The spectra of some discrete radio sources in 10?5000 MHz frequency range

1970 ◽  
Vol 8 (2) ◽  
pp. 275-322 ◽  
Author(s):  
S. Ya. Braude ◽  
A. V. Megn ◽  
B. P. Ryabov ◽  
I. N. Zhouck
Keyword(s):  
Radio Sources ◽  
Frequency Range ◽  
Discrete Radio Sources

scholarly journals Measurements Of The Flux Density Of Discrete Radio Sources At 6 Cm Wavelength

1966 ◽  
Vol 19 (4) ◽  
pp. 577 ◽  
Keyword(s):  
Flux Density ◽  
Radio Telescope ◽  
Power Law ◽  
Radio Sources ◽  
Frequency Range ◽  
Thermal Radio ◽  
Discrete Radio Sources ◽  
Selection Of ◽  
Lower Frequencies

The flux densities of 67 non-thermal radio sources have been measured at a frequency of 5000 Mc/s with the CSIRO 210 ft radio telescope at Parkes. The sources were chosen from the stronger objects in the 3C catalogue (Edge et al. 1959), the CTA and CTD catalogues (Harris and Roberts 1960; Kellermann and Read 1965), and the Parkes catalogue (Bolton, Gardner, and Mackey 1964; Price and Milne 1965; Day et al. 1966). In the selection of sources observed in this program, special emphasis was placed on objects whose spectra at lower frequencies showed significant departures from the usual power law with an index near -0�8. Most of the sources reported here have not been previously measured at wavelengths shorter than 10 cm and thus the present observations extend the frequency range of their spectra by nearly a factor of two.

scholarly journals Observations of Galactic and Extragalactic Jets

1986 ◽  
Vol 89 ◽  
pp. 403-424
Author(s):  
R.A. Perley
Keyword(s):  
Radio Sources ◽  
Fourier Synthesis ◽  
Original Design ◽  
Quality Of Information ◽  
Very Large Array ◽  
Imaging Interferometer ◽  
Extragalactic Jets ◽  
Angular Extent ◽  
Discrete Radio Sources

Since nearly all discrete radio sources of astronomical interest are of insufficient angular extent for their detailed structural properties to be accessible to single-dish radio telescopes, radio interferometry must be employed to gain information on the morphologies of these objects. Recently constructed imaging interferometer arrays which employ the technique of Fourier synthesis, particularly MERLIN and the VLA (Very Large Array), and the more recent VLBI arrays, have given unprecedented imaging capabilities, with the result that our knowledge, and hence perceptions, of discrete radio sources have vastly changed over the last few years. An equally important parallel development has been image processing algorithms. These have vastly improved the quality of information produced by these arrays, so that an instrument such as the VLA can now produce images with speed and quality exceeding original design specifications by factors of 100 to 1000.

Discrete Radio Sources in the Spiral Galaxy NGC 6946

2000 ◽  
Vol 119 (4) ◽  
pp. 1711-1719 ◽  
Author(s):  
Scott D. Hyman ◽  
Christina K. Lacey ◽  
Kurt W. Weiler ◽  
Schuyler D. Van Dyk
Keyword(s):  
Spiral Galaxy ◽  
Radio Sources ◽  
Ngc 6946 ◽  
Discrete Radio Sources

Apparent Angular Sizes of Discrete Radio Sources: Observations at Sydney

Nature ◽  
1952 ◽  
Vol 170 (4338) ◽  
pp. 1063-1064 ◽  
Author(s):  
B. Y. MILLS
Keyword(s):  
Radio Sources ◽  
Discrete Radio Sources

scholarly journals Novel Interferometer for Studies of Discrete Radio Sources.

1962 ◽  
Vol 67 ◽  
pp. 575
Author(s):  
James N. Douglas ◽  
Clinton C. Brooks
Keyword(s):  
Radio Sources ◽  
Discrete Radio Sources

scholarly journals FIGARO simulation: FIlaments & GAlactic RadiO simulation

2021 ◽  
Vol 38 ◽  
Author(s):  
Torrance Hodgson ◽  
Franco Vazza ◽  
Melanie Johnston-Hollitt ◽  
Benjamin McKinley
Keyword(s):  
Cross Correlation ◽  
Radio Sources ◽  
Dark Matter Halos ◽  
Frequency Range ◽  
Extragalactic Radio Sources ◽  
Star Forming ◽  
Public Resource ◽  
Magnetohydrodynamic Simulation ◽  
Relic Population ◽  
Galactic Radio

