Ram pressure stripping and galaxy orbits: The case of the Virgo Cluster

We investigate the role of ram pressure stripping in the Virgo Cluster usin g N-body simulations. Radial orbits within the Virgo Cluster's gravitationa l potential are modeled and analyzed with respect to ram pressure stripping . The N-body model consists of 10,000 gas cloud complexes that can have ine lastic collisions. Ram pressure is modeled as an additional acceleration on the clouds located at the surface of the gas distribution in the direction of the galaxy's motion within the cluster. We made several simulations, ch anging the orbital parameters in order to recover different stripping scena rios using realistic temporal ram pressure profiles. We investigate systema tically the influence of the inclination angle between the disk and the orb ital plane of the galaxy on the gasdynamics. We show that ram pressure can lead to a temporary increase of the central gas surface density. In some ca ses a considerable part of the total atomic gas mass (several 10(8) M-circl e dot) can fall back onto the galactic disk after the stripping event. A qu antitative relation between the orbit parameters and the resulting H I deDc iency is derived containing explicitly the inclination angle between the di sk and the orbital plane. The comparison between existing H I observations and the results of our simulations shows that the H I deficiency depends st rongly on galaxy orbits. It is concluded that the scenario in which ram pre ssure stripping is responsible for the observed H I deficiency is consisten t with all H I 21 cm observations in the Virgo Cluster.