This is a high-level research talk designed for professional astronomers. It is part of the Caltech Astronomy Tea Talk Series, hour-long presentations given weekly by top scientists from around the world to the members of our department. All are welcome to watch these presentations; however, for talks specifically designed for the general public, please see our Caltech Astro Outreach channel: Timestamps and abstract are included below.
Speaker: Colin Burke – University of Illinois at Urbana-Champaign
Title: Optical variability of intermediate-mass black holes and implications for their identification
Optical variability is a novel probe of accreting intermediate-mass black hole (IMBH) candidates in dwarf galaxies. In this talk, I will show our recent results demonstrating the characteristic “damping” timescale of AGN optical light curves correlates strongly with the mass of the black hole. Extension to stellar-mass accretion disks suggests the interpretation may be universal, and could be a powerful new tool for identifying the elusive population of accreting IMBHs. To that end, we have developed a forward model to constrain the local black hole mass function (BHMF) using optical variability with Rubin Observatory. The ultimate goal is that this relic BHMF, when probed in the IMBH regime, will reveal the signature of how supermassive black holes were seeded at high redshifts.