scholarly journals John Bolton's Variable-baseline Interferometer and the Structure of Radio Galaxies

1994 ◽  
Vol 47 (5) ◽  
pp. 569
Author(s):  
RD Ekers
Keyword(s):  
Radio Galaxies ◽  
Radio Sources ◽  
California Institute ◽  
Owens Valley ◽  
Extragalactic Radio Sources ◽  
Flexible Cable

John Bolton was a pioneer in the study of extragalactic radio sources, first at the CSIRO Radiophysics Laboratory and then at the California Institute of Technology's Owens Valley interferometer. I became his Ph.D. student after he returned to the Parkes Observatory from California, and I helped in the construction of the Parkes interferometer. This consisted of a 60-ft dish connected to the existing 210-ft dish by a flexible cable trailing from the 60-footer. The interferometer was used to observe continuously at 467 and 1401 MHz while the 60-ft dish was pulled along a track. The wisdom of the design is illustrated by comparing observations of Pictor A made at Parkes and at Owens Valley.

Tables of physical and morphological properties of nearby extended radio galaxies

2021 ◽  
pp. 75-89
Author(s):  
R. R. Andreasyan ◽  
H. V. Abrahamyan
Keyword(s):  
Radio Galaxies ◽  
Elliptical Galaxies ◽  
Morphological Data ◽  
Morphological Properties ◽  
Radio Sources ◽  
Extragalactic Radio Sources ◽  
Extended Radio

It is brought the physical and morphological data of 267 nearby radio galaxies identified with elliptical galaxies brighter than 18th magnitude (sample 1) and for 280 extragalactic radio sources with known position angles between the integrated intrinsic radio polarization and radio axes (sample 2).

Optical Observations of Extragalactic Radio Sources

1967 ◽  
Vol 1 (1) ◽  
pp. 23-23
Author(s):  
B. E. Westerlund ◽  
J. V. Wall ◽  
N. R. Stokes
Keyword(s):  
Radio Galaxies ◽  
Optical Observations ◽  
Radio Sources ◽  
Extragalactic Radio Sources ◽  
Photometric Observations

Photometric observations on the UBV system have been made of a number of optically identified radio sources. The measurements are basically of two types: (1) offset photometry with the Siding Spring 40-inch reflector of objects identified as probable quasars or N galaxies, and (2) observations with the Siding Spring 24-inch reflector of radio galaxies brighter than V = 14m.0.

scholarly journals Spectral Index - Redshift Relation for Radio Galaxies and Quasars

1996 ◽  
Vol 175 ◽  
pp. 569-570
Author(s):  
R.D. Dagkesamanskii
Keyword(s):  
Flux Density ◽  
Spectral Index ◽  
Low Frequency ◽  
Radio Galaxies ◽  
Cosmological Evolution ◽  
Radio Sources ◽  
Spectral Indices ◽  
Extragalactic Radio Sources

Cosmological evolution of synchrotron spectra of the powerful extragalactic radio sources was studied by many authors. Some indications of such an evolution had been found firstly by analysis of ‘spectral index - flux density’ (α – S) relation for the sample of relatively strong radio sources. Later Gopal-Krishna and Steppe extended the analysis to weaker sources and found that the slope of αmed(S) curve changes dramatically at intermediate flux densities. Gopal-Krishna and Steppe pointed out that the maxima of the αmed(S) curve and of differential source counts are at almost the same flux density ranges (see, Fig. 2). It has to be noticed that the all mentioned results were obtained using the low-frequency spectral indices and on the basis of low frequency samples.

scholarly journals On the Magnetic Fields of Galaxies

2021 ◽  
pp. 470-477
Author(s):  
R. R. Andreasyan
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Faraday Rotation ◽  
Radio Galaxies ◽  
Morphological Properties ◽  
Radio Sources ◽  
Extragalactic Radio Sources

We bring results of some our investigations of magnetic field of our Galaxy and extragalactic radio sources. For the study were used data of Faraday rotation of pulsars and extragalactic radio sources as well as data of physical and morphological properties of more than 500 radio galaxies of different morphological classes.

