The Dwarf Galaxy Population at z ∼ 0.7: A Catalog of Emission Lines and Redshifts from Deep Keck Observations

Abstract

We present a catalog of spectroscopically measured redshifts over 0 < z < 2 and emission-line fluxes for 1440 galaxies. The majority (∼65%) of the galaxies come from the HALO7D survey, with the remainder from the DEEPwinds program. This catalog includes redshifts for 646 dwarf galaxies with log ( M ⋆ / M ⊙ ) < 9.5 . Eight-hundred and ten catalog galaxies did not have previously published spectroscopic redshifts, including 454 dwarf galaxies. HALO7D used the DEIMOS spectrograph on the Keck II telescope to take very deep (up to 32 hr exposure, with a median of ∼7 hr) optical spectroscopy in the COSMOS, EGS, GOODS-North, and GOODS-South CANDELS fields, and in some areas outside CANDELS. We compare our redshift results to existing spectroscopic and photometric redshifts in these fields, finding only a 1% rate of discrepancy with other spectroscopic redshifts. We measure a small increase in median photometric redshift error (from 1.0% to 1.3%) and catastrophic outlier rate (from 3.5% to 8%) with decreasing stellar mass. We obtained successful redshift fits for 75% of massive galaxies, and demonstrate a similar 70%–75% successful redshift measurement rate in 8.5 < 9.5 galaxies, suggesting similar survey sensitivity in this low-mass range. We describe the redshift, mass, and color–magnitude distributions of the catalog galaxies, finding HALO7D galaxies representative of CANDELS galaxies up to i -band magnitudes of 25. The catalogs presented will enable studies of star formation, the mass–metallicity relation, star formation–morphology relations, and other properties of the z ∼ 0.7 dwarf galaxy population.