Environmental Effects on Galaxies in Clusters and Groups

Abstract

International audienceGalaxies in clusters and groups are perturbed by the effects of the environment due to ram pressure stripping of their HI gas by an intra-cluster X-ray gas or to gravitational interactions between galaxies or with the cluster potential well. We will review the most recent results concerning some galaxies in the Virgo Cluster and in the Stephan's Quintet and show how extragalactic HII regions can be formed from debris stripped by ram pressure or tidal interactions