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., that are red, is systematically higher than that of centrals, as seen locally in the Sloan Digital Sky Survey (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. analysis of the SDSS groups. Together, these results indicate that the effect of the group environment in quenching satellite galaxies was very similar to what it is today when the universe was about half its present age.
C. Knobel, S. J. Lilly, K. Kovac, Y. Peng, T. J. Bschorr, C. M. Carollo, et al. (2013). The colors of central and satellite galaxies in zCOSMOS out to z~0.8 and implications for quenching. THE ASTROPHYSICAL JOURNAL, 769, 24-33 [10.1088/0004-637X/769/1/24].
The colors of central and satellite galaxies in zCOSMOS out to z~0.8 and implications for quenching
CUCCIATI, OLGA;CIMATTI, ANDREA;MORESCO, MICHELE ENNIO MARIA;
2013
Abstract
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., that are red, is systematically higher than that of centrals, as seen locally in the Sloan Digital Sky Survey (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. analysis of the SDSS groups. Together, these results indicate that the effect of the group environment in quenching satellite galaxies was very similar to what it is today when the universe was about half its present age.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.