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Cosmology using the Parkes HI Multibeam Southern-Sky Survey

P. A. Thomas
Astronomy Centre, CPES, University of Sussex
Falmer, Brighton, BN19QH, UK
p.a.thomas@sussex.ac.uk

Abstract:

I discuss the implications of the Parkes Multibeam Southern-Sky HI\ Survey for cosmology. It will determine the local mass function of HI clouds, detecting several hundred per decade of mass. Each of these will come with a redshift and, for the more massive clouds, an estimate of the velocity width. This will provide an ideal database for peculiar motion studies and for measurements of biasing of galaxies relative to the underlying matter distribution.

Surveys -- Galaxies: luminosity function, mass function -- large-scale structure of the Universe

In this paper, I wish to discuss the implications for cosmology of the Parkes HI Multibeam Southern-Sky Survey (hereafter referred to as `the Multibeam Survey'). Most importantly, it will provide the first unbiased survey for HI clouds, either associated with galaxies or truly isolated: I will show below that many thousand new objects should be discovered whose mass-function will place great constraints on models of galaxy formation. The second important feature of the Multibeam Survey is that it will map the velocity structure of the local Universe in great detail. When combined with accurate Tully-Fisher distances, this will enable strong constraints to be placed on cosmological parameters, principally the density parameter.

© Copyright Astronomical Society of Australia 1997