Star formation quenching in galaxies

¹ Department of Astronomy, Yonsei University, Seoul 120-749, Korea ;
email: tskim@galaxy.yonsei.ac.kr
² Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218, USA
³ Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
⁴ National Optical Astronomy Observatory, 950 North Cherry Ave., Tucson, AZ 85719, USA
⁵ Dipartimento di Astronomia, Università di Trieste, via Tiepolo 11, 34143 Trieste, Italy
⁶ INAF-Osservatorio Astronomico, via Tiepolo 11, 34143 Trieste, Italy
⁷ Department of Astronomy, University of Massachusetts, Amherst, MA 01003-9305, USA
⁸ Department of Physics and Astronomy, University of California, USA
⁹ Shanghai Astronomical Observatory, China

Abstract

We investigate the correlation of star formation quenching with internal galaxy properties and environment by comparing observation and theoretical models. We first classify galaxies as the most massive “central” or “satellite” in each halo in order to investigate the environmental effect. For observed central galaxies, we are unable to determine whether star formation quenching is primarily connected with halo mass or stellar mass, because these two quantities are strongly correlated. For satellite galaxies, a nearly equal dependence on halo mass and stellar mass is seen. We find that theoretical models with AGN feedback reproduce the dependence on colours and specific star formation rates for central galaxies reasonably. However, the same models seriously fail to reproduce the star formation rates of satellite galaxies by over-quenching star formation via strong strangulation: satellite over-quenching problem.