Evolution and Final Fates of Rapidly Accreting Supermassive Stars

Abstract

The formation of supermassive stars (SMSs) is a possible pathway to seed supermassive black holes in the early universe. This chapter summarizes recent theoretical efforts to understand their evolution, highlighting effects of very rapid accretion at the rates of ${\dot{M}}_{\ast }\gtrsim 0.1$M${}_{\odot }$ yr${}^{-1}$. Stellar evolution calculations predict that such an accreting SMS has a characteristic feature, i.e., a very large radius that monotonically increases as the stellar mass increases. The radius exceeds $7000$ R${}_{\odot }$ (or $30$ AU) after the star accretes the gas of more than $10^3$ M${}_{\odot }$. We show that the emergence of the "supergiant protostar" stage is a key for the formation of SMSs, because resulting radiative feedback against the accretion flow is substantially weakened during this stage. We also show that these SMSs end their lives while the accretion continues, and that their final fates vary with different accretion rates.

Preprint of the Chapter "Evolution and Final Fates of Rapidly Accreting Supermassive Stars", to be published in the review volume "Formation of the First Black Holes", Latif M. and Schleicher D.R.G., eds., World Scientific Publishing Company, 2018, pp. [see https://www.worldscientific.com/worldscibooks/10.1142/10652]

References in corpus (9)

• Primordial Star Formation under the Influence of Far Ultraviolet Radiation: 1540 Cosmological Halos and the Stellar Mass Distribution
• The Formation of the First Stars II. Radiative Feedback Processes and Implications for the Initial Mass Function
• The Evolution of Supermassive Population III Stars
• Formation of an embryonic supermassive star in the first galaxy
• Formation of primordial supermassive stars by burst accretion
• Does disk fragmentation prevent the formation of supermassive stars in protogalaxies?
• On the Rotation of Supermassive Stars
• Do Stellar Winds Prevent the Formation of Supermassive Stars by Accretion?
• Primordial protostars accreting beyond the $\Omega \Gamma$-limit: radiation effect around the star-disk boundary

Cited by in corpus (4)

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• Astrophysical black holes
• Jet-driven active galactic nucleus feedback in galaxy formation before black hole formation
• Signatures of Exploding Supermassive PopIII Stars at High Redshift in JWST, EUCLID and Roman Space Telescope