Photometric catalog of nearby globular clusters - II. A large homogeneous (V, I) color-magnitude diagram data-base

Citation
A. Rosenberg et al., Photometric catalog of nearby globular clusters - II. A large homogeneous (V, I) color-magnitude diagram data-base, ASTR AST SS, 145(3), 2000, pp. 451-465
Citations number
44
Categorie Soggetti
Space Sciences
Journal title
ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES
ISSN journal
03650138 → ACNP
Volume
145
Issue
3
Year of publication
2000
Pages
451 - 465
Database
ISI
SICI code
0365-0138(200009)145:3<451:PCONGC>2.0.ZU;2-8
Abstract
In this paper we present the second and final part of a large and photometr ically homogeneous CCD color-magnitude diagram (CMD) data base, comprising 52 nearby Galactic globular clusters (GGC) imaged in the V and I bands. The catalog has been collected using only two telescopes tone for each hemi sphere). The observed clusters represent 75% of the known Galactic globular s with (m - M)(v) less than or equal to 16.15 mag, cover most of the globul ar cluster metallicity range (-2.2 less than or equal to [Fe/H] less than o r equal to -0.4), and span Galactocentric distances from similar to 1.2 to similar to 18.5 kpc. In particular, here we present the CMDs for the 13 GGCs observed in the Nor thern hemisphere. The remaining 39 Southern hemisphere clusters of the cata log have been presented in a companion paper (Rosenberg et al. 2000). We pr esent the first CCD color magnitude diagram for NGC 6779 (M 56). All the CMDs extend from at least similar to 2 magnitudes below the turn-of f (i.e. V-lim greater than or equal to 22) to the tip of the red giant bran ch. The calibration has been done using a large number of standard stars, a nd the absolute calibration is reliable to a similar to 0.02 mag level in b oth filters. This catalog, because of its homogeneity, is expected to represent a useful data base for the measurement of the main absolute and relative parameters characterizing the CMD of GGCs.