Colloquium on May. 18, 2023

Repeating Nuclear Transients as Extreme Mass Ratio Inspiral Candidates

Speaker: Dheeraj Pasham (MIT)

Venue: Video Conference

Time: 15:00 PM, Thursday, May. 18, 2023

Abstract:

Extreme Mass Ratio Inspirals (EMRIs) are binaries containing a massive black hole (>~a few hundred 1000 solar masses, Msol) and an orbiting smaller object (0.1-100 Msol). A subset of these are poised to be sources of gravitational waves with space-based gravitational wave detectors that will start operating in the next decade. The identification of electromagnetic counterparts of these gravitational wave emitters would transform our understanding of supermassive black hole growth, probe dark energy and put fundamental constraints on gravity. I will present the various flavors of repeating nuclear transients that we have identified using multiwavelength studies of several classes of cosmic transients including stellar tidal distribution events, quasi-periodic eruptions from nuclei of external galaxies, and outbursts from active galactic nuclei. Using supporting general relativistic hydrodynamic simulations, I will present the case for these quasi-periodic modulations as manifestations of EMRIs and will highlight the prospects they hold for the coming decade.