Journal ArticleDOI
The Evolution and Space Density of Damped Lyman-alpha Galaxies
TLDR
The results of a new spectroscopic survey of 66 $z \simgt 4$ quasars for Damped Lyman-alpha absorption systems are presented in this paper.Abstract:
The results of a new spectroscopic survey of 66 $z \simgt 4$ quasars for Damped Lyman-alpha absorption systems are presented. The search led to the discovery of 30 new DLA candidates which are analysed in order to compute the comoving mass density of neutral gas in a non-zero lambda Universe. The possible sources of uncertainty are discussed and the implications of our results for the theories of galaxy formation and evolution are emphasized. A subsequent paper will present details of the calculations summarised here and a more extensive explanation of the consequences of our observations for the understanding of the nature of DLAs.read more
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Journal ArticleDOI
The 1000 brightest hipass galaxies: The HI mass function and Omega(HI)
Martin Zwaan,Lister Staveley-Smith,Baerbel Koribalski,P. A. Henning,Virginia A. Kilborn,Stuart D. Ryder,David G. Barnes,R. Bhathal,P. J. Boyce,W. J. G. de Blok,M. J. Disney,Michael J. Drinkwater,Ron Ekers,Kenneth C. Freeman,Brad K. Gibson,A. J. Green,R. F. Haynes,Helmut Jerjen,S. Juraszek,Michael Kesteven,P. M. Knezek,Renee C. Kraan-Korteweg,Stacy Mader,M. Marquarding,Martin Meyer,Robert F. Minchin,J. R. Mould,J. O'Brien,Tom Oosterloo,R. M. Price,Mary E. Putman,Emma V. Ryan-Weber,Emma V. Ryan-Weber,Elaine M. Sadler,A. C. Schröder,Ian M. Stewart,F. Stootman,B. A. Warren,M. Waugh,Rachel L. Webster,Alan E. Wright +40 more
TL;DR: In this article, the authors present a new, accurate measurement of the H I mass function of galaxies from the HIPASS Bright Galaxy Catalog, a sample of 1000 galaxies with the highest H I peak flux densities in the southern (delta < 0D) hemisphere.
Journal ArticleDOI
Abundance of damped Lyman α absorbers in cosmological smoothed particle hydrodynamics simulations
TL;DR: In this article, the authors used cosmological smoothed particle hydrodynamics (SPH) simulations of the A cold dark matter (CDM) model to study the abundance of damped Lyman a absorbers (DLAs) in the redshift range z = 0-4.5.
Journal ArticleDOI
Probing dark energy with baryonic oscillations and future radio surveys of neutral hydrogen
F. B. Abdalla,Steve Rawlings +1 more
TL;DR: In this article, the authors present a new calculation of the number of galaxies future radio telescopes will detect in surveys of the sky in neutral hydrogen (H 1), and estimate the likely statistical errors if the standard ruler method were to be applied to such surveys.
Journal ArticleDOI
Weak lensing reconstruction through cosmic magnification I: a minimal variance map reconstruction
Xin-Juan Yang,Pengjie Zhang +1 more
TL;DR: In this article, a minimal variance linear estimator is proposed to minimize both the dominant systematic and statistical errors in the map reconstruction, which is applicable to all galaxy surveys with reasonable redshift information.