Evolution Chimique des Galaxies


ABSTRACT The basic equations for the chemical evolution of galaxies with their physical assumptions are presented. We review the analytical solutions for single zone models, with gas loss and gas accretion and focus on which properties of the closed box Simple Model solution remain valid and which do not. Also, models with imperfect mixing of the gas are discussed. We give a summary of the stellar yields computed from stellar evolution. The modeling of the radial abundance gradients in disk galaxies is briefly reviewed, and on how the different physical processes affect the value of the gradient and its time evolution. To overcome the limitations of the chemical evolution models with free fitting parameters, current models include the dynamics of the gas and the stars, the multiphase structure of the interstellar medium, and the energy input into the gas by the stars. Assumptions and properties of these types of models are summarized.