The Cosmological Evolution of Quasar Damped Lyman-Alpha Systems

We present results from an efficient, non-traditional survey to discover damped Lyman-alpha (DLA) absorption-line systems with neutral hydrogen column densities N(HI)>2x10^{20} atoms cm^{-2} and redshifts z<1.65. Contrary to previous studies at higher redshift that showed a decrease in the cosmological mass density of neutral gas in DLA absorbers, Omega_{DLA}, with time, our results indicate that Omega_{DLA} is consistent with remaining constant from redshifts z \approx 4 to z \approx 0.5. There is no evidence that Omega_{DLA} is approaching the value at z=0. Other interesting results from the survey are also presented.