scholarly journals The Angular Size of the Variable Radio Source Hydra?A

1955 ◽  
Vol 8 (4) ◽  
pp. 564 ◽  
Author(s):  
AWL Carter
Keyword(s):  
Radio Source ◽  
Angular Size ◽  
Cosmic Radio ◽  
The Sun ◽  
Cosmic Radio Source ◽  
Variable Radio ◽  
Variable Radio Source

Slee (1955) has shown that the discrete cosmic radio source Hydra-A shows variations in intensity at metre wavelengths. This is the first variable radio source to be found, other than the Sun, although Ryle and Elsmore (1951) investigated about one hundred northerly sources and found no significant variations in their intensities over a period of 18 months. The observations to be described here were undertaken firstly to check the variability of the source, then suspected by Slee, and secondly to measure its angular size and see whether this might also be variable.

New highly variable radio source, possible counterpart of γ-ray source CG135+1

Nature ◽  
1978 ◽  
Vol 272 (5655) ◽  
pp. 704-706 ◽  
Author(s):  
P. C. GREGORY ◽  
A. R. TAYLOR
Keyword(s):  
Radio Source ◽  
Γ Ray ◽  
Variable Radio ◽  
Variable Radio Source

scholarly journals Strong, Variable Circular Polarization in PKS 1519–273

2001 ◽  
Vol 182 ◽  
pp. 135-138
Author(s):  
Jean-Pierre MacQuart ◽  
Lucyna Kedziora-Chudczer ◽  
David Jauncey ◽  
David Rayner
Keyword(s):  
Brightness Temperature ◽  
Frequency Dependence ◽  
Radio Source ◽  
Circular Polarization ◽  
Stokes Parameters ◽  
Variable Component ◽  
Circularly Polarized ◽  
Interstellar Scintillation ◽  
Variable Radio ◽  
Variable Radio Source

AbstractWe find strong (> 1%) circular polarization in the intraday-variable radio source PKS 1519–273. The source exhibits ~ 12 hourly variability in all four Stokes parameters at 4.8 and 8.6 GHz, and longer timescale variability at 2.5 and 1.4 GHz. The characteristics and frequency dependence of the variability suggest that it is due to interstellar scintillation. VSOP limits on the distance to the scattering screen constrain the brightness temperature to TB > 5 × 1013 K. The fluctuations in total intensity are well-correlated with those in circular polarization, implying that the variable component of the source is −3.8 ±0.4% circularly polarized at 4.8 GHz. The origin of the circular polarization is unclear.

A variable radio source in the clumpy irregular galaxy Markarian 297

1983 ◽  
Vol 267 ◽  
pp. L73 ◽  
Author(s):  
D. S. Heeschen ◽  
J. Heidmann ◽  
Q. F. Yin
Keyword(s):  
Radio Source ◽  
Irregular Galaxy ◽  
Variable Radio ◽  
Variable Radio Source

Ray paths from a cosmic radio source to a satellite in orbit

1961 ◽  
Vol 261 (1306) ◽  
pp. 423-434 ◽  
Keyword(s):  
Point Source ◽  
Radio Source ◽  
Numerical Calculations ◽  
Cosmic Radio ◽  
Strong Signal ◽  
Cosmic Radio Source ◽  
Ray Paths

A receiver mounted on a satellite in orbit above the maximum of the F 2 layer can receive radiation of frequencies that are totally reflected by the ionosphere. Two effects of reflexion in the upper part of the ionosphere are discussed in this paper; both occur particularly when the satellite enters or leaves a region in which it can receive radiation from a point source. The first of these effects is focusing, which will give a very strong signal at these points, and the second is interference between the two possible rays from the point source to the satellite. The theory of these two effects is discussed and some numerical calculations are described which demonstrate them for a particular model ionosphere.

scholarly journals Interferometric observation of Cygnus-А discrete radiosource scintillations at Irkutsk Incoherent Scatter radar

2016 ◽  
Vol 2 (1) ◽  
pp. 34-43
Author(s):  
Мария Глоба ◽  
Mariia Globa ◽  
Роман Васильев ◽  
Roman Vasilyev ◽  
Дмитрий Кушнарев ◽  
...  
Keyword(s):  
Radio Source ◽  
Angular Size ◽  
Brightness Distribution ◽  
Statistical Characteristics ◽  
Cosmic Radio ◽  
Incoherent Scatter Radar ◽  
Incoherent Scatter ◽  
Cygnus A ◽  
Scatter Radar ◽  
Interferometric Observation

We propose a new method for analyzing data from the Irkutsk Incoherent Scatter Radar. The method allows us to accomplish interferometric observation of discrete cosmic radio source characteristics. In this study, we analyze ionospheric scintillations of the radio source Cygnus-A. Observations were made in 2013 during regular radar sessions within 5–15 days for different seasons; the effective time of observation was 15–30 minutes per day. For interferometric analysis, the properties of correlation (coherence) coefficient of two independent recording channels were used. The statistical analysis of data from the independent channels allows us to construct two-dimensional histograms of radio source brightness distribution with a period of 18 s and to determine parameters (the maximum position and the histogram width) representing position and angular size of the radio source for each histogram. It is shown that the change of statistical characteristics does not correlate with fluctuations in power (scintillations) of the signal induced by radio wave propagation through ionospheric irregularities.

scholarly journals Universal time control of AKR: Earth is a spin-modulated variable radio source

2013 ◽  
Vol 118 (3) ◽  
pp. 1123-1131 ◽  
Author(s):  
Akira Morioka ◽  
Yoshizumi Miyoshi ◽  
Satoshi Kurita ◽  
Yasumasa Kasaba ◽  
Vassilis Angelopoulos ◽  
...  
Keyword(s):  
Radio Source ◽  
Universal Time ◽  
Time Control ◽  
Variable Radio ◽  
Variable Radio Source
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