THE FIRST GALAXIES: CHEMICAL ENRICHMENT, MIXING, AND STAR FORMATION

Journal Article · Thu Jun 10 00:00:00 EDT 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/716/1/510· OSTI ID:21450851

Greif, Thomas H ^[1]; Glover, Simon C. O.; Klessen, Ralf S ^[2]; Bromm, Volker ^[3]

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1. Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Strasse 1, 85740 Garching bei Muenchen (Germany)
2. Zentrum fuer Astronomie der Universitaet Heidelberg, Institut fuer Theoretische Astrophysik, Albert-Ueberle-Strasse 2, 69120 Heidelberg (Germany)
3. Department of Astronomy, University of Texas, Austin, TX 78712 (United States)

Using three-dimensional cosmological simulations, we study the assembly process of one of the first galaxies, with a total mass of {approx}10{sup 8} M {sub sun}, collapsing at z {approx_equal} 10. Our main goal is to trace the transport of the heavy chemical elements produced and dispersed by a pair-instability supernova exploding in one of the minihalo progenitors. To this extent, we incorporate an efficient algorithm into our smoothed particle hydrodynamics code that approximately models turbulent mixing as a diffusion process. We study this mixing with and without the radiative feedback from Population III (Pop III) stars that subsequently form in neighboring minihalos. Our simulations allow us to constrain the initial conditions for second-generation star formation, within the first galaxy itself, and inside of minihalos that virialize after the supernova explosion. We find that most minihalos remain unscathed by ionizing radiation or the supernova remnant, while some are substantially photoheated and enriched to supercritical levels, likely resulting in the formation of low-mass Pop III or even Population II (Pop II) stars. At the center of the newly formed galaxy, {approx}10{sup 5} M {sub sun} of cold, dense gas uniformly enriched to {approx}10{sup -3} Z {sub sun} is in a state of collapse, suggesting that a cluster of Pop II stars will form. The first galaxies, as may be detected by the James Webb Space Telescope, would therefore already contain stellar populations familiar from lower redshifts.

• OSTI ID: 21450851
• Journal Information: Astrophysical Journal, Vol. 716, Issue 1; Other Information: DOI: 10.1088/0004-637X/716/1/510; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ALGORITHMS
COSMOLOGY
GALAXIES
HYDRODYNAMICS
IONIZING RADIATIONS
MASS
RED SHIFT
SIMULATION
SUPERNOVA REMNANTS
SUPERNOVAE
TELESCOPES
THREE-DIMENSIONAL CALCULATIONS
BINARY STARS
COSMIC RADIO SOURCES
ERUPTIVE VARIABLE STARS
FLUID MECHANICS
MATHEMATICAL LOGIC
MECHANICS
RADIATIONS
STARS
VARIABLE STARS