The zCOSMOS survey: the role of the environment in the evolution of the luminosity function of different galaxy types - Astrophysics > Cosmology and Nongalactic AstrophysicsReport as inadecuate




The zCOSMOS survey: the role of the environment in the evolution of the luminosity function of different galaxy types - Astrophysics > Cosmology and Nongalactic Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: Abridged We studied the evolution in the B band luminosity function to z~1in the zCOSMOS 10k sample, for which both accurate galaxy classifications and adetailed description of the local density field are available.The global LF exhibits a brightening of ~0.7 mag in M* from z~0.2 to z~0.9.At low z, late types dominate at faint magnitudes, while the bright end ispopulated mainly by early types. At higher z, late-type galaxies evolvesignificantly and, at z~1, the contribution from the various types to thebright end of the LF is comparable. The evolution for early types is in bothluminosity and normalization. A similar behaviour is exhibited by late types,but with an opposite trend for the normalization. Studying the role of theenvironment, we find that the global LF of galaxies in overdense regions hasalways a brighter M* and a flatter slope. In low density environments, the maincontribution to the LF is from blue galaxies, while for high densityenvironments there is an important contribution from red galaxies to the brightend. The differences between the global LF in the two environments are not dueto only a difference in the relative numbers of red and blue galaxies, but alsoto their relative luminosity distributions: the value of M* for both types inunderdense regions is always fainter than in overdense environments.The -specular- evolution of late- and early-type galaxies is consistent witha scenario where a part of blue galaxies is transformed in red galaxies withincreasing cosmic time, without significant changes in the fraction ofintermediate-type galaxies. The bulk of this tranformation in overdense regionsprobably happened before z~1, while it is still ongoing at lower z inunderdense environments.



Author: E.Zucca, S.Bardelli, M.Bolzonella, G.Zamorani, O.Ilbert, L.Pozzetti, M.Mignoli, K.Kovac, S.Lilly, L.Tresse, L.Tasca, P.Cassata, C

Source: https://arxiv.org/







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