Theoretical Isochrones for Metal-Rich Globular Clusters
Abstract
Model evolutionary sequences have been obtained for the compositions Y = 0.2, 0.3, 0.4 at z = 10-2 for a range in masses around 1 . The results are presented in the form of individual evolutionary tracks and isochrones. These new data have been combined with the most recent results of other workers for Z = 10-2, to form analytical expressions relating isochrone turnoff luminosity, with age, helium abundance, and heavy-element abundance. Application of the results to the metal-rich globular clusters 47 Tuc and M71 yields ages which are 40 percent lower than those found recently for the halo globular clusters. Subject headings: globular clusters - interiors, stellar - stellar evolution
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 1973
- DOI:
- 10.1086/152463
- Bibcode:
- 1973ApJ...185..887H