Star Formation and Chemical Evolution in Damped Lya Clouds

Abstract

Using the redshift evolution of the neutral hydrogen density, as inferred from observations of damped Ly$\alpha$ clouds, we calculate the evolution of star formation rates and elemental abundances in the universe. For most observables our calculations are in rough agreement with previous results based on the instantaneous re-cycling approximation (IRA). However, for the key metallicity tracer Zn, we find a better match to the observed abundance at high redshift than that given by the constant-yield IRA model. We investigate whether the redshift evolution of deuterium, depressions in the diffuse extragalactic gamma-ray background, and measurement of the MeV neutrino background may help determine if observational bias due to dust obscuration is important. We also indicate how the importance of dust on the calculations can be significantly reduced if correlations of the HI column density with metallicity are present. The possibilities for measuring $q_o$ with observations of elemental abundances in damped Ly$\alpha$ systems are discussed.

12 pages, tex, 9 figures available by anon ftp at ftp://ftp.cita.utoronto.ca/ftp/cita/malaney/figure1.ps (thro figure8.ps)

Cited by in corpus (24)

• Damped Lyman alpha Systems
• Chemical Abundances of the Damped Lya Systems at z>1.5
• Intensity Mapping of the [CII] Fine Structure Line during the Epoch of Reionization
• Dust in High Redshift Galaxies
• A Homogeneous Sample of Sub-DLAs III: Total Gas Mass Omega_(HI+HeII) at z>2
• Hubble Space Telescope Observations of Element Abundances in Low-redshift Damped Lyman-alpha Galaxies and Implications for the Global Metallicity-Redshift Relation
• Metallicity Evolution in the Early Universe
• The ESO UVES Advanced Data Products Quasar Sample - VI. Sub-Damped Lyman-$\alpha$ Metallicity Measurements and the Circum-Galactic Medium
• Metals and Dust in Intermediate-redshift Damped Ly-alpha Galaxies
• Metallicity evolution of AGNs from UV emission-lines based on a new index
• Metallicity Evolution of Damped Lyman-Alpha Galaxies
• The Most Metal-Rich Intervening Quasar Absorber Known
• Evolution of the Cosmic Gas and the Relic Supernova Neutrino Background
• Metal-rich Damped/sub-Damped Lyman-alpha Quasar Absorbers at z<1
• Metallicity Evolution of Damped Lyman Alpha Systems In Lambda CDM Cosmology
• Galactic Chemical Abundances at z>3 I: First Results from the Echellette Spectrograph and Imager
• Metal abundances at z<1.5: new measurements in sub-Damped Lyman-alpha Absorbers
• Chemical enrichment of Damped Lyman Alpha systems as a direct constraint on Population III star formation
• Cosmic metal production and the mean metallicity of the Universe
• Metallicity in damped Lyman-alpha systems: evolution or bias?
• A Stochastic Approach to Chemical Evolution
• Is Deuterium in High Redshift Lyman Limit Systems Primordial?
• Cosmic evolution of metal densities: the enrichment of the Inter-Galactic Medium
• Global Evolution Models and the Extragalactic Background Light