Thursday December 6th, 2012

Alexander L. Muratov, Oleg Y. Gnedin, Nickolay Y. Gnedin, Marcel Zemp (Submitted on 5 Dec 2012)
We revisit the formation and evolution of the first galaxies using new hydrodynamic cosmological simulations with the ART code. Our simulations feature a recently developed model for H2 formation and dissociation, and a star formation recipe that is based on molecular rather than atomic gas. Here, we develop and implement a new recipe for the formation of metal-free Population III stars. We find the epoch during which Pop III stars dominated the energy and metal budget of the first galaxies to be short-lived. Galaxies which host Pop III stars do not retain dynamical signatures of their thermal and radiative feedback for more than 10^8 yr after the lives of the stars end in pair-instability supernovae, even when we consider the maximum reasonable efficiency of the feedback. Though metals ejected by the supernovae can travel well beyond the virial radius of the host galaxy, they will typically begin to fall back quickly, and do not enrich a large fraction of the intergalactic medium. Galaxies more massive than 3 x 10^6 Msun re-accrete most of their baryons and transition to metal-enriched Pop II star formation.
Comments: 12 pages, 9 figures, submitted to ApJ
Subjects: Cosmology and Extragalactic Astrophysics (astro-ph.CO) Cite as: arXiv:1212.0909 [astro-ph.CO]
(or arXiv:1212.0909v1 [astro-ph.CO] for this version)

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