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

We investigate Ly alpha, [O III] lambda 5007, H alpha, and [C II] 158 mu m emission from 1124 galaxies at z = 4.9-7.0. Our sample is composed of 1092 Ly alpha 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 mu m data in the literature. Fluxes of strong rest-frame optical lines of [O III] and H alpha (H beta) are constrained by significant excesses found in the SPLASH 3.6 and 4.5 mu m photometry. At z = 4.9, we find that the rest-frame H alpha equivalent width and the Ly alpha escape fraction f(Ly alpha) positively correlate with the rest-frame Ly alpha equivalent width EWLy alpha 0. The f(Ly alpha)-EWLy alpha 0 correlation is similarly found at z similar to 0-2, suggesting no evolution of the correlation over z similar or equal to 0-5. The typical ionizing photon production efficiency of LAEs is log(xi(ion)/[Hz erg(-1)]) similar or equal to 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]/H alpha flux ratio increases in EWLy alpha 0, similar or equal to 0-30 angstrom and then decreases out to EWLy alpha 0 similar or equal to 130 angstrom. We also identify an anticorrelation between a ratio of [C II] luminosity to star formation rate (L-[C II]/SFR) and EWLy alpha 0 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 EWLy alpha 0, and metallicity explains self-consistently all of the correlations of Ly alpha, H alpha, [O III]/H alpha, and [C II] identified in our study, indicating detections of metal-poor (similar to 0.03 Z(circle dot)) galaxies with EWLy alpha 0, similar or equal to 200 angstrom.