Searching for Low-redshift Faint Galaxies with MMT/Hectospec

Abstract

We present redshifts for 2753 low-redshift galaxies between 0.03 ≲ z spec ≲ 0.5 with 18 ≤ r ≤ 22 obtained with Hectospec at the Multi-Mirror Telescope. The observations targeted the XMM-LSS, ELAIS-N1 and DEEP2-3 fields, each of which covers ∼1 deg 2 . These fields are also part of the recently completed Canada–France–Hawaii Telescope Large Area U -band Deep Survey and ongoing Hyper Suprime-Cam deep fields surveys. The efficiency of our technique for selecting low-redshift galaxies is confirmed by the redshift distribution of our sources. In addition to redshifts, these high signal-to-noise ratio spectra are used to measure ages, metallicities, and nuclear activity levels. In combination with the photometric catalog in u , g , r , i , z , y down to 27 AB mag, we are able to study the galaxy population down to stellar masses of ∼10 8 M ⊙ . This paper presents the observational strategy, the reduction procedure and properties of the galaxy sample. (The catalog can be accessed through the survey’s website at http://mips.as.arizona.edu/~cnaw/Faint_Low_z/ .)