scholarly journals ON THE PROGRAM AND PRELIMINARY RESULTS OF INVESTIGATIONS OF INTRADAY AND INTERDIURNAL FLUX VARIABILITY OF EXTRAGALACTIC RADIO SOURCES AT TELESCOPES OF VENTSPILS INTERNATIONAL RADIO ASTRONOMY CENTER (VIRAC)

2017 ◽  
Vol 22 (4) ◽  
pp. 256-269
Author(s):  
A. L. Sukharev ◽  
◽  
V. V. Bezrukovs ◽  
M. Y. Bleiders ◽  
A. A. Orbidans ◽  
...  
Keyword(s):  
Radio Astronomy ◽  
Radio Sources ◽  
Extragalactic Radio Sources ◽  
Preliminary Results ◽  
Flux Variability

scholarly journals Results from a monitoring program of low frequency variable sources

1986 ◽  
Vol 119 ◽  
pp. 149-155
Author(s):  
L. Padrielli ◽  
R. Fanti ◽  
A. Ficarra ◽  
L. Gregorini ◽  
F. Mantovani
Keyword(s):  
Monitoring Program ◽  
Low Frequency ◽  
Radio Sources ◽  
Main Question ◽  
Extragalactic Radio Sources ◽  
Low Frequency Variability ◽  
Flux Variability

The flux variability of extragalactic radio sources at decimetric wavelengths (Low Frequency Variability LFV) is mostly associated with the nuclei of compact radio sources. But is a not yet well understood phenomenon. The main question still is: where does this phenomenon take place?

scholarly journals Centiarcsecond Structure and Variability of AGN

1994 ◽  
Vol 159 ◽  
pp. 389-389
Author(s):  
D.R. Altschuler ◽  
L.I. Gurvits ◽  
W. Alef ◽  
D. Graham ◽  
B. Dennison ◽  
...  
Keyword(s):  
Fine Structure ◽  
Radio Galaxy ◽  
Radio Sources ◽  
Extragalactic Radio Sources ◽  
Vlbi Observations ◽  
Flux Variability ◽  
Source Sample ◽  
Flux Monitoring ◽  
Bl Lacs

One possible approach to distinguish between “intrinsic” and “external” mechanisms for variability implies a study of possible correlations between flux variability and the fine structure of sources. We present results of snapshot global VLBI observations at 327 MHz of a sample of 16 extragalactic radio sources (1 radio galaxy, 9 quasars, 4 BL Lacs, 2 unidentified) selected on the basis of the bi-monthly flux monitoring at five frequencies (1400, 880, 606, 430, and 318 MHz). The observed source sample is presented in the Table I.

scholarly journals Determination of Optical Positions for Extragalactic Radio Sources under the Collaboration Between SHAO and NAO

2000 ◽  
Vol 180 ◽  
pp. 57-60
Author(s):  
Z.H. Tang ◽  
W.J. Jin ◽  
S.H. Wang ◽  
G. Pinigin ◽  
A. Shulga ◽  
...  
Keyword(s):  
Astronomical Observatory ◽  
Radio Sources ◽  
Meridian Circle ◽  
Extragalactic Radio Sources ◽  
Preliminary Results ◽  
Cooperative Project

AbstractThe optical positions of 9 compact extragalactic radio sources have been determined by using the 1.56m, 1m and 60/90cm telescopes with CCDs in China and the Axial Meridian Circle at Nikolaev Astronomical Observatory since Jan. 1996 in a cooperative project between the two observatories. The instrumentation, observations and reduction are briefly described, and the preliminary results are presented. The comparison between the optical and radio positions for 9 sources are also given. More optical positions of radio sources are being processed.

scholarly journals Are the bandwidth synthesis delay and delay rate observables useful for VLBI imaging?

1991 ◽  
Vol 131 ◽  
pp. 302-306
Author(s):  
P. Charlot
Keyword(s):  
Radio Source ◽  
Band Width ◽  
Radio Sources ◽  
Extragalactic Radio Sources ◽  
Preliminary Results

AbstractThe Band Width Synthesis (BWS) delay and delay rate observables measured by VLBI are used in astrometry to determine positions of extragalactic radio sources with a precision of 0.001”. At this level of precision, extragalactic radio sources exhibit “extended structures that induce significant effects in the measured BWS delays and delay rates. The question whether closure BWS delays and delay rates could supplement the amplitudes and closure phases for VLBI imaging is studied. Preliminary results for the radio source NRAO140 observed in July 1983 are presented.

scholarly journals The Low Frequency Variability of Extragalactic Radio Sources

1984 ◽  
Vol 110 ◽  
pp. 169-176 ◽  
Author(s):  
L. Padrielli
Keyword(s):  
Low Frequency ◽  
Radio Sources ◽  
Extragalactic Radio Sources ◽  
Low Frequency Variability ◽  
Flux Variability

The flux variability of extragalactic radio sources at decimetric wavelengths (L.F.V.) is now considered a classical astrophysical subject connected with compact radio sources.

scholarly journals Multi-Frequency Monitoring of a Sample of Extragalactic Radio Sources

1998 ◽  
Vol 164 ◽  
pp. 279-280 ◽  
Author(s):  
M. Mingaliev ◽  
A. Botashev ◽  
V. Stolyarov
Keyword(s):  
Radio Telescope ◽  
Light Curves ◽  
Radio Sources ◽  
Extragalactic Radio Sources ◽  
Preliminary Results ◽  
Frequency Monitoring

AbstractThe preliminary results of monitoring of simultaneous spectra of a sample of extragalactic sources are given. Eight sets of observations were done at the RATAN-600 radio telescope in 1995-1996 at six frequencies (0.96, 2.3, 3.9, 7.7, 11.2, and 22 GHz). The light curves as well as the variability parameters are given

scholarly journals 5-GHz VLBI Imaging Observations of 7 Equatorial AGNs

2002 ◽  
Vol 184 ◽  
pp. 304-305
Author(s):  
Z.-Q. Shen ◽  
D. R. Jiang ◽  
Y.J. Chen ◽  
T.-S. Wan
Keyword(s):  
Radio Sources ◽  
Preliminary Results ◽  
The Third ◽  
5 Ghz

AbstractSince 1992 we have been conducting a 5-GHz VLBI imaging survey of southern and equatorial radio sources. So far, we have published the results of two observing sessions with 26 southern radio sources imaged in total (Shen et al. 1997; 1998). In this paper, we present the preliminary results of the third session of observations of 7 equatorial sources in the sample.

Super-luminal expansion in extragalactic radio sources

Nature ◽  
1977 ◽  
Vol 267 (5608) ◽  
pp. 211-216 ◽  
Author(s):  
R. D. Blandford ◽  
C. F. McKee ◽  
M. J. Rees
Keyword(s):  
Radio Sources ◽  
Extragalactic Radio Sources
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