Interstellar scattering of the compact radio source 2005 + 403

1990 ◽  
Vol 349 ◽  
pp. L47 ◽  
Author(s):  
R. L. Mutel ◽  
Jean-Francois Lestrade
Keyword(s):  
Radio Source ◽  
Compact Radio Source ◽  
Interstellar Scattering

scholarly journals The Kinematic and Spectral Ages of the Compact Radio Source CTD 93

2006 ◽  
Vol 648 (1) ◽  
pp. 148-157 ◽  
Author(s):  
Hiroshi Nagai ◽  
Makoto Inoue ◽  
Keiichi Asada ◽  
Seiji Kameno ◽  
Akihiro Doi
Keyword(s):  
Radio Source ◽  
Compact Radio Source

scholarly journals A compact radio source in the high-redshift soft gamma-ray blazar IGR J12319–0749

2013 ◽  
Vol 552 ◽  
pp. A109 ◽  
Author(s):  
S. Frey ◽  
Z. Paragi ◽  
K. É. Gabányi ◽  
T. An
Keyword(s):  
Radio Source ◽  
Gamma Ray ◽  
High Redshift ◽  
Compact Radio Source

Evolution of the Compact Radio Source 3C 345

Quasars ◽  
1986 ◽  
pp. 157-158
Author(s):  
J. Biretta ◽  
M. Cohen ◽  
R. Moore
Keyword(s):  
Radio Source ◽  
Compact Radio Source

scholarly journals Long-Term Variations of the Compact Radio Source Sgr A∗ at the Galactic Center

1989 ◽  
Vol 136 ◽  
pp. 535-541 ◽  
Author(s):  
Jun-Hui Zhao ◽  
R. D. Ekers ◽  
W. M. Goss ◽  
K. Y. Lo ◽  
Ramesh Narayan
Keyword(s):  
Radio Source ◽  
Flux Density ◽  
High Velocity ◽  
Galactic Center ◽  
Light Curves ◽  
Radio Flux ◽  
Compact Radio Source ◽  
Sgr A ◽  
Long Term Variations

We investigate the long-term flux density variations of the compact radio source Sgr A∗ at the galactic center by combining recent VLA observations with previous Green Bank interferometer data. We present radio flux density light-curves for Sgr A∗ at 20, 11, 6 and 3.7 cm from 1974 to 1987. Long-term variability with a timescale of at least 5 years is seen at 20 cm and there is evidence for more rapid variations at the shorter wavelengths. The variability timescales at 20, 11 and 6 cm fit the λ2 scaling predicted by the theory of refractive scintillation suggesting that the variability could be due to this cause. However, the timescales are relatively short, implying an unusually high velocity in the scattering screen. The modulation index of the variability is large and relatively independent of wavelength.

An angular size for the compact radio source at the galactic center

1977 ◽  
Vol 218 ◽  
pp. 668 ◽  
Author(s):  
K. Y. Lo ◽  
M. H. Cohen ◽  
R. T. Schilizzi ◽  
H. N. Ross
Keyword(s):  
Radio Source ◽  
Galactic Center ◽  
Angular Size ◽  
Compact Radio Source

The compact radio source 2021 + 614 - A peculiar narrow-line radio galaxy

1984 ◽  
Vol 279 ◽  
pp. 112 ◽  
Author(s):  
N. Bartel ◽  
I. I. Shapiro ◽  
J. P. Huchra ◽  
H. Kuhr
Keyword(s):  
Radio Source ◽  
Radio Galaxy ◽  
Narrow Line ◽  
Compact Radio Source

A compact radio source in the nucleus of M82

1977 ◽  
Vol 215 ◽  
pp. L5 ◽  
Author(s):  
B. J. Geldzahler ◽  
K. I. Kellermann ◽  
D. B. Shaffer ◽  
B. G. Clark
Keyword(s):  
Radio Source ◽  
Compact Radio Source

scholarly journals A Counterjet in the Nucleus of Centaurus A

1996 ◽  
Vol 175 ◽  
pp. 23-24
Author(s):  
D.L. Jones ◽  
S.J. Tingay ◽  
R.A. Preston ◽  
D.L. Jauncey ◽  
J.E. Reynolds ◽  
...  
Keyword(s):  
Radio Source ◽  
Radio Galaxy ◽  
Dense Plasma ◽  
Jet Formation ◽  
Radio Jets ◽  
Compact Radio Source ◽  
Centaurus A

Centaurus A (NGC 5128) is the nearest giant radio galaxy. It is a Fanaroff-Riley type 1 (low luminosity) radio source, but the compact radio source in the nucleus is strong enough that VLBI imaging has been possible with both the SHEVE array and the VLBA at several frequencies. These observations have detected a sub-parsec scale counterjet. This shows that jet formation in at least some FR I sources is intrinsically two-sided over very small distances and the radio jets in Centaurus A are probably only moderately relativistic. We also find evidence that the center of activity in Centaurus A is partially obscured by a disk or torus of dense plasma.

scholarly journals High Resolution Imaging of Compact Radio Sources by Gridding with Regularization

1998 ◽  
Vol 164 ◽  
pp. 411-412 ◽  
Author(s):  
S. F. Likhachev ◽  
R. M. Hjellming
Keyword(s):  
High Resolution ◽  
Image Reconstruction ◽  
Radio Source ◽  
Radio Sources ◽  
High Resolution Imaging ◽  
Traditional Methods ◽  
Compact Radio Source ◽  
Ill Posed ◽  
Resolution Imaging

AbstractThe problem of VLBI image reconstruction is a classical example of an ill-posed problem. A new procedure of gridding with regularization has been developed. This procedure was used in traditional methods (CLEAN, Hybrid) to improve the quality of compact radio source images. A few sources (GRO J1655–40, RY Scuti and Cyg X-1), observed with the VLA and VLBA, were processed with this procedure.

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