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Multiple populations in globular clusters

Lessons learned from the Milky Way globular clusters

  • Review Article
  • Published:
The Astronomy and Astrophysics Review Aims and scope

Abstract

Recent progress in studies of globular clusters has shown that they are not simple stellar populations, but rather are made up of multiple generations. Evidence stems both from photometry and spectroscopy. A new paradigm is arising for the formation of massive star clusters, which includes several episodes of star formation. While this provides an explanation for several features of globular clusters, including the second-parameter problem, it also opens new perspectives on the relation between globular clusters and the halo of our Galaxy, and by extension on all populations with a high specific frequency of globular clusters, such as, e.g., giant elliptical galaxies. We review progress in this area, focussing on the most recent studies. Several points remain to become properly understood, in particular those concerning the nature of the polluters producing the abundance pattern in the clusters and the typical timescale, the range of cluster masses where this phenomenon is active, and the relation between globular clusters and other satellites of our Galaxy.

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  1. INAF, Osservatorio Astronomico di Padova, Padova, Italy

    Raffaele G. Gratton

  2. INAF, Osservatorio Astronomico di Bologna, Bologna, Italy

    Eugenio Carretta & Angela Bragaglia

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  1. Raffaele G. Gratton
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Gratton, R.G., Carretta, E. & Bragaglia, A. Multiple populations in globular clusters. Astron Astrophys Rev 20, 50 (2012). https://doi.org/10.1007/s00159-012-0050-3

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