J/AJ/112/171 K Giants in Baade's Window. II (Sadler+ 1996)
K Giants in Baade's Window. II. The Abundance Distribution
Sadler E.M., Rich R.M., Terndrup D.M.
<Astron. J. 112, 171 (1996)>
=1996AJ....112..171S 1996AJ....112..171S
ADC_Keywords: Stars, giant ; Magnitudes ; Abundances, [Fe/H] ;
Effective temperatures
Abstract:
This is the second in a series of papers in which we analyze spectra
of over 400 K and M giants in Baade's Window, including most of the
stars with proper motions measured by Spaenhauer et al.
(1992AJ....103..297S 1992AJ....103..297S). In our first paper, we measured line-strength
indices of Fe, Mg, CN, and HBeta and calibrated them on the system of
Faber et al. (1985ApJS...57..711F 1985ApJS...57..711F). Here, we use the <Fe> index to
derive an abundance distribution of [Fe/H] for 322 stars with
effective temperatures between 3900K and 5160K. Our derived values
of [Fe/H] agree well with those measured from high-resolution echelle
spectra (e.g., McWilliam & Rich, 1994ApJS...91..749M 1994ApJS...91..749M) for the small
number of stars in common. We find a mean abundance
<[Fe/H]≥-0.11±0.04 for our sample of Baade's Window K giants. More
than half the sample lie in the range -0.4<[Fe/H]<+0.3. We estimate
line-of-sight distances for individual stars in our sample and confirm
that, in Baade's Window, most K giants with V<15.5 are foreground disk
stars, but the great majority (more than 80%) with V>16 belong to the
bulge. We also compare the metallicities derived from the CN and Mg2
indices to those from iron. Most of the metal-rich stars in our sample
appear to be CN-weak, in contrast to the situation in metal-rich
globular clusters and elliptical galaxies. The metal-poor half of our
sample ([Fe/H]<0) shows evidence for a mild Mg overenhancement
([Mg/Fe]~+0.2); but this is not seen in the more metal-rich stars
([Fe/H]≥0). The K giants in Baade's Window therefore share some, but
not all, of the characteristics of stars in elliptical galaxies as
inferred from their integrated light.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 50 322 Measurements of [Fe/H] for Baade's Window K giants
table1.tex 77 341 AASTeX version of table1.dat
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See also:
J/AJ/110/1774 : K giants in Baade's window. I. (Terndrup+ 1995)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Star Star name
7- 12 F6.2 mag Vmag V magnitude
14- 18 F5.2 mag V-I V-I color
20- 24 I5 K Teff Effective temperature
26- 31 F6.2 Sun [Fe/H] Metallicity, [Fe/H]
33- 36 F4.2 --- e_[Fe/H] Error in [Fe/H]
38- 42 F5.1 kpc R Distance
44- 47 F4.1 kpc e_R Error in R
50 A1 --- Class *[CBDH] Star classification
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Note on Class:
C = bulge clump/RGB
B = bulge giant branch
D = disk giant branch
H = halo giant
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Origin: AAS CD-ROM series, Volume 7, 1996 Lee Brotzman [ADS] 09-Oct-1996
(End) [CDS] 30-Jan-1997