The Sdss Damped Lyα Survey: Data Release 1 the Quasar Sample Was Drawn from Data Release 1 of the Sloan Digital Sky Survey to a Limiting Pertosian Mag- 1

نویسنده

  • Jason X. Prochaska
چکیده

We present the results from an automated search for damped Lyα (DLA) systems in the quasar spectra of Data Release 1 from the Sloan Digital Sky Survey (SDSS-DR1). At z ≈ 2.5, this homogeneous dataset exceeds the statistical significance of the previous two decades of research. We derive a statistical sample of 71 damped Lyα systems (> 50 previously unpublished) at z > 2.1 and measure H I column densities directly from the SDSS spectra. The number of DLA systems per unit redshift is consistent with previous measurements suggesting our survey has > 95% completeness. We examine the cosmological baryonic mass density of neutral gas Ωg inferred from the damped Lyα systems from the SDSS-DR1 survey and a combined sample drawing from past efforts. Contrary to previous results, the Ωg values do not require a significant correction from Lyman limit systems at any redshift. Furthermore, the Ωg values for the SDSS-DR1 sample do not decline at high redshift and the combined sample shows a (statistically insignificant) decrease only at z > 4. Future data releases from SDSS will provide the definitive survey of DLA systems at z ≈ 2.5 and will significantly reduce the uncertainty of Ωg at higher redshift. Subject headings: Galaxies: Evolution, Galaxies: Intergalactic Medium, Galaxies: Quasars: Absorption Lines

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تاریخ انتشار 2004