Publications (11)
A Geodetic and Astrometric VLBI Experiment at 22/43/88/132 GHz
Shuangjing Xu, Taehyun Jung, Bo Zhang +14
Extending geodetic and astrometric Very Long Baseline Interferometry (VLBI) observations from traditional centimeter wavebands to millimeter wavebands offers numerous scientific po…
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…
Astrometrically Registered Simultaneous Observations of the 22 GHz HO and the 43GHz SiO masers towards R Leonis Minoris using KVN and Source/Frequency Phase Referencing
Richard Dodson, MarÃa J. Rioja, Tae-Hyun Jung +22
Oxygen-rich Asymptotic Giant Branch (AGB) stars can be intense emitters of SiO (=1 and 2, J=10) and HO maser lines at 43 and 22 GHz, respectively. VLBI observat…
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…
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…
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…
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…
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 a…
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…
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…
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…