The FMOS-COSMOS Survey of Star-forming Galaxies at z∼1.6. VI. Redshift and Emission-line Catalog and Basic Properties of Star-forming Galaxies

We present a new data release from the Fiber Multi-Object Spectrograph (FMOS)-COSMOS survey that contains the measurements of the spectroscopic redshift and flux of rest-frame optical emission lines (H alpha, [N II], [S II], H beta, [O III]) for 1931 galaxies out of a total of 5484 objects observed over the 1.7 deg(2) COSMOS field. We obtained H- and J-band medium-resolution (R similar to 3000) spectra with FMOS mounted on the Subaru telescope, which offers an in-fiber line flux sensitivity limit of similar to 1 x 10(-17) erg s(-1) cm(-2) for an on-source exposure time of 5 hr. The full sample contains the main population of star-forming galaxies at z similar to 1.6 over the stellar mass range 10(9.5) less than or similar to M-*/M-circle dot less than or similar to 10(11.5), as well as other subsamples of infrared-luminous galaxies detected by Spitzer and Herschel at the same and lower (z similar to 0.9) redshifts and X-ray-emitting galaxies detected by Chandra. This paper presents an overview of our spectral analyses, a description of the sample characteristics, and a summary of the basic properties of emission-line galaxies. We use the larger sample to redefine the stellar mass-star formation rate relation based on the dust-corrected H alpha luminosity and find that the individual galaxies are better fit with a parameterization including a bending feature at M-* approximate to 10(10.2) M-circle dot, and that the intrinsic scatter increases with M-* from 0.19 to 0.37 dex. We also confirm with higher confidence that the massive (M-* greater than or similar to 10(10.5) M-circle dot) galaxies are chemically mature as much as local galaxies with the same stellar masses, and that the massive galaxies have lower [S II]/H alpha ratios for their [O III]/H beta as compared to local galaxies, which is indicative of enhancement in the ionization parameter.