New Damped Lya Metallicities from ESI Spectroscopy of Five Palomar Sky Survey Quasars

Abstract

This paper presents chemical abundance measurements for 12 new z>3 damped Lya systems discovered toward five quasars from the Palomar Sky Survey. We determine HI column densities from profile fits to the observed damped Lya profiles and measure ionic column densities and limits for all observed metal-line transitions. This dataset, acquired with the Echellette Spectrograph and Imager on the KeckII telescope, adds to the rapidly growing database of damped Lya abundances. It will impact studies of chemical evolution in the early universe and help identify candidates for detailed follow-up observations with echelle spectrographs. We report the discovery of the first quasar sightline with four cosmologically distinct damped Lya systems.