Early Cosmic Chemical Evolution: Relating the Origin of a Diffuse Intergalactic Medium and the First Long-Lived Stars

Abstract

Nucleosynthetic signatures in common between the gas responsible for the high redshift Lyman alpha forest and a subsample of extremely metal poor stars are found. A simple mass loss model of chemical evolution with physically motivated parameters provides a consistent picture in which the gas is identified with that lost by supernova-driven winds during the first generation of star formation. Substantial mass loss occurs which can account for a diffuse IGM with up to 80% of the total baryon content and a peak [C-O/H] abundance of \~-2.9. This mass loss component differs from one produced later during galaxy formation and evolution that contributes to a circum-galactic medium (CGM). The CGM was shown earlier to have a mass of ~10% of all baryons and peak [Fe/H]~-1.