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Galactic stellar populations: current and new perspectives

Published online by Cambridge University Press:  14 November 2014

M. Haywood
M. Haywood*
Affiliation:
GEPI, Observatoire de Paris, CNRS UMR 8111, 5 place Jules Janssen, 92195 Meudon Cedex, France
*
e-mail: Misha.Haywood@obspm.fr
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Abstract

Present studies on the evolution of the Milky Way are driven and shaped by how we conceive its stellar populations, in an on going process started by W. Baade seventy years ago. Despite much progress and advances in our understanding of these populations, inspection of their main properties is however hardly indicative of the path the Milky Way has followed to build up its mass. This is not only a matter of (stellar) age measurement, but more so the consequence of how we interprete the structures that we see in our Galaxy, often through the filter of our definitions of stellar populations. The panorama presented in the following pages opens the possibility that the present “filter” is not fully adequate. I start these Lectures with a summary of the main properties of the disks, bulge, and halo, and then present some of the new directions in the interpretation of the structure and evolution of the disk(s), with emphasis on chemical evolution. I discuss recent results in our understanding of the bulge, its stellar components and chemical evolution. Finally, I present the ideas currently proposed to explain the formation of the Galactic stellar halo. I conclude by examining how deeply all these new results question our present definition of stellar populations.

Type
Research Article
Information
European Astronomical Society Publications Series , Volume 65: The Ages of Stars , 2014 , pp. 349 - 407
Copyright
© EAS, EDP Sciences, 2014

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