13 citations · 47 across the 36 of their papers we have counts for
33 papers · 1 filter
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…
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…
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…
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…
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…
Euclid: Scaled-up little red dots and other sources with v-shaped spectral energy distributions at z>4
Euclid Collaboration, A. A. Tumborang, K. I. Caputi +169
Little Red Dots (LRDs) are some the most intriguing galaxy populations recently identified at z>~4 with JWST. They constitute the most extreme class of a more abundant population o…
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-…
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…
Subaru High- Exploration of Low-Luminosity Quasars (SHELLQs). XXV. Large-scale environments of low-luminosity quasars at traced by Ly emitters
Junya Arita, Nobunari Kashikawa, Yoshiki Matsuoka +18
High- quasars are believed to reside in massive dark matter haloes (DMHs), suggesting that they reside in galaxy overdense regions. However, previous observations have shown a r…
SHELLQs-JWST: Revealing the Spectra of Extended Emission in 12 z > 6 Quasar Host Galaxies using the JWST NIRSpec Fixed Slit
Camryn L. Phillips, Michael A. Strauss, Masafusa Onoue +15
We present an analysis of the rest frame optical JWST NIRSpec Fixed Slit spectra of extended host galaxy emission in 12 quasars from the Subaru High-z Exploration of Low-Luminosity…
A Possible Shutting-Down Event of Mass Accretion in An Active Galactic Nucleus at z~1.8
Tomoki Morokuma, Malte Schramm, Toshihiro Kawaguchi +11
We present the discovery of a large gradual apparent fading event in optical and near-infrared wavelengths in a quasar at z=1.767 by a factor of 20-30 (in optical) over a period of…
A z ~ 0.4 Galaxy Reflecting the high-redshift Little Red Dots: An Extended Starburst with an Overmassive Black Hole
Xiaoyang Chen, Kohei Ichikawa, Masayuki Akiyama +10
One of the most remarkable discoveries of JWST is a population of compact, red sources at z > 4, commonly referred to as Little Red Dots (LRDs). Spectroscopic identifications repor…
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…
Merger fraction in galaxy groups and clusters at z < 0.2: A non-parametric morphological study with Subaru Hyper Suprime-Cam
Anri Yanagawa, Yoshiki Toba, Naomi Ota +7
We investigate the environmental dependence of galaxy mergers using high-resolution imaging data from the Hyper Suprime-Cam (HSC) Subaru Strategic Program. We focus on galaxy group…
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…
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…
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…
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.…
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…
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…
SHELLQs-JWST Unveils the Host Galaxies of 12 Quasars at z>6
Xuheng Ding, Masafusa Onoue, John D. Silverman +35
The advent of JWST has opened new horizons in the study of quasar host galaxies during the reionization epoch (z>6). Building upon our previous initial measurements of stellar ligh…
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…
Subaru High- Exploration of Low-Luminosity Quasars (SHELLQs). XXIII. The powering mechanisms of the Ly haloes around high- quasars probed by slit spectroscopy
Hiroki Hoshi, Rikako Ishimoto, Nobunari Kashikawa +15
We present the analysis of Ly haloes around faint quasars at and . We use 20 and 162 quasars at and , taken by slit spectroscopy, and detect Ly…
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…