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Colloquia

Spin Evolution of Massive Black Holes in Galactic Centers

by Prof. Youjun Lu (NAOC)

Asia/Shanghai
ONLINE

ONLINE

Description
Abstract

Massive Black Holes (MBHs) in galactic centers are believed to be described by the Kerr metric with only two parameters (mass and spin; no-hair theorem). The distribution of those MBHs on the mass and spin plane contains rich information on the MBH growth history. In this talk, I will report our recent investigations on the spin evolution of MBHs under various accretion processes. We show that different accretion modes (e.g., coherent, chaotic, or tidal star accretion) result in quite different spin distribution. Assuming a two phase accretion model, an initial coherent accretion followed by a later chaotic accretion phase, we use the current available spin measurements to obtain constraints on the MBH growth history and discuss future prospects for such constraints . I will also talk about the possible correlation between the radiative efficiency of QSOs and the MBH mass.

Biography

Prof. Youjun Lu got his PhD from USTC in 1997 and subsequently spent ~10 years working at various leading institutes in north America including Princeton, CITA, UC Berkeley and UCSC, before joining NAOC as a professor in 2014. He is now leading the gravitational wave astrophysics group at NAOC. Prof. Lu's research covers many theoretical astrophysics fields, including black holes, gravitational wave, high energy astrophysics, dynamics, galaxies and cosmology.

Chair
Dr. Jiaxin Han
Division
Astronomy and Astrophysics
Other information

Meeting ID: 523 477 035

Password: 1245
Joining Link:https://zoom.com.cn/j/523477035