Mixing of Primordial Gas in Lyman Break Galaxies

Abstract

Motivated by an interpretation of $z\sim 3$ objects by Jimenez and Haiman (2006), we examine processes that control the fraction of primordial ($Z=0$) gas, and so primordial stars, in high-SFR Lyman break galaxies. A primordial fraction different from 1 or 0 requires microscopic diffusion catalyzed by a velocity field with timescale comparable to the duration of star formation. The only process we found that satisfies this requirement for LBGs without fine-tuning is turbulence-enhanced mixing induced by exponential stretching and compressing of metal-rich ejecta. The time-dependence of the primordial fraction for this model is calculated. We show that conclusions for all the models discussed here are virtually independent of the IMF, including extremely top-heavy IMFs.

5 pages, 1 figure. Accepted for publication in ApJ Letters

References in corpus (6)

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• Star Formation in Close Pairs Selected from the Sloan Digital Sky Survey
• Significant primordial star formation at redshifts z ~ 3-4
• On the First Generation of Stars
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• Following The Cosmic Evolution Of Pristine Gas I: Implications For Milky Way Halo Stars
• Alignment of the scalar gradient in evolving magnetic fields
• Searching for Pop III stars and galaxies at high redshift