Suzuki, Tomoko L. and Kodama, Tadayuki and Onodera, Masato and Shimakawa, Rhythm and Hayashi, Masao and Tadaki, Ken-ichi and Koyama, Yusei and Tanaka, Ichi and Sobral, David and Smail, Ian and Best, Philip N. and Khostovan, Ali A. and Minowa, Yosuke and Yamamoto, Moegi (2017) The Interstellar Medium in [O III]-selected Star-forming Galaxies at z similar to 3.2. The Astrophysical Journal, 849 (1). ISSN 0004-637X
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Abstract
We present new results from near-infrared spectroscopy with Keck/MOSFIRE of [O III]-selected galaxies at z similar to 3.2. With our H and K band spectra, we investigate the interstellar medium (ISM) conditions, such as ionization states and gas metallicities. [O III] emitters at z similar to 3.2 show a typical gas metallicity of 12+ log(O/H)= 8.07 +/- 0.07 at log(M-*/M-circle dot) similar to 9.0-9.2 and 12+ log(O/H)= 8.31 +/- 0.04 at log(M-*/M-circle dot) similar to 9.7-10.2 when using the empirical calibration method. We compare the [O III] emitters at z similar to 3.2 with UV-selected galaxies and Lya emitters at the same epoch and find that the [O III]-based selection does not appear to show any systematic bias in the selection of star-forming galaxies. Moreover, comparing with star-forming galaxies at z similar to 2 from the literature, our samples show similar ionization parameters and gas metallicities as those obtained by the previous studies that used the same calibration method. We find no strong redshift evolution in the ISM conditions between z similar to 3.2 and z similar to 2. Considering that the star formation rates at a fixed stellar mass also do not significantly change between the two epochs, our results support the idea that the stellar mass is the primary quantity to describe the evolutionary stages of individual galaxies at z > 2.