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Discovery of Sub- to Superluminal Motions in the M87 Jet: An Implication of the Acceleration from Sub-relativistic to Relativistic Speeds
Keiichi Asada, Masanori Nakamura, Akihiro Doi +2
The velocity field of the M87 jet from milli-arcsecond (mas) to arcsecond scales is extensively investigated together with new radio images taken by EVN observations. We detected p…
Evidence for nuclear radio jet and its structure down to <100 Schwarzschild radii in the center of the Sombrero galaxy (M 104, NGC 4594)
Kazuhiro Hada, Akihiro Doi, Hiroshi Nagai +4
Abridged: We investigated the detailed radio structure of the nucleus of the Sombrero galaxy using high-resolution, quasi-simultaneous, multi-frequency, phase-referencing VLBA obse…
High-Angular-Resolution and High-Sensitivity Science Enabled by Beamformed ALMA
Vincent Fish, Walter Alef, James Anderson +66
An international consortium is presently constructing a beamformer for the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile that will be available as a facility instrum…
Innermost collimation structure of the M87 jet down to ~ten Schwarzschild radii
Kazuhiro Hada, Motoki Kino, Akihiro Doi +6
We investigated the detailed inner jet structure of M87 using the Very Long Baseline Array data at 2, 5, 8.4, 15, 23.8, 43, and 86 GHz, especially focusing on the multi-frequency p…
VLBA Multi-frequency Polarimetric imaging of Radio-loud Broad Absorption Line Quasars
Takayuki J. Hayashi, Akihiro Doi, Hiroshi Nagai
We conducted the first multi-frequency polarimetric imaging of four broad absorption line (BAL) quasars using Very Long Baseline Array at milli-arcsecond resolutions to investigate…
Multifrequency VLBI Observations of the Broad Absorption Line Quasar J1020+4320: Recently Restarted Jet Activity?
Akihiro Doi, Yasuhiro Murata, Nanako Mochizuki +14
This paper reports very-long-baseline interferometry observations of the radio-loud broad absorption line (BAL) quasar J1020+4320 at 1.7, 2.3, 6.7, and 8.4 GHz using the Japanese V…