Column density distribution and cosmological mass density of neutral gas: Sloan Digital Sky Survey-III Data Release 9

We present the first results from an ongoing survey for damped Lyman-α 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...

Full description

Saved in:

Bibliographic Details
Published in:	Astronomy and astrophysics (Berlin) 2012-11, Vol.547, p.L1
Main Authors:	Noterdaeme, P., Petitjean, P., Carithers, W. C., Pâris, I., Font-Ribera, A., Bailey, S., Aubourg, E., Bizyaev, D., Ebelke, G., Finley, H., Ge, J., Malanushenko, E., Malanushenko, V., Miralda-Escudé, J., Myers, A. D., Oravetz, D., Pan, K., Pieri, M. M., Ross, N. P., Schneider, D. P., Simmons, A., York, D. G.
Format:	Article
Language:	eng
Subjects:	Astronomy Astrophysics Cosmology and Extra-Galactic Astrophysics cosmology: observations Earth, ocean, space Exact sciences and technology galaxies: evolution Physics quasars: absorption lines Sciences of the Universe
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	We present the first results from an ongoing survey for damped Lyman-α 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 1022 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 \hbox{$\omegagdla \approx 10^{-3}$}ΩgDLA≈10-3, evolving only mildly over the past 12 billion years.
ISSN:	0004-6361 1432-0746