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20162026
most citedThe Hyper Suprime-Cam SSP Survey: Overview and Survey Design

1.1k citations · 2.7k across the 42 of their papers we have counts for

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42 papers · 1 filter

astro-ph.GA2026

Diverse Metallicities in Protoclusters at detected by Deep Learning

Yoshihiro Takeda, Nobunari Kashikawa, Kei Ito +12

We present spectroscopic follow-up observations with Subaru/MOIRCS of four protocluster candidate regions identified by the deep-learning model PCFNet. In three candidate regions,…

astro-ph.GA2026

Probing Spatial Variations in IGM Transmission: Higher Ly Visibility in an H-Selected Galaxy Overdensity at

Shunta Shimizu, Nobunari Kashikawa, Junya Arita +13

The visibility of Ly emission during the epoch of reionization depends on both galaxy properties and the transmission of Ly photons through the intergalactic medium (IGM). Us…

astro-ph.GA2026

PEGASUS (Pfs Emission-line GAlaxy SUrvey with Subaru): II. Metal Poor AGNs in High Equivalent-Width Narrow-Band Emitters

Hisakazu Uchiyama, Tohru Nagao, Mariko Kubo +19

We present Subaru 'Ōnohi'ula Prime Focus Spectrograph (PFS) optical--NIR spectroscopic follow-up of high-equivalent-width (EW) narrow-band (NB) emission-line galaxies selected from…

astro-ph.GA2026

PEGASUS (Pfs Emission-line GAlaxy SUrvey with Subaru): I. Three-dimensional large-scale structures at probed with emission-line galaxies

Mariko Kubo, Tadayuki Kodama, Rhythm Shimakawa +16

To comprehensively understand the environmental effects on galaxy evolution, it is crucial to precisely map the distribution and thoroughly examine the properties of galaxies, incl…

astro-ph.GA2026

H I Absorbers as Beacons of Hidden Structure at : Multi-Component, Metal-Rich Absorption System near a Protocluster

Kentaro Koretomo, Nobunari Kashikawa, Toru Misawa +12

H I gas traces the large-scale structure and provides the primary fuel for star formation. High- protoclusters are ideal laboratories to study how H I gas is accreted and consum…

astro-ph.GA2026

Subaru meets JWST: A Direct Measurement of Ly Escape Fraction at with Dual Narrow-Band Imaging

Shunta Shimizu, Nobunari Kashikawa, Ryo Emori +15

We present a direct measurement of the Ly escape fraction, , for H emitters (HAEs) at in the JWST CEERS field by combining JWST/NIRCam F47…

astro-ph.GA2026

A Wide and Deep Exploration of Radio-detected Active Galactic Nuclei with Subaru HSC (WERGS). XIII. High-z Radio Quasar Selection from HSC--VLASS over deg

Youwen Kong, Kohei Ichikawa, Hisakazu Uchiyama +12

We report the results of , , , and dropout selections based on optical identifications of Very Large Array Sky Survey (VLASS) radio sources using the Hyper Suprime-…

astro-ph.GA2026

A Wide and Deep Exploration of Radio-detected Active Galactic Nuclei with Subaru HSC (WERGS). XII. Final Optical Identification of VLASS Radio Sources from the Subaru/HSC-SSP Wide Survey Over 1200 deg

Hisakazu Uchiyama, Kohei Ichikawa, Youwen Kong +11

We present a wide-area and deep optical identification catalog for radio sources based on the VLASS Epoch 2 catalog at 3 GHz. Optical counterparts are identified using the final-ye…

astro-ph.GA2025

Quasar Negative Feedback to Surrounding Galaxies Probed with Ly Emitters and Continuum-Selected Galaxies

Yuta Suzuki, Yoshiki Matsuoka, Satoshi Kikuta +3

We report on the statistical analysis of quasar photoevaporation at by comparing the density of surrounding Ly Emitters (LAEs) and continuum-selected galaxies, based…

astro-ph.GA2025★ 2 cited

Environment of SDSS quasars at explored by Subaru HSC

Kohei Shibata, Tohru Nagao, Hisakazu Uchiyama +5

The relationship between quasars and their galaxy environment is important for understanding the evolution of galaxies and supermassive black holes, but it is not fully understood.…

astro-ph.GA2025★ 2 cited

UNIONS: The Ultraviolet Near-Infrared Optical Northern Survey

Stephen Gwyn, Alan W. McConnachie, Jean-Charles Cuillandre +86

The Ultraviolet Near-Infrared Optical Northern Survey (UNIONS) is a "collaboration of collaborations" that is using the Canada-France-Hawai'i Telescope, the Pan-STARRS telescopes,…

astro-ph.GA2024

A Wide and Deep Exploration of Radio Galaxies with Subaru HSC (WERGS). X. The Massive and Passive Nature of Radio Galaxies at

