scholarly journals Towards a Complete Sample of Giant Radio Galaxies at z > 0.4

1996 ◽  
Vol 175 ◽  
pp. 315-316
Author(s):  
A.P. Schoenmakers ◽  
H. Röttgering ◽  
H. Van Der Laan ◽  
A.G. De Bruyn
Keyword(s):  
Selection Effect ◽  
Radio Galaxies ◽  
Space Distribution ◽  
Radio Sources ◽  
Complete Sample

Giant Radio Galaxies are the largest radio sources associated with galaxies. They have linear sizes exceeding 1 Mpc (e.g. Saripalli et al., 1986). They used to be known only at redshifts below 0.2, and it has been argued that this was not only due to a selection effect, but that there is a real cutoff in the space distribution of these objects (e.g. Gopal-Krishna & Wiita, 1987). Recently, a small number of giants have been found at redshifts largely exceeding 0.3, indicating that such a cutoff does not exist (e.g. Cotter et al., 1995).

scholarly journals VLBI Morphology of GHz-Peaked Spectrum Radio Galaxies

1994 ◽  
Vol 159 ◽  
pp. 425-425
Author(s):  
D. Dallacasa ◽  
C. Fanti ◽  
R. Fanti
Keyword(s):  
Radio Galaxies ◽  
Radio Sources ◽  
Complete Sample ◽  
Spectrum Radio ◽  
5 Ghz

GHz-Peaked Spectrum (GPS) radio sources are intrinsically small (< 1 kpc) and unbeamed objects. The galaxies considered here (0316+161, 0404+768, 0428+205, 1323+321, 1358+624, 1819+39, 1829+29) have been selected from the Peacock and Wall (1981) catalogue, and belong to a complete sample of Compact Steep-Spectrum (CSS) radio sources (Fanti et al., 1990). Their radio spectra show a turnover which could be explained in terms of synchrotron self-absorption. It occurs at frequencies ranging from about 100 MHz to 5 GHz and for this reason they do not appear in the 3CR catalogue.

scholarly journals Optical Properties of FRI Radio Galaxies

1996 ◽  
Vol 175 ◽  
pp. 238-239
Author(s):  
Michael J. Ledlow ◽  
Frazer N. Owen
Keyword(s):  
Optical Properties ◽  
Flux Density ◽  
Radio Galaxies ◽  
Cluster Center ◽  
Radio Sources ◽  
Complete Sample ◽  
Abell Clusters ◽  
Ccd Observations ◽  
Twin Jets ◽  
Compact Sources

From the VLA 20cm survey of ≃ 500 Abell clusters reported by (Ledlow and Owen, 1995), we have obtained optical R-Band CCD observations and optical spectra for 265 radio galaxies. The survey is complete for 20cm flux density greater than 10 mJy within 0.3 corrected Abell radii of the cluster center. All Abell clusters with measured z < 0.09 were surveyed. This statistically complete sample was supplemented by ≃ 200 clusters with 0.09 < z < 0.25 including sources with flux density > 200 mJy. Only 6% of the sample consists of FR II radio sources, the remainder are twin-jets, tailed, or compact sources associated with the FR I class.

scholarly journals A Complete Sample of Radio Galaxies

1982 ◽  
Vol 97 ◽  
pp. 55-57 ◽  
Author(s):  
P.A. Shaver ◽  
I.J. Danziger ◽  
R.D. Ekers ◽  
R.A.E. Fosbury ◽  
W.M. Goss ◽  
...  
Keyword(s):  
Radio Galaxies ◽  
Radio Sources ◽  
Complete Sample ◽  
Preliminary Results ◽  
Multi Wavelength

We report here some preliminary results of a multi-wavelength study of a complete sample of radio galaxies. The sample is comprised of 93 radio sources from the Parkes 11 cm catalog which are identified with galaxies of 17th magnitude or brighter in the declination zone −17° to −40°. Our objective is to cross-correlate the radio, infrared, optical, and other properties of a properly defined sample of radio galaxies.

