The PRIsm MUlti-Object Survey (PRIMUS) I: Survey Overview and Characteristics

TL;DR

PRIMUS is a large-scale spectroscopic survey of faint galaxies up to redshift 1, providing extensive redshift data and multi-wavelength coverage to study galaxy evolution and large-scale structure.

Contribution

This paper introduces PRIMUS, the largest faint galaxy survey to date, detailing its observational techniques, survey design, and initial data characteristics.

Findings

Approximately 130,000 robust redshifts obtained

Redshift precision of dz/(1+z)~0.005 achieved

Survey covers 9.1 deg^2 with high targeting efficiency

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 ~2,500 objects at once in a 0.18 deg^2 field of view, using the IMACS camera on the Magellan I Baade 6.5m telescope at Las Campanas Observatory. PRIMUS covers a total of 9.1 deg^2 of sky to a depth of i_AB~23.5 in seven different deep, multi-wavelength fields that have coverage from GALEX, 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 dz/(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 AGN. The motivation, observational techniques, fields, target selection, slitmask design, and observations are presented here, with a brief summary of the redshift precision; a companion 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.