Contributed Talk - Splinter BlackHoles
Wednesday, 15 September 2021, 09:30 (virtual BH)
Probing the active supermassive black hole with VLTI/GRAVITY
Max-Planck Institute for Extraterrestrial Physics
Supermassive black holes in the center of galaxies can be discovered while they are accreting gas and become active galactic nuclei (AGNs) even at distant Universe. Recombination line emission of ionized gas, broadened by the gravity of the central black hole, is a powerful probe of measuring the mass of black holes. The measurement has been traditionally conducted by resolving the so-called broad line region (BLR) temporally using the reverberation mapping technique. Near-infrared interferometry provides a new tool for high spatial resolution studies of the inner structure of AGNs. Spectro-astrometry with VLTI/GRAVITY allows us now to resolve the BLR on micro-arcsec scale. This has enabled us to resolve the kinematics of BLRs of three bright AGNs. Black hole mass and BLR properties are found consistent with the reverberation mapping method. Combining interferometry with reverberation mapping, we can constrain the black hole mass much better than those based on either methods individually. I will end the talk with the prospects of GRAVITY+, which will allow us to probe black hole evolution out to the cosmic noon.