scholarly journals An Asymmetric Relativistic Model for FRII Radio Sources

1999 ◽  
Vol 194 ◽  
pp. 301-305
Author(s):  
T. G. Arshakian ◽  
M. S. Longair
Keyword(s):  
Observational Data ◽  
Critical Angle ◽  
Relativistic Effects ◽  
Radio Galaxies ◽  
Radio Sources ◽  
Relativistic Model ◽  
Complete Sample ◽  
Wide Range ◽  
The Mean ◽  
Translational Speed

An asymmetric relativistic model for FRII radio sources is described which takes account of both relativistic effects and intrinsic/environmental asymmetries to explain the observed structural asymmetry of their radio lobes. A key feature of the model is jet-sidedness, which can now be determined for about 80% of the FRII sources in the 3CRR complete sample. It is shown that a simple asymmetric relativistic model can account for a wide range of observational data, and that the relativistic and intrinsic asymmetry effects are of comparable importance. The mean translational speed of the lobes is . The results are in agreement with an orientation-based unified scheme in which the critical angle separating the radio galaxies from the radio quasars is about 50°.

scholarly journals Optical Properties of High Redshift Radio Galaxies

1989 ◽  
Vol 134 ◽  
pp. 543-545
Author(s):  
Patrick J. McCarthy ◽  
Hyron Spinrad ◽  
Wil van Breugel
Keyword(s):  
Optical Properties ◽  
High Redshift ◽  
Radio Galaxies ◽  
Radio Sources ◽  
Complete Sample ◽  
Redshift Range ◽  
Extragalactic Radio Sources ◽  
Look Back ◽  
Hubble Time

The 3CR catalogue of extragalactic radio sources is now completely identified for b > 15° and redshifts have been determined for > 98% of them (see Djorgovski et al. 1988 for the latest update). The radio galaxies in this catalogue span the redshift range from 0 to 2.48. This sample provides us with a unique opportunity to examine the optical and radio properties of a complete sample over a look-back time comparable to the Hubble time.

scholarly journals Soft X-Ray Properties of a Complete Sample of Radio Sources

1996 ◽  
Vol 175 ◽  
pp. 263-264
Author(s):  
J. Siebert ◽  
W. Brinkmann ◽  
R. Morganti ◽  
C.N. Tadhunter ◽  
I.J. Danziger ◽  
...  
Keyword(s):  
Sample Selection ◽  
Radio Galaxies ◽  
Full Description ◽  
Radio Sources ◽  
Selection Effects ◽  
Broad Line ◽  
Radio Luminosity ◽  
Complete Sample ◽  
X Ray ◽  
Object Classes

We investigate the X–ray properties of a complete sample of 88 radio sources derived from the Wall & Peacock 2–Jy sample. We find that Lx correlates well with core radio luminosity for all object classes, whereas the Lx – Ltotal is probably introduced by sample selection effects. Further, evidence for an anisotropic X–ray component in broad line radio galaxies is reported. A full description of the results will be given elsewhere (Siebert et al. 1996).

scholarly journals Morphologies in Mpc-Size Radio Galaxies

1996 ◽  
Vol 175 ◽  
pp. 313-314
Author(s):  
L. Saripalli ◽  
R. Subrahmanyan ◽  
R. W. Hunstead
Keyword(s):  
Temporal Evolution ◽  
Ambient Medium ◽  
Radio Galaxies ◽  
Radio Sources ◽  
Galactic Halos ◽  
Complete Sample ◽  
Size Regime ◽  
Extended Radio

