Published online by Cambridge University Press: 05 September 2013
This is a summary of my lectures during the 2011 Canary Islands Winter School in Puerto de la Cruz. I give an introduction to the field of stellar populations in galaxies, and highlight some new results. Since the title of the Winter School is Secular Evolution in Galaxies I mostly concentrate on nearby galaxies, which are best suited to study this theme. Of course, the understanding of stellar populations is intimately connected to understanding the formation and evolution of galaxies, one of the great outstanding problems of astronomy. We are currently in a situation where very large observational advances have been made in recent years. Galaxies have been detected up to a redshift of ten. A huge effort has to be made so that stellar population theory can catch up with observations. Since most galaxies are far away, information about them has to come from stellar population synthesis of integrated light. Here I will discuss how stellar evolution theory, together with observations in our Milky Way and Local Group, are used as building blocks to analyse these integrated stellar populations.
We are living in an era in which we are able to see the light of galaxies at or close to redshift ten. Many galaxies above a redshift of three are already known, and we are starting to discover their clustering properties. These galaxies must undergo an evolution which leads to the galaxies we see around us, of which we have catalogues containing millions of individuals. Understanding how this evolution has taken place is a major task that the current generation of astronomers will have to address. A major tool needed to study galaxy evolution is stellar population synthesis.