Black Hole Formation and Growth

Overview

Essentially every massive galaxy hosts a central black hole, yet the origin of these objects remains one of the central open problems in astrophysics. Three families of seeding channels are usually considered: light seeds of order 10² M_☉ left behind by the first generation of metal-free stars, heavy seeds of 10⁴–10⁵ M_☉ produced by the direct collapse of pristine gas clouds, and intermediate seeds built by runaway stellar and stellar-remnant mergers in the dense cores of young clusters. Each scenario predicts a distinct black hole occupation fraction and mass distribution in low-mass galaxies today, and each is subsequently reshaped by gas accretion and by galaxy–galaxy mergers. The existence of billion-solar-mass quasars already at z > 6 demands extremely rapid early growth, while the black holes in nearby dwarf galaxies and star clusters are the least-evolved relics available and therefore retain the clearest memory of the seeds themselves.

My Research

My work attacks this problem from the observational side by building homogeneous, dynamically measured black hole masses across the whole accessible mass range. Using JWST/NIRSpec and NIRCam data, ALMA molecular-gas observations, and end-to-end simulations of ELT instruments, I measure masses in systems from dwarf galaxies and nuclear star clusters up to giant ellipticals, so that the low-mass end of the local mass function — the regime that discriminates most strongly between seeding channels — can be populated with reliable measurements rather than upper limits.

Literature Review

Summary of Findings