The star formation history of early-type galaxies as a function of environment

I present a short summary of some of the results from my thesis. In this work we analyse a sample of 98 early-type galaxies situated in different environments. Using new models, that include a new and improved stellar library, we derive mean ages, metallicities and study the qualitative behaviour of different chemical elements. We conclude that more massive galaxies formed their stars on shorter time-scales than less massive ones. The formation epoch and time-scale of the star formation in the most massive galaxies is very similar in the field and in more dense environments, but the star formation is progressively more extended for less massive galaxies in less dense environments.