Name    E_mail_Address  Scientific_Session      Contribution_type       Title   Authors_affiliations    Abstract        
Jachym Pavel    jachym@ig.cas.cz        EAS Symp.6:Dynamics of Galaxies and Galactic Nuclei.    oral    Galaxy evolution in clusters and groups - numerical simulations Jachym, P., Palous, J./Astronomical Institute, Academy of Sciences of the Czech Republic        In dense environments of galaxy clusters many processes affect the evolution of galaxies. We perform tree/SPH simulations of galaxies crossing on radial orbits about the cluster center the intracluster
medium (ICM). Density and distribution of the ICM, and velocity and shape of the orbital trajectory of the galaxy determine effects of the ram pressure on the interstellar gas of the galaxy. If the pressure exceeds the restoring gravitational force, the ISM can be swept out and frequently observed HI-deficient galaxies with a quenched star formation form. We follow the stripping amounts in galaxies of various types orbiting in different clusters. Before the galaxies enter the cluster, they reside in galaxy groups and are pre-processed by mutual tidal encounters and by hydrodynamical effects of the group environment. We study the combined tidal/ram-pressure effects by means of numerical simulations.