Colloquium – Smadar Naoz

Smadar Naoz, University of California, Los Angeles

It’s Raining Black Holes…Hallelujah!

Gravitational wave (GW) emissions from extreme-mass-ratio inspirals (EMRIs) are promising sources for low-frequency GW detectors. EMRIs are the result of a supermassive black hole (SMBH) that captures a stellar-mass compact object, such as BH. The channel often considered in the literature involves weak two-body kicks from the population of stars and compact objects surrounding the SMBH that can change the BH’s orbit over time, driving it into the SMBH. On the other hand, perturbations from SMBH companions via the eccentric Kozai-Lidov (EKL) mechanism can excite the SMBH to high eccentricities, thereby forming EMRIs. In this talk, I will demonstrate that combining these two processes is essential to comprehending the dynamics of EMRI progenitors. I will also show that EMRIs are naturally formed in SMBH binaries with higher efficiency than either of these processes considered alone. Thus, it is truly raining black holes! This scenario results in a large stochastic background for future GW detectors such as LISA. Finally, I will demonstrate the implications that this physical mechanism has on tidal disruption events.

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Sept 26, 2024 @ 4:10pm Central in Stevenson Center 5326; light refreshments available at 3:50pm in Stevenson Center 5326

Host: S Taylor