The ACS Virgo Cluster Survey II . Data Reduction Procedures 1

The ACS Virgo Cluster Survey is a large program to carry out multi-color imaging of 100 early-type members of the Virgo Cluster using the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope. Deep F475W and F850LP images (≈ SDSS g and z) are being used to study the central regions of the program galaxies, their globular cluster systems, and the three-dimensional structure of Virgo itself. In this paper, we describe in detail the data reduction procedures used for the survey, including image registration, drizzling strategies, the computation of weight images, object detection, the identification of globular cluster candidates, and the measurement of their photometric and structural parameters. Based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555 Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854; [email protected], [email protected], [email protected], [email protected] Claudio Anguita Fellow Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218; [email protected], [email protected] Institute of Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822; [email protected] Department of Physics, Rochester Institute of Technology, 84 Lomb Memorial Drive, Rochester, NY 14623; [email protected] Theoretical Astrophysics, California Institute of Technology, Pasadena, CA 91125; [email protected]. Sherman M. Fairchild Fellow Department of Physics & Astronomy, University of Hawaii, Hilo, HI 96720; [email protected].