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Integrated-light spectroscopy of globular clusters at the infrared Ca II linesIntegrated-light spectroscopy has been obtained for 27 globular clusters at the Ca II IR triplet. Line strengths and radial velocities have been measured from the spectra. For the well-studied clusters in the sample, the strength of the Ca II lines is very well correlated with previous metallicity estimates. Thus, the triplet is useful as a metallicity indicator in globular cluster integrated-light spectra. The greatly reduced effect of interstellar extinction at these wavelengths (compared to the blue region of the spectrum) has permitted observations of some of the most heavily reddened clusters in the Galaxy. For several such clusters, the Ca II triplet metallicities are in poor agreement with metallicity estimates from IR photometry by Malkan (1981). The strength of an interstellar band at 8621A has been used to estimate the amount of extinction towards these clusters. Using the new metallicity and radial-velocity data, the metallicity distribution, kinematics, and spatial distribution of the disk globular cluster system have been analyzed. Results very similar to those of Zinn (1985) have been found. The relation of the disk globulars to the stellar thick disk is discussed.
Document ID
19880057905
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Armandroff, Taft E. (Yale Univ. Observatory New Haven, CT, United States)
Zinn, Robert (Yale University Observatory, New Haven, CT, United States)
Date Acquired
August 13, 2013
Publication Date
July 1, 1988
Publication Information
Publication: Astronomical Journal
Volume: 96
ISSN: 0004-6256
Subject Category
ASTROPHYSICS
Funding Number(s)
CONTRACT_GRANT: NAGW-778
CONTRACT_GRANT: NSF AST-83-04034
Distribution Limits
Public
Copyright
Other