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Title: THE FORMATION OF MASSIVE POPULATION III STARS IN THE PRESENCE OF TURBULENCE

Population III stars forming in the infant universe at z = 30 heralded the end of the cosmic dark ages. They are presumed to be assembled in the so-called minihalos with virial temperatures of a few thousand K where collapse is triggered by molecular hydrogen cooling. A central question concerns their final masses, and whether fragmentation occurs during their formation. While studies employing Lagrangian codes suggest fragmentation via a self-gravitating disk, recent high-resolution simulations indicated that disk formation is suppressed. Here we report the first high-resolution large-eddy simulations performed with the Eulerian grid-based code Enzo following the evolution beyond the formation of the first peak to investigate the accretion of the central massive clump and potential fragmentation. For a total of three halos, we see that a disk forms around the first clump. The central clump reaches {approx}10 solar masses after 40 yr, while subsequent accretion is expected at a rate of 10{sup -2} solar masses per year. In one of these halos, additional clumps form as a result of fragmentation which proceeds at larger scales. We note that subgrid-scale (SGS) turbulence yields relevant contributions to the stability of the protostellar disks. Both with and without the SGS model, themore » disk evolution appears rather stable during the timescale considered here. We conclude that the first protostar may reach masses up to 40-100 M{sub Sun }, which are only limited by the effect of radiative feedback.« less
Authors:
; ; ;  [1]
  1. Institut fuer Astrophysik, Georg-August-Universitaet, Friedrich-Hund-Platz 1, D-37077 Goettingen (Germany)
Publication Date:
OSTI Identifier:
22118667
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 772; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTRONOMY; ASTROPHYSICS; COOLING; COSMOLOGY; E CODES; FRAGMENTATION; GALACTIC EVOLUTION; GRAVITATIONAL COLLAPSE; HYDROGEN; LAGRANGIAN FUNCTION; LARGE-EDDY SIMULATION; MASS; RESOLUTION; STAR EVOLUTION; STARS; TURBULENCE; UNIVERSE