Bibcode
Bolzonella, M.; Kovač, K.; Pozzetti, L.; Zucca, E.; Cucciati, O.; Lilly, S. J.; Peng, Y.; Iovino, A.; Zamorani, G.; Vergani, D.; Tasca, L. A. M.; Lamareille, F.; Oesch, P.; Caputi, K.; Kampczyk, P.; Bardelli, S.; Maier, C.; Abbas, U.; Knobel, C.; Scodeggio, M.; Carollo, C. M.; Contini, T.; Kneib, J.-P.; Le Fèvre, O.; Mainieri, V.; Renzini, A.; Bongiorno, A.; Coppa, G.; de la Torre, S.; de Ravel, L.; Franzetti, P.; Garilli, B.; Le Borgne, J.-F.; Le Brun, V.; Mignoli, M.; Pelló, R.; Perez-Montero, E.; Ricciardelli, E.; Silverman, J. D.; Tanaka, M.; Tresse, L.; Bottini, D.; Cappi, A.; Cassata, P.; Cimatti, A.; Guzzo, L.; Koekemoer, A. M.; Leauthaud, A.; Maccagni, D.; Marinoni, C.; McCracken, H. J.; Memeo, P.; Meneux, B.; Porciani, C.; Scaramella, R.; Aussel, H.; Capak, P.; Halliday, C.; Ilbert, O.; Kartaltepe, J.; Salvato, M.; Sanders, D.; Scarlata, C.; Scoville, N.; Taniguchi, Y.; Thompson, D.
Bibliographical reference
Astronomy and Astrophysics, Volume 524, id.A76
Advertised on:
12
2010
Journal
Citations
197
Refereed citations
190
Description
We study the impact of the environment on the evolution of galaxies in
the zCOSMOS 10 k sample in the redshift range 0.1 ≤ z ≤ 1.0 over
an area of ~1.5 deg2. The considered sample of secure
spectroscopic redshifts contains about 8500 galaxies, with their stellar
masses estimated by SED fitting of the multiwavelength optical to
near-infrared (NIR) photometry. The evolution of the galaxy stellar mass
function (GSMF) in high and low density regions provides a tool to study
the mass assembly evolution in different environments; moreover, the
contributions to the GSMF from different galaxy types, as defined by
their SEDs and their morphologies, can be quantified. At redshift z ~ 1,
the GSMF is only slightly dependent on environment, but at lower
redshifts the shapes of the GSMFs in high- and low-density environments
become extremely different, with high density regions exhibiting a
marked bimodality, not reproducible by a single Schechter function. As a
result of this analysis, we infer that galaxy evolution depends on both
the stellar mass and the environment, the latter setting the probability
of a galaxy to have a given mass: all the galaxy properties related to
the stellar mass show a dependence on environment, reflecting the
difference observed in the mass functions. The shapes of the GSMFs of
early- and late-type galaxies are almost identical for the extremes of
the density contrast we consider, ranging from isolated galaxies to rich
group members. The evolution toward z = 0 of the transition mass
M_cross, i.e., the mass at which the early- and late-type GSMFs match
each other, is more rapid in high density environments, because of a
difference in the evolution of the normalisation of GSMFs compared to
the total one in the considered environment. The same result is found by
studying the relative contributions of different galaxy types, implying
that there is a more rapid evolution in overdense regions, in particular
for intermediate stellar masses. The rate of evolution is different for
sets of galaxy types divided on the basis of their SEDs or their
morphologies, tentatively suggesting that the migration from the blue
cloud to the red sequence occurs on a shorter timescale than the
transformation from disc-like morphologies to ellipticals. Our analysis
suggests that environmental mechanisms of galaxy transformation start to
be more effective at z < 1. The comparison of the observed GSMFs to
the same quantities derived from a set of mock catalogues based on
semi-analytical models shows disagreement, in both low and high density
environments: in particular, blue galaxies in sparse environments are
overproduced in the semi-analytical models at intermediate and high
masses, because of a deficit of star formation suppression, while at z
< 0.5 an excess of red galaxies is present in dense environments at
intermediate and low masses, because of the overquenching of satellites.
Based on observations obtained at the European Southern Observatory(ESO)
Very Large Telescope (VLT), Paranal, Chile, as part of the Large Program
175.A-0839 (the zCOSMOS Spectroscopic Redshift Survey).
Related projects
Traces of Galaxy Formation: Stellar populations, Dynamics and Morphology
We are a large, diverse, and very active research group aiming to provide a comprehensive picture for the formation of galaxies in the Universe. Rooted in detailed stellar population analysis, we are constantly exploring and developing new tools and ideas to understand how galaxies came to be what we now observe.
Ignacio
Martín Navarro