2006ApJ...640...41H

Nucleosynthetic signatures in common are found between the gas responsible for the high-redshift Lyα forest and a subsample of extremely metal-poor stars. 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, which contributes to a circumgalactic medium (CGM). The CGM has earlier been shown to have a mass of ∼10% of all baryons and peak [Fe/H]~-1.