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THE AGE OF THE GALACTIC GLOBULAR CLUSTER SYSTEM

THE AGE OF THE GALACTIC GLOBULAR CLUSTER SYSTEM ▪ Abstract A careful assessment of current uncertainties in stellar physics (opacities, nuclear reaction rates, equation of state effects, diffusion, rotation, and mass loss), in the chemistry of globular cluster (GC) stars, and in the cluster distance scale, suggests that the most metal-poor (presumably the oldest) of the Galaxy's GCs have ages near 15 Gyr. Ages below 12 Gyr or above 20 Gyr appear to be highly unlikely. If these ≈ 2 σ limits are increased by ∼ 1 Gyr to account for the formation time of the globulars, and if standard Friedmann cosmologies with the cosmological constant set to zero are assumed, then the GC constraint on the present age of the Universe ( t 0 ≥ 13 Gyr) implies that the Hubble constant H 0 ≤ 51 km s −1 Mpc −1 if the density parameter Ω = 1 or ≤ 62 km s −1 Mpc −1 if Ω = 0.3. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Annual Review of Astronomy and Astrophysics Annual Reviews

THE AGE OF THE GALACTIC GLOBULAR CLUSTER SYSTEM

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References (269)

Publisher
Annual Reviews
Copyright
Copyright © 1996 by Annual Reviews Inc. All rights reserved
Subject
Review Articles
ISSN
0066-4146
eISSN
1545-4282
DOI
10.1146/annurev.astro.34.1.461
Publisher site
See Article on Publisher Site

Abstract

▪ Abstract A careful assessment of current uncertainties in stellar physics (opacities, nuclear reaction rates, equation of state effects, diffusion, rotation, and mass loss), in the chemistry of globular cluster (GC) stars, and in the cluster distance scale, suggests that the most metal-poor (presumably the oldest) of the Galaxy's GCs have ages near 15 Gyr. Ages below 12 Gyr or above 20 Gyr appear to be highly unlikely. If these ≈ 2 σ limits are increased by ∼ 1 Gyr to account for the formation time of the globulars, and if standard Friedmann cosmologies with the cosmological constant set to zero are assumed, then the GC constraint on the present age of the Universe ( t 0 ≥ 13 Gyr) implies that the Hubble constant H 0 ≤ 51 km s −1 Mpc −1 if the density parameter Ω = 1 or ≤ 62 km s −1 Mpc −1 if Ω = 0.3.

Journal

Annual Review of Astronomy and Astrophysics – Annual Reviews

Published: Sep 1, 1996

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