activity
20172026
most citedPrecessing jet nozzle connecting to a spinning black hole in M87

109 citations · 511 across the 19 of their papers we have counts for

collaborators

21 papers

astro-ph.IM2026

Very Long Baseline Interferometry with the SKA Observatory

J. F. Radcliffe, J. Yang, Z. Paragi +129

Very Long Baseline Interferometry (VLBI) is a fundamental technique that combines signals from telescopes separated by thousands of kilometres to obtain some of the highest-resolut…

astro-ph.HE2026

A Jet from a Nearly Dormant Black Hole

Xiaopeng Cheng, Hai Yang, Jun Yang +11

Most galaxies host supermassive black holes (SMBHs) that remain weakly accreting or dormant for much of their lifetimes. At the lowest accretion rates, these systems may represent…

astro-ph.HE2026★ 1 cited

Transverse Oscillations and Wave Propagation in the Magnetically Dominated M87 Jet

Hyunwook Ro, Motoki Kino, Kazuhiro Hada +6

We present an in-depth analysis of transverse oscillations in the M87 jet, as identified in our previous study (Ro et al. 2023a), which reported oscillatory patterns with a charact…

astro-ph.HE2025

Constraining the Mass of a Hypothetical Secondary Black Hole in M87 with the NANOGrav 15-Year Data Set

Motoki Kino, Masahiro Nagashima, Hyunwook Ro +3

Galaxy mergers, each hosting a supermassive black hole (SMBH), are thought to form SMBH binaries. Motivated by recent observations from the East Asian VLBI Network (EAVN) showing p…

astro-ph.HE2024★ 17 cited

Discovery of Limb Brightening in the Parsec-scale Jet of NGC 315 through Global Very Long Baseline Interferometry Observations and Its Implications for Jet Models

Jongho Park, Guang-Yao Zhao, Masanori Nakamura +19

We report the first observation of the nearby giant radio galaxy NGC 315 using a global VLBI array consisting of 22 radio antennas located across five continents, including high-se…

astro-ph.HE2024

Mapping the distribution of the magnetic field strength along the NGC 315 jet

Motoki Kino, Hyunwook Ro, Masaaki Takahashi +4

We study magnetic field strengths along the jet in NGC~315. First, we estimated the angular velocity of rotation in the jet magnetosphere by comparing the measured velocity profile…

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.GA2023

The Past and Future of East Asia to Italy: Nearly Global VLBI

Gabriele Giovannini, Yuzhu Cui, Kazuhiro Hada +29

We present here the East Asia to Italy Nearly Global VLBI (EATING VLBI) project. How this project started and the evolution of the international collaboration between Korean, Japan…

astro-ph.HE2023★ 14 cited

Transverse Oscillations of the M87 Jet Revealed by KaVA Observations

Hyunwook Ro, Kunwoo Yi, Yuzhu Cui +6

Recent VLBI monitoring has found transverse motions of the M87 jet. However, due to the limited cadence of previous observations, details of the transverse motion have not been ful…

astro-ph.HE2023★ 5 cited

Super-Resolved Image of M87 Observed with East Asian VLBI Network

Fumie Tazaki, Yuzhu Cui, Kazuhiro Hada +11

Obtaining high-resolution images at centimeter-or-longer wavelengths is vital for understanding the physics of jets. We reconstructed images from the M87 22 GHz data observed with…

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.HE2022★ 20 cited

Implications from the velocity profile of the M87 jet: a possibility of a slowly rotating black hole magnetosphere

Motoki Kino, Masaaki Takahashi, Tomohisa Kawashima +4

Motivated by the measured velocity profile of the M87 jet using the KVN and VERA Array (KaVA) by Park et al. indicating that the starting position of the jet acceleration is farthe…

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.IM2019

Source-Frequency Phase-Referencing Observation of AGNs with KaVA Using Simultaneous Dual-Frequency Receiving

Guang-Yao Zhao, Taehyun Jung, Bong Won Sohn +27

The KVN(Korean VLBI Network)-style simultaneous multi-frequency receiving mode is demonstrated to be promising for mm-VLBI observations. Recently, other Very long baseline interfer…

astro-ph.HE2018★ 93 cited

Faraday rotation in the jet of M87 inside the Bondi radius: indication of winds from hot accretion flows confining the relativistic jet

Jongho Park, Kazuhiro Hada, Motoki Kino +3

We study Faraday rotation in the jet of M87 inside the Bondi radius using eight Very Long Baseline Array data sets, one at 8 GHz, four at 5 GHz, and three at 2 GHz. We obtain Farad…

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.HE2017★ 11 cited

White Paper on East Asian Vision for mm/submm VLBI: Toward Black Hole Astrophysics down to Angular Resolution of 1~R

K. Asada, M. Kino, M. Honma +35

This White Paper details the intentions and plans of the East Asian Very Long Baseline Interferometry (VLBI) community for pushing the frontiers of millimeter/submillimeter VLBI. T…