Abstract We produce the first low to mid-frequency radio simulation that incorporates both traditional extragalactic radio sources as well as synchrotron cosmic web emission. The FIlaments & GAlactic RadiO (FIGARO) simulation includes 10 unique 4° × 4° fields, incorporating active galactic nucleii (AGNs), star-forming galaxies (SFGs), and synchrotron cosmic web emission out to a redshift of z = 0.8 and over the frequency range 100–1 400 MHz. To do this, the simulation brings together a recent 1003 Mpc3 magnetohydrodynamic simulation (Vazza et al. 2019, A&A, 627, A5), calibrated to match observed radio relic population statistics, alongside updated ‘T-RECS’ code for simulating extragalactic radio sources (Bonaldi et al. 2019, MNRAS, 482, 2). Uniquely, the AGNs and SFGs are populated and positioned in accordance with the underlying matter density of the cosmological simulation. In this way, the simulation provides an accurate understanding of the apparent morphology, angular scales, and brightness of the cosmic web as well as—crucially—the clustering properties of the cosmic web with respect to the embedded extragalactic radio population. We find that the synchrotron cosmic web does not closely trace the underlying mass distribution of the cosmic web, but is instead dominated by shocked shells of emission surrounding dark matter halos and resembles a large, undetected population of radio relics. We also show that, with accurate kernels, the cosmic web radio emission is clearly detectable by cross-correlation techniques and this signal is separable from the embedded extragalactic radio population. We offer the simulation as a public resource towards the development of techniques for detecting and measuring the synchrotron cosmic web.

scholarly journals Formation of additional virtual reception channels when processing signals at the outputs of elements of the antenna array of a promising cellular base station

2021 ◽  
Vol 24 (2) ◽  
pp. 79-87
Author(s):  
Alexander A. Bolkunov ◽  
Leonid A. Ovcharenko ◽  
Yuri G. Pasternak ◽  
Vladimir A. Pendyurin ◽  
Igor V. Popov ◽  
...  
Keyword(s):  
Antenna Array ◽  
Antenna Arrays ◽  
Antenna System ◽  
Base Station ◽  
Radio Sources ◽  
Linear Antenna ◽  
Frequency Range ◽  
The Earth ◽  
Receiving Antenna ◽  
Reception Mode

The results of research on the layout of the antenna array for a promising cellular base station in the frequency range 1,81,88 GHz, which includes a linear antenna array of 12 slotted elements with rectangular directors, the diagram forming scheme of which uses a modification of the Rotman lens, characterized in that for the sake of reducing its overall dimensions, the lens is folded in half the earth is located in the center, and on both sides of it-the halves of the lens body with exponential strip transformers. It is shown that to reduce the level of the side lobes of the antenna system in the reception mode, interpolation and extrapolation antenna arrays can be used. An extrapolation array can also be formed in order to increase the directional coefficient of the receiving antenna system and resolve radio sources that are not resolved by the real antenna array.

scholarly journals 21. The low-frequency spectrum of Cygnus A and Cassiopeia A

1957 ◽  
Vol 4 ◽  
pp. 145-147
Author(s):  
R. J. Lamden ◽  
A. C. B. Lovell
Keyword(s):  
Lower Limit ◽  
Radio Telescope ◽  
Low Frequency ◽  
Radio Sources ◽  
Pencil Beam ◽  
Frequency Range ◽  
Present Communication ◽  
Cassiopeia A ◽  
Cygnus A ◽  
Radio Transmitters

The published measurements of the intensity of the radio sources cover a frequency range down to a lower limit of 22·6 Mc./s., at which measurements have been made on Cygnus and Cassiopeia by Hey and Hughes (1954)[1]. Information about the spectrum at still lower frequencies is difficult to obtain because of interference arising from ionospheric reflexion of distant radio transmitters. Some of this trouble can be alleviated by using a narrow pencil-beam radio telescope for reception and the present communication describes measurements made on frequencies of 16·5, 19·0, 22·6 and 30·0 Mc./s. using the 218 ft. transit radio telescope at Jodrell Bank.

scholarly journals 28. The angular diameter of discrete radio sources

1957 ◽  
Vol 4 ◽  
pp. 162-165
Author(s):  
H. P. Palmer
Keyword(s):  
Resolving Power ◽  
Angular Diameter ◽  
Radio Sources ◽  
Discrete Radio Sources ◽  
Angular Diameters

An interferometer of readily varied resolving power has been constructed at Jodrell Bank, and since 1953 it has been used to measure the angular diameters of all but the faintest of the discrete sources reported in the survey of Brown and Hazard [1].

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