Flux Density Measurements of Optically Identified B2 Radio Sources at 5 GHz

1971 ◽  
Vol 76 ◽  
pp. 530 ◽  
Author(s):  
Gavril Grueff
Keyword(s):  
Flux Density ◽  
Radio Sources ◽  
Density Measurements ◽  
5 Ghz

scholarly journals VLBI Survey of a Complete Sample of Active Nuclei and Quasars

1984 ◽  
Vol 110 ◽  
pp. 15-24 ◽  
Author(s):  
T. J. Pearson ◽  
A.C.S. Readhead
Keyword(s):  
Flux Density ◽  
Radio Sources ◽  
Complete Sample ◽  
Limited Sample ◽  
Extragalactic Radio Sources ◽  
5 Ghz ◽  
Number Of Classes ◽  
Compact Sources ◽  
Continuous Range

We have conducted a VLBI survey of a complete, flux-density limited sample of 65 extragalactic radio sources, selected at 5 GHz. We have made hybrid maps at 5 GHz of all of the sources accessible to the Mark-II system. The sources can be divided provisionally into a number of classes with different properties: central components of extended double sources, steep-spectrum compact sources, very compact (almost unresolved) sources, asymmetric sources (sometimes called “core-jet” sources), and “compact double” sources. It is not yet clear whether any of these classes is physically distinct from the others, or whether there is a continuous range of properties.

7.8-GHz Flux Density Measurements of Variable Radio Sources

1972 ◽  
Vol 77 ◽  
pp. 819 ◽  
Author(s):  
William A. Dent ◽  
Gabriel Kojoian
Keyword(s):  
Flux Density ◽  
Radio Sources ◽  
Density Measurements ◽  
Variable Radio

9.5-mm Flux Density Measurements of a Sample of Sources from the 5-GHZ s4 Survey

1978 ◽  
Vol 83 ◽  
pp. 475 ◽  
Author(s):  
A. Witzel ◽  
I. I. K. Pauliny-Toth ◽  
K. I. Kellerman
Keyword(s):  
Flux Density ◽  
Density Measurements ◽  
5 Ghz

scholarly journals Bulk Relativistic Motion in a Complete Sample of Flat Spectrum Radio Sources

1988 ◽  
Vol 129 ◽  
pp. 71-72
Author(s):  
C. J. Schalinski ◽  
A. Witzel ◽  
Th.P. Krichbaum ◽  
C. A. Hummel ◽  
P. L. Biermann ◽  
...  
Keyword(s):  
Flux Density ◽  
Status Report ◽  
Radio Sources ◽  
Supporting Evidence ◽  
X Rays ◽  
Relativistic Motion ◽  
Bl Lac Objects ◽  
Vlbi Observations ◽  
Wide Range ◽  
5 Ghz

As part of a multi-epoch and multi-wavelength study of the physics of core dominated radio sources we have investigated the occurrence of apparent superluminal motion and other indications for bulk relativistic motion (b.r.m) in a statistically complete, flux density limited (S5GHz ≥ 1Jy) sample of 13 objects with flat radio spectra These sources come from the S5-survey (Kühr et al., 1981) and are optically identified as 7 quasars and 6 BL-Lac objects. They have been observed over a wide range of frequencies, from radio through X-rays (s. Eckart et al., 1986 and references therein). Radiomaps have been obtained at frequencies from 327 MHz to 22.2 GHz with resolutions from arcseconds to 0.2 mas, using the VLA, MERLIN and telescopes of the US- and European-VLBI networks. A recent status report on the VLBI-observations is given by Witzel (1987). In this paper we summarize the results on the direct evidence for b.r.m. in this sample as derived from repeated VLBI-observations at 5 GHz, as well as supporting evidence from SSC-calculations and flux density variability of the 5GHz VLBI core components (Table 1).

scholarly journals Unveiling the high-frequency radio source population with the AT20G survey

2013 ◽  
Vol 9 (S304) ◽  
pp. 205-208
Author(s):  
Elizabeth K. Mahony
Keyword(s):  
Radio Source ◽  
Flux Density ◽  
High Frequency ◽  
Gamma Ray ◽  
Low Frequency ◽  
Radio Sources ◽  
Source Population ◽  
Frequency Source ◽  
Galaxy Population ◽  
5 Ghz

