THE ACS NEARBY GALAXY SURVEY TREASURY

Abstract

The ACS Nearby Galaxy Survey Treasury (ANGST) is a systematic survey to establish a legacy of uniform multicolorphotometry of resolved stars for a volume-limited sample of nearby galaxies (D < 4Mpc). The survey volumeencompasses 69 galaxies in diverse environments, including close pairs, small and large groups, filaments, and trulyisolated regions. The galaxies include a nearly complete range of morphological types spanning a factor of 104 inluminosity and star formation rate. The survey data consist of images taken with the Advanced Camera for Surveys(ACS) on the Hubble Space Telescope (HST), supplemented with archival data and new Wide Field PlanetaryCamera 2 (WFPC2) imaging taken after the failure of ACS. Survey images include wide field tilings covering thefull radial extent of each galaxy, and single deep pointings in uncrowded regions of the most massive galaxies inthe volume. The new wide field imaging in ANGST reaches median 50% completenesses of mF475W =28.0 mag,mF606W=27.3 mag, and mF814W=27.3 mag, several magnitudes below the tip of the red giant branch (TRGB). Thedeep fields reach magnitudes sufficient to fully resolve the structure in the red clump. The resulting photometriccatalogs are publicly accessible and contain over 34 million photometric measurements of >14 million stars. Inthis paper we present the details of the sample selection, imaging, data reduction, and the resulting photometriccatalogs, along with an analysis of the photometric uncertainties (systematic and random), for bothACS and WFPC2imaging.We also present uniformly derived relative distances measured from the apparent magnitude of the TRGB.