Formation of SMBH seeds in Pop III star clusters through collisions : the importance of mass loss

Abstract

Runaway collisions in dense clusters may lead to the formation of supermassive black hole (SMBH) seeds, and this process can be further enhanced by accretion, as recent models of SMBH seed formation in Population III star clusters have shown. This may explain the presence of supermassive black holes already at high redshift, $z>6$. However, in this context, mass loss during collisions was not considered and could play an important role for the formation of the SMBH seed. Here, we study the effect of mass loss, due to collisions of protostars, in the formation and evolution of a massive object in a dense primordial cluster. We consider both constant mass loss fractions as well as analytic models based on the stellar structure of the collision components. Our calculations indicate that mass loss can significantly affect the final mass of the possible SMBH seed. Considering a constant mass loss of 5% for every collision, we can lose between 60-80% of the total mass that is obtained if mass loss were not considered. Using instead analytical prescriptions for mass loss, the mass of the final object is reduced by 15-40%, depending on the accretion model for the cluster we study. Altogether, we obtain masses of the order of $10^4{M}_{\odot }$, which are still massive enough to be SMBH seeds.

12 pages, 9 figures, accepted by MNRAS

References in corpus (14)

• A luminous quasar at a redshift of z = 7.085
• Formation of the first nuclear clusters and massive black holes at high redshift
• Fragmentation of star-forming clouds enriched with the first dust
• Resolving the Formation of Protogalaxies. II. Central Gravitational Collapse
• A multiphysics and multiscale software environment for modeling astrophysical systems
• Feedback-regulated Super Massive Black Hole Seed Formation
• The critical radiation intensity for direct collapse black hole formation: dependence on the radiation spectral shape
• How realistic UV spectra and X-rays suppress the abundance of direct collapse black holes
• Collisions and close encounters involving massive main-sequence stars
• Revised rate coefficients for H${}_2$ and H${}^{-}$ destruction by realistic stellar spectra
• Mixing in massive stellar mergers
• Evolution of stellar collision products in open clusters. II. A grid of low-mass collisions
• The formation of massive primordial stars in the presence of moderate UV backgrounds
• Formation of carbon-enhanced metal-poor stars in the presence of far ultraviolet radiation

Cited by in corpus (7)

• Very high redshift quasars and the rapid emergence of super-massive black holes
• Formation of supermassive stars in the first star clusters
• Origin of supermassive black holes in massive metal-poor protoclusters
• Dynamical evolution of Population III stellar systems and the resulting binary statistics
• The effects of a background potential in star cluster evolution: a delay in the relaxation time-scale and runaway collision processes
• Hyper-Eddington Black Hole Growth in Star-Forming Molecular Clouds and Galactic Nuclei: Can It Happen?
• The physical origin of super-competitive accretion during the formation of the first supermassive black holes