Related papers: The ESI/KeckII Damped Lya Abundance Database
We publish the Keck/HIRES and Keck/ESI spectra that we have obtained during the first 10 years of Keck observatory operations. Our full sample includes 42 HIRES spectra and 39 ESI spectra along 65 unique sightlines providing abundance…
We present new chemical abundance measurements of 16 damped Lya systems at z>1.5 and update our previous abundance analyses. The entire database presented here was derived from HIRES observations on the Keck I telescope, reduced with the…
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…
We present the first results from an ongoing survey to discover and measure the metallicity of z>3 damped Lya systems with the Echellette Spectrograph and Imager (ESI) on the Keck II telescope. Our motivation arises from a recent study on…
We present a comprehensive analysis of the damped Lya abundance database presented in the first paper of this series. This database provides a homogeneous set of abundance measurements for many elements including Si, Cr, Ni, Zn, Fe, Al, S,…
We present chemical abundance measurements for 19 damped lya systems observed with HIRES on the 10m W.M. Keck Telescope. Our principal goal is to investigate the abundance patterns of the damped systems and thereby determine the underlying…
We analyze Keck HIRES observations of a Lyman limit system at z=2.652 toward Q2231-00. These observations afford the most comprehensive study of the physical properties of a LL system to date. By comparing the ionic column densities for…
In this first paper of a series, we report on the use of quasar spectra obtained with the UVES high resolution spectrograph and available through the ESO VLT archive to build the first sample of sub-DLA systems, absorbers with HI column…
We investigate the ionization state of the damped Lya system at z=2.62 toward GB1759+7539 through an analysis of ionic ratios sensitive to photoionization: ArI/SII, FeIII/FeII, NII/NI, AlIII/AlII. Approximately half of the metals arise in a…
We present 14 N^0 measurements from our HIRES/Keck database of damped Lya abundances. These data are combined with measurements from the recent and past literature to build an homogeneous, uniform set of observations. We examine…
We present high resolution ($\approx 8$ \kms) spectra of the QSO Q0201+365 obtained with HIRES, the echelle spectrograph on the 10m W.M. Keck Telescope. Although we identify over $80\%$ of the absorption features and analyze several of the…
We present HIRES observations for 30 damped Lyman alpha systems, selected on the basis of their large metal column densities from previous, lower resolution data. The measured metal column densities for Fe, Zn, S, Si, Cr, Mn, and Ni are…
Damped Ly-alpha Systems (DLAs), with N(HI)>2*10^20 cm^{-2}, observed in quasars have allowed us to quantify the chemical content of the Universe over cosmological scales. Such studies can be extended to lower N(HI), in the sub-DLA range…
We present high resolution, high SNR spectra of the QSO Q2206-199 obtained with HIRES on the 10m W.M. Keck Telescope. Our analysis focuses on the two previously identified damped \lya systems found at $z=1.920$ and $z=2.076$. For each…
We present elemental abundance measurements for 9 damped Ly-alpha systems (DLAs) and 1 sub-DLA at 0.1 < z < 1.5 from recent observations with the Multiple Mirror Telescope. Most of these absorbers are found to be metal-poor, while 2 are…
We present Keck/HIRES abundance measurements and metal-line kinematic profiles of the damped Lyman alpha systems (DLAs) towards the quasars Q0933+733 (z_abs=1.479) and Q0948+433 (z_abs=1.233). These two DLAs have among the five highest HI…
The Damped and sub-Damped Lyman-alpha (DLA and sub-DLA) systems seen in the spectra of QSOs offer a unique way to study the interstellar medium of high redshift galaxies. In this paper we report on new abundance determinations in a sample…
We have completed spectroscopic observations using LRIS on the Keck 1 telescope of 30 very high redshift quasars, 11 selected for the presence of damped Ly-alpha absorption systems and 19 with redshifts z > 3.5 not previously surveyed for…
We use the average E(B-V) and ZnII column densities of a sample of z~1 CaII (3935, 3970) absorption line systems selected from the Sloan Digital Sky Survey (SDSS DR4) to show that on average, with conservative assumptions regarding…
We study metal abundances in the z=0.9313 damped Lya system observed in the two lines-of-sight, A and B, toward the gravitationally-lensed double QSO HE0512-3329. Spatially resolved STIS spectra constrain the neutral-gas column density to…