61 citations · 78 across the 16 of their papers we have counts for
16 papers · 1 filter
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…
A VLBA-resolved Jet Associated with Super-Eddington Accretion in a Radio-loud Quasar at
Sakiko Obuchi, Ingyin Zaw, Kazuhiro Hada +2
We report the detailed jet properties of eROSITA Final Equatorial Depth Survey (eFEDS) J084222.9+001000 (hereafter ID830), a radio-loud super-Eddington quasar at , reveal…
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…
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…
Discovery of an X-ray Luminous Radio-Loud Quasar at : A Possible Transitional Super-Eddington Phase
Sakiko Obuchi, Kohei Ichikawa, Satoshi Yamada +11
We report the multiwavelength properties of eFEDS J084222.9+001000 (hereafter ID830), a quasar at , identified as the most X-ray luminous radio-loud quasar in the eROSITA…
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…
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…
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…
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,…
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…
Little Red Dots: Rapidly Growing Black Holes Reddened by Extended Dusty Flows
Zhengrong Li, Kohei Inayoshi, Kejian Chen +2
The James Webb Space Telescope (JWST) observations have revolutionized extragalactic research, particularly with the discovery of little red dots (LRD), which we propose are dust-r…
Observational Properties of AGN Obscuration During the Peak of Accretion Growth
Bovornpratch Vijarnwannaluk, Masayuki Akiyama, Malte Schramm +11
We investigated the gas obscuration and host galaxy properties of active galactic nuclei (AGN) during the peak of cosmic accretion growth of supermassive black holes (SMBHs) at red…
Birth of Rapidly Spinning, Overmassive Black Holes in the Early Universe
Kohei Inayoshi, Kohei Ichikawa
The James Webb Space Telescope (JWST) has unveiled numerous massive black holes (BHs) in faint, broad-line active galactic nuclei (AGNs). The discovery highlights the presence of d…
Exploring Low-Mass Black Holes through Tidal Disruption Events in the Early Universe: Perspectives in the Era of JWST, RST, and LSST Surveys
Kohei Inayoshi, Kazumi Kashiyama, Wenxiu Li +3
The James Webb Space Telescope (JWST) has recently uncovered the presence of low-luminosity active galactic nuclei (AGNs) at . Spectroscopic observations have provided esti…