@article{ly_malhotra_malkan_rigby_kashikawa_reyes_rhoads_2016, title={The metal abundances across cosmic time (mact) survey. I. Optical spectroscopy in the subaru deep field}, volume={226}, DOI={10.3847/0067-0049/226/1/5}, abstractNote={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     , which will obtain rest-frame optical spectra for ∼3000 emission-line galaxies. This paper describes the optical spectroscopy that has been conducted with MMT/Hectospec and Keck/DEIMOS for ≈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]λ4363 line (66 with at least 3σ 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     survey (Ly et al.) presents the first results on the stellar mass–gas metallicity relation at z ≲ 1 using the sample with [O iii]λ4363 measurements.}, number={1}, journal={Astrophysical Journal Supplement Series}, author={Ly, C. and Malhotra, S. and Malkan, M. A. and Rigby, J. R. and Kashikawa, N. and Reyes, M. A. and Rhoads, J. E.}, year={2016} } @article{de los reyes_ly_lee_salim_peeples_momcheva_feddersen_dale_ouchi_ono_et al._2015, title={THE RELATIONSHIP BETWEEN STELLAR MASS, GAS METALLICITY, AND STAR FORMATION RATE FOR H-alpha-SELECTED GALAXIES AT z approximate to 0.8 FROM THE NEWH alpha SURVEY}, volume={149}, ISSN={["1538-3881"]}, DOI={10.1088/0004-6256/149/2/79}, abstractNote={Using a sample of 299 Hα-selected galaxies at z ≈ 0.8 ?> , we study the relationship between galaxy stellar mass, gas-phase metallicity, and star formation rate (SFR), and compare to previous results. We use deep optical spectra obtained with the IMACS spectrograph at the Magellan telescope to measure strong oxygen lines. We combine these spectra and metallicities with (1) rest-frame UV-to-optical imaging, which allows us to determine stellar masses and dust attenuation corrections, and (2) Hα narrowband imaging, which provides a robust measurement of the instantaneous SFR. Our sample spans stellar masses of ∼109–6 × 1011 M ⊙ ?> , SFRs of 0.4–270 M ⊙ ?> yr−1, and metal abundances of 12 + log ( O / H ) ≈ 8.3 ?> –9.1 ( ≈ 0.4 ?> –2.6 Z ⊙ ?> ). The correlations that we find between the Hα-based SFR and stellar mass (i.e., the star-forming “main sequence”) and between the stellar mass and metallicity are both consistent with previous z ∼ 1 ?> studies of star-forming galaxies. We then study the relationship between the three properties using various plane-fitting techniques and a curve-fitting projection. In all cases, we exclude strong dependence of the M ⋆ ?> –Z relation on SFR, but are unable to distinguish between moderate and no dependence. Our results are consistent with previous mass–metallicity–SFR studies. We check whether data set limitations may obscure a strong dependence on the SFR by using mock samples drawn from the Sloan Digital Sky Survey. These experiments reveal that the adopted signal-to-noise ratio cuts may have a significant effect on the measured dependence. Further work is needed to investigate these results, and to test whether a “fundamental metallicity relation” or a “fundamental plane” describes star-forming galaxies across cosmic time.}, number={2}, journal={ASTRONOMICAL JOURNAL}, author={De Los Reyes, Mithi A. and Ly, Chun and Lee, Janice C. and Salim, Samir and Peeples, Molly S. and Momcheva, Ivelina and Feddersen, Jesse and Dale, Daniel A. and Ouchi, Masami and Ono, Yoshiaki and et al.}, year={2015}, month={Feb} }