The Giant, Horizontal, and Asymptotic Branches of Galactic Globular Clusters. I. The Catalog, Photometric Observables, and Features

A catalog including a set of the most recent Color Magnitude Diagrams (CMDs)is presented for a sample of 61 Galactic Globular Clusters (GGCs). We used thisdata-base to perform an homogeneous systematic analysis of the evolvedsequences (namely, Red Giant Branch (RGB), Horizontal Branch (HB) andAsymptotic Giant Branch (AGB)). Based on this analysis, we present: (1) a newprocedure to measure the level of the ZAHB (V_ZAHB) and an homogeneous set ofdistance moduli obtained adopting the HB as standard candle; (2) an independentestimate for RGB metallicity indicators and new calibrations of theseparameters in terms of both spectroscopic ([Fe/H]_CG97) and global metallicity([M/H], including also the alpha-elements enhancement). The set of equationspresented can be used to simultaneously derive a photometric estimate of themetal abundance and the reddening from the morphology and the location of theRGB in the (V,B-V)-CMD. (3) the location of the RGB-Bump (in 47 GGCs) and theAGB-Bump (in 9 GGCs). The dependence of these features on the metallicity isdiscussed. We find that by using the latest theoretical models and the newmetallicity scales the earlier discrepancy between theory and observations(~0.4 mag) completely disappears.Comment: 51 pages, 23 figures, AAS Latex, macro rtrpp4.sty included, accepted by A