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.

Jan 18, 2024 @ 4:00pm Central in Stevenson 4327; reception beforehand at 3:30pm in Stevenson 6333

Hosts: S Taylor / K Jani

Smadar Naoz is a professor at the Physics and Astronomy department at the University of California, Los Angeles (UCLA), and a Howard & Astrid Preston Chair in Astrophysics. Before joining UCLA’s faculty, she was an Einstein Fellow at the Institute for Theory and Computation at Harvard University’s Center of Astrophysics. Prior to that, she was an IAU Gruber postdoctoral fellow and a CIERA fellow at Northwestern University. She did her Ph.D. studies in the Department of Astronomy and Astrophysics at Tel Aviv University and graduated from the Racah Institute at The Hebrew University. She received several awards and prizes, such as the Annie Jump Cannon and the Helen B. Warner Prize, both awarded by the American Astronomical Society.

Naoz is interested in a broad range of topics in theoretical astrophysics, emphasizing dynamical research problems from cosmology to black holes, Gravitational-Wave sources, stars, and extrasolar planets. In the past ten years, she has studied the underlying physics of the triple-body problem and showed that these systems are far more exciting and richer than initially thought of in the past. These new developments are now being applied by the community to a diverse range of astrophysical systems at different scales.