ABUNDANCE HISTORIES FOR QSO ABSORPTION-LINE SYSTEMS

Abundance histories for QSO absorption-line systems as a function of r edshift are presented for all metals lighter than gallium. Coupling va rious conventional cosmological models with a simple, first-order mode l for the chemical evolution of the QSO absorption-line systems allows transformation of the observed abundance trends in the Galaxy to abun dance histories for the gas in QSO absorption-line systems. Comparison of the transformed abundance patterns with the zinc to hydrogen [Zn/H ] and silicon to hydrogen [Si/H] ratios observed in damped Ly alpha sy stems finds agreement over more than two orders of magnitude in abunda nce with a Lambda = 0, Omega = 0.2-1.0, and tau(delay) = 3 Gyr cosmolo gy, where tau(delay) is the time between the start of the big bang and the beginning of galaxy formation. Alternative meanings for the requi red time delay are explored, along with extensions to the simple first -order model. Predictions are made for the abundance histories of elem ents not yet observed in QSO absorption-line systems.