scholarly journals Clusters of Galaxies and Radio Sources

1977 ◽  
Vol 74 ◽  
pp. 305-316 ◽  
Author(s):  
Walter Jaffe
Keyword(s):  
Luminosity Function ◽  
Radio Galaxies ◽  
Radio Sources ◽  
Clusters Of Galaxies ◽  
Cluster Environment ◽  
Different Characteristics

For some time there have been suggestions that there is a special association of radio galaxies with rich clusters of galaxies, and more recently that the radio galaxies in clusters may show different characteristics from those outside. I will discuss the evidence for three types of such differences, in luminosity function, morphology, and occurance of steep spectrum sources. In each case I will try to connect any difference I find to the cluster environment.

Radio Observations of Clusters of Galaxies

1967 ◽  
Vol 1 (1) ◽  
pp. 24-24
Author(s):  
B. Y. Mills ◽  
R. R. Shobbrook
Keyword(s):  
High Resolution ◽  
Luminosity Function ◽  
Radio Galaxies ◽  
Detailed Examination ◽  
Statistical Information ◽  
Radio Sources ◽  
Clusters Of Galaxies ◽  
Radio Observations ◽  
Radio Frequencies

High resolution studies of clusters of galaxies at radio frequencies may contribute substantially to our knowledge of the properties of radio galaxies, their evolution and their luminosity function. A considerable amount of statistical information is already available on the correspondence of radio sources and clusters; the present investigation is aimed rather at a detailed examination of the sources and their identification with actual galaxies or other objects.

scholarly journals Extragalactic jets as probes of distant clusters of galaxies and the clusters occupied by bent radio AGN (COBRA) survey

2014 ◽  
Vol 10 (S313) ◽  
pp. 315-320
Author(s):  
Elizabeth L. Blanton ◽  
Rachel Paterno-Mahler ◽  
Joshua D. Wing ◽  
M. L. N. Ashby ◽  
Emmet Golden-Marx ◽  
...  
Keyword(s):  
Radio Galaxies ◽  
Radio Sources ◽  
Clusters Of Galaxies ◽  
Wide Range ◽  
Extragalactic Jets ◽  
Large Survey ◽  
Kinetic Mode ◽  
Group Environments ◽  
Initial Results ◽  
Quasars And Radio Galaxies

AbstractWe are conducting a large survey of distant clusters of galaxies using radio sources with bent jets and lobes as tracers. These radio sources are driven by AGN and achieve their bent morphologies through interaction with the surrounding gas found in clusters of galaxies. Based on low-redshift studies, these types of sources can be used to identify clusters very efficiently. We present initial results from our survey of 653 bent-double radio sources with optical hosts too faint to appear in the SDSS. The sample was observed in the infrared with Spitzer, and it has revealed ~200 distant clusters or proto-clusters in the redshift range z ~ 0.7 - 3.0. The sample of bent-doubles contains both quasars and radio galaxies enabling us to study both radiative and kinetic mode feedback in cluster and group environments at a wide range of redshifts.

scholarly journals Observations of Straight-angle Tailed Radio Galaxies in Rich Clusters of Galaxies

1996 ◽  
Vol 175 ◽  
pp. 349-350
Author(s):  
Aileen A. O'Donoghue ◽  
Jean A. Eilek ◽  
Frazer N. Owen
Keyword(s):  
Spectral Index ◽  
Radio Galaxies ◽  
Radio Sources ◽  
Clusters Of Galaxies ◽  
Data Set ◽  
Dynamical Properties

We have begun VLA observations of straight-angle tailed radio sources (SATs) at 1.5 and 4.8 GHz (L and C band) to achieve one arcsecond resolution at each frequency. This will provide a SAT data set similar to the O'Donoghue, Owen, and Eilek (1990) WAT data set with both total intensity and spectral index information. We will use these data to examine morphological and dynamical properties of straight-tailed radio sources in clusters of galaxies.

Steep-Spectrum Radio Sources in Clusters of Galaxies—The Southern Sample

1984 ◽  
Vol 5 (4) ◽  
pp. 516-529 ◽  
Author(s):  
O. B. Slee ◽  
J. E. Reynolds
Keyword(s):  
Radio Galaxies ◽  
High Energy ◽  
Radio Spectrum ◽  
Radio Sources ◽  
Clusters Of Galaxies ◽  
Detailed Review ◽  
X Ray ◽  
High Energy Electrons ◽  
Spectrum Radio ◽  
Inverse Compton

It is well established (e.g. Slee et al. 1983) that radio galaxies near the centres of rich clusters of galaxies tend to have steeper radio spectra than field radio galaxies. The fact that the sources with the steepest spectra occur in clusters that are highly luminous X-ray emitters has generally been interpreted in terms of the confining influence of a hot (~108 K), relatively dense (10-2 to 10-3 electrons cm-3) intra-cluster gas; the confined relativistic plasma then preferentially loses its high-energy electrons through synchrotron and inverse Compton losses, resulting in a steepening of the radio spectrum. A more detailed review of the evidence for this process is given by Robertson (1983).