Yuta Yamamoto, Tohru Nagao, Takuji Yamashita +8

High- radio galaxies (HzRGs) are considered important objects for understanding the formation and evolution of massive galaxies in the early universe. However, till date, detail…

astro-ph.GA2024

Mining for Protoclusters at from Photometric Datasets with Deep Learning

Yoshihiro Takeda, Nobunari Kashikawa, Kei Ito +9

Protoclusters are high- overdense regions that will evolve into clusters of galaxies by , making them ideal for studying galaxy evolution expected to be accelerated by envi…

astro-ph.GA2024★ 4 cited

Environments around quasars at 3 revealed by wide-field imaging with Subaru HSC and CFHT

Yuta Suzuki, Hisakazu Uchiyama, Yoshiki Matsuoka +7

We examine the local density environments around 67 quasars at , by combining the imaging data of Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) and Canada-France-Haw…

astro-ph.GA2024

Galaxy properties from the outskirts to the core of a protocluster at z=3.699

Jun Toshikawa, Stijn Wuyts, Nobunari Kashikawa +6

We present follow-up spectroscopy on a protocluster candidate selected from the wide-field imaging of the Hyper SuprimeCam Subaru Strategic Programme. The target protocluster candi…

astro-ph.GA2024

Cosmic Himalayas: The Highest Quasar Density Peak Identified in a 10,000 deg Sky with Spatial Discrepancies between Galaxies, Quasars, and IGM HI

Yongming Liang, Masami Ouchi, Dongsheng Sun +27

We report the identification of a quasar overdensity in the BOSSJ0210 field, dubbed Cosmic Himalayas, consisting of 11 quasars at , the densest overdensity of quasars…

astro-ph.GA2023

New technique to select recent fast-quenching galaxies at using the optical colors

Mariko Kubo, Tohru Nagao, Hisakazu Uchiyama +4

Many massive quiescent galaxies have been discovered at thanks to multi-wavelength deep and wide surveys, however, substantial deep near-infrared spectroscopic observations a…

astro-ph.GA2023

An enhanced abundance of bright galaxies in protocluster candidates at z~3-5

Jun Toshikawa, Stijn Wuyts, Nobunari Kashikawa +11

We present a protocluster search covering to based on the combination of the Hyper SuprimeCam Subaru Strategic Programme and the CFHT Large Area -band Deep Sur…

astro-ph.GA2022★ 6 cited

A Wide and Deep Exploration of Radio Galaxies with Subaru HSC (WERGS). IX. The Most Overdense Region at z~5 Inhabited by a Massive Radio Galaxy

Hisakazu Uchiyama, Takuji Yamashita, Tohru Nagao +13

We report on the galaxy density environment around a high-z radio galaxy (HzRG) at z=4.72, HSC J083913.17+011308.1 (HSC J0839+0113), probed using an r-dropout Lyman break galaxy (L…

astro-ph.GA2022★ 18 cited

The physical origin for spatially large scatter of IGM opacity at the end of reionization: the IGM Ly opacity-galaxy density relation

Rikako Ishimoto, Nobunari Kashikawa, Daichi Kashino +9

The large opacity fluctuations in the Ly forest may indicate inhomogeneous progress of reionization. To explain the observed large scatter of the effective Ly optic…

astro-ph.GA2022★ 11 cited

A Wide and Deep Exploration of Radio Galaxies with Subaru HSC (WERGS). VII. Redshift Evolution of Radio Galaxy Environments at z=0.3-1.4

Hisakazu Uchiyama, Takuji Yamashita, Tohru Nagao +9

We examine the redshift evolution of density environments around 2,163 radio galaxies with the stellar masses of between redshifts of , base…

astro-ph.GA2021★ 12 cited

A Wide and Deep Exploration of Radio Galaxies with Subaru HSC (WERGS). VI. Distant Filamentary Structures Pointed by High-z Radio Galaxies at z~4

Hisakazu Uchiyama, Takuji Yamashita, Jun Toshikawa +13

We present the environmental properties around high- radio galaxies (HzRGs) at , which have been poorly investigated because of their rarity. We use the largest samples…

astro-ph.GA2021★ 17 cited

A Wide and Deep Exploration of Radio Galaxies with Subaru HSC (WERGS). IV. Rapidly Growing (Super-)Massive Black Holes in Extremely Radio-Loud Galaxies

Kohei Ichikawa, Takuji Yamashita, Yoshiki Toba +19

We present the optical and infrared properties of 39 extremely radio-loud galaxies discovered by cross-matching the Subaru/Hyper Suprime-Cam (HSC) deep optical imaging survey and V…

astro-ph.GA2021★ 16 cited

Interrelation of the environment of Ly emitters and massive galaxies at

Kei Ito, Nobunari Kashikawa, Masayuki Tanaka +7

We present a comparison of the spatial distributions of Ly emitters (LAEs) and massive star-forming and quiescent galaxies (SFGs and QGs) at . We use the photometric re…