S0 Galaxies: Outer Gas Accretion through Tidal Interaction and Minor Merging

To clarify the sources of outer gas accretion onto disk galaxies, we study the vicinity of four interacting galaxy systems in the H alpha emission line by using the scanning Fabry-Perot interferometer of the 6m telescope of the Special Astrophysical Observatory RAS. We find perspective accretion flows seen as ionized-gas emission filaments between the galaxies. We discuss the whole kinematics and origin of these flows.