The radio luminosity function and the luminosity diameter function of extragalactic radio sources

1971 ◽  
Vol 293 (3) ◽  
pp. 111-117 ◽  
Author(s):  
G. M. Richter
Keyword(s):  
Luminosity Function ◽  
Radio Sources ◽  
Radio Luminosity ◽  
Extragalactic Radio Sources ◽  
Radio Luminosity Function

scholarly journals Radio Evolution in High Redshift Clusters

1982 ◽  
Vol 97 ◽  
pp. 425-426
Author(s):  
Walter Jaffe
Keyword(s):  
Galaxy Clusters ◽  
Luminosity Function ◽  
High Redshift ◽  
Radio Sources ◽  
Radio Luminosity ◽  
High Luminosity ◽  
General Radio ◽  
Parent Sample ◽  
Radio Luminosity Function

In this project we try to follow the evolution of the Radio Luminosity Function (RLF) with redshift by observing a set of galaxy clusters with known spectroscopic redshifts. This method has the advantage over previous studies, based on general radio surveys, that most of the redshifts are accurately known, that intrinsically weaker sources are well represented, and that the parent sample of galaxies is well defined. The chief disadvantages are that, because the sample is optically selected, there are few high luminosity radio sources, and that we cannot examine differences between cluster and field populations.

scholarly journals On the Identification of Extragalactic Radio Sources

1960 ◽  
Vol 13 (3) ◽  
pp. 550 ◽  
Author(s):  
BY Mills
Keyword(s):  
Luminosity Function ◽  
Great Majority ◽  
Brightness Distribution ◽  
Optical Data ◽  
Radio Sources ◽  
Clusters Of Galaxies ◽  
Radio Luminosity ◽  
National Geographic Society ◽  
Limited Region ◽  
Radio Luminosity Function

Identifications of radio sources with galaxies and clusters of galaxies have been sought systematically in a limited region of the sky. The optical data have been taken principally from the National Geographic Society-Palomar Observatory Sky Atlas and a catalogue of clusters of galaxies prepared by Abell (1958) from the same Atlas. The radio data are taken from results obtained with the Sydney cross-type radio telescope, supplemented at times with additional information from a recent Cambridge Catalogue (3C). A total of 46 possible identifications with galaxies are listed and 55 possible identifications with clusters of galaxies, the great majority of which are new. Most of these galaxies are double systems, but no other common features could be recognized: it seems probable that many galaxies of completely normal appearance are very strong radio emitters. The possible nature of the double galaxies is discussed briefly and attention is drawn to a corresponding duplicity in the radio brightness distribution observed in some strong radio sources. In many cases the emission from clusters appears to be associated with a single galaxy or pair of galaxies in the cluster; evidence for the existence of radiation of intergalactic origin is inconclusive. A selection of the possible galaxy identifications has been used to derive a provisional radio luminosity function; it appears probable that there is no distinct class of " radio galaxies", but all radio luminosities appear to be represented, the numbers of radio sources in a given volume of space falling rapidly with increasing luminosity. A radio luminosity function of the form derived is capable of accounting for a substantial number of the radio sources of small size observed at high galactic latitudes; the remainder could be accommodated by the uncertainty in the data. It is found that, at the levels to which source counts can currently be taken, cosmological effects are likely to be small, although the most distant sources are markedly affected.

scholarly journals Determining the Core Radio Luminosity Function of Radio AGNs via Copula

2018 ◽  
Vol 239 (2) ◽  
pp. 33 ◽  
Author(s):  
Zunli Yuan ◽  
Jiancheng Wang ◽  
D. M. Worrall ◽  
Bin-Bin Zhang ◽  
Jirong Mao
Keyword(s):  
Luminosity Function ◽  
Radio Luminosity ◽  
The Core ◽  
Radio Luminosity Function

scholarly journals The optically selected 1.4-GHz quasar luminosity function below 1 mJy

2020 ◽  
Vol 492 (4) ◽  
pp. 5297-5312 ◽  
Author(s):  
Eliab Malefahlo ◽  
Mario G Santos ◽  
Matt J Jarvis ◽  
Sarah V White ◽  
Jonathan T L Zwart
Keyword(s):  
Luminosity Function ◽  
Significant Contribution ◽  
Detection Threshold ◽  
Simulated Data ◽  
Sloan Digital Sky Survey ◽  
Radio Luminosity ◽  
Host Galaxies ◽  
Star Forming ◽  
Sky Survey ◽  
Radio Luminosity Function

ABSTRACT We present the radio luminosity function (RLF) of optically selected quasars below 1 mJy, constructed by applying a Bayesian-fitting stacking technique to objects well below the nominal radio flux density limit. We test the technique using simulated data, confirming that we can reconstruct the RLF over three orders of magnitude below the typical 5σ detection threshold. We apply our method to 1.4-GHz flux densities from the Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) survey, extracted at the positions of optical quasars from the Sloan Digital Sky Survey over seven redshift bins up to z = 2.15, and measure the RLF down to two orders of magnitude below the FIRST detection threshold. In the lowest redshift bin (0.2 < z < 0.45), we find that our measured RLF agrees well with deeper data from the literature. The RLF for the radio-loud quasars flattens below $\log _{10}[L_{1.4}/{\rm W\, Hz}^{-1}] \approx 25.5$ and becomes steeper again below $\log _{10}[L_{1.4}/{\rm W\, Hz}^{-1}] \approx 24.8$, where radio-quiet quasars start to emerge. The radio luminosity where radio-quiet quasars emerge coincides with the luminosity where star-forming galaxies are expected to start dominating the radio source counts. This implies that there could be a significant contribution from star formation in the host galaxies, but additional data are required to investigate this further. The higher redshift bins show a similar behaviour to the lowest z bin, implying that the same physical process may be responsible.

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