A Comprehensive JWST/NIRSpec Census of Broad-line Active Galactic Nuclei: Faint, Low-mass Accretors and a Population of Little Red Dots
astro-ph.GA
Submitted: 2025-12-02
Updated: 2026-09-20
Comments: Submitted to the Astrophysical Journal, 19 pages, 7 figures
Journal ref: Astrophys. J. 1006, 165 (2026)
Project page: https://dawn-cph.github.io/dja/spectroscopy/nirspec
License: http://creativecommons.org/licenses/by/4.0/
The gist: We present a sample of 252 broad-line Active Galactic Nuclei (BLAGNs), incorporating 171 newly identified sources, spanning a redshift interval from z = 0.8 to 7.2.
Terminology
Abstract
We present a sample of 252 broad-line Active Galactic Nuclei (BLAGNs), incorporating 171 newly identified sources, spanning a redshift interval from z = 0.8 to 7.2. We have analyzed spectroscopic data from the NIRSpec instrument aboard the James Webb Space Telescope, using the G140H, G140M, G235H, G235M, G395H, and G395M gratings to survey N about 80,000 galaxies for BLAGNs. Through emission-line fitting, using a sum of Gaussian models for H α, H β, [N II] λ lambda6548, 6584, and [O III] λ lambda4959, 5007, we separate AGN broad-line components from narrow-line emission. We find the detection rate of BLAGNs to be relatively consistent across our redshift range. Compared to typical low- z AGNs (z 1), the high- z BLAGNs are systematically fainter and less massive, yet they accrete more efficiently, with most showing Eddington ratios between 0.1 and 1.0. This confirms the rapid black hole growth during the early cosmic epochs. The detection of faint, low-mass BLAGNs at high redshift also helps bridge the observational gap between local supermassive black holes and remote luminous quasars, providing a more complete view of black hole-galaxy coevolution across cosmic time.
Sources
- New Methods of Identifying AGN in the Early Universe using Spectroscopy and Photometry in the JWST Era
- RUBIES: a complete census of the bright and red distant Universe with JWST/NIRSpec
- Overview of the JWST Advanced Deep Extragalactic Survey (JADES)
- What you see is what you get: empirically measured bolometric luminosities of Little Red Dots
- JADES: comprehensive census of broad-line AGN from Reionization to Cosmic Noon revealed by JWST
- The case for super-Eddington accretion in JWST broad-line AGN during the first billion years
- Quasars and Galaxy Formation
- Broad-Line AGN at 3.5<z<6: The Black Hole Mass Function and a Connection with Little Red Dots
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