~150 promising candidates and prospects for future detections in the massive dataset of the upcoming Rubin Observatory. I will also discuss how we are building a galactic scale detector that probes low-frequency GWs from SMBHBs and recent limits on SMBHBs derived from GW data. Finally, I will present my research plan that aims to bring the first multi-messenger detection of a SMBHB within closer reach pushing the frontier in both EM and GW searches.