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1. 6 and 20cm flux densities of radio galaxies
ID:
ivo://CDS.VizieR/J/A+A/342/378
Title:
6 and 20cm flux densities of radio galaxies
Short Name:
J/A+A/342/378
Date:
21 Oct 2021
Publisher:
CDS
Description:
We discuss the "angular size-redshift" relation for compact radio sources distributed over a wide range of redshifts 0.011<=z<=4.72. Our study is based on a sample of 330 5 GHz VLBI contour maps taken from the literature. Unlike extended source samples, the "angular size - redshift" relation for compact radio sources appears consistent with the predictions of standard Friedmann world models with q_0_=~0.5 without the need to consider evolutionary or selection effects due to a "linear size-luminosity" dependence. By confining our analysis to sources having a spectral index, -0.38<={alpha}<=0.18, and a total radio luminosity, Lh^2^>= 10^26^W/Hz (H_0_=100hkm/s/Mpc, q_0_=0.5 used as a numerical example), we are able to restrict the dispersion in the "angular size-redshift" relation. The best fitting regression analysis in the framework of the Friedmann-Robertson-Walker model gives the value of the deceleration parameter q_0_=0.21+/-0.30 if there are no evolutionary or selection effects due to a "linear size-luminosity", "linear size-redshift" or "linear size-spectral index" dependence.
2. Bright extragalactic radio sources at 2.7 GHz
ID:
ivo://CDS.VizieR/J/MNRAS/216/173
Title:
Bright extragalactic radio sources at 2.7 GHz
Short Name:
J/MNRAS/216/173
Date:
21 Oct 2021
Publisher:
CDS
Description:
The brightest extragalactic radio sources at 2.7 GHz are catalogued. The complete sample comprises 233 sources found in the major centimeter wavelength surveys carried out at ANRAO/Parkes, NNRAO/Greenbank, and MPIfR/Bonn: the sample covers 9.81 sr and has limits S(27) = 2.0 Jy and |b| > 10{deg}. A critical reanalysis of the data shows that 227 (97 percent) have optical identifications and 171 (73 percent) have measured redshifts. The implications of the catalogue statistics for the luminosity functions of different radio-source populations are considered.
3. Bright radio sources at 178 MHz (3CRR)
ID:
ivo://CDS.VizieR/J/MNRAS/204/151
Title:
Bright radio sources at 178 MHz (3CRR)
Short Name:
J/MNRAS/204/151
Date:
21 Oct 2021
Publisher:
CDS
Description:
A revised sample of bright radio sources at 178MHz is defined in order to correct the biases introduced into the 3CR catalog by confusion and partial resolution. The sample is shown to be 96 percent complete to a flux-density limit of 10Jy for sources smaller than 10arcmin. The bias of the 3CR catalog against objects of larger angular size is also reduced. Optical identifications are presented for 96 percent of the sources, 71 percent with galaxies and 25 percent with quasars. The radio-galaxy population is found to show strong space-density evolution for luminosities in excess of approximately 10^26.5^W/Hz/sr at 178MHz (redshifts greater than or approximately equal to 0.2), while the evolutionary properties of galaxies and quasars of the same luminosity and redshift are very similar.
4. B3-VLA CSS sample
ID:
ivo://CDS.VizieR/J/A+A/426/463
Title:
B3-VLA CSS sample
Short Name:
J/A+A/426/463
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of VLBA observations at 6 and 3.6cm for eighteen Compact Steep Spectrum radio sources (CSS) from the B3-VLA CSS sample. In most cases these VLBA images display a "Double/Triple" morphology, and the core is unambiguously detected in seven sources. Multifrequency images allow us to study the spectral properties of the individual source components and to constrain the spectral age. In lobe-dominated sources the radiative ages deduced from the synchrotron theory are in the range of up 5x10^3^ years, if equipartition magnetic field is assumed. Polarized emission is detected at a few percent level for two sources only. They were the only two sources displaying polarized emission in VLA A configuration data, and this implies that beam depolarization is not effective in reducing the integrated fractional polarization for these sources.
5. Candidate ICRF flat-spectrum radio sources. III.
ID:
ivo://CDS.VizieR/J/AJ/153/157
Title:
Candidate ICRF flat-spectrum radio sources. III.
Short Name:
J/AJ/153/157
Date:
21 Oct 2021
Publisher:
CDS
Description:
In extending our spectroscopic program, which targets sources drawn from the International Celestial Reference Frame (ICRF) Catalog, we have obtained spectra for ~160 compact, flat-spectrum radio sources and determined redshifts for 112 quasars and radio galaxies. A further 14 sources with featureless spectra have been classified as BL Lac objects. Spectra were obtained at three telescopes: the 3.58m European Southern Observatory New Technology Telescope, and the two 8.2m Gemini telescopes in Hawaii and Chile. While most of the sources are powerful quasars, a significant fraction of radio galaxies is also included from the list of non-defining ICRF radio sources.