AbstractUntil recently, the radio sky above 5 GHz was relatively unexplored. This has changed with the completion of the Australia Telescope 20 GHz survey (AT20G; Murphy et al., 2010); a blind survey of the southern sky down to a limiting flux density of 40 mJy. The AT20G survey provides by far the largest and most complete sample of high-frequency radio sources yet obtained, offering new insights into the nature of the high-frequency active galaxy population. Whilst the radio data provides a unique sample of objects, these data alone are insufficient to completely constrain models of radio source properties and the evolution of radio galaxies. Complementary multiwavelength data is vital in understanding the physical properties of the central black hole.In this talk I will provide a brief overview of the AT20G survey, followed by a discussion of the multiwavelength properties of the high-frequency source population. In particular, I will focus on the optical properties of AT20G sources, which are very different to those of a low-frequency selected sample, along with the gamma-ray properties where we find a correlation between high-frequency radio flux density and gamma-ray flux density. By studying the multiwavelength properties of a large sample of high-frequency radio sources we gain a unique perspective on the inner dynamics of some of the most active AGN.

scholarly journals Surveys of Radio Sources at 5 GHz

1977 ◽  
Vol 74 ◽  
pp. 63-74
Author(s):  
I. I. K. Pauliny-Toth
Keyword(s):  
Flux Density ◽  
Radio Astronomy ◽  
Radio Sources ◽  
Astronomy Observatory ◽  
Max Planck ◽  
Radio Astronomy Observatory ◽  
Density Relation ◽  
Strong Source ◽  
Optical Identifications ◽  
5 Ghz

A number of surveys have been carried out at a frequency of 5 GHz at the National Radio Astronomy Observatory (NRAO) and at the Max-Planck-Institut für Radioastronomie (MPIfR), with the aim of determining the number-flux density relation for the sources detected and also of obtaining their radio spectra and optical identifications. The surveys fall into two categories: first, the strong source (S) surveys, which are intended in due course to cover the whole northern sky and to be complete above a flux density of about 0.6 Jy; second, surveys of limited areas of sky down to lower levels of the flux density.

scholarly journals A VLA Survey of Rich Clusters of Galaxies II. The Stronger Sources: Maps, Polarisations and Identifications

1994 ◽  
Vol 47 (2) ◽  
pp. 145 ◽  
Author(s):  
OB Slee ◽  
AL Roy ◽  
Ann Savage
Keyword(s):  
Flux Density ◽  
Source Parameters ◽  
Angular Size ◽  
Optical Parameters ◽  
Radio Sources ◽  
Very Large Array ◽  
Contour Maps ◽  
Optical Images ◽  
5 Ghz ◽  
Linear Polarisation

We present detailed radio and optical parameters for the stronger radio sources in 58 Abell cluster fields observed with the Very Large Array (VLA) using scaled arrays at 1�5 and 4�9 GHz. These sources comprise a complete sample with 1� 5 GHz flux density :;::20 mJy and cover a combined sky area of 3�5 X 10-5 sr. The cluster fields were distributed over 24 h of RA and between declinations +350 and -300 Contour maps at two frequencies are presented and source parameters such as position, angular size, spectral index, linear polarisation and core flux density are tabulated. We also derive the emitted power and linear size for those sources close to the cluster centres and therefore highly likely to be cluster members. We attempt to identify all these radio sources with optical images on the Palomar and SERC survey plates and give their accurate optical coordinates, morphologies and apparent magnitudes.

scholarly journals 5000 MHz Flux Densities and Spectra for 325 Small-diameter Radio Sources at Low Galactic Latitudes

1975 ◽  
Vol 28 (5) ◽  
pp. 633 ◽  
Author(s):  
JL Caswell ◽  
RF Haynes ◽  
DH Clark
Keyword(s):  
Flux Density ◽  
Small Diameter ◽  
Radio Sources ◽  
Density Measurements

Flux density measurements at 5000 MHz are presented for 325 of the small-diameter sources detected in the Molonglo 408 MHz galactic survey. By investigating the spectra we show that probably between 10 % and 15 % of the sources are galactic and the remainder extragalactic.

15.5-GHz flux-density measurements of variable radio sources

1974 ◽  
Vol 79 ◽  
pp. 1232 ◽  
Author(s):  
W. A. Dent ◽  
J. E. Kapitzky ◽  
G. Kojoian
Keyword(s):  
Flux Density ◽  
Radio Sources ◽  
Density Measurements ◽  
Variable Radio
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