Title：3D Dynamics of Embedded Stellar-Mass Binary Black Holes within AGN Disks and Their Feedback Effects

Speaker：Hui Li (Los Alamos National Laboratory)

Time：3:00 pm Dec. 22th (Friday)

Tencent Meeting：576-157-8290 password: 6360

Location: Large conference room, 3rd floor

Abstract：

The recent GW190521 event – an 85 Msun and a 66 Msun black hole (BH) coalescing to a 142 Msun BH – the heaviest binary black hole (BBH) merger to date has opened up new discussions on the formation channels of BBHs. In this talk, we focus on the scenario where BBHs are embedded inside an AGN disk (disk around a supermassive black hole at the center of a galaxy). We will present simulations on how stellar mass black hole binaries could form in AGN disks. We will also use high-resolution 2D and 3D hydrodynamical simulations to examine the physical processes that regulate their orbital evolution. We demonstrate that there is a hierarchy of disk structures in such an embedded BBH, including the circum-single disk and the circum-binary disk, both of which play an essential role in regulating the angular momentum evolution.  Along with the BBH evolution, it is likely that accretion onto these stellar-mass black holes will produce powerful jets that will produce and maintain large-scale cavities. We present 3D magnetohydrodynamic simulations to study their properties, and particularly GR-MHD simulations showing strong accretion and powerful jets. Lastly, we explore the likely electromagnetic signatures from such events.

CV：

Hui Li got his B.S. in Physics from Peking University (1990), then PhD in Astrophysics from Rice University (1995). After a Director’s Fellowship and an Oppenheimer Postdoc Fellowship at Los Alamos National Laboratory (1995-2000), he has been a staff member at LANL since then. He became an American Physical Society Fellow in 2005, and is now a Laboratory Fellow at LANL. Hui is interested in astrophysics and plasma physics research, and is actively engaged in promoting such areas among laboratory, space, and astrophysical communities.