1. Seeding Supermassive Black Holes with Self-interacting Dark Matter: A Unified Scenario with Baryons
- Author
-
Hai-Bo Yu, Wei-Xiang Feng, and Yi-Ming Zhong
- Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,010504 meteorology & atmospheric sciences ,Astrophysics::High Energy Astrophysical Phenomena ,Dark matter ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,01 natural sciences ,High Energy Physics - Phenomenology (hep-ph) ,0103 physical sciences ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences ,Physics ,Supermassive black hole ,Self-interacting dark matter ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Galaxy ,Baryon ,Black hole ,Dark matter halo ,High Energy Physics - Phenomenology ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Halo ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
Observations show that supermassive black holes (SMBHs) with a mass of $\sim10^9 M_\odot$ exist when the Universe is just $6\%$ of its current age. We propose a scenario where a self-interacting dark matter halo experiences gravothermal instability and its central region collapses into a seed black hole. The presence of baryons in protogalaxies could significantly accelerate the gravothermal evolution of the halo and shorten collapse timescales. The central halo could dissipate its angular momentum remnant via viscosity induced by the self-interactions. The host halo must be on high tails of density fluctuations, implying that high-$z$ SMBHs are expected to be rare in this scenario. We further derive conditions for triggering general relativistic instability of the collapsed region. Our results indicate that self-interacting dark matter can provide a unified explanation for diverse dark matter distributions in galaxies today and the origin of SMBHs at redshifts $z\sim6-7$., Comment: 6 pages, 3 figures, and Supplemental Material; Accepted for publication in the Astrophysical Journal Letters
- Published
- 2021