HST color-magnitude diagrams of 74 galactic globular clusters in the HST F439W and F555W bands ⋆

We present the complete photometric database and the color-magnitude diagrams for 74 Galactic globular clusters observed with the HST/WFPC2 camera in the F439W and F555W bands. A detailed discussion of the various reduction steps is also presented, and of the procedures to transform instrumental magnitudes into both the HST F439W and F555W flight system and the standard Johnson B and V systems. We also describe the artificial star experiments which have been performed to derive the star count completeness in all the relevant branches of the color magnitude diagram. The entire photometric database and the completeness function will be made available on the Web immediately after the publication of the present paper.

[1]  Mauro Ranchicchio,et al.  Tesi di Laurea , 2002 .

[2]  G. Piotto,et al.  Asymptotic Giant Branch predictions: Theoretical uncertainties , 2001, astro-ph/0112111.

[3]  G. Piotto,et al.  Star Counts across the Red Giant Branch Bump and Below , 2001 .

[4]  A. Dolphin.  The Charge‐Transfer Efficiency and Calibration of WFPC2 , 2000, astro-ph/0006237.

[5]  S. Djorgovski,et al.  On the Helium Content of Galactic Globular Clusters via the R-Parameter , 2000, astro-ph/0003004.

[6]  G. Piotto,et al.  Galactic Globular Cluster Relative Ages , 1999, astro-ph/9907394.

[7]  S. Djorgovski,et al.  HUBBLE SPACE TELESCOPE Observations of Galactic Globular Cluster Cores. II. NGC 6273 and the Problem of Horizontal-Branch Gaps , 1999, astro-ph/9906269.

[8]  S. Djorgovski,et al.  Hubble Space Telescope Observations of Galactic Globular Cluster Cores. I. NGC 6362 and NGC 6934 , 1999 .

[9]  S. Djorgovski,et al.  Discovery of Extended Blue Horizontal Branches in Two Metal-rich Globular Clusters , 1997, astro-ph/9705039.

[10]  S. Djorgovski,et al.  Peculiar Multimodality on the Horizontal Branch of the Globular Cluster NGC 2808 , 1997, astro-ph/9702063.

[11]  William E. Harris,et al.  A Catalog of Parameters for Globular Clusters in the Milky Way , 1996 .

[12]  Garth D. Illingworth,et al.  The Hubble Space Telescope Key Project on the Extragalactic Distance Scale. VI. The Cepheids in NGC 925 , 1996 .

[13]  Stefano Casertano,et al.  THE PHOTOMETRIC PERFORMANCE AND CALIBRATION OF WFPC2 , 1995 .

[14]  Peter B. Stetson,et al.  THE CENTER OF THE CORE-CUSP GLOBULAR CLUSTER M15: CFHT AND HST OBSERVATIONS, ALLFRAME REDUCTIONS , 1994 .

[15]  P. Stetson.  DAOPHOT: A COMPUTER PROGRAM FOR CROWDED-FIELD STELLAR PHOTOMETRY , 1987 .