Glimmers in the Cosmic Dawn. III. On the Photometrically Determined Black Hole Mass to Stellar Mass Relation across Cosmic Time*

Key Points

• The study aims to investigate the relationship between black hole mass and stellar mass across different cosmic epochs in variable active galactic nuclei.
• Performed spectral energy distribution fitting on 121 AGN candidates
• Utilized photometry from Hubble and James Webb Space Telescopes
• Decomposed total SED into stellar and AGN contributions
• Estimated black hole masses using luminosity measurements at 5100 Å
• Analyzed trends in black hole mass relative to stellar mass across redshifts.
• Identified a significant AGN contribution for 26 sources out of 121 examined
• Observed overmassive black holes in high-redshift sources relative to host stellar mass
• Found two intermediate-mass black hole candidates in dwarf galaxies at z < 1 with similar characteristics
• Successfully retrieved AGN nature for one source at z > 6, estimating a lower limit for its black hole mass.