Insights into Early SMBH Growth from JWST (Dale Kocevski)

The capabilities of JWST are now allowing us to measure the host demographics of AGN beyond cosmic noon and detect lower luminosity quasars out to the epoch of reionization. I will discuss recent AGN-related results from the CEERS Survey and what they tell us about the growth of SMBHs in the early universe. This includes the discovery of an actively accreting SMBH at z=8.67, which is one of the most distant AGN ever discovered. The mass of the black hole and its extreme redshift place tight constraints on its formation and subsequent growth. I will also discuss the discovery of multiple low-luminosity, broad-line AGN at z gt 5 found with our NIRSpec observations. These sources are powered by black holes with masses of order 10^7 Msol, making them the least-massive BHs known in the early universe. We derive host stellar masses for each AGN, allowing us to place constraints on the BH-galaxy mass relationship in the lowest mass range yet probed in the early universe. Studies in this low-mass regime are key to constraining models of BH seeding and the early growth history of SMBHs. Finally, I will discuss the discovery of a large population of faint, obscured AGN at z gt 5 known as little red dots (LRDs). Roughly 80% of these sources exhibit broad emission lines in their spectra and our X-ray spectral analysis confirms that they are moderately obscured, with column densities of log (nH/cm-2) gt 23. The number density of these sources is 2-3 dex above that of bright quasars at z ~ 5-7 and 1 dex higher than current samples of X-ray AGN at z~5, suggesting a large population of previously-hidden, dust-obscured AGN may lie waiting to be uncovered by next-generation X-ray missions like AXIS.