Rmag surface brightness of HIDEEP galaxies

Minchin et al. (2004, Cat. <J/MNRAS/346/787>) have recently placed limits on the cosmological significance of gas-rich low surface brightness (LSB) galaxies as a proportion of the total population of gas-rich galaxies by carrying out a very deep survey (HIDEEP) for neutral hydrogen (HI) with the Parkes multibeam system. Such a survey avoids the surface brightness selection effects that limit the usefulness of optical surveys for finding LSB galaxies.

To complement the HIDEEP survey, we have digitally stacked eight 1-h R-band Tech Pan films from the UK Schmidt Telescope covering 36{deg}^2^ of the survey area to reach a very deep isophotal limit of 26.5Rmag/arcsec^2^. At this level, we find that all of the 129 HI sources within this area have optical counterparts and that 107 of them can be identified with individual galaxies.