The extended radio structures or lobes found in edge-brightened radio galaxies represent interactions with the ambient medium over the source lifetimes. Their study probes the temporal evolution in the radio sources and the properties of the ambient medium encountered at different locations. Previous studies (Leahy & Williams, 1984; Leahy et al., 1989) involved radio galaxies with sizes ≃ 400 kpc, and revealed radio morphologies with a variety of off-axis distortions that could be interpreted as due to different ways in which the lobes interact with the galactic halos. Such studies are lacking for radio galaxies having Megaparsec sizes, which extend to distances well beyond the observed galactic halos and are suspected of evolving in a different regime (Baldwin, 1982). Towards learning the evolution of radio galaxies in this size regime, we have carried out a study of a complete sample of Mpc-size radio galaxies; details are presented in Subrahmanyan, Saripalli & Hunstead (to appear in MNRAS, 1996).

scholarly journals Relations Between Radio and Optical Properties of Radio Sources - Radio Astronomer's Point of View

1977 ◽  
Vol 74 ◽  
pp. 237-243
Author(s):  
J. M. Riley ◽  
C. J. Jenkins
Keyword(s):  
Optical Properties ◽  
Radio Galaxies ◽  
Point Of View ◽  
Radio Sources ◽  
Optical Identification ◽  
Complete Sample ◽  
Radio Structure ◽  
Quasars And Radio Galaxies

One particular aspect of the relations between the radio and optical properties of radio sources has been examined for a complete sample of 3CR sources, namely the relation between the radio structure of a source and its optical identification. Possible differences between the radio structures of quasars and radio galaxies are investigated, and the data provide clues as to the optical nature of the unidentified sources.

scholarly journals Westerbork Observations of Low Luminosity Radio Sources

1982 ◽  
Vol 97 ◽  
pp. 193-194
Author(s):  
P. Parma
Keyword(s):  
Radio Galaxies ◽  
Radio Sources ◽  
Complete Sample

The two radio galaxies 0326+39 and 1321+31 are both part of a complete sample of low luminosity radio galaxies which was obtained by identifying B2 radio sources with galaxies from the Zwicky Catalogue. Both sources have a very symmetrical double jet, like many other sources of the sample (Ekers et al. 1981a).

scholarly journals High-resolution VLA low radio frequency observations of the Perseus cluster: radio lobes, mini-halo, and bent-jet radio galaxies

2020 ◽  
Vol 499 (4) ◽  
pp. 5791-5805
Author(s):  
M Gendron-Marsolais ◽  
J Hlavacek-Larrondo ◽  
R J van Weeren ◽  
L Rudnick ◽  
T E Clarke ◽  
...  
Keyword(s):  
High Resolution ◽  
Dynamic Range ◽  
Galaxy Cluster ◽  
High Dynamic Range ◽  
Radio Galaxies ◽  
Radio Sources ◽  
Nearby Galaxy ◽  
Cluster Galaxy ◽  
Ngc 1275 ◽  
Perseus Cluster

ABSTRACT We present the first high-resolution 230–470 MHz map of the Perseus cluster obtained with the Karl G. Jansky Very Large Array. The high dynamic range and resolution achieved have allowed the identification of previously unknown structures in this nearby galaxy cluster. New hints of sub-structures appear in the inner radio lobes of the brightest cluster galaxy NGC 1275. The spurs of radio emission extending into the outer X-ray cavities, inflated by past nuclear outbursts, are seen for the first time at these frequencies, consistent with spectral aging. Beyond NGC 1275, we also analyse complex radio sources harboured in the cluster. Two new distinct, narrowly collimated jets are visible in IC 310, consistent with a highly projected narrow-angle tail radio galaxy infalling into the cluster. We show how this is in agreement with its blazar-like behaviour, implying that blazars and bent-jet radio galaxies are not mutually exclusive. We report the presence of filamentary structures across the entire tail of NGC 1265, including two new pairs of long filaments in the faintest bent extension of the tail. Such filaments have been seen in other cluster radio sources such as relics and radio lobes, indicating that there may be a fundamental connection between all these radio structures. We resolve the very narrow and straight tail of CR 15 without indication of double jets, so that the interpretation of such head–tail sources is yet unclear. Finally, we note that only the brightest western parts of the mini-halo remain, near NGC 1272 and its bent double jets.

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