Zusammenfassung
We examine the red fraction of central and satellite galaxies in the large
zCOSMOS group catalog out to z ~ 0.8 correcting for both the incompleteness in
stellar mass and for the less than perfect purities of the central and
satellite samples. We show that, at all masses and at all redshifts, the
fraction of satellite galaxies that have been quenched, i.e., are red, is
systematically higher than that of centrals, as seen locally in the SDSS. The
satellite quenching efficiency, which is the probability that a satellite is
quenched because it is a satellite rather than a central, is, as locally,
independent of stellar mass. Furthermore, the average value is about 0.5, which
is also very similar to that seen in the SDSS. We also construct the mass
functions of blue and red centrals and satellites and show that these broadly
follow the predictions of the Peng et al. (2012) analysis of the SDSS groups.
Together, these results indicate that the effect of the group environment in
quenching satellite galaxies was very similar when the Universe was about a
half its present age, as it is today.
Nutzer