Little Red Dots from Ultra-Strongly Self-Interacting Dark Matter

2025/07/04 by Roberts, M. Grant, Braff, Lila, Garg, Aarna +2 · 4 citations
#Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences

paper · doi:10.48550/arxiv.2507.03230

Abstract

We investigate the possibility that the recently identified population of high-redshift, obscured quasars - known as "Little Red Dots" (LRDs) - originates from early black hole seed formation driven by ultra-strongly self-interacting dark matter (uSIDM). In this framework, dark matter halos undergo gravothermal core collapse due to large self-interaction cross sections, resulting in the rapid formation of massive black hole (BH) seeds with masses \gtrsim 10⁵ M_\odot at redshifts z \gtrsim 5. We develop a semi-analytic model that tracks the evolution of the dark matter halo population, the redshift of collapse z_{\rm coll}, and the corresponding BH mass function. Black hole growth is modeled stochastically via a log-normal Eddington ratio distribution and a finite duty cycle. We find that the uSIDM scenario naturally reproduces key observed properties of LRDs, including their abundance, compactness, and characteristic BH masses, while offering a mechanism for early, obscured black hole formation that is difficult to achieve in standard CDM-based models. The predicted SMBH mass function at z ∼ 5 shows excellent agreement with LRD observational data and SIDM merger-tree simulations, particularly at the high-mass end (m_{\rm BH} \gtrsim 10⁷ M_\odot). These results suggest that LRDs may serve as powerful observational tracers of exotic dark sector physics and that SMBH formation in the early universe could be significantly shaped by non-gravitational dark matter interactions.

Citations

• Ultra-Strongly Self-Interacting Dark Matter: From Phenomenology to Astrophysical Observables
• Not-quite-primordial black holes
• JWST Insights into Narrow-line Little Red Dots
• Chandra Rules Out Super-Eddington Accretion Models For Little Red Dots
• Black Hole Envelopes in Little Red Dots
• Formation of the Little Red Dots from the Core-collapse of Self-interacting Dark Matter Halos
• Massive Black Holes Seeded by Dark Matter -- Implications for Little Red Dots and Gravitational Wave Signatures
• Little Red Dots as the Very First Activity of Black Hole Growth
• Analysis of Multi-epoch JWST Images of ∼ 300 Little Red Dots: Tentative Detection of Variability in a Minority of Sources
• Sub-Eddington accreting supermassive primordial black holes explain Little Red Dots
• RUBIES: a complete census of the bright and red distant Universe with JWST/NIRSpec
• Stacking X-ray Observations of "Little Red Dots": Implications for their AGN Properties
• The Rise of Faint, Red AGN at z>4: A Sample of Little Red Dots in the JWST Extragalactic Legacy Fields
• RUBIES: JWST/NIRSpec Confirmation of an Infrared-luminous, Broad-line Little Red Dot with an Ionized Outflow
• Little Red Dots: An Abundant Population of Faint Active Galactic Nuclei at z ∼ 5 Revealed by the EIGER and FRESCO JWST Surveys
• A Census of Photometrically Selected Little Red Dots at 4 < z < 9 in JWST Blank Fields
• Astrophysical Tests of Dark Matter Self-Interactions
• The Assembly of the First Massive Black Holes
• Dissipative dark matter explains rotation curves

Cited by

• Black Hole Cold Brew: Fermi Degeneracy Pressure
• Ultra-Strongly Self-Interacting Dark Matter: From Phenomenology to Astrophysical Observables
• Novel Challenges in Tracking Self-Interacting Dark Matter Subhalos
• Little Red Dots from Small-Scale Primordial Black Hole Clustering

Related

• Formation of the Little Red Dots from the Core-collapse of Self-interacting Dark Matter Halos
• Massive Black Holes Seeded by Dark Matter -- Implications for Little Red Dots and Gravitational Wave Signatures
• A cosmologist's take on Little Red Dots
• The Clustering of Little Red Dots from Ultra-Strongly Self-Interacting Dark Matter
• Little Red Dots and their Progenitors from Direct Collapse Black Holes