scholarly journals Radio Source Evolution Derived from Low Frequency Surveys

2002 ◽  
Vol 199 ◽  
pp. 50-53
Author(s):  
C.A. Jackson ◽  
J.V. Wall
Keyword(s):  
Radio Source ◽  
Luminosity Function ◽  
Low Frequency ◽  
Radio Galaxies ◽  
Parametric Models ◽  
Radio Luminosity ◽  
Space Density ◽  
Radio Data ◽  
Radio Luminosity Function

We find simple parametric models to describe the space density evolution of radio-loud AGN, treating FRI and FRII radio galaxies separately as the two parent populations in our dual-population unified scheme. In this we use low frequency radio data (v < 500 MHz), where radio samples are unbiased by Doppler beaming. Incorporated into this latest analysis is a new determination of the local radio luminosity function at 1.4 GHz from galaxies common to both the 2dFGRS and NVSS surveys.

scholarly journals The radio luminosity function of the NEP distant cluster radio galaxies

2006 ◽  
Vol 446 (1) ◽  
pp. 97-111 ◽  
Author(s):  
M. Branchesi ◽  
I. M. Gioia ◽  
C. Fanti ◽  
R. Fanti ◽  
R. Perley
Keyword(s):  
Luminosity Function ◽  
Radio Galaxies ◽  
Radio Luminosity ◽  
Distant Cluster ◽  
Radio Luminosity Function

scholarly journals The radio luminosity function from the low-frequency 3CRR, 6CE and 7CRS complete samples

2001 ◽  
Vol 322 (3) ◽  
pp. 536-552 ◽  
Author(s):  
C. J. Willott ◽  
S. Rawlings ◽  
K. M. Blundell ◽  
M. Lacy ◽  
S. A. Eales
Keyword(s):  
Luminosity Function ◽  
Low Frequency ◽  
Radio Luminosity ◽  
Radio Luminosity Function

The radio-luminosity function for radio galaxies

Astrophysics ◽  
1973 ◽  
Vol 6 (4) ◽  
pp. 297-300
Author(s):  
Yu. K. Melik-Alaverdyan
Keyword(s):  
Luminosity Function ◽  
Radio Galaxies ◽  
Radio Luminosity ◽  
Radio Luminosity Function

scholarly journals Cosmic evolution of star-forming galaxies to z ≃ 1.8 in the faint low-frequency radio source population

2019 ◽  
Vol 491 (4) ◽  
pp. 5911-5924 ◽  
Author(s):  
E F Ocran ◽  
A R Taylor ◽  
M Vaccari ◽  
C H Ishwara-Chandra ◽  
I Prandoni ◽  
...  
Keyword(s):  
Luminosity Function ◽  
Formation Rate ◽  
Low Frequency ◽  
Source Population ◽  
Radio Luminosity ◽  
Photometric Redshifts ◽  
Space Density ◽  
Star Forming ◽  
Steep Decline ◽  
Luminosity Evolution

ABSTRACT We study the properties of star-forming galaxies selected at 610 MHz with the GMRT in a survey covering ∼1.86 deg2 down to a noise of ∼7.1 μJy beam−1. These were identified by combining multiple classification diagnostics: optical, X-ray, infrared, and radio data. Of the 1685 SFGs from the GMRT sample, 496 have spectroscopic redshifts whereas 1189 have photometric redshifts. We find that the IRRC of star-forming galaxies, quantified by the infrared-to-1.4 GHz radio luminosity ratio $\rm {\mathit{ q}_{IR}}$, decreases with increasing redshift: $\rm {\mathit{ q}_{IR}\, =\, 2.86\pm 0.04(1\, +\, \mathit{ z})^{-0.20\pm 0.02}}$ out to z ∼ 1.8. We use the $\rm {\mathit{ V}/\mathit{ V}_{max}}$ statistic to quantify the evolution of the comoving space density of the SFG sample. Averaged over luminosity our results indicate $\rm {\langle \mathit{ V}/\mathit{ V}_{max} \rangle }$ to be $\rm {0.51\, \pm \, 0.06}$, which is consistent with no evolution in overall space density. However, we find $\rm \mathit{ V}/\mathit{ V}_{max}$ to be a function of radio luminosity, indicating strong luminosity evolution with redshift. We explore the evolution of the SFGs radio luminosity function by separating the source into five redshift bins and comparing to theoretical model predictions. We find a strong redshift trend that can be fitted with a pure luminosity evolution of the form $\rm {\mathit{ L}_{610\, MHz}\, \propto \, (\, 1+\, \mathit{ z})^{(2.95\pm 0.19)-(0.50\pm 0.15)z}}$. We calculate the cosmic SFR density since $\rm {\mathit{ z} \sim 1.5}$ by integrating the parametric fits of the evolved 610 MHz luminosity function. Our sample reproduces the expected steep decline in the star formation rate density since $\rm {\mathit{ z}\, \sim \, 1}$.

The radio luminosity function of radio galaxies in distant clusters

2006 ◽  
Vol 327 (5-6) ◽  
pp. 571-572 ◽  
Author(s):  
M. Branchesi ◽  
I. M. Gioia ◽  
C. Fanti ◽  
R. Fanti ◽  
R. Perley
Keyword(s):  
Luminosity Function ◽  
Radio Galaxies ◽  
Radio Luminosity ◽  
Radio Luminosity Function

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 Surface Density of Quasars

1978 ◽  
Vol 79 ◽  
pp. 295-303 ◽  
Author(s):  
J.G. Bolton ◽  
Ann Savage
Keyword(s):  
Surface Density ◽  
Luminosity Function ◽  
Statistical Significance ◽  
Comprehensive Investigation ◽  
Space Density ◽  
Close Pairs

A knowledge of the surface density of quasars as a function of magnitude is important for two reasons. Firstly it is necessary in order to assess the possible statistical significance of close pairs of quasars or the association between quasars and bright galaxies. Secondly it is a necessary step in the determination of the space density or luminosity function of QSOs. We have carried out what we believe to be currently the most comprehensive investigation into the surface density of quasars. Three techniques have been used in this investigation. These are

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