Introduction to Galactic Chemical Evolution
  In this lecture I will introduce the concept of galactic chemical evolution,
namely the study of how and where the chemical elements formed and how they
were distributed in the stars and gas in galaxies. The main ingredients to
build models of galactic chemical evolution will be described. They include:
initial conditions, star formation history, stellar nucleosynthesis and gas
flows in and out of galaxies. Then some simple analytical models and their
solutions will be discussed together with the main criticisms associated to
them. The yield per stellar generation will be defined and the hypothesis of
instantaneous recycling approximation will be critically discussed. Detailed
numerical models of chemical evolution of galaxies of different morphological
type, able to follow the time evolution of the abundances of single elements,
will be discussed and their predictions will be compared to observational data.
The comparisons will include stellar abundances as well as interstellar medium
ones, measured in galaxies. I will show how, from these comparisons, one can
derive important constraints on stellar nucleosynthesis and galaxy formation
mechanisms. Most of the concepts described in this lecture can be found in the
monograph by Matteucci (2012).
