A 16 deg$^2$ survey of emission-line galaxies at z<1.6 from HSC-SSP PDR2 and CHORUS

TL;DR

This paper presents a large-scale survey of emission-line galaxies at redshifts below 1.6, using narrowband imaging data from HSC-SSP PDR2 and CHORUS, revealing the evolution of star formation rate densities over cosmic time.

Contribution

It provides updated catalogs and analysis of emission-line galaxies over a wide area, utilizing new data from PDR2 and CHORUS, and investigates large-scale structures and luminosity functions across cosmic history.

Findings

Star formation rate density decreases monotonically from z~1.6 to present.

Large samples of 75,377 emission-line galaxies enable detailed evolution studies.

Distribution of large-scale structures traced by emission-line galaxies.

Abstract

We have conducted a comprehensive survey of emission-line galaxies at $z\lesssim1.6$ based on narrowband (NB) imaging data taken with Hyper Suprime-Cam (HSC) on the Subaru telescope. In this paper, we update the catalogs of H$\alpha$, [OIII], and [OII] emission-line galaxies using the data from the second Public Data Release (PDR2) of Subaru Strategic Program (SSP) of HSC and Cosmic HydrOgen Reionization Unveiled with Subaru (CHORUS) survey along with the spectroscopic redshifts for 2,019 emission-line galaxies selected with the PDR1 data. The wider effective coverage of NB816 and NB921, 16.3 deg$^2$ and 16.9 deg$^2$ respectively, are available in the Deep and UltraDeep layers of HSC-SSP from the PDR2. The CHORUS survey provides us with data with additional three NBs (NB527, NB718, and NB973) in the COSMOS field in the UltraDeep layer (1.37 deg$^2$). The five NB datasets allow us to investigate the star-forming galaxies presenting emission-lines at 14 specific redshifts ranging from $z\sim1.6$ down to $z\sim0.05$. We revisit the distribution of large-scale structures and luminosity functions (LFs) for the emission-line galaxies with the large samples of 75,377 emission-line galaxies selected. The redshift revolution of LFs shows that the star formation rate densities (SFRDs) decreases monotonically from $z\sim1.6$, which is consistent with the cosmic SFRD ever known. Our samples of emission-line galaxies covering a sufficiently large survey volume are useful to investigate the evolution of star-forming galaxies since the cosmic noon in a wide range of environments including galaxy clusters, filaments, and voids.