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J/AJ/109/1095       Thick Disk Chemical Abundance Distribution (Gilmore+ 1995)

A determination of the thick disk chemical abundance distribution: implications for galaxy evolution. Gilmore G., Wyse R.F.G., Jones J.B. <Astron. J. 109, 1095 (1995)> =1995AJ....109.1095G
ADC_Keywords: Photometry, photographic ; Stars, distances ; Effective temperatures Description: We present a determination of the thick disk iron abundance distribution obtained from an in situ sample of F/G stars. These stars are faint, 15≤V=<18, selected on the basis of color, being a subset of the larger survey of Gilmore and Wyse designed to determine the properties of the stellar populations several kiloparsecs from the Sun. The fields studied in the present paper probe the iron abundance distribution of the stellar populations of the galaxy at 500-3000pc above the plane, at the solar Galactocentric distance. The derived chemical abundance distributions are consistent with no metallicity gradients in the thick disk over this range of vertical distance, and with an iron abundance distribution for the thick disk that has a peak at -0.7dex. The lack of a vertical gradient argues against slow, dissipational settling as a mechanism for the formation of the thick disk. The photometric and metallicity data support a turn-off of the thick disk that is comparable in age to the metal-rich globular clusters, or ≥12Gyr, and are consistent with a spread to older ages. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 55 133 Observed and derived data for South Galactic Pole stars table4.dat 55 87 Observed and derived data for UK Schmidt Field 117 stars (l, b)=(270, -45)
Byte-by-byte Description of file: table2.dat table4.dat
Bytes Format Units Label Explanations
1 I1 h RAh Right ascension 1950.0 3- 4 I2 min RAm Right ascension 1950.0 6- 10 F5.2 s RAs Right ascension 1950.0 12 A1 --- DE- Declination sign 13- 14 I2 deg DEd Declination 1950.0 16- 17 I2 arcmin DEm Declination 1950.0 19- 22 F4.1 arcsec DEs Declination 1950.0 24- 28 F5.2 mag Vmag V magnitude 30- 33 F4.2 mag B-V B-V color index 35- 38 F4.2 mag V-I V-I color index 40- 44 F5.2 Sun [Fe/H] Metallicity 46- 49 I4 pc Dist Distance from photometric parallax 51- 54 I4 K Teff Effective temperature from V-I
Courtesy: Rosie Wyse
(End) Patricia Bauer [CDS] 14-Jun-1996
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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