Oral Presentation

Star formation history of interacting galaxies in clusters

Author(s): Jianling Gan (SHAO)

Presenter: Jianling Gan (Shanghai Astronomical Observatory, Chinese Academy of Sciences)

Using a semi-analytical model of Galacticus and the dark matter halo merger trees output by Phoenix simulation, we study the various effects of galaxy interaction in the rich galaxy cluster. The main physical process about the galaxy interaction are the ram pressure stripping and tidal stripping on the satellite galaxies when they travel in the galaxy cluster. In the results, we select a large sample of isolated, central and satellite from the modeling clusters and compare the probability distribution of star formation rate (SFR), color and morphology of different galaxy group. We find that the central galaxies strip gas from
their satellite and the SFR increase remarkably at the early stage, while at the later stage, the SFR decrease as there are strong feedback. We find that the star formation in satellite are strongly suppressed by gas stripping. The satellite life time, which are determined by their formation time and the dynamical friction, also play an important role in the evolution of satellite SFR. Those satellites have shorter life time will be less affected by the gas stripping and have higher SFR. In the group environment of galaxy cluster, the galaxies are moving toward the cluster and the gas stripping tend to be more efficiently, which increases the star formation of central galaxies and decrease that of satellite galaxies, respectively.