Stellar Populations

TL;DR

This paper introduces stellar populations in galaxies, emphasizing recent observational advances and the importance of stellar population synthesis in understanding galaxy evolution, especially in nearby galaxies.

Contribution

It provides an overview of stellar population theory and highlights recent results and challenges in linking observations with models for galaxy evolution.

Findings

Galaxies detected up to redshift 10.

Large observational advances in recent years.

Stellar population synthesis is crucial for distant galaxy analysis.

Abstract

This is a summary of my lectures during the 2011 IAC 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 was {\it Secular Evolution of 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 10. 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 analyze these integrated stellar populations.