Olga CUCCIATI
(Laboratoire d'Astrophysique de Marseille)
Using the zCOSMOS spectroscopic data (about 10000 galaxies), we analyze density effects on galaxy U-B colour, D4000 Angstrom break and OII equivalent width up to z=1, with local environment ranging from very low densities up to the highest density peaks. We pay attention at the role of both luminosity and stellar mass in selecting galaxy populations for environmental studies, and in particular we focus on the triple
colour-mass-density relation, disentangling density effects on the two properties.