Speaker
Description
Accurate supermassive black hole (SMBH) mass measurements are essential for understanding their formation and coevolution with host galaxies. Recent advances with the GRAVITY instrument on the Very Large Telescope Interferometer have revolutionized our ability to study active galactic nuclei (AGNs) and luminous quasars at unprecedented angular resolution. In this talk, I will present GRAVITY results spanning a wide redshift range. For low-redshift AGNs, our observations of ionized gas dynamics in the broad-line region (BLR) reveal a BLR radius–luminosity relation that is shallower than canonical. I will also report the first dynamical measurement of a high-redshift SMBH, showing that the single-epoch method overestimates the mass for this highly accreting SMBH, and that it appears undermassive relative to its host galaxy w.r.t. the local relation. I will conclude with prospects for GRAVITY+, whose enhanced adaptive optics and wide-angle phase referencing will expand our AGN sample and illuminate early SMBH growth.