Formation of the Little Red Dots from the Core-collapse of Self-interacting Dark Matter Halos

Fuente: arXiv
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Main Authors: Jiang, Fangzhou, Jia, Zixiang, Zheng, Haonan, Ho, Luis C., Inayoshi, Kohei, Shen, Xuejian, Vogelsberger, Mark, Feng, Wei-Xiang
Format: Preprint
Published: 2025
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author Jiang, Fangzhou
Jia, Zixiang
Zheng, Haonan
Ho, Luis C.
Inayoshi, Kohei
Shen, Xuejian
Vogelsberger, Mark
Feng, Wei-Xiang
author_facet Jiang, Fangzhou
Jia, Zixiang
Zheng, Haonan
Ho, Luis C.
Inayoshi, Kohei
Shen, Xuejian
Vogelsberger, Mark
Feng, Wei-Xiang
contents We present a statistical study of black hole (BH) formation and growth seeded by gravothermal core collapse of self-interacting dark matter (SIDM) halos at high redshift, using a cosmological semi-analytical framework based on Monte Carlo merger trees. We demonstrate that gravothermal collapse naturally leads to BH formation in high-concentration halos at a characteristic mass scale set by the SIDM cross section, and occurs predominantly in the early Universe. This mechanism is particularly promising for explaining the abundance of the little red dots (LRDs) -- a population of early, apparently galaxy-less active galactic nuclei hosting supermassive BHs. By incorporating this seeding process with simple models of BH growth and assuming a 100% duty cycle, we reproduce the observed LRD mass function for velocity-dependent cross sections of $σ_{0m} \sim 30\,\mathrm{cm}^2\,\mathrm{g}^{-1}$ and $ω\sim 80\,\mathrm{km}\,\mathrm{s}^{-1}$, which are consistent with independent constraints from local galaxies. While higher values of $σ_{0m}$ (or $ω$) would overpredict the low-mass (or high-mass) end of the BH mass function, such deviations could be reconciled by invoking a reduced duty cycle or lower Eddington ratio. Our results suggest that the demographics of high-redshift BHs can serve as a novel and complementary probe of SIDM physics.
format Preprint
id arxiv_https___arxiv_org_abs_2503_23710
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Formation of the Little Red Dots from the Core-collapse of Self-interacting Dark Matter Halos
Jiang, Fangzhou
Jia, Zixiang
Zheng, Haonan
Ho, Luis C.
Inayoshi, Kohei
Shen, Xuejian
Vogelsberger, Mark
Feng, Wei-Xiang
Astrophysics of Galaxies
Cosmology and Nongalactic Astrophysics
We present a statistical study of black hole (BH) formation and growth seeded by gravothermal core collapse of self-interacting dark matter (SIDM) halos at high redshift, using a cosmological semi-analytical framework based on Monte Carlo merger trees. We demonstrate that gravothermal collapse naturally leads to BH formation in high-concentration halos at a characteristic mass scale set by the SIDM cross section, and occurs predominantly in the early Universe. This mechanism is particularly promising for explaining the abundance of the little red dots (LRDs) -- a population of early, apparently galaxy-less active galactic nuclei hosting supermassive BHs. By incorporating this seeding process with simple models of BH growth and assuming a 100% duty cycle, we reproduce the observed LRD mass function for velocity-dependent cross sections of $σ_{0m} \sim 30\,\mathrm{cm}^2\,\mathrm{g}^{-1}$ and $ω\sim 80\,\mathrm{km}\,\mathrm{s}^{-1}$, which are consistent with independent constraints from local galaxies. While higher values of $σ_{0m}$ (or $ω$) would overpredict the low-mass (or high-mass) end of the BH mass function, such deviations could be reconciled by invoking a reduced duty cycle or lower Eddington ratio. Our results suggest that the demographics of high-redshift BHs can serve as a novel and complementary probe of SIDM physics.
title Formation of the Little Red Dots from the Core-collapse of Self-interacting Dark Matter Halos
topic Astrophysics of Galaxies
Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2503.23710