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Title: Globular cluster system of the galaxy. II. The spatial and metallicity distributions, the second parameter phenomenon, and the formation of the cluster system

Abstract

The metal abundance measurements that were collected for 84 globular clusters in the first paper of this series are used here to describe the cluster system. The ranking of the clusters by metallicity has been calibrated by a new (Fe/H) scale, which is based in part on the measurement of (Fe/H)=-1.2 for M71. According to this scale, the metal abundance gradient between the inner and outer halo clusters (i.e., R<9 kpc and 9< or =R< 40 kpc) is only a small fraction of that found with previous (Fe/H) scales. It is not clear, however, that the new scale is to be preferred over the old ones; consequently the size of this gradient remains in doubt. The most significant properties of the cluster system that do not depend on the validity of the (Fe/H) scale are the following; (i) there is a wide range in metal abundance among the cluster in the zone 9< or =R<40 kpc, but no evidence of a gradient with R or with distance from the galactic plane, Vertical BarZVertical Bar; (ii) among the clusters with R<9 kpc, there is a metal abundance gradient with Vertical BarZVertical Bar; and (iii) the magnitude of the second parameter effectmore » increases with R, and if age is the second parameter, then over the range 0<40 kpc, the mean cluster age declines by approx.3 Gyr and the scatter in age increases from less than 1 Gyr to approx.2 Gyr.« less

Authors:
Publication Date:
Research Org.:
Mount Wilson and Las Campanas Observatory, Carnegie Institution of Washington; and Yale University Observatory
OSTI Identifier:
6848625
Resource Type:
Journal Article
Journal Name:
Astrophys. J.; (United States)
Additional Journal Information:
Journal Volume: 241:2
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; MILKY WAY; CHEMICAL COMPOSITION; ABUNDANCE; GALACTIC EVOLUTION; HYDROGEN; IRON; SPATIAL DISTRIBUTION; STAR CLUSTERS; DISTRIBUTION; ELEMENTS; GALAXIES; METALS; NONMETALS; TRANSITION ELEMENTS; 640105* - Astrophysics & Cosmology- Galaxies

Citation Formats

Zinn, R. Globular cluster system of the galaxy. II. The spatial and metallicity distributions, the second parameter phenomenon, and the formation of the cluster system. United States: N. p., 1980. Web. doi:10.1086/158375.
Zinn, R. Globular cluster system of the galaxy. II. The spatial and metallicity distributions, the second parameter phenomenon, and the formation of the cluster system. United States. https://doi.org/10.1086/158375
Zinn, R. 1980. "Globular cluster system of the galaxy. II. The spatial and metallicity distributions, the second parameter phenomenon, and the formation of the cluster system". United States. https://doi.org/10.1086/158375.
@article{osti_6848625,
title = {Globular cluster system of the galaxy. II. The spatial and metallicity distributions, the second parameter phenomenon, and the formation of the cluster system},
author = {Zinn, R},
abstractNote = {The metal abundance measurements that were collected for 84 globular clusters in the first paper of this series are used here to describe the cluster system. The ranking of the clusters by metallicity has been calibrated by a new (Fe/H) scale, which is based in part on the measurement of (Fe/H)=-1.2 for M71. According to this scale, the metal abundance gradient between the inner and outer halo clusters (i.e., R<9 kpc and 9< or =R< 40 kpc) is only a small fraction of that found with previous (Fe/H) scales. It is not clear, however, that the new scale is to be preferred over the old ones; consequently the size of this gradient remains in doubt. The most significant properties of the cluster system that do not depend on the validity of the (Fe/H) scale are the following; (i) there is a wide range in metal abundance among the cluster in the zone 9< or =R<40 kpc, but no evidence of a gradient with R or with distance from the galactic plane, Vertical BarZVertical Bar; (ii) among the clusters with R<9 kpc, there is a metal abundance gradient with Vertical BarZVertical Bar; and (iii) the magnitude of the second parameter effect increases with R, and if age is the second parameter, then over the range 0<40 kpc, the mean cluster age declines by approx.3 Gyr and the scatter in age increases from less than 1 Gyr to approx.2 Gyr.},
doi = {10.1086/158375},
url = {https://www.osti.gov/biblio/6848625}, journal = {Astrophys. J.; (United States)},
number = ,
volume = 241:2,
place = {United States},
year = {Wed Oct 15 00:00:00 EDT 1980},
month = {Wed Oct 15 00:00:00 EDT 1980}
}