Automated Search For Compact Groups of Galaxies in The Southern Sky

We present a new sample of compact groups of galaxies obtained, for the first time, through a purely automated search. The 59 new groups, found over an area of ~1300 sq. deg. and complete down to b_j_ group ~15.2, have been extracted from the digitized COSMOS/UKST Southern Galaxy Catalogue using an algorithm implementing the same criteria used in the visual search by Hickson (ApJ, 255,382(1982)]. A comparison between the new sample and Hickson's shows that the latter is incomplete in terms of the selection criteria, satisfying tighter constraints than those stated explicitly. As a consequence of this, the peculiar luminosity properties claimed for Hickson's compact groups are, at least partially, due to visual biases. On the other hand, analysis of the new sample has confirmed the morphological concordance of member galaxies within each group. The observational followup of our new sample, which is free from any subjective bias, will allow us to answer the many puzzling questions raised by the study of Hickson's groups.