J/AJ/112/171 J/AJ/112/171 K Giants in Baade's Window. II E M Sadler R M Rich D M Terndrup Astron. J. 112 171 1996 1996AJ....112..171S J/AJ/110/1774 : K giants in Baade's window. I. (Terndrup+ 1995) Abundances, [Fe/H] Effective temperatures Magnitudes Stars, giant 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). 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). 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) 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.

Star Star name --- Vmag V magnitude mag V-I V-I color mag Teff Effective temperature K [Fe/H] Metallicity, [Fe/H] Sun e_[Fe/H] Error in [Fe/H] --- R Distance kpc e_R Error in R kpc Class Star classification C = bulge clump/RGB B = bulge giant branch D = disk giant branch H = halo giant --- table1.texAASTeX version of table1.dat CDS 1997Jan30AAS CD-ROM series, Volume 7, 1996 Lee Brotzman [ADS] 09-Oct-1996 J_AJ_112_171.xml