Title: The most precise and the most distant supermassive black hole masses ever measured

Speaker: Hengyue Zhang

Abstract: Supermassive black holes (SMBHs) at the hearts of galaxies play a crucial role in galaxy evolution, as implied by the tight correlations between the SMBH mass and the properties of the galaxy. However, direct measurements of SMBH masses are thus far limited to the local universe and subject to systematic inaccuracies. I will present accurate SMBH mass measurements in two local galaxies, NGC 383 and NGC 1574, using ultra-high-resolution ALMA observations of the molecular gas kinematics, which revealed central warps in the kinematic position angle that biased previous measurements using lower-resolution data. I will also present an ongoing effort to dynamically measure the mass of a SMBH for the first time beyond z > 2 using strong gravitational lensing and a novel dynamical forward modelling pipeline.

Bio: Hengyue Zhang is a third-year PhD student at the University of Oxford, working with Prof. Martin Bureau on measuring the masses of supermassive black holes with ALMA gas kinematics as part of the WISDOM collaboration. Before joining Oxford, Hengyue was an undergraduate student at the University of California, Santa Barbara, working on direct imaging of exoplanets. 

Time: 13:00-14:00, 9/Jan, Thursday

Venue: Room 506 (Large seminar room), Department of Astronomy