Radio Galaxies and Quasars in Clusters of Galaxies

1983 ◽  
Vol 5 (2) ◽  
pp. 144-151 ◽  
Author(s):  
J. Gordon Robertson
Keyword(s):  
Radio Galaxies ◽  
Radio Sources ◽  
Clusters Of Galaxies ◽  
Intracluster Medium ◽  
X Ray ◽  
Broad Field

The study of radio galaxies situated within clusters of galaxies has become a broad field, with hundreds of papers published in the last few years. This review will therefore be restricted mainly to consideration of the interactions between the extended components of radio sources in clusters and the diffuse gas (intracluster medium, ICM) which occurs in clusters. In particular, attention will be focused on what we can learn about the ICM from this interaction, in conjunction with other data such as X-ray observations. In the case of quasars in clusters of galaxies the emphasis is rather different, so discussion of this topic is deferred to section 6.

scholarly journals Diffuse radio sources in clusters of galaxies: models and long-wavelength radio observations

2006 ◽  
Vol 2 (14) ◽  
pp. 369-371
Author(s):  
Craig L. Sarazin
Keyword(s):  
Large Scale ◽  
Low Frequency ◽  
Radio Sources ◽  
Clusters Of Galaxies ◽  
Radio Observations ◽  
Hadronic Interactions ◽  
Long Wavelength ◽  
Cluster Environment ◽  
Cluster Mergers ◽  
Radio Halos

AbstractClusters of galaxies contain several types of diffuse radio sources with very steep radio spectra which are associated with the cluster environment, including central radio bubbles, cluster radio relics, and cluster radio halos. Radio halos and relics are found only in merging clusters. Cluster radio relics may be produced by particle acceleration in merger shocks, while radio halos, may result from electron re-acceleration by turbulence produced by mergers. Secondary production of electrons and positrons by hadronic interactions also plays a role. If cluster radio halos and relics are related to mergers, then deep low frequency radio surveys could detect 1000's of clusters. Long-wavelength radio observations have a great potential to help us understand clusters and large scale structure, and can provide a diagnostic of cluster mergers, which affect the use of clusters in cosmological and dark energy studies.

scholarly journals Properties of Radio Sources in Clusters of Galaxies

1977 ◽  
Vol 4 (1) ◽  
pp. 321-328 ◽  
Author(s):  
Daniel E. Harris
Keyword(s):  
Radio Source ◽  
Radio Galaxies ◽  
Radio Sources ◽  
Clusters Of Galaxies ◽  
Coma Cluster ◽  
Cluster A

“The properties of radio sources in clusters” presupposes that we know something about radio sources out of clusters, or that we even know whether a radio source is “in” or “out” of a cluster. Thus we are faced with the problem of defining what we mean by a cluster. Most of us use Abell’s catalogue of RICH clusters and assume that we are really “in” a cluster. However, most radio sources are identified with faint, distant objects and it is often difficult to know whether the remark “galaxy in a group” or “galaxy in a cluster” indicates a cluster such as the Coma Cluster, a cluster similar to an “open” Zwicky cluster, or a group of galaxies which may be gravitationally bound.This uncertainty must not be forgotten, and in the following discussion, we will try to limit the effects of this by concentrating on catalogued clusters; ignoring most distant radio galaxies, many of which may be in rich clusters; and also by neglecting quasars, some or all of which may be in clusters.

scholarly journals Radio Surveys and Large Scale Structure

1991 ◽  
Vol 44 (6) ◽  
pp. 759 ◽  
Author(s):  
PA Shaver
Keyword(s):  
Radio Source ◽  
Large Scale ◽  
Three Dimensional ◽  
Large Scale Structure ◽  
Radio Galaxies ◽  
Scale Structure ◽  
Radio Sources ◽  
Clusters Of Galaxies ◽  
Normal Galaxies ◽  
Dimensional Distribution

An analysis of the Molonglo Reference Catalogue indicates that significant departures from isotropy are present in the sky distribution of strong extragalactic radio sources. This has been shown to be due to local large scale structure, specifically a concentration to the supergalactic plane, which also influences the slope of the source counts. A study of the three-dimensional distribution of local radio galaxies shows that they are more strongly concentrated to the supergalactic plane than are optically�selected galaxies, and that the supergalactic concentration is more extensive than hitherto believed. It appears that radio galaxies (and clusters of galaxies) trace the 'skeleton' of large scale structure, about which normal galaxies are more loosely distributed. Thus, while large scale structure evidently complicates the interpretation of radio source counts, it appears that radiO surveys can be of value in exploring structures on the largest scales.

scholarly journals The statistics of radio galaxies & quasars at high redshift

1986 ◽  
Vol 119 ◽  
pp. 455-462
Author(s):  
J.A. Peacock ◽  
J.S. Dunlop
Keyword(s):  
Gravitational Lensing ◽  
Luminosity Function ◽  
High Redshift ◽  
Radio Galaxies ◽  
Active Galaxies ◽  
Radio Sources ◽  
Extragalactic Radio Sources

Evidence is now accumulating that the most powerful extragalactic radio sources display a cutoff in comoving density at relatively low redshift. For both radio galaxies and quasars, the luminosity function falls by a factor ≥ 3 between z = 2 and 4. We describe the data which lead to this conclusion, and discuss the prospects for studying the behaviour of low-luminosity active galaxies at high redshift. The strong evolution of highly luminous radio-quiet quasars at z > 2 may be an artifact of gravitational lensing.

scholarly journals A Radio Study of Abell Clusters

1977 ◽  
Vol 30 (4) ◽  
pp. 509 ◽  
Author(s):  
BY Mills ◽  
DG Hoskins
Keyword(s):  
Radio Source ◽  
Luminosity Function ◽  
Radio Sources ◽  
Clusters Of Galaxies ◽  
Multiple Sources ◽  
Radio Observatory ◽  
Cluster Membership ◽  
Abell Clusters

A search for radio sources close to 247 clusters of galaxies in the Abell catalogue has been carried out at the Molonglo Radio Observatory at a frequency of 408 MHz. A list of 116 sources near 89 clusters is given, identifications have been made and criteria for cluster membership have been established. A cluster luminosity function is derived in the range 1()23_1025 WHz-l SCi, and spectra have been obtained for sources in 25 clusters utilizing published surveys made at other frequencies. It is found that there is no correlation between the richness of a cluster and its inclusion of at least one radio source, but those clusters containing multiple sources are significantly richer than average.

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