The Vimos VLT Deep Survey: Stellar mass segregation and large-scale\n galaxy environment in the redshift range 0.2<z<1.4

Abstract

Hierarchical models of galaxy formation predict that the properties of a dark\nmatter halo depend on the large-scale environment surrounding the halo. As a\nresult of this correlation, we expect massive haloes to be present in larger\nnumber in overdense regions than in underdense ones. Given that a correlation\nexists between a galaxy stellar mass and the hosting dark matter halo mass, the\nsegregation in dark matter halo mass should then result in a segregation in the\ndistribution of stellar mass in the galaxy population. In this work we study\nthe distribution of galaxy stellar mass and rest-frame optical color as a\nfunction of the large-scale galaxy distribution using the VLT VIMOS Deep Survey\nsample, in order to verify the presence of segregation in the properties of the\ngalaxy population. We use the VVDS redshift measurements and multi-band\nphotometric data to derive estimates of the stellar mass, rest-frame optical\ncolor, and of the large-scale galaxy density, on a scale of approximately 8\nMpc, for a sample of 5619 galaxies in the redshift range 0.2<z<1.4. We observe\na significant mass and optical color segregation over the whole redshift\ninterval covered by our sample, such that the median value of the mass\ndistribution is larger and the rest-frame optical color is redder in regions of\nhigh galaxy density. The amplitude of the mass segregation changes little with\nredshift, at least in the high stellar mass regime that we can uniformely\nsample over the 0.2<z<1.4 redshift interval. The color segregation, instead,\ndecreases significantly for z>0.7. However, when we consider only galaxies in\nnarrow bins of stellar mass, in order to exclude the effects of the stellar\nmass segregation on the galaxy properties, we do not observe any more any\nsignificant color segregation.\n