First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
- K. Akiyama, A. Alberdi, L. Ziurys
- PhysicsAstrophysical Journal
- 10 April 2019
When surrounded by a transparent emission region, black holes are expected to reveal a dark shadow caused by gravitational light bending and photon capture at the event horizon. To image and study…
The Astrophysical Journal Supplement
- H. Qiao, S. Breen, Zhi-qiang Shen
- Physics
- 20 February 2020
A size of ∼1 au for the radio source Sgr A* at the centre of the Milky Way
- Zhi-qiang Shen, K. Lo, M. Liang, P. Ho, J.-H. Zhao
- PhysicsNature
- 3 November 2005
Although it is widely accepted that most galaxies have supermassive black holes at their centres, concrete proof has proved elusive. Sagittarius A* (Sgr A*), an extremely compact radio source at the…
A 95 GHz CLASS I METHANOL MASER SURVEY TOWARD GLIMPSE EXTENDED GREEN OBJECTS (EGOs)
- Xi Chen, S. Ellingsen, Zhi-qiang Shen, A. Titmarsh, C. Gan
- Physics
- 14 July 2011
We report the results of a systematic survey for 95 GHz class I methanol masers toward a new sample of 192 massive young stellar object candidates associated with ongoing outflows (known as extended…
A SEARCH FOR INFALL EVIDENCE IN EGOs. I. THE NORTHERN SAMPLE
- Xi Chen, Zhi-qiang Shen, Jingjing Li, Ye Xu, Jinhua He
- Physics
- 18 December 2009
We report the first systematic survey of molecular lines (including HCO+ (1–0) and 12CO, 13CO, C18O (1–0) lines at the 3 mm band) toward a new sample of 88 massive young stellar object (MYSO)…
Intrinsic Size of Sagittarius A*: 72 Schwarzschild Radii
- K. Lo, Zhi-qiang Shen, Jun-Hui Zhao, P. Ho
- Physics
- 16 September 1998
Recent proper motion studies of stars at the very center of the Galaxy strongly suggest that Sagittarius A*, the compact nonthermal radio source at the Galactic center, is a 2.5×106 M☉ black hole. By…
The VLBI Space Observatory Programme and the Radio-Astronomical Satellite HALCA
- H. Hirabayashi, H. Hirosawa, M. Popov
- Physics
- 1 December 2000
The radio astronomy satellite HALCA was launched by the Institute of Space and Astronautical Science in 1997 February to participate in Very Long Baseline Interferometry (VLBI) observations with…
THE RADIO PROPERTIES OF RADIO-LOUD NARROW-LINE SEYFERT 1 GALAXIES ON PARSEC SCALES
- M. Gu, Yongjun Chen, J. Zensus
- Physics
- 7 September 2015
We present the detection of the compact radio structures of 14 radio-loud narrow-line Seyfert 1 (NLS1) galaxies from Very Long Baseline Array (VLBA) observations at 5 GHz performed in 2013. While 50%…
The Expanding Radio Lobe of 3C 84 Revealed by VSOP Observations
- K. Asada, S. Kameno, Zhi-qiang Shen, S. Horiuchi, D. Gabuzda, M. Inoue
- Physics
- 25 April 2006
The expansion and inner proper motions of a young radio lobe associated with the bright radio source 3C 84 in the Seyfert galaxy NGC 1275 have been detected by VSOP observations. These proper motions…
The VSOP 5 GHz AGN Survey I. Compilation and Observations
- H. Hirabayashi, E. Fomalont, J. Gimeno
- Physics
- 1 December 2000
The VSOP mission is a Japanese-led project to image radio sources with sub-milliarcsec resolution by correlating the signal from the orbiting 8-m telescope, HALCA, with a global array of telescopes.…
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