zCOSMOS 10k-bright spectroscopic sample: exploring mass and environment dependence in early-type galaxies

Understand

We present the analysis of the U-V rest-frame color distribution and some spectral features as a function of mass and environment for two sample of early-type galaxies up to z=1 extracted from the zCOSMOS spectroscopic survey.

• The first sample ("red galaxies") is defined with a photometric classification, while the second ("ETGs") by combining morphological, photometric, and spectroscopic properties to obtain a more reliable sample.
• We find that the color distribution of red galaxies is not strongly dependent on environment for all mass bins, with galaxies in overdense regions redder than galaxies in underdense regions with a difference of 0.027\pm0.008 mag.
• The dependence on mass is far more significant, with average colors of massive galaxies redder by 0.093\pm0.007 mag than low-mass galaxies throughout the entire redshift range.