@article{1d6964e7f613486198a823f4202dcfe6,
title = "Column density distribution and cosmological mass density of neutral gas: Sloan Digital Sky Survey-III Data Release 9",
abstract = "We present the first results from an ongoing survey for damped Lyman-a systems (DLAs) in the spectra of z > 2 quasars observed in the course of the Baryon Oscillation Spectroscopic Survey (BOSS), which is part of the Sloan Digital Sky Survey (SDSS) III. Our full (non-statistical) sample, based on Data Release 9, comprises 12 081 systems with log N(H i) = 20, out of which 6839 have log N(H i) = 20.3. This is the largest DLA sample ever compiled, superseding that from SDSS-II by a factor of seven. Using a statistical sub-sample and estimating systematics from realistic mock data, we probe the N(H i) distribution at z = 2.5. Contrary to what is generally believed, the distribution extends beyond 10 22 cm -2 with a moderate slope of index ≈-3.5. This result matches the opacity-corrected distribution observed at z = 0 surprisingly well. The cosmological mass density of neutral gas in DLAs is found to be ω DLA g ≈ 10 -3, evolving only mildly over the past 12 billion years.",
author = "P. Noterdaeme and P. Petitjean and Carithers, \{W. C.\} and I. Pĝris and A. Font-Ribera and S. Bailey and E. Aubourg and D. Bizyaev and G. Ebelke and H. Finley and J. Ge and E. Malanushenko and V. Malanushenko and J. Miralda-Escud{\'e} and Myers, \{A. D.\} and D. Oravetz and K. Pan and Pieri, \{M. M.\} and Ross, \{N. P.\} and Schneider, \{D. P.\} and A. Simmons and York, \{D. G.\}",
note = "Funding Information: We thank the anonymous referee for helpful comments and suggestions. The French participation group to SDSS-III was supported by the Agence Nationale de la Recherche under grant ANR-08-BLAN-0222. Funding for SDSS-III has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, and the US Department of Energy Office of Science. The SDSS-III web site is http://www.sdss3.org/ . SDSS-III is managed by the Astrophysical Research Consortium for the Participating Institutions of the SDSS-III Collaboration including the University of Arizona, the Brazilian Participation Group, Brookhaven National Laboratory, University of Cambridge, Carnegie Mellon University, University of Florida, the French Participation Group, the German Participation Group, Harvard University, the Instituto de Astrof{\'i}sica de Canarias, the Michigan State/Notre Dame/JINA Participation Group, Johns Hopkins University, Lawrence Berkeley National Laboratory, Max Planck Institute for Astrophysics, Max Planck Institute for Extraterrestrial Physics, New Mexico State University, New York University, Ohio State University, Pennsylvania State University, University of Portsmouth, Princeton University, the Spanish Participation Group, University of Tokyo, University of Utah, Vanderbilt University, University of Virginia, University of Washington, and Yale University.",
year = "2012",
doi = "10.1051/0004-6361/201220259",
language = "English (US)",
volume = "547",
journal = "Astronomy and Astrophysics",
issn = "0004-6361",
publisher = "EDP Sciences",
}