Finding the bivariate brightness distribution of galaxies from an HI selected sample

A method is presented that will enable the bivariate luminosity/surface bri ghtness distribution of galaxies to be determined from a relatively small H I selected sample. This will be taken from the HI Parkes All Sky Survey (HI PASS). The advantages of using an HI sample in order to avoid the selection effects that are present at optical wavelengths are discussed. We are deve loping an algorithm to automatically extract a uniform sample of galaxies f rom the HIPASS data cubes and to determine the parameters of these galaxies . We have so far conducted tests involving both simulated sources injected into cubes with real noise and data from the Multibeam Deep survey. Results from these tests are encouraging.