Oral Presentation

The effect of group environment on the star-forming sequence and quiescent fraction in the PanSTARRSS Medium Deep Survey

Author(s): Lihwai Lin, Hung-Yu Jian, Sebastien Foucaud, + PS1 team

Presenter: Lihwai Lin (ASIAA)

Using groups and clusters identified with probability friend-of-friend (PFOF) group finder from the PS1 Medium Deep Survey, we study the impacts of the environment on the star formation activities of galaxies. While the fraction of quiescent galaxies increases from the field, to the group- and cluster-like environment, the slope and amplitude of the star-forming sequence is insensitive to the environment, favoring a fast quenching process operating in the overdense environments. By studying the stellar mass dependence of the mass- and environment- quenching efficiency, we conclude that the mass quenching is a dominant process in quenching the star formation for massive galaxies, while the environment quenching is more important for less massive galaxies.