Bibcode
Brooks, Madisyn; Trump, Jonathan R.; Simons, Raymond C.; Cole, Justin; Taylor, Anthony J.; Bagley, Micaela B.; Finkelstein, Steven L.; Davis, Kelcey; Amorín, Ricardo O.; Backhaus, Bren E.; Cleri, Nikko J.; Giavalisco, Mauro; Grogin, Norman A.; Hirschmann, Michaela; Holwerda, Benne W.; Huertas-Company, Marc; Kartaltepe, Jeyhan S.; Kocevski, Dale D.; Koekemoer, Anton M.; Lucas, Ray A.; Pacucci, Fabio; Wang, Xin
Bibliographical reference
The Astrophysical Journal
Advertised on:
5
2026
Journal
Citations
7
Refereed citations
0
Description
JWST has revealed an abundance of low-luminosity active galactic nuclei (AGN) at high redshifts (z > 3), pushing the limits of black hole (BH) science in the early Universe. Results have claimed that these BHs are significantly more massive than expected from the BH mass─host galaxy stellar mass relation derived from the local Universe. We present a comprehensive census of the BH populations in the early Universe through a detailed stacking analysis of galaxy populations, binned by luminosity and redshift, using JWST spectroscopy from the CEERS, JADES, RUBIES, and GLASS extragalactic deep field surveys. Broad Hα detections in 31% of the stacked spectra (5/16 bins) imply median BH masses of 105.16─106.08 M⊙, and the stacked spectral energy distributions of these bins indicate median stellar masses of 107.84─108.56 M⊙. This suggests that the median galaxy hosts a BH that is at most a factor of 10 times overmassive compared to its host galaxy, and lies closer to the locally derived MBH─M* relation. We investigate the seeding properties of the inferred BHs and find that they can be well explained by light stellar-remnant seeds undergoing moderate Eddington accretion. Our results indicate that individual detections of AGN are more likely to sample the upper envelope of the MBH─M* distribution, while stacking of "normal" galaxies and searching for AGN signatures can overcome the selection bias of individual detections.