Seminar by Junehyoung Jeon, UT Austin
The James Webb Space Telescope (JWST) has identified abundant supermassive black holes (SMBHs) already during the first few hundred million years of cosmic history, including a new population of objects known as the Little Red Dots (LRDs) proposed to be SMBH systems. To understand how they came to be, we use the cosmological code GIZMO to study SMBH seed formation considering two scenarios: low-mass stellar remnant and high-mass direct collapse black hole (DCBH) seeds. Forming the massive SMBHs observed at early times requires massive seeds accreting more efficiently than the fiducial Bondi–Hoyle model. Furthermore, using the semi-analytical code A-SLOTH, we show both seeding channels can reproduce the SMBH population and mass function observations at z∼5–6 but diverge at z∼10. Specifically, JWST observations have the potential to constrain the fraction of super-Eddington SMBHs as well as the existence and prevalence of DCBHs, particularly through blank-field ultra-deep or gravitational lensing surveys. Such observations will provide key insights into SMBH formation and evolution during the emergence of the first galaxies. Notably, we find that the DCBH population can reproduce the observed LRD population statistics, with individual extreme DCBH systems reproducing spectral properties of extreme LRDs.
Host: Viraj Pandya