Maximally Rotating Supermassive Stars at the Onset of Collapse: Effects of Gas Pressure

Abstract

The "direct collapse" scenario has emerged as a promising evolutionary track for the formation of supermassive black holes early in the Universe. In an idealized version of such a scenario, a uniformly rotating supermassive star spinning at the mass-shedding (Keplerian) limit collapses gravitationally after it reaches a critical configuration. Under the assumption that the gas is dominated by radiation pressure, this critical configuration is characterized by unique values of the dimensionless parameters $J/M^2$ and $R_p/M$, where $J$ is the angular momentum, $R_p$ the polar radius, and $M$ the mass. Motivated by a previous perturbative treatment we adopt a fully nonlinear approach to evaluate the effects of gas pressure on these dimensionless parameters for a large range of masses. We find that gas pressure has a significant effect on the critical configuration even for stellar masses as large as $M\simeq 10^6{M}_{\odot }$. We also calibrate two approximate treatments of the gas pressure perturbation in a comparison with the exact treatment, and find that one commonly used approximation in particular results in increasing deviations from the exact treatment as the mass decreases, and the effects of gas pressure increase. The other approximation, however, proves to be quite robust for all masses $M\gtrsim 10^4{M}_{\odot }$.

13 pages, 7 figures, version accepted for publication in MNRAS

References in corpus (17)

• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• A luminous quasar at a redshift of z = 7.085
• Formation of Supermassive Black Holes by Direct Collapse in Pregalactic Halos
• An ultra-luminous quasar with a twelve-billion-solar-mass black hole at redshift 6.30
• Supermassive black hole formation during the assembly of pre-galactic discs
• Accretion onto the First Stellar Mass Black Holes
• Formation of massive black holes in rapidly growing pre-galactic gas clouds
• Resolving the Formation of Protogalaxies. II. Central Gravitational Collapse
• The Evolution of Supermassive Population III Stars
• The Final Fates of Accreting Supermassive Stars
• The formation of compact massive self-gravitating discs in metal-free haloes with virial temperatures of ~ 13000-30000 K
• Formation of primordial supermassive stars by burst accretion
• Gravitational waves from supermassive stars collapsing to a supermassive black hole
• On the Rotation of Supermassive Stars
• A No-Go Theorem for Direct Collapse Black Holes Without a Strong Ultraviolet Background
• Magnetorotational collapse of very massive stars to black holes in full general relativity
• Formation of Supermassive Black Holes: Simulations in General Relativity

Cited by in corpus (2)

• Spin Evolution of Stellar-mass Black Holes Embedded in AGN disks: Orbital Eccentricity Produces Retrograde Circumstellar Flows
• Spectral properties and detectability of supermassive stars in protoglobular clusters at high redshift