scholarly journals Multi-Frequency Polarization Studies of Radio Galaxies

1982 ◽  
Vol 97 ◽  
pp. 53-54
Author(s):  
G. G. Pooley
Keyword(s):  
High Resolution ◽  
Radio Galaxies ◽  
Radio Sources ◽  
Frequency Range ◽  
Extragalactic Radio Sources ◽  
High Resolution Mapping ◽  
New Instrument ◽  
Resolution Mapping ◽  
Polarization Studies ◽  
The One

This is a brief report on some of the work in progress at Cambridge, with emphasis on studies of extragalactic radio sources using the One-mile and 5-km telescopes; together with the 6C survey and a new instrument now being commisioned at 151 MHz, we have a frequency range of 100:1 available for high-resolution mapping. The 6C survey has resulted in the discovery of a number of giant radio galaxies, most notably NGC 6251. At 151 MHz, the beautiful jet is not prominent; we have mapped it with the One-mile and 5-km instruments and a paper (by Saunders et al.) will shortly appear in Monthly Notices. Dr Willis will speak later on the structure of this source.

scholarly journals Spatial Correlation Functions of Bright Radio Galaxies

1988 ◽  
Vol 130 ◽  
pp. 580-580 ◽  
Author(s):  
You-yuan Zhou ◽  
Yi-peng Jing
Keyword(s):  
Correlation Function ◽  
Spatial Correlation ◽  
Correlation Functions ◽  
Radio Galaxies ◽  
Radio Sources ◽  
Spatial Correlation Function ◽  
Extragalactic Radio Sources ◽  
Large Separation ◽  
The Universe

Because of their large separation bright radio galaxies characterize the structure of the universe on the scales of clusters and superclusters. In order to calculate the spatial correlation function we choose radio galaxies in radio surveys, for which the redshift values have been measured. One is from Bright Radio Sources at 178 MHz (Liang, Riley and Longair 1983), and another is from All-Sky Catalogue of Bright Extragalactic Radio Sources at 2.7 GHz (Wall and Peacock 1985).

scholarly journals Extragalactic Radio Sources and the Role of Relativistic Jets

1994 ◽  
Vol 47 (5) ◽  
pp. 669 ◽  
Author(s):  
Geoffrey V Bicknell
Keyword(s):  
Radio Galaxies ◽  
Class I ◽  
Radio Sources ◽  
Relativistic Jets ◽  
Extragalactic Radio Sources ◽  
Cygnus A ◽  
Evolutionary Connection ◽  
The Relationship

This paper summarises some of the ideas surrounding the role of relativistic jets in radio galaxies and quasars and describes work presented in two recent papers (Bicknell 1994a,b) relating relativistic jets to the Fanaroff~Riley classification of radio galaxies. I conclude with some speculation on the evolutionary connection between Fanaroff~Riley Class I and Class II radio galaxies and the relationship between mergers and radio galaxies, an idea which was discussed at the time of the discovery of Cygnus A and Ccntaurus A.

scholarly journals 18 cm High Resolution Observations of 15 Extragalactic Radio Sources

1988 ◽  
Vol 129 ◽  
pp. 141-142
Author(s):  
J. A. Waak ◽  
J. H. Spencer ◽  
R. S. Simon ◽  
K. J. Johnston
Keyword(s):  
High Resolution ◽  
Dynamic Range ◽  
Radio Sources ◽  
Owens Valley ◽  
Extragalactic Radio Sources ◽  
Self Calibration

On 8–12 October 1981 a 5-station MkII VLBI experiment at 1660 MHz was performed using antennas at Westford, Maryland Point, Green Bank, Fort Davis, and Owens Valley. Fifteen extragalactic sources (Table 1) were observed with an average synthesized beam of roughly 10 mas. The data were processed using the NRAO correlator, globally fringe-fit, and mapped with the AIPS package. In addition to the usual self-calibration techiques, corrections were made to eliminate baseline-dependent calibration errors. Some of the sources, for example 1641+399 (3C345), display extended components not before observed at the dynamic range of the maps, which on the average is roughly 200:1.

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