THE METAL ABUNDANCES ACROSS COSMIC TIME (MACT) SURVEY. I. OPTICAL SPECTROSCOPY IN THE SUBARU DEEP FIELD

Deep rest-frame optical spectroscopy is critical for characterizing and understanding the physical conditions and properties of the ionized gas in galaxies. Here, we present a new spectroscopic survey called "Metal Abundances across Cosmic Time" or MACT, which will obtain rest-frame optical spectra for similar to 3000 emission-line galaxies. This paper describes the optical spectroscopy that has been conducted with MMT/Hectospec and Keck/DEIMOS for approximate to 1900 z = 0.1-1 emission-line galaxies selected from our narrowband and intermediate-band imaging in the Subaru Deep Field. In addition, we present a sample of 164 galaxies for which we have measured the weak [O III] lambda 4363 line (66 with at least 3 sigma detections and 98 with significant upper limits). This nebular emission line determines the gas-phase metallicity by measuring the electron temperature of the ionized gas. This paper presents the optical spectra, emission-line measurements, interstellar properties (e.g., metallicity, gas density), and stellar properties (e.g., star formation rates, stellar mass). Paper II of the MACT survey (Ly et al.) presents the first results on the stellar mass-gas metallicity relation at z less than or similar to 1 using the sample with [O III] lambda 4363 measurements.