Little Red Dots on FIRE: The Ability of Bursty Galaxies to Host an Abundant Population of High-Redshift AGN

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Authors: Andrew Marszewski, Claude‐André Faucher‐Giguère, Guochao Sun, Daniel Anglés‐Alcázar, Robert Feldmann, Kung-Yi Su, Tim B. Miller, Niranjan Roy
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Abstract

The James Webb Space Telescope has unveiled an abundant population of potential active galactic nuclei (AGN) at high redshift ($z\gtrsim4$) known as little red dots (LRDs), which are likely hosted in relatively low-mass galaxies. However, previous theoretical models have highlighted the difficulty in continuously feeding massive black holes in the central regions of bursty, high-redshift galaxies because of repeated gas evacuation by stellar feedback. We analyze galaxies in high-redshift FIRE-2 simulations to understand whether they are capable of hosting the observed abundant population of high-redshift AGN. We use a gravitational torque-driven accretion (GTDA) model and a simple free-fall accretion model to derive black hole accretion rates and construct predicted AGN bolometric luminosity functions for $z=5-7$. The GTDA model and the free-fall model with black holes accreting $\lesssim 1$ percent of their central gas supply ($

Fields of Study & Subjects

Galaxies: Formation Evolution Phenomena Astrophysical Phenomena and Observations Astrophysics and Star Formation Studies

Publication details

Journal / source
arXiv (Cornell University)
Publication date
29 January 2026
Document type
Preprint