The ACS Nearby Galaxy Survey Treasury
Abstract
The ACS Nearby Galaxy Survey Treasury (ANGST) is a systematic survey to establish a legacy of uniform multi-color photometry of resolved stars for a volume-limited sample of nearby galaxies (D<4 Mpc). The survey volume encompasses 69 galaxies in diverse environments, including close pairs, small & large groups, filaments, and truly isolated regions. The galaxies include a nearly complete range of morphological types spanning a factor of ~10^4 in luminosity and star formation rate. The survey data consists of images taken with ACS on HST, supplemented with archival data and new WFPC2 imaging taken after the failure of ACS. Survey images include wide field tilings covering the full radial extent of each galaxy, and single deep pointings in uncrowded regions of the most massive galaxies in the volume. The new wide field imaging in ANGST reaches median 50% completenesses of m_F475W=28.0 mag, m_F606W=27.3 mag, and m_F814W=27.3 mag, several magnitudes below the tip of the red giant branch (TRGB). The deep fields reach magnitudes sufficient to fully resolve the structure in the red clump. The resulting photometric catalogs are publicly accessible and contain over 34 million photometric measurements of >14 million stars. In this paper we present the details of the sample selection, imaging, data reduction, and the resulting photometric catalogs, along with an analysis of the photometric uncertainties (systematic and random), for both the ACS and WFPC2 imaging. We also present uniformly derived relative distances measured from the apparent magnitude of the TRGB.
Keywords
Cite
@article{arxiv.0905.3737,
title = {The ACS Nearby Galaxy Survey Treasury},
author = {Julianne J. Dalcanton and Benjamin F. Williams and Anil C. Seth and Andrew Dolphin and Jon Holtzman and Keith Rosema and Evan D. Skillman and Andrew Cole and Leo Girardi and Stephanie M. Gogarten and Igor D. Karachentsev and Knut Olsen and Daniel Weisz and Charlotte Christensen and Ken Freeman and Karoline Gilbert and Carme Gallart and Jason Harris and Paul Hodge and Roelof S. de Jong and Valentina Karachentseva and Mario Mateo and Peter B. Stetson and Maritza Tavarez and Dennis Zaritsky and Fabio Governato and Thomas Quinn},
journal= {arXiv preprint arXiv:0905.3737},
year = {2009}
}
Comments
54 pages, including 24 pages of figures and 16 pages of tables. Project website and data available at http://www.nearbygalaxies.org/ . Data is also available through MAST. Scheduled to appear in the Astrophysical Journal Supplements. (Replaced to fix several figures that were damaged during compression)