The Lumina Project: The Demographics of Active Galactic Nuclei from Quasars to Little Red Dots at z ≥ 3
13 affiliations
- 1Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology Department of Physics, , Cambridge, MA 02139 ,
- 2Center for Astrophysics | Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138 ,
- 3The University of Texas at Dallas Department of Physics, , Richardson, TX 75080 ,
- 4York University Department of Physics and Astronomy, , 4700 Keele Street, Toronto, ON M3J 1P3 ,
- 5Fachbereich Physik, Philipps Universität Marburg , D-35032 Marburg ,
- 6Max Planck Institute for Astronomy , Königstuhl 17, D-69117 Heidelberg ,
- 7Durham University Centre for Extragalactic Astronomy, Department of Physics, , Durham DH1 3LE ,
- 8Kavli Institute for Astronomy and Astrophysics, Peking University , Beijing 100871 ,
- 9School of Physics, Peking University Department of Astronomy, , Beijing 100871 ,
- 10The University of Texas at Austin Department of Astronomy, , Austin, TX 78712 ,
- 11Cosmic Frontier Center, The University of Texas at Austin , Austin, TX 78712 ,
- 12Dartmouth College Department of Physics and Astronomy, , 6127 Wilder Laboratory, Hanover, NH 03755 ,
- 13Max Planck Institute for Astrophysics , Karl-Schwarzschild-Str. 1, D-85741 Garching ,
Abstract
High-redshift active galactic nuclei (AGN) are powerful probes of early black-hole growth, galaxy formation, and the evolving intergalactic medium (IGM). We use Lumina, a cosmological radiation-hydrodynamic simulation spanning the epochs of hydrogen and helium reionization, which combines a large (500 cMpc)3 volume with 2 × 60003 resolution elements, to explore high-redshift AGN. The simulation self-consistently follows hundreds of millions of galaxies and supermassive black holes (SMBHs), together with their impact on the IGM. We exploit this uniquely large dynamic range to predict multi-band AGN luminosity functions (LFs) at z ≥ 3, from hard X-rays to the mid-infrared. These predictions encompass both moderately luminous quasars and the faint “Little Red Dots” (LRDs) uncovered by JWST. We develop an empirical model that maps simulated SMBHs onto observed AGN using bolometric and extinction/absorption corrections for canonical AGN and LRDs, and in which SMBHs with MBH≤ 10 Mseed ∼ 107 M⊙ stay in the LRD phase with a duty cycle of 30%. This simple framework reproduces the observed LFs and clustering of LRDs. Meanwhile, the pre-JWST quasar LF constraints are recovered, although we find that a ∼0.3 dex log-normal scatter in bolometric luminosity is required to reproduce the bright end. We quantify the redshift evolution of AGN and LRD number densities, and their contributions to the integrated BH mass densities. The same AGN population is the dominant driver for the He ii reionization modelled self-consistently in Lumina. This paves the way for general population-synthesis models of high-redshift AGN, including LRDs, in a unified cosmological framework.
Related
- The Lumina Project: Intergalactic Clumping and Recombination Sinks
- The Lumina Project: Intergalactic Clumping and Recombination Sinks
- Introducing the Lumina project: large-volume radiation-hydrodynamic simulations of the epochs of hydrogen and helium reionization
- The Lumina Project: Morphology of Ionized Bubbles and Neutral Islands
- Galactic archaeology meets exoplanets: linking stellar birth radii to exoplanet demographics
BibTeX
@article{shen2026lumina,
title = {{The Lumina Project: The Demographics of Active Galactic Nuclei from Quasars to Little Red Dots at z ≥ 3}},
author = {Xuejian Shen and Oliver Zier and Aaron Smith and Rongrong Liu and Rahul Kannan and Teodora-Elena Bulichi and Sonja M Koehler and Volker Springel Mark Vogelsberger and Lars Hernquist and Rohan P Naidu and Anna de Graaff and Elia Pizzati and David M Alexander and Luis C Ho and Vasily Kokorev and Gene Leung and Anna-Christina Eilers and Ryan C Hickox},
journal = {Monthly Notices of the Royal Astronomical Society},
year = {2026},
month = oct,
doi = {10.1093/mnras/stag2082},
url = {https://academic.oup.com/mnras/advance-article/doi/10.1093/mnras/stag2082/9005965},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - The Lumina Project: The Demographics of Active Galactic Nuclei from Quasars to Little Red Dots at z ≥ 3
AU - Xuejian Shen
AU - Oliver Zier
AU - Aaron Smith
AU - Rongrong Liu
AU - Rahul Kannan
AU - Teodora-Elena Bulichi
AU - Sonja M Koehler
AU - Volker Springel Mark Vogelsberger
AU - Lars Hernquist
AU - Rohan P Naidu
AU - Anna de Graaff
AU - Elia Pizzati
AU - David M Alexander
AU - Luis C Ho
AU - Vasily Kokorev
AU - Gene Leung
AU - Anna-Christina Eilers
AU - Ryan C Hickox
PY - 2026
DA - 2026/10/31
JO - Monthly Notices of the Royal Astronomical Society
DO - 10.1093/mnras/stag2082
UR - https://academic.oup.com/mnras/advance-article/doi/10.1093/mnras/stag2082/9005965
AB - High-redshift active galactic nuclei (AGN) are powerful probes of early black-hole growth, galaxy formation, and the evolving intergalactic medium (IGM). We use Lumina, a cosmological radiation-hydrodynamic simulation spanning the epochs of hydrogen and helium reionization, which combines a large (500 cMpc)3 volume with 2 × 60003 resolution elements, to explore high-redshift AGN. The simulation self-consistently follows hundreds of millions of galaxies and supermassive black holes (SMBHs), together with their impact on the IGM. We exploit this uniquely large dynamic range to predict multi-band AGN luminosity functions (LFs) at z ≥ 3, from hard X-rays to the mid-infrared. These predictions encompass both moderately luminous quasars and the faint “Little Red Dots” (LRDs) uncovered by JWST. We develop an empirical model that maps simulated SMBHs onto observed AGN using bolometric and extinction/absorption corrections for canonical AGN and LRDs, and in which SMBHs with M_BH≤ 10 M_seed ∼ 10^7 M_⊙ stay in the LRD phase with a duty cycle of 30%. This simple framework reproduces the observed LFs and clustering of LRDs. Meanwhile, the pre-JWST quasar LF constraints are recovered, although we find that a ∼0.3 dex log-normal scatter in bolometric luminosity is required to reproduce the bright end. We quantify the redshift evolution of AGN and LRD number densities, and their contributions to the integrated BH mass densities. The same AGN population is the dominant driver for the He ii reionization modelled self-consistently in Lumina. This paves the way for general population-synthesis models of high-redshift AGN, including LRDs, in a unified cosmological framework.
SN - 0035-8711
SN - 1365-2966
ER -