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

TL;DR

This study investigates how galaxy stellar mass and color vary with large-scale environment across redshifts 0.2 to 1.4, revealing persistent mass segregation and evolving color segregation linked to galaxy density.

Contribution

It provides observational evidence of galaxy mass and color segregation over a wide redshift range, highlighting the evolution of these properties with environment and redshift.

Findings

Mass segregation persists across all studied redshifts.

Color segregation diminishes at z>0.7.

Color segregation disappears when controlling for stellar mass.

Abstract

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