Galactic Globular Cluster Metallicity Scale from the CA II Triplet I. Catalog

Abstract

We have obtained 2640 CCD spectra with resolution $\sim$4~\AA\ in the region 7250--9000~\AA\ for 976 stars lying near the red giant branches in color-magnitude diagrams of 52 Galactic globular clusters. Radial velocities of $\sim$16 \kms\ accuracy per star determined from the spectra are combined with other criteria to assess quantitative membership probabilities. Measurements of the equivalent widths of the infrared calcium triplet lines yield a relative metal-abundance ranking with a precision that compares favorably to other techniques. Regressions between our system and those of others are derived. Our reduction procedures are discussed in detail, and the resultant catalog of derived velocities and equivalent widths is presented. The metal abundances derived from these data will be the subject of a future pape. (SECTION: Stellar Clusters and Associations)