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Title: THE GROWTH OF THE STELLAR SEEDS OF SUPERMASSIVE BLACK HOLES

Journal Article · · Astrophysical Journal
;  [1];  [2]
  1. Nuclear and Particle Physics, Astrophysics and Cosmology Group (T-2), Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)
  2. Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States)

The collapse of baryons into extremely massive stars with masses {approx}>10{sup 4} M{sub Sun} in a small fraction of protogalaxies at z {approx}> 10 is a promising candidate for the origin of supermassive black holes (SMBHs), some of which grow to a billion solar masses by z {approx} 7. We determine the maximum masses such stars can attain by accreting primordial gas. We find that at relatively low accretion rates the strong ionizing radiation of these stars limits their masses to M{sub *} {approx} 10{sup 3} M{sub Sun} ( M-dot{sub acc}/10{sup -3} M{sub Sun} yr{sup -1}){sup 8/7}, where M-dot{sub acc} is the rate at which the star gains mass. However, at the higher central infall rates usually found in numerical simulations of protogalactic collapse ({approx}>0.1 M{sub Sun} yr{sup -1}), the lifetime of the star instead limits its final mass to {approx}10{sup 6} M{sub Sun }. Furthermore, for the spherical accretion rates at which the star can grow, its ionizing radiation is confined deep within the protogalaxy, so the evolution of the star is decoupled from that of its host galaxy. Ly{alpha} emission from the surrounding H II region is trapped in these heavy accretion flows and likely reprocessed into strong Balmer series emission, which may be observable by the James Webb Space Telescope. This, strong He II {lambda}1640, and continuum emission are likely to be the key observational signatures of the progenitors of SMBHs at high redshift.

OSTI ID:
22034549
Journal Information:
Astrophysical Journal, Vol. 750, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
Country of Publication:
United States
Language:
English