Colloquium Abstract - Li - 2024Feb02
February 2, 2024
11:00am Mountain
Hui Li (LANL)
Binary Stellar Mass Black Holes in AGN Disks as Possible LIGO Sources
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 stellar mass BBHs. In this talk, we focus on the scenario where stellar BBHs are embedded inside an AGN disk – the so-called AGN channel for LIGO sources. Through detailed multi-dimensional simulations, we address several basic questions related to this scenario: How BBHs form inside an AGN disk? Will they harden their binary orbit after becoming a binary? How will accretion unto individual black holes and their feedback impact the flow around BBHs? Perhaps more importantly, will there be any electromagnetic signatures associated with such BBH mergers that can be observed? We will use high-resolution 2D and 3D hydrodynamical and magnetohydrodynamic (MHD) simulations to examine the physical processes that regulate their formation and orbital evolution. We demonstrate that there is a hierarchy of disk structures in such an embedded BBH, including the circum-single disk (CSD) and the circum-binary disk (CBD), both of which play an essential role in regulating the angular momentum evolution. In addition, general relativistic MHD simulations are used to investigate the accretion and outflow, from which we calculate the expected power of jet/outflows. Implications for possible observational signatures will be discussed as well.
Local Host: Frank Schinzel
