Chemical Evolution of Early Type Galaxies

Abstract

In this chapter, we first summarize the observational constraints for early-type galaxies: ellipticals, bulges, and dwarf spheroidals. Then, we describe the theories that have been developed for the formation and evolution of early type galaxies. Models of chemical evolution are presented. The importance of gas loss from ellipticals and dwarf spheroidals is discussed together with downsizing in star formation. A comparison between model results and observational data is presented, and constraints on the mechanism of formation of ellipticals from the chemical and photometric properties of their stellar populations are derived. The evolution of ellipticals hosting quasars is discussed. The properties of dwarf spheroidal galaxies in the local group are discussed, and by comparing the predicted and observed abundances, we try to understand whether they could have been the building blocks of the Milky Way.