Galactic Chemical Abundances at z>3 I: First Results from the Echellette Spectrograph and Imager

Abstract

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 the damped Lya systems suggesting only mild evolution in the cosmic metallicity from z~2 to 4. The Echellette Spectrograph and Imager, which provides two complementary spectroscopic modes, is the ideal instrument for a z>3 damped Lya survey. We describe our observing strategy and report on the discovery and analysis of 5 new z>3 damped Lya systems acquired in a single night of observing. These observations further support the principal conclusions of the previous study: (1) the cosmic metallicity in neutral gas inferred from the damped Lya systems does not evolve significantly from z~2 to 4; (2) the unweighted metallicity exhibits a statistically significant decrease with increasing redshift; and (3) not a single damped Lya system has a metallicity below [Fe/H]=-3. We discuss the implications of these results and comment on recent theoretical studies which attempt to explain the observations.

6 pages, 3 encapsulated color figures, uses emulateapj5.sty. Accepted for publication in the Astrophysical Journal, Dec 22 2000

References in corpus (1)

• UVES observations of a damped Ly-alpha system at z_abs = 4.466 towards the quasar APM BR J0307-4945

Cited by in corpus (47)

• The Rest Frame Optical Spectra of Lyman Break Galaxies: Star Formation, Extinction, Abundances, and Kinematics
• ESI, a new Keck Observatory echellette spectrograph and imager
• Metallicity Evolution of Damped Lyman-alpha Systems out to z~5
• The Age-Metallicity Relation of the Universe in Neutral Gas: The First 100 Damped Lya Systems
• Velocity-Metallicity Correlation for high-z DLA Galaxies: Evidence for a Mass-Metallicity Relation?
• A Direct Precision Measurement of the Intergalactic Lyman-alpha Opacity at 2<z<4.2
• The evolution of Omega(HI) and the epoch of formation of damped Lyman-alpha absorbers
• The UCSD HIRES/KeckI Damped Lya Abundance Database: II. The Implications
• Monte Carlo Simulation of Lyman Alpha Scattering and Application to Damped Lyman Alpha Systems
• Metallicities and Abundance Ratios from Quasar Broad Emission Lines
• A physical upper limit on the HI column density of gas clouds
• Hubble Space Telescope Observations of Element Abundances in Low-redshift Damped Lyman-alpha Galaxies and Implications for the Global Metallicity-Redshift Relation
• The UCSD HIRES/KeckI Damped Lya Abundance Database: I. The Data
• The ESI/KeckII Damped Lya Abundance Database
• The 1.6um Bump as a Photometric Redshift Indicator
• A Homogeneous Sample of Sub-DLAs I: Construction of the Sample and Chemical Abundance Measurements
• The Ucsd/Keck Damped Lya Abundance Database: A Decade of High Resolution Spectroscopy
• A Homogeneous Sample of Sub-DLAs II: Statistical, Kinematic and Chemical Properties
• Approaching Reionization: The Evolution of the Lyman Alpha Forest from Redshifts Four to Six
• The ESO UVES Advanced Data Products Quasar Sample - VI. Sub-Damped Lyman-$\alpha$ Metallicity Measurements and the Circum-Galactic Medium
• Determination of Nucleosynthetic Yields of Supernovae and Very Massive Stars from Abundances in Metal-Poor Stars
• The Role of Sub-damped Lyman-alpha Absorbers in the Cosmic Evolution of Metals
• Metals and Dust in Intermediate-redshift Damped Ly-alpha Galaxies
• Chemical evolution and nature of Damped Lyman-Alpha systems
• Metallicity Evolution of Damped Lyman-Alpha Galaxies
• Bimodality in Damped Lyman alpha Systems
• The color excess of quasars with intervening DLA systems- Analysis of the SDSS data release five
• Metallicity Evolution of Damped Lyman Alpha Systems In Lambda CDM Cosmology
• Molecular hydrogen in the z = 2.66 damped Lyman-alpha absorber toward Q J0643-5041
• Hubble Space Telescope Observations of Sub-Damped Lyman-alpha Absorbers at z < 0.5, and Implications for Galaxy Chemical Evolution
• Metal abundances at z<1.5: new measurements in sub-Damped Lyman-alpha Absorbers
• The connection between metallicity and metal-line kinematics in (sub-)damped Lyman-alpha systems
• The Implications of the New Z=0 Stellar Models and Yields on the Early Metal Pollution of the Intergalactic Medium
• Distinct Abundance Patterns in Multiple Damped Ly-alpha Galaxies: Evidence for Truncated Star Formation?
• The chemistry of the most metal-rich damped Lyman $\alpha$ systems at z$\sim 2$ II. Context with the Local Group
• Probing the metallicity and ionization state of the circumgalactic medium at z~6 and beyond with OI absorption
• A catalogue of damped Lyman alpha absorption systems and radio flux densities of the background quasars
• Element Abundances at High-redshift: Magellan MIKE Observations of sub-Damped Lyman-alpha Absorbers at 1.7 < z <2.4
• The Prompt Inventory from Very Massive Stars and Elemental Abundances in Ly Alpha Systems
• New Damped Lya Metallicities from ESI Spectroscopy of Five Palomar Sky Survey Quasars
• A new measurement of zinc metallicity in a DLA at z=3.35
• Are Simulations of CDM Consistent with Galactic-Scale Observations at High Redshift?
• The most metal-rich damped Lyman alpha systems at z>1.5 I: The Data
• Empirical Constraints on Core Collapse Supernova Yields using Very Metal Poor Damped Lyman Alpha Absorbers
• KBSS-InCLOSE I: Design and First Results from the Inner CGM of QSO Line Of Sight Emitting Galaxies at z~2-3
• Exploring the cosmic dark ages with the next generation of space and ground-based facilities
• A 22GHz search for molecular absorption at z~3 with the upgraded ATCA