activity
20152026
most citedALMA Deep Field in SSA22: Blindly Detected CO Emitters and [CII] Emitter Candidates

29 citations · 121 across the 30 of their papers we have counts for

collaborators

31 papers

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

SHELLQs. Black Hole Mass and Eddington Ratio Distributions of Intermediate-Luminosity Quasars at 6<z<7

Masafusa Onoue, John D. Silverman, Yoshiki Matsuoka +31

We present near-infrared spectroscopy of 21 quasars at 6.07 < z < 6.90 obtained with JWST/NIRSpec and Subaru/MOIRCS. These targets have absolute ultraviolet magnitudes of -25 < M_1…

astro-ph.GA2026

Discovery of four Narrow-line Type-1 Quasars at z = 2.54 -- 6.06 with Subaru 'Onohi'ula PFS-SSP

Ayumi Takahashi, Yoshiki Matsuoka, Yoshiki Toba +21

We report the discovery of four narrow-line type-1 quasars (NLQ1s) from the Subaru 'Onohi'ula Prime Focus Spectrograph Subaru Strategic Program (PFS-SSP). To extend a comprehensive…

astro-ph.GA2026

Blackbody Quasar and Radio Source (BBQSORS): A Candidate of Transitional Little Red Dots with a Blackbody Spectrum

Yuxing Zhong, Xiaoyang Chen, Kohei Ichikawa +12

We report Subaru/PFS spectroscopic follow-up of a radio-loud quasar at from the UNVEIL radio AGN catalog and with X-ray detections. The PFS spectrum displays a broad MgII…

astro-ph.GA2026

Dense Ionized Outflow with Five Narrow Components in a Dust-obscured Galaxy

Taketo Yoshida, Tohru Nagao, Yoshiki Toba +4

We present our discovery of a complex ionized outflow in SDSS J101034.28+372514.7 (J1010+3725), a dust-obscured galaxy (DOG) at . The SDSS optical spectrum of J1010+3725 s…

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

ALMA Deep Field in SSA22: Reconstructed [CII] Luminosity Function at z = 6

Natsuki H. Hayatsu, Rob J. Ivison, Paola Andreani +19

The ADF22 line survey reported detections of two high- line-emitting source candidates above 6-, both of which were shown to be spurious after follow-up observations. We inve…

astro-ph.GA2025

Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). XXIV. 54 New Quasars and Candidate Obscured Quasars at

Yoshiki Matsuoka, Kazushi Iwasawa, Masafusa Onoue +18

We present spectroscopic identification of 43 quasars and 11 candidate obscured quasars in the epoch of reionization (EoR) at , along with 29 galaxies at simil…

astro-ph.GA2025

SHELLQs-JWST perspective on the intrinsic mass relation between supermassive black holes and their host galaxies at z > 6

John Silverman, Junyao Li, Xuheng Ding +36

The relation between the masses of supermassive black holes (SMBHs) and their host galaxies encodes information on their mode of growth, especially at the earliest epochs. The Jame…

astro-ph.GA2025★ 4 cited

UNIONS Optical Identifications for VLASS Radio Sources in the Euclid Sky (UNVEIL) I. A Catalog of ~146,000 Radio Galaxies up to z~5

Yuxing Zhong, Kohei Ichikawa, Hendrik Hildebrandt +11

We present results of optical identifications for Very Large Array Sky Survey (VLASS) radio sources using the Ultraviolet Near Infrared Optical Northern Survey (UNIONS). A cross-ma…

astro-ph.GA2025★ 2 cited

Dust-obscured Galaxies with Broken Power-law Spectral Energy Distributions Discovered by UNIONS

Taketo Yoshida, Tohru Nagao, Yoshiki Toba +11

We report on the spectral energy distributions (SEDs) of infrared-bright dust-obscured galaxies (DOGs) with . Using photometry from the deep and wide…

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★ 1 cited

Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs) XXII. Chandra observations of narrow-line quasar candidates at z>6

K. Iwasawa, R. Gilli, F. Vito +13

We report on Chandra X-ray observations of four narrow-line quasar candidates at z~6, selected from the SHELLQs project, based on the Subaru Hyper Suprime-Cam survey. These objects…

astro-ph.GA2025★ 13 cited

SHELLQs. Bridging the Gap: JWST Unveils Obscured Quasars in the Most Luminous Galaxies at z > 6

Yoshiki Matsuoka, Masafusa Onoue, Kazushi Iwasawa +17

The unprecedented sensitivity of the James Webb Space Telescope (JWST) has uncovered a surprisingly abundant population of mildly obscured, low-luminosity active galactic nuclei (A…

astro-ph.GA2025

The X-ray statistical properties of dust-obscured galaxies detected by eROSITA

Akatoki Noboriguchi, Kohei Ichikawa, Yoshiki Toba +15

Dust-obscured galaxies (DOGs) are considered to be in a co-evolution phase, with the associated active galactic nuclei (AGN) obscured by dust and gas. Although the DOGs are thought…

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

EMPRESS. X. Spatially resolved mass-metallicity relation in extremely metal-poor galaxies: evidence of episodic star-formation fueled by a metal-poor gas infall

Kimihiko Nakajima, Masami Ouchi, Yuki Isobe +47

Using the Subaru/FOCAS IFU capability, we examine the spatially resolved relationships between gas-phase metallicity, stellar mass, and star-formation rate surface densities (Sigma…

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

The Physical Origin of Extreme Emission Line Galaxies at High redshifts: Strong {\sc [Oiii]} Emission Lines Produced by Obscured AGNs

Chenghao Zhu, Yuichi Harikane, Masami Ouchi +21

We present deep Subaru/FOCAS spectra for two extreme emission line galaxies (EELGs) at with strong {\sc[Oiii]}5007 emission lines, exhibiting equivalent widths (EWs) o…

astro-ph.GA2024★ 2 cited

A Post-Starburst Pathway for the Formation of Massive Galaxies and Black Holes at z>6

Masafusa Onoue, Xuheng Ding, John D. Silverman +45

Understanding the rapid formation of supermassive black holes (SMBHs) in the early universe requires insight into stellar mass growth in host galaxies. Here, we present NIRSpec res…

astro-ph.GA2024

Discovery of a hyperluminous quasar at z = 1.62 with Eddington ratio > 3 in the eFEDS field confirmed by KOOLS-IFU on Seimei Telescope

Yoshiki Toba, Keito Masu, Naomi Ota +17

We report the discovery of a hyperluminous type 1 quasar (eFEDS J082826.9-013911; eFEDSJ0828-0139) at = 1.622 with a super-Eddington ratio (). We perfor…

astro-ph.GA2024★ 8 cited

Detection of the [O I] 63 m emission line from the quasar J2054-0005

Nozomi Ishii, Takuya Hashimoto, Carl Ferkinhoff +23

We report the highest-redshift detection of [O I] 63 m from a luminous quasar, J2054-0005, at based on the Atacama Large Millimeter/sub-millimeter Array Band 9 observat…

astro-ph.GA2024

Ongoing and fossil large-scale outflows detected in a high-redshift radio galaxy: [C II] observations of TN J09242201 at

Kianhong Lee, Masayuki Akiyama, Kotaro Kohno +13

We present Atacama Large Millimeter/submillimeter Array observations of the [C II] 158 m line and the underlying continuum emission of TN J09242201, which is one of the most…