The prism multi-object survey (PRIMUS). I. Survey overview and characteristics

Abstract

We present the PRIsm MUlti-object Survey (PRIMUS), a spectroscopic faint galaxy redshift survey to z 1. PRIMUS uses a low-dispersion prism and slitmasks to observe 2500 objects at once in a 0.18deg2 field of view, using the Inamori Magellan Areal Camera and Spectrograph camera on the Magellan I Baade 6.5m telescope at Las Campanas Observatory. PRIMUS covers a total of 9.1deg2 of sky to a depth of i AB 23.5 in seven different deep, multi-wavelength fields that have coverage from the Galaxy Evolution Explorer, Spitzer, and either XMM or Chandra, as well as multiple-band optical and near-IR coverage. PRIMUS includes 130,000 robust redshifts of unique objects with a redshift precision of σz/(1 + z) 0.005. The redshift distribution peaks at z 0.6 and extends to z = 1.2 for galaxies and z = 5 for broad-line active galactic nuclei. The motivation, observational techniques, fields, target selection, slitmask design, and observations are presented here, with a brief summary of the redshift precision; a forthcoming paper presents the data reduction, redshift fitting, redshift confidence, and survey completeness. PRIMUS is the largest faint galaxy survey undertaken to date. The high targeting fraction (80%) and large survey size will allow for precise measures of galaxy properties and large-scale structure to z 1. © 2011 The American Astronomical Society. All rights reserved.