SILVERRUSH. V. Census of Lyα, [O III] λ5007, Hα, and [C II] 158 μm Line Emission with ∼1000 LAEs at z = 4.9-7.0 Revealed with Subaru/HSC

Yuichi Harikane, Masami Ouchi, Takatoshi Shibuya, Takashi Kojima, Haibin Zhang, Ryohei Itoh, Yoshiaki Ono, Ryo Higuchi, Akio K. Inoue, Jacopo Chevallard, Peter L. Capak, Tohru Nagao, Masato Onodera, Andreas L. Faisst, Crystal L. Martin, Michael Rauch, Gustavo A. Bruzual, Stephane Charlot, Iary Davidzon, Seiji FujimotoMiftahul Hilmi, Olivier Ilbert, Chien Hsiu Lee, Yoshiki Matsuoka, John D. Silverman, Sune Toft

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99 Citations (Scopus)


We investigate Lyα, [O iii] λ5007, Hα, and [C ii] 158 μm emission from 1124 galaxies at z = 4.9-7.0. Our sample is composed of 1092 Lyα emitters (LAEs) at z = 4.9, 5.7, 6.6, and 7.0 identified by Subaru/Hyper-Suprime-Cam (HSC) narrowband surveys covered by Spitzer Large Area Survey with Hyper-Suprime-Cam (SPLASH) and 34 galaxies at z = 5.148-7.508 with deep ALMA [C ii] 158 μm data in the literature. Fluxes of strong rest-frame optical lines of [O iii] and Hα (Hβ) are constrained by significant excesses found in the SPLASH 3.6 and 4.5 μm photometry. At z = 4.9, we find that the rest-frame Hα equivalent width and the Lyα escape fraction f Lyα positively correlate with the rest-frame Lyα equivalent width fLyα positively correlate with the rest-frame Lyα equivalent width EWL0 . The correlation is similarly found at z ∼ 0-2, suggesting no evolution of the correlation over z ≃ 0-5. The typical ionizing photon production efficiency of LAEs is log(ξ ion/[Hz erg-1]) ≃ 25.5, significantly (60%-100%) higher than those of LBGs at a given UV magnitude. At z = 5.7-7.0, there exists an interesting turnover trend that the [O iii]/Hα flux ratio increases in and then decreases out to . We also identify an anticorrelation between a ratio of [C ii] luminosity to star formation rate (L [C ii]/SFR) and at the >99% confidence level.. We carefully investigate physical origins of the correlations with stellar-synthesis and photoionization models and find that a simple anticorrelation between and metallicity explains self-consistently all of the correlations of Lyα, Hα, [O iii]/Hα, and [C ii] identified in our study, indicating detections of metal-poor (∼0.03 Z o) galaxies with .

Original languageEnglish
Article number84
JournalAstrophysical Journal
Issue number2
Publication statusPublished - 2018 Jun 1
Externally publishedYes


  • galaxies: evolution
  • galaxies: formation
  • galaxies: high-redshift

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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