Paper detail

The HI properties of galaxies in the Coma I cloud revisited

Pre-processing within small groups has been proposed to explain several of the properties of galaxies inhabiting rich clusters. The aim of the present work is to see whether pre-processing is acting in the nearby universe, where the structures that are merging to form rich clusters are rather large and massive. We study the HI gas properties of a large sample of late-type galaxies belonging to the Coma I cloud, an association of objects close to the Virgo cluster. Contrary to what previously claimed, late-type galaxies in the Coma I cloud are not deficient in HI gas (HI-def=0.06+-0.44). If the Coma I cloud is representative of infalling groups in nearby clusters, this result suggests that, in the local universe, the evolution of late-type galaxies belonging to loose structures with high velocity dispersions (>= 300 km/s)associated to rich clusters such as Virgo is not significantly perturbed by pre-processing.