6. Chandra large-scale extragalactic jets. I.
ID:
ivo://CDS.VizieR/J/ApJS/197/24
Title:
Chandra large-scale extragalactic jets. I.
Short Name:
J/ApJS/197/24
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this paper, we report the first stages of an investigation into the X-ray properties of extragalactic jets (XJET project). Our approach is to subject all sources for which X-ray emission has been detected by Chandra to uniform reduction procedures. Using Chandra archival data for 106 such sources, we measure X-ray fluxes in three bands and compare these to radio fluxes. We discuss the sample, the reduction methods, and present first results for the ratio of X-ray to radio flux for jet knots and hotspots. In particular, we apply statistical tests to various distributions of key observational parameters to evaluate differences between the different classes of sources.
7. Comparison of Radio-loud and Quiet Quasars
ID:
ivo://CDS.VizieR/J/ApJ/511/612
Title:
Comparison of Radio-loud and Quiet Quasars
Short Name:
J/ApJ/511/612
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have made radio observations of 87 optically selected quasars at 5 GHz with the VLA in order to measure the radio power for these objects and hence determine how the fraction of radio-loud quasars varies with redshift and optical luminosity. The sample has been selected from the recently completed Edinburgh Quasar Survey and covers a redshift range of 0.3{<=}z{<=}1.5 and an optical absolute magnitude range of (-26.5){<=}M_B_{<=}(-23.5) (h=1/2, q_o_=1/2). We have also matched other existing surveys with the Faint Images of the Radio Sky at Twenty Centimeters and NRAO VLA Sky Survey radio catalogs and combined these data so that the optical luminosity-redshift plane is now far better sampled than before. We have fitted a model to the probability of a quasar being radio-loud as a function of absolute magnitude and redshift, and from this model we infer the radio-loud and radio-quiet optical luminosity functions. The radio-loud optical luminosity function is featureless and flatter than the radio-quiet one. It evolves at a marginally slower rate if quasars evolve by density evolution, but the difference in the rate of evolutions of the two different classes is much less than was previously thought.
8. Core dominance in extragalactic radio sources
ID:
ivo://CDS.VizieR/J/A+A/407/899
Title:
Core dominance in extragalactic radio sources
Short Name:
J/A+A/407/899
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this paper, based on a paper by Liu and Zhang (2002, Cat. <J/A+A/381/757>), we have chosen a sample of 542 extragalactic sources (27 BL Lac objects, 300 galaxies (radio galaxies and Seyfert galaxies), and 215 quasars), for which we have calculated the core-dominance parameters and investigated the relation between core-dominance parameter and the core and extended luminosities. The core-dominance parameter of galaxies is smaller than that in quasars, which is smaller than that in BL Lac objects.
9. Extragalactic radio-sources at 95GHz
ID:
ivo://CDS.VizieR/J/MNRAS/385/1656
Title:
Extragalactic radio-sources at 95GHz
Short Name:
J/MNRAS/385/1656
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have used the Australia Telescope Compact Array (ATCA) at 95GHz to carry out continuum observations of 130 extragalactic radio sources selected from the Australia Telescope 20GHz (AT20G) survey. We use a triple-correlation method to measure simultaneous 20- and 95-GHz flux densities for these objects, and over 90 per cent of our target sources are detected at 95GHz. We demonstrate that the ATCA can robustly measure 95-GHz flux densities with an accuracy of ~10 per cent in a few minutes for sources stronger than about 50mJy. We measure the distribution of radio spectral indices in a flux-limited sample of extragalactic sources, and show that the median 20-95GHz spectral index does not vary significantly with flux density for S_20_>150mJy . This finding allows us to estimate the extragalactic radio source counts at 95GHz by combining our observed 20-95GHz spectral-index distribution with the accurate 20-GHz source counts measured in the AT20G survey.
10. Extragalactic sources at 22, 37 and 87GHz
ID:
ivo://CDS.VizieR/J/A+A/427/769
Title:
Extragalactic sources at 22, 37 and 87GHz
Short Name:
J/A+A/427/769
Date:
21 Oct 2021
Publisher:
CDS
Description:
Long term monitoring results from mid 1995 to the end of 2000 of quasar observations at 22, 37 and 87GHz done at the Metsahovi radio observatory are presented. Approximately 15700 observations are published here.

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