ar X iv : a st ro - p h / 05 10 40 8 v 1 1 3 O ct 2 00 5 Abundances of Baade ’ s Window Giants from Keck / HIRES Spectra : I . Stellar

We present the first results of a new abundance survey of the Milky Way bulge based on Keck/HIRES spectra of 27 K-giants in the Baade’s Window (l = 1, b = −4) field. The spectral data used in this study are of much higher resolution and signal-to-noise than previous optical studies of Galactic bulge stars. The [Fe/H] values of our stars, which range between −1.29 and +0.51, were used to recalibrate large low resolution surveys of bulge stars. Our best value for the mean [Fe/H] of the bulge is −0.10 ± 0.04. This mean value is similar to the mean metallicity of the local disk and indicates that there cannot be a strong metallicity gradient inside the solar circle. The metallicity distribution of stars confirms that the bulge does not suffer from the so-called “G-dwarf” problem. This paper also details the new abundance techniques necessary to analyze very metal-rich K-giants, including a new Fe line list and regions of low blanketing for continuum identification. Subject headings: stars: abundances;