April 23, 2024 | Mar Mezcua, Fabio Pacucci, Hyewon Suh, Malgorzata Siudek, Priyamvada Natarajan
This study reports the discovery of 12 supermassive black holes (SMBHs) hosted by low-mass galaxies at cosmic noon (z ~ 1-3), a period of peak star formation. These SMBHs are significantly more massive than expected based on the local relationship between SMBH mass and host galaxy stellar mass. They share similar properties with high-redshift SMBHs observed by the James Webb Space Telescope (JWST), including black hole-to-stellar mass ratio, bolometric luminosity, and Eddington ratio. The overmassive nature of these SMBHs is not due to selection effects but is consistent with theoretical models suggesting they may have formed from heavy seed black holes. Environmental factors, such as tidal stripping in galaxy nuclei, may contribute to their overmassive state. The findings link the early Universe (z > 4) observed by JWST with the present-day Universe (z < 1), providing insights into the growth and co-evolution of SMBHs and their host galaxies. The study also shows that overmassive SMBHs are found in low-mass galaxies across cosmic time, indicating a possible universal mechanism for their formation. The results highlight the importance of AGN feedback and environmental effects in shaping galaxy evolution. The study underscores the need for further research to understand the detailed physics of AGN feedback and the role of environmental factors in SMBH growth.This study reports the discovery of 12 supermassive black holes (SMBHs) hosted by low-mass galaxies at cosmic noon (z ~ 1-3), a period of peak star formation. These SMBHs are significantly more massive than expected based on the local relationship between SMBH mass and host galaxy stellar mass. They share similar properties with high-redshift SMBHs observed by the James Webb Space Telescope (JWST), including black hole-to-stellar mass ratio, bolometric luminosity, and Eddington ratio. The overmassive nature of these SMBHs is not due to selection effects but is consistent with theoretical models suggesting they may have formed from heavy seed black holes. Environmental factors, such as tidal stripping in galaxy nuclei, may contribute to their overmassive state. The findings link the early Universe (z > 4) observed by JWST with the present-day Universe (z < 1), providing insights into the growth and co-evolution of SMBHs and their host galaxies. The study also shows that overmassive SMBHs are found in low-mass galaxies across cosmic time, indicating a possible universal mechanism for their formation. The results highlight the importance of AGN feedback and environmental effects in shaping galaxy evolution. The study underscores the need for further research to understand the detailed physics of AGN feedback and the role of environmental factors in SMBH growth.