A Library of Integrated Spectra of Galactic Globular Clusters

We present a new library of integrated spectra of 40 Galactic globularclusters, obtained with the Blanco 4-m telescope and the R-C spectrograph atthe Cerro Tololo Interamerican Observatory. The spectra cover the range ~ 3350-- 6430 A with ~ 3.1 A (FWHM) resolution. The spectroscopic observations anddata reduction were designed to integrate the full projected area within thecluster core radii in order to properly sample the light from stars in allrelevant evolutionary stages. The S/N values of the flux-calibrated spectrarange from 50 to 240/A at 4000 A and from 125 to 500/A at 5000 A. The selectedtargets span a wide range of cluster parameters, including metallicity,horizontal-branch morphology, Galactic coordinates, Galactocentric distance,and concentration. The total sample is thus fairly representative of the entireGalactic globular cluster population and should be valuable for comparison withsimilar integrated spectra of unresolved stellar populations in remote systems.For most of the library clusters, our spectra can be coupled with deepcolor-magnitude diagrams and reliable metal abundances from the literature toenable the calibration of stellar population synthesis models. In this paper wepresent a detailed account of the observations and data reduction. The spectrallibrary is publicly available in electronic format from the National OpticalAstronomical Observatory website.Comment: 39 Pages, including 2 tables and 15 Figures. To appear in the Astrophysical Journal, Supplement Serie