Making a supermassive star by stellar bombardment

Abstract

Approximately two hundred supermassive black holes (SMBHs) have been discovered within the first $\sim$Gyr after the Big Bang. One pathway for the formation of SMBHs is through the collapse of supermassive stars (SMSs). A possible obstacle to this scenario is that the collapsing gas fragments and forms a cluster of main-sequence stars. Here we raise the possibility that stellar collisions may be sufficiently frequent and energetic to inhibit the contraction of the massive protostar, avoiding strong UV radiation driven outflows, and allowing it to continue growing into an SMS. We investigate this scenario with semianalytic models incorporating star formation, gas accretion, dynamical friction from stars and gas, stellar collisions, and gas ejection. We find that when the collapsing gas fragments at a density of $\lesssim 3\times 10^{10}\mathrm{c}{\mathrm{m}}^{-3}$, the central protostar contracts due to infrequent stellar mergers, and in turn photoevaporates the remaining collapsing gas, resulting in the formation of a $\lesssim 10^4{\mathrm{M}}_{\odot }$ object. On the other hand, when the collapsing gas fragments at higher densities (expected for a metal-poor cloud with $Z\lesssim 10^{-5}{\mathrm{Z}}_{\odot }$ with suppressed ${\mathrm{H}}_2$ abundance) the central protostar avoids contraction and keeps growing via frequent stellar mergers, reaching masses as high as $\sim 10^5-10^6{\mathrm{M}}_{\odot }$. We conclude that frequent stellar mergers represent a possible pathway to form massive BHs in the early universe.

20 pages, 8 figures, accepted in ApJ

References in corpus (40)

• 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
• Intermediate and Extreme Mass-Ratio Inspirals -- Astrophysics, Science Applications and Detection using LISA
• Accretion disc viscosity: how big is alpha?
• Gravitational waves from scattering of stellar-mass black holes in galactic nuclei
• Protostar Formation in the Early Universe
• The Final SDSS High-Redshift Quasar Sample of 52 Quasars at z>5.7
• The Mass Spectrum of the First Stars
• Formation of the first nuclear clusters and massive black holes at high redshift
• Accretion onto the First Stellar Mass Black Holes
• Fluctuations in the High-Redshift Lyman-Werner Background: Close Halo Pairs as the Origin of Supermassive Black Holes
• Can Supermassive Black Holes Form in Metal-Enriched High-Redshift Protogalaxies ?
• The Formation of the First Stars II. Radiative Feedback Processes and Implications for the Initial Mass Function
• The evolution of runaway stellar collision products
• Formation of massive black holes in rapidly growing pre-galactic gas clouds
• Quasars at z=6: the survival of the fittest
• Rapid growth of seed black holes in the early universe by supra-exponential accretion
• The Evolution of Supermassive Population III Stars
• Initial mass function of intermediate mass black hole seeds
• Feedback-regulated Super Massive Black Hole Seed Formation
• The critical radiation intensity for direct collapse black hole formation: dependence on the radiation spectral shape
• Constraining the high redshift formation of black hole seeds in nuclear star clusters with gas inflows
• Accretion onto Intermediate-Mass Black Holes in Dense Protogalactic Clouds
• Dynamical Friction of a Circular-Orbit Perturber in a Gaseous Medium
• Supersonic Gas Streams Enhance the Formation of Massive Black Holes in the Early Universe
• Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). X. Discovery of 35 Quasars and Luminous Galaxies at 5.7 $\le$ z $\le$ 7.0
• Formation of massive protostars in atomic cooling haloes
• Direct collapse black hole formation from synchronized pairs of atomic cooling halos
• The Final Fates of Accreting Supermassive Stars
• Formation of an embryonic supermassive star in the first galaxy
• Numerical Simulations of Turbulent, Molecular Clouds Regulated by Radiation Feedback Forces I: Star Formation Rate and Efficiency
• Formation of primordial supermassive stars by burst accretion
• Highly efficient star formation in NGC 5253 possibly from stream-fed accretion
• Conditions for Optimal Growth of Black Hole Seeds
• Revised rate coefficients for H${}_2$ and H${}^{-}$ destruction by realistic stellar spectra
• Beyond Jcrit: a critical curve for suppression of H2-cooling in protogalaxies
• Formation of SMBH seeds in Pop III star clusters through collisions : the importance of mass loss
• Bondi-Hoyle-Lyttleton Accretion onto Star Clusters
• On the Prevalence of Super-Massive Black Holes over Cosmic Time

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• Hunting for Massive Black Holes in Dwarf Galaxies
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• How the super-Eddington regime regulates black hole growth in high-redshift galaxies
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• Rapid growth of seed black holes during early bulge formation
• Quiescent and active galactic nuclei as factories of merging compact objects in the era of gravitational-wave astronomy
• Hyper-Eddington accretion flows onto black holes accompanied by powerful outflows
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• Formation of supermassive black hole seeds in nuclear star clusters via gas accretion and runaway collisions
• Origin of supermassive black holes in massive metal-poor protoclusters
• Formation of super-massive black holes in galactic nuclei I: delivering seed intermediate-mass black holes in massive stellar clusters
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• Direct collapse of exceptionally heavy black holes in the merger-driven scenario
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• Intermediate-mass Black Holes on the Run from Young Star Clusters
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• The formation of supermassive black holes from Population III.1 seeds. II. Evolution to the local universe
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• Rapid formation of a very massive star >50000 $M_{\odot }$ and subsequently an IMBH from runaway collisions. Direct N-body and Monte Carlo simulations of dense star clusters
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• Pulsation-driven mass loss from massive stars behind stellar mergers in metal-poor dense clusters
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• The physical origin of super-competitive accretion during the formation of the first supermassive black holes
• Radiative feedback for supermassive star formation in a massive cloud with H2 molecules in an atomic-cooling halo
• The mean free path approximation and stellar collisions in star clusters: Numerical exploration of the analytic rates and the role of perturbations on binary star mergers
• Connecting the Dots: UV-Bright Companions of Little Red Dots as Lyman-Werner Sources Enabling Direct Collapse Black Hole Formation
• Formation of supermassive stars in the first stellar clusters: Dependence on the gas temperature
• Astrophysics with the Laser Interferometer Space Antenna
• Gravitational collapse at low to moderate Mach numbers: The relationship between star formation efficiency and the fraction of mass in the massive object
• Constraints on dynamically-formed massive black holes in Little Red Dots from X-ray non-detections
• Jet-driven active galactic nucleus feedback in galaxy formation before black hole formation
• Probing supermassive stars and massive black hole seeds through gravitational wave inspirals
• Black hole merger rates for LISA and LGWA from semi-analytical modelling of light seeds
• Merger rates of intermediate-mass black hole binaries in nuclear star clusters
• Massive star clusters detected by JWST as natural birth places to form intermediate-mass black holes
• Host galaxies and electromagnetic counterparts to binary neutron star mergers across the cosmic time: Detectability of GW170817-like events