Participant List
Early Enrichment of the Lyman Alpha Forest
We examine the dynamical evolution and statistical properties of the
supernova ejecta of massive primordial stars in a cosmological
framework to determine whether this first population of stars could
have enriched the universe to the levels and dispersions seen by the
most recent observations of the Lyman-Alpha forest. We evolve a lambda
CDM model in a 1 Mpc3 volume to a redshift of z = 15 and add
``bubbles'' of metal corresponding to the supernova ejecta of the
first generation of massive stars in all dark matter halos with masses
greater than 5 times 105 solar masses. These initial conditions are
then evolved to z = 3 and the distribution and levels of metals are
compared to observations. In the absence of further star formation the
primordial metal is initially contained in halos and filaments.
Photoevaporation of metal-enriched gas due to the metagalactic
ultraviolet background radiation at the epoch of reionization (z ~ 6)
causes a sharp increase of the metal volume filling factor. At z = 3,
~ 2.5% of the simulation volume (approx. 20% of the total gas mass) is
filled with gas enriched above a metallicity of 10^-4 Z_solar, and
less than 0.6% of the volume is enriched above a metallicity of 10^-3
Z_solar. This suggests that, even with the most optimistic
prescription for placement of primordial supernova and the amount of
metals produced by each supernova, this population of stars cannot
entirely be responsible for the enrichment of the Lyman-$\alpha$
forest to the levels and dispersions seen by current observations
unless we have severely underestimated the duration of the Pop III
epoch. However, comparison to observations show that Pop III
supernovae can be significant contributors to the very low overdensity
Lyman-Alpha forest.