Title: Resolving Supermassive Black Hole Binary Evolution in Galaxy Formation Simulations

Speaker: Professor Shihong Miao (National Astronomical Observatory, Chinese Academy of Sciences)

Time: 14:00pm, May 14, 2024

Location: 3-402, PMO Xianlin Campus

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 series simulations will improve the estimation of the SMBH merger time-scales and ultimately enhance our predictions of GW event rates and the stochastic background.