The Metal Abundances across Cosmic Time ($\mathcal{MACT}$) Survey. I. Optical Spectroscopy in the Subaru Deep Field

TL;DR

The $ ext{MACT}$ survey provides extensive optical spectroscopy of approximately 1900 emission-line galaxies in the Subaru Deep Field, enabling detailed analysis of their gas-phase metallicities and properties across cosmic time.

Contribution

This paper introduces the $ ext{MACT}$ survey and presents new optical spectroscopic data for nearly 1900 galaxies, including measurements of weak [OIII]$ ext{4363}$ lines crucial for metallicity determination.

Findings

Spectroscopic data for ~1900 galaxies in the Subaru Deep Field.

Measurement of [OIII]$ ext{4363}$ line in 164 galaxies for metallicity analysis.

Derived properties include metallicity, star formation rates, and stellar mass.

Abstract

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 $\mathcal{MACT}$, which will obtain rest-frame optical spectra for $\sim$3000 emission-line galaxies. This paper describes the optical spectroscopy that has been conducted with MMT/Hectospec and Keck/DEIMOS for $\approx$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 [OIII]$\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 $\mathcal{MACT}$ survey (Ly et al.) presents the first results on the stellar mass--gas metallicity relation at $z\lesssim1$ using the sample with [OIII]$\lambda$4363 measurements.