scholarly journals Radio luminosity function of brightest cluster galaxies

2016 ◽  
Vol 460 (4) ◽  
pp. 3669-3678 ◽  
Author(s):  
Z. S. Yuan ◽  
J. L. Han ◽  
Z. L. Wen
1980 ◽  
Vol 5 ◽  
pp. 715-721 ◽  
Author(s):  
Edwin A. Valentijn

In the Westerbork Survey of Rich Clusters of galaxies (WSRC), seven nearby and rich clusters of galaxies have been observed with the Westerbork Synthesis Radio Telescope. The results obtained at different frequencies are published in several papers of a series, and Table 1 serves as a general reference to these publications. In these papers, both discussions on individual radio sources and the presentation of cluster radio luminosity functions (RLF) are given. Here we summarize some of the results of the WSRC which, from a statistical point of view, impose some constraints on the rate of the radio activity of galaxies and on the influence of the galaxy environments on their activity. The rate of radio activity of a sample of galaxies in a cluster can be described by the integral RLF of the cluster, which represents the fraction of galaxies that emit in the radio domain above a certain power. When it is presented as a function of the optical luminosities of the cluster galaxies, it is called the bivariate radio luminosity function (BRLF). The BRLFs are most suitable for representing in an unbiased way the rate of activity of a sample of galaxies, since they are presented in absolute parameters and are normalized to the optical luminosity function (or distribution) of the galaxy samples. This is important since, both inside and outside clusters, it has been shown that the RLF depends strongly on the optical luminosities.


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

2020 ◽  
Vol 492 (4) ◽  
pp. 5297-5312 ◽  
Author(s):  
Eliab Malefahlo ◽  
Mario G Santos ◽  
Matt J Jarvis ◽  
Sarah V White ◽  
Jonathan T L Zwart

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.


2019 ◽  
Vol 487 (4) ◽  
pp. 5813-5813 ◽  
Author(s):  
Sumit K Sarbadhicary ◽  
Carles Badenes ◽  
Laura Chomiuk ◽  
Damiano Caprioli ◽  
Daniel Huizenga

Nature ◽  
1988 ◽  
Vol 333 (6168) ◽  
pp. 49-51 ◽  
Author(s):  
Gopal-Krishna ◽  
Paul J. Wiita

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