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Related papers: Low-Frequency study of two clusters of galaxies: A…

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New radio data at 330 MHz are presented for the rich clusters Abell 665 and Abell 2163, whose radio emission is characterized by the presence of a radio halo. These images allowed us to derive the spectral properties of the two clusters…

Astrophysics · Physics 2009-11-10 L. Feretti , E. Orru' , G. Brunetti , G. Giovannini , N. Kassim , G. Setti

Synchrotron radio emission is being detected from an increasing number of galaxy clusters. Spectral index images are a powerful tool to investigate the origin, nature, and connection of these sources with the dynamical state of the cluster.…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 V. Vacca , L. Feretti , G. Giovannini , F. Govoni , M. Murgia , R. A. Perley , T. E. Clarke

We performed GMRT low frequency observations of the radio halos, relics and new candidates belonging to the GMRT Radio Halo Cluster Sample first observed at 610 MHz. High sensitivity imaging was performed using the GMRT at 325 MHz and 240…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Tiziana Venturi , Simona Giacintucci , Daniele Dallacasa , Rossella Cassano , Gianfranco Brunetti , Giulia Macario , Ramana Athreya

We present a multi-wavelength analysis of the merging rich cluster of galaxies Abell 2256. We have observed A2256 at 150 MHz using the Giant Metrewave Radio Telescope and successfully detected the diffuse radio halo and the relic emission…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Kale Ruta , K. S. Dwarakanath

Spectral index studies of halos, relics, and radio galaxies provide useful information on their origin and connection with merger processes. We present WSRT multi-wavelength observations of the galaxy cluster Abell 2255 at 25 cm, 85 cm, and…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 R. F. Pizzo , A. G. de Bruyn

The knowledge of the origin and statistical properties of diffuse radio emission in galaxy clusters has appreciably improved thanks to the GMRT Radio Halo Survey, a project based on 610 MHz observations of clusters belonging to a…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-10 Simona Giacintucci

High sensitivity observations of radio halos in galaxy clusters at frequencies lower than 330 MHz are still relatively rare, and very little is known compared to the classical 1.4 GHz images. The few radio halos imaged down to 150-240 MHz…

Cosmology and Nongalactic Astrophysics · Physics 2011-07-13 T. Venturi , S. Giacintucci , D. Dallacasa

We present the first deep low frequency radio observations of the massive and highly disturbed galaxy cluster Abell 2744 using the upgraded Giant Metrewave Radio Telescope (uGMRT). The cluster is experiencing a very complex multiple merger…

Clusters of galaxies may contain cluster-wide, centrally located, diffuse radio sources, called halos. They have been found to show morphologies similar to those of the X-ray emission. To quantify this qualitative statement we performed a…

Astrophysics · Physics 2009-11-06 F. Govoni , T. A. Ensslin , L. Feretti , G. Giovannini

We present new, high frequency radio observations of the merging galaxy clusters PLCK G287.0+32.9, Abell 2744, and Bullet. These clusters are known to host $\sim$Mpc scale sources, known as radio halos, which are formed by the acceleration…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-20 K. Rajpurohit , A. Botteon , E. O'Sullivan , W. Forman , M. Balboni , L. Bruno , R. J. van Weeren , M. Hoeft , G. Brunetti , C. Jones , A. S. Rajpurohit , S. P. Sikhosana

The Intra-Cluster Medium is characterized by thermal emission, and by the presence of large scale magnetic fields. In some clusters of galaxies a diffuse non-thermