Arxiv:1204.0010V1 [Astro-Ph.CO] 30 Mar 2012
Draft version April 3, 2012 Preprint typeset using LATEX style emulateapj v. 5/2/11 THE PANCHROMATIC HUBBLE ANDROMEDA TREASURY Julianne J. Dalcanton1, Benjamin F. Williams1, Dustin Lang2, Tod R. Lauer3, Jason S. Kalirai4, Anil C. Seth5, Andrew Dolphin6, Philip Rosenfield1, Daniel R. Weisz1, Eric F. Bell7, Luciana C. Bianchi8, Martha L. Boyer4, Nelson Caldwell9, Hui Dong3, Claire E. Dorman10, Karoline M. Gilbert1,11,Leo´ Girardi12, Stephanie M. Gogarten1, Karl D. Gordon4, Puragra Guhathakurta10, Paul W. Hodge1, Jon A. Holtzman13, L. Clifton Johnson1, Søren S. Larsen14, Alexia Lewis1, Jason L. Melbourne15, Knut A. G. Olsen3, Hans-Walter Rix16, Keith Rosema17, Abhijit Saha3, Ata Sarajedini18, Evan D. Skillman19, Krzysztof Z. Stanek20 Draft version April 3, 2012 ABSTRACT The Panchromatic Hubble Andromeda Treasury (PHAT) is an on-going Hubble Space Telescope (HST) Multicycle Treasury program to image ∼1/3 of M31's star forming disk in six filters, spanning from the ultraviolet (UV) to the near-infrared (NIR). We use the Wide Field Camera 3 (WFC3) and Advanced Camera for Surveys (ACS) to resolve the galaxy into millions of individual stars with projected radii from 0{20 kpc. The full survey will cover a contiguous 0.5 square degree area in 828 orbits. Imaging is being obtained in the F275W and F336W filters on the WFC3/UVIS camera, F475W and F814W on ACS/WFC, and F110W and F160W on WFC3/IR. The resulting wavelength coverage gives excellent constraints on stellar temperature, bolometric luminosity, and extinction for most spectral types. The data produce photometry with a signal-to-noise ratio of 4 at mF275W = 25:1, mF336W = 24:9, mF475W = 27:9, mF814W = 27:1, mF110W = 25:5, and mF160W = 24:6 for single pointings in the uncrowded outer disk; in the inner disk, however, the optical and NIR data are crowding limited, and the deepest reliable magnitudes are up to 5 magnitudes brighter.
[Show full text]