activity
20142026
most citedPrecessing jet nozzle connecting to a spinning black hole in M87

109 citations · 480 across the 15 of their papers we have counts for

collaborators

15 papers

astro-ph.GA2026

Jet-torus interaction revealed by sub-parsec SO absorption in NGC 1052

Satoko Sawada-Satoh, Seiji Kameno, Nozomu Kawakatsu +10

We report the first λ2-mm very long baseline interferometry (VLBI) observations of the radio galaxy NGC 1052, conducted with the Korean VLBI Network (KVN) using a wide-band recordi…

astro-ph.HE2023★ 109 cited

Precessing jet nozzle connecting to a spinning black hole in M87

Yuzhu Cui, Kazuhiro Hada, Tomohisa Kawashima +76

The nearby radio galaxy M87 offers a unique opportunity to explore the connections between the central supermassive black hole and relativistic jets. Previous studies of the inner…

astro-ph.HE2023★ 26 cited

Spectral analysis of a parsec-scale jet in M87: Observational constraint on the magnetic field strengths in the jet

Hyunwook Ro, Motoki Kino, Bong Won Sohn +49

Because of its proximity and the large size of its black hole, M87 is one of the best targets for studying the launching mechanism of active galactic nucleus jets. Currently, magne…

astro-ph.IM2022★ 16 cited

Overview of the Observing System and Initial Scientific Accomplishments of the East Asian VLBI Network (EAVN)

Kazunori Akiyama, Juan-Carlos Algaba, Tao An +101

The East Asian VLBI Network (EAVN) is an international VLBI facility in East Asia and is operated under mutual collaboration between East Asian countries, as well as part of Southe…

astro-ph.GA2022★ 6 cited

EAVN Astrometry toward the Extreme Outer Galaxy: Kinematic distance with the proper motion of G034.84-00.95

Nobuyuki Sakai, Bo Zhang, Shuangjing Xu +22

We aim to reveal the structure and kinematics of the Outer-Scutum-Centaurus (OSC) arm located on the far side of the Milky Way through very long baseline interferometry (VLBI) astr…

astro-ph.HE2021★ 27 cited

The intrinsic structure of Sagittarius A* at 1.3 cm and 7 mm

Ilje Cho, Guang-Yao Zhao, Tomohisa Kawashima +63

Sagittarius A* (Sgr A*), the Galactic Center supermassive black hole (SMBH), is one of the best targets to resolve the innermost region of SMBH with very long baseline interferomet…

astro-ph.GA2021★ 19 cited

East Asian VLBI Network Observations of Active Galactic Nuclei Jets: Imaging with KaVA+Tianma+Nanshan

Yuzhu Cui, Kazuhiro Hada, Motoki Kino +74

The East Asian very-long-baseline interferometry (VLBI) Network (EAVN) is a rapidly evolving international VLBI array that is currently promoted under joint efforts among China, Ja…

astro-ph.HE2019★ 72 cited

Kinematics of the M87 jet in the collimation zone: gradual acceleration and velocity stratification

Jongho Park, Kazuhiro Hada, Motoki Kino +36

We study the kinematics of the M87 jet using the first year data of the KVN and VERA Array (KaVA) large program, which has densely monitored the jet at 22 and 43 GHz since 2016. We…

astro-ph.GA2019★ 18 cited

Jet Kinematics of the Quasar 4C +21.35 from Observations with the KaVA Very Long Baseline Interferometry Array

Taeseok Lee, Sascha Trippe, Motoki Kino +39

We present the jet kinematics of the flat spectrum radio quasar (FSRQ) 4C +21.35 using time-resolved KaVA very long baseline interferometry array radio maps obtained from September…

astro-ph.GA2019★ 10 cited

A broad HCO+ absorption line associated with the circumnuclear torus of NGC 1052

Satoko Sawada-Satoh, Do-Young Byun, Sang-Sung Lee +8

In the circumnuclear region of the nearby radio galaxy NGC~1052. Our 3mm VLBI observations with the Korean VLBI Network have spatially resolved the broad HCO absorption at…

astro-ph.HE2017★ 63 cited

Pilot KaVA monitoring on the M87 jet: confirming the inner jet structure and superluminal motions at sub-pc scales

Kazuhiro Hada, Jong Ho Park, Motoki Kino +34

We report the initial results of our high-cadence monitoring program on the radio jet in the active galaxy M87, obtained by the KVN and VERA Array (KaVA) at 22 GHz. This is a pilot…

astro-ph.GA2016★ 14 cited

Spatially Resolved HCN Absorption Features in the Circumnuclear Region of NGC 1052

Satoko Sawada-Satoh, Duk-Gyoo Roh, Se-Jin Oh +7

We present the first VLBI detection of HCN molecular absorption in the nearby active galactic nucleus NGC 1052. Utilizing the 1 milliarcsecond resolution achieved by the Korean VLB…

astro-ph.IM2015★ 28 cited

Amplitude Correction Factors of KVN Observations

Sang-Sung Lee, Do-Young Byun, Chung Sik Oh +7

We report results of investigation of amplitude calibration for very long baseline interferometry (VLBI) observations with Korean VLBI Network (KVN). Amplitude correction factors a…

astro-ph.IM2014★ 44 cited

VLBI observations of bright AGN jets with KVN and VERA Array (KaVA): Evaluation of Imaging Capability

Kotaro Niinuma, Sang-Sung Lee, Motoki Kino +69

The Korean very-long-baseline interferometry (VLBI) network (KVN) and VLBI Exploration of Radio Astrometry (VERA) Array (KaVA) is the first international VLBI array dedicated to hi…

astro-ph.GA2014★ 28 cited

The First Very Long Baseline Interferometry Image of 44 GHz Methanol Maser with the KVN and VERA Array (KaVA)

Naoko Matsumoto, Tomoya Hirota, Koichiro Sugiyama +58

We have carried out the first very long baseline interferometry (VLBI) imaging of 44 GHz class I methanol maser (7_{0}-6_{1}A^{+}) associated with a millimeter core MM2 in a massiv…