4 papers
The simultaneous VLA observations of Sgr A* from 90 to 0.7 cm
T. An, J. -H. Zhao, X. -Y. Hong +4
We present a spectrum of Sgr A* observed simultaneously on June 17, 2003 at wavelengths from 90 to 0.7 cm with the VLA. In the spectrum, we also include the measurements of Sgr A*…
Multi-Frequency VLBI Observations of GHz-Peaked Spectrum Sources
S. Kameno, M. Inoue, Z. -Q. Shen +2
We report results of pentachromatic VLBI survey for 18 GHz-peaked spectrum sources. Spectral fitting at every pixel across five frequencies allows us to illustrate distribution of…
The Central Parsecs of the Bright Quasar PKS 1921 - 293
Z. -Q. Shen, J. M. Moran, K. I. Kellermann
We report on a VLBA imaging study of the nearby bright southern blazar PKS 1921 - 293 (OV - 236). High resolution VLBA observations, made at four frequencies (5, 12, 15, and 43 GHz…
Intrinsic Size and Shape of Sgr A*: 3.6 AU by <1 AU
K. Y. Lo, Z. -Q. Shen, J. -H. Zhao +1
By means of near-simultaneous multi-wavelength VLBA measurements, we determine for the first time the intrinsic size of Sgr A* to be 3.6 AU by <1 AU with the major axis oriented es…