Title:  Resolving supermassive black hole binary evolution in galaxy formation simulations

Speaker: 廖世鸿

Institute: 国家天文台

Host: 于浩然/杜敏

Time: 2025.3.20 周四 14:30

Location: 物理楼 552

Abstract:

Supermassive black hole (SMBH) binaries within galaxy mergers are the primary target for low-frequency gravitational wave (GW) observatories. Understanding the coalescence process of SMBH binaries in a cosmological framework is pivotal for accurate GW predictions. However, traditional galaxy formation simulations often merge SMBHs instantaneously at kpc or sub-kpc separation scales due to resolution limitations, leading to significant uncertainty in estimating SMBH coalescence time-scales. In this talk, I will introduce the KETJU code, a newly developed numerical tool capable of simultaneously following galaxy (hydro-)dynamics and resolving SMBH dynamics with post-Newtonian corrections down to a few tens of Schwarzschild radii. Based on this novel numerical tool, our on-going RABBITS (Resolving supermAssive Black hole Binaries In galacTic hydrodynamical Simulations) series study will improve the estimation of the SMBH merger time-scales and ultimately enhance our predictions of GW event rates.

Bio:

Dr. Shihong Liao obtained his PhD from the Chinese University of Hong Kong and subsequently conducted postdoctoral research at the National Astronomical Observatories, CAS (NAOC) and the University of Helsinki. He is currently an associate researcher at NAOC. His research focuses on galaxy formation, supermassive black holes, and cosmological simulations.

Related papers:

(1) Liao et al. 2023, MNRAS 520, 4463 https://ui.adsabs.harvard.edu/abs/2023MNRAS.520.4463L

(2) Liao et al. 2024a, MNRAS 528, 5080 https://ui.adsabs.harvard.edu/abs/2024MNRAS.528.5080L

(3) Liao et al. 2024b, MNRAS 530, 4058 https://ui.adsabs.harvard.edu/abs/2024MNRAS.530.4058L