Mass and environment as drivers of galaxy evolution in SDSS and zCOSMOS and the origin of the Schechter function
Creators: name: Peng, Y.
name: Lilly, S. J.
name: Kovac, K.
name: Bolzonella, M.
name: Pozzetti, L.
name: Renzini, A.
name: Zamorani, G.
name: Ilbert, O.
name: Knobel, C.
name: Iovino, A.
name: Maier, C.
name: Cucciati, O.
name: Tasca, L.
name: Carollo, C. M.
name: Silverman, J.
name: Kampczyk, P.
name: de Ravel, L.
name: Sanders, D.
name: Scoville, N.
name: Contini, T.
name: Mainieri, V.
name: Scodeggio, M.
name: Kneib, J. -P.
name: Fevre, O. Le
name: Bardelli, S.
name: Bongiorno, A.
name: Caputi, K.
name: Coppa, G.
name: de la Torre, S.
name: Franzetti, P.
name: Garilli, B.
name: Lamareille, F.
name: Borgne, J. -F. Le
name: Brun, V. Le
name: Mignoli, M.
name: Montero, E. Perez
name: Pello, R.
name: Ricciardelli, E.
name: Tanaka, M.
name: Tresse, L.
name: Vergani, D.
name: Welikala, N.
name: Zucca, E.
name: Oesch, P.
name: Abbas, U.
name: Barnes, L.
name: Bordoloi, R.
name: Bottini, D.
name: Cappi, A.
name: Cassata, P.
name: Cimatti, A.
name: Fumana, M.
name: Hasinger, G.
name: Koekemoer, A. M.
name: Leauthaud, A.
name: Maccagni, D.
name: Marinoni, C.
name: McCracken, H. J.
name: Memeo, P.
name: Meneux, B.
name: Nair, P.
name: Porciani, C.
name: Presotto, V.
name: Scaramella, R.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We explore the inter-relationships between mass, star-formation rate and environment in the SDSS, zCOSMOS and other surveys. The differential effects of mass and environment are completely separable to z ~ 1, indicating that two distinct processes are operating, "mass-quenching" and "environment-quenching". Environment-quenching, at fixed over-density, evidently does not change with epoch to z ~ 1, suggesting that it occurs as large-scale structure develops in the Universe. The observed constancy of the mass-function shape for star-forming galaxies, demands that the mass-quenching of galaxies around and above M*, must be proportional to their star-formation rates at all z &lt; 2. We postulate that this simple mass-quenching law also holds over a much broader range of stellar mass and epoch. These two simple quenching processes, plus some additional quenching due to merging, then naturally produce (a) a quasi-static Schechter mass function for star-forming galaxies with a value of M* that is set by the proportionality between the star-formation and mass-quenching rates, (b) a double Schechter function for passive galaxies with two components: the dominant one is produced by mass-quenching and has exactly the same M* as the star-forming galaxies but an alpha shallower by +1, while the other is produced by environment effects and has the same M* and alpha as the star-forming galaxies, and is larger in high density environments. Subsequent merging of quenched galaxies modifies these predictions somewhat in the denser environments, slightly increasing M* and making alpha more negative. All of these detailed quantitative relationships between the Schechter parameters are indeed seen in the SDSS, lending strong support to our simple empirically-based model. The model naturally produces for passive galaxies the "anti-hierarchical" run of mean ages and alpha-element abundances with mass.
description: 66 pages, 19 figures, 1 movie, accepted for publication in ApJ. The movie is also available at http://www.exp-astro.phys.ethz.ch/zCOSMOS/MF_simulation_d1_d4.mov