New template-fitting selection yields 241 BH*-dominated LRD candidates at z~1.7-9.3 with number density peaking at z~5-6, demonstrating persistence to lower redshifts.
Rapidly Accreting Supergiant Protostars: Embryos of Supermassive Black Holes?
4 Pith papers cite this work. Polarity classification is still indexing.
abstract
Direct collapse of supermassive stars (SMSs) is a possible pathway for generating supermassive black holes in the early universe. It is expected that an SMS could form via very rapid mass accretion with Mdot ~ 0.1 - 1 Msun/yr during the gravitational collapse of an atomic-cooling primordial gas cloud. In this paper we study how stars would evolve under such extreme rapid mass accretion, focusing on the early evolution until the stellar mass reaches 1000 Msun. To this end we numerically calculate the detailed interior structure of accreting stars with primordial element abundances. Our results show that for accretion rates higher than 0.01 Msun/yr, stellar evolution is qualitatively different from that expected at lower rates. While accreting at these high rates the star always has a radius exceeding 100 Rsun, which increases monotonically with the stellar mass. The mass-radius relation for stellar masses exceeding ~ 100 Msun follows the same track with R_* \propto M_*^0.5 in all cases with accretion rates > 0.01 Msun/yr; at a stellar mass of 1000 Msun the radius is about 7000 Rsun (~= 30 AU). With higher accretion rates the onset of hydrogen burning is shifted towards higher stellar masses. In particular, for accretion rates exceeding Mdot > 0.1 Msun/yr, there is no significant hydrogen burning even after 1000 Msun have accreted onto the protostar. Such "supergiant" protostars have effective temperatures as low as Teff ~= 5000 K throughout their evolution and because they hardly emit ionizing photons, they do not create an HII region or significantly heat their immediate surroundings. Thus, radiative feedback is unable to hinder the growth of rapidly accreting stars to masses in excess of 1000 Msun, as long as material is accreted at rates Mdot > 0.01 Msun/yr.
years
2026 4verdicts
UNVERDICTED 4representative citing papers
FIRE-2 simulations show per-galaxy tidal disruption rates peak near z=2.5 at 4e-4 per year, correlate with SFR and central density, and remain high in satellite galaxies at early times.
Cosmological hydrodynamical simulations predict that UV diversity in Little Red Dots encodes direct-collapse black hole ages via a rapid transition from BH- to stellar-dominated emission after ~30 Myr.
High-resolution cosmological zoom-in simulations find that major mergers do not trigger sustained super-Eddington black hole accretion in low-mass halos when feedback is included; episodes occur only immediately after seeding or with feedback disabled.
citing papers explorer
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Black Hole Stars Across the Universe: Identifying Central Engine Dominated Little Red Dots at $z\sim1.5-9.5$
New template-fitting selection yields 241 BH*-dominated LRD candidates at z~1.7-9.3 with number density peaking at z~5-6, demonstrating persistence to lower redshifts.
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TDEs on FIRE: Illuminating the Cosmic Evolution of Tidal Disruption Rates
FIRE-2 simulations show per-galaxy tidal disruption rates peak near z=2.5 at 4e-4 per year, correlate with SFR and central density, and remain high in satellite galaxies at early times.
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Ultraviolet diversity of Little Red Dots as a probe for direct-collapse black hole ages
Cosmological hydrodynamical simulations predict that UV diversity in Little Red Dots encodes direct-collapse black hole ages via a rapid transition from BH- to stellar-dominated emission after ~30 Myr.
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The role of major mergers in triggering super-Eddington accretion
High-resolution cosmological zoom-in simulations find that major mergers do not trigger sustained super-Eddington black hole accretion in low-mass halos when feedback is included; episodes occur only immediately after seeding or with feedback disabled.