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Globular cluster ages: are they converging?

Published online by Cambridge University Press:  25 May 2016

Don A. VandenBerg*
Affiliation:
Dept. of Physics & Astronomy, University of Victoria P.O. Box 3055, Victoria, B.C., Canada V8W 3P6

Abstract

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Since the early 1970's, the consensus “best estimate” of the age of the Galactic globular cluster (GC) system has been 15–16 ±3 Gyr. However, a number of recent studies, which are briefly reviewed herein, have suggested that this estimate is too high by ≳ 15%. Based on a consideration of new stellar models and the latest developments concerning the cluster distance scale, the present paper lends support to the notion that the first globulars began to form in the Galaxy 13–14 Gyr ago. In addition, our analysis of absolute GC ages adds to the mounting evidence that the dispersion in age among clusters having similar metallicities is probably quite small. As a consequence, age can hardly be the primary factor causing the wide diversity in their horizontal-branch morphologies.

Type
Stellar Ages
Copyright
Copyright © Kluwer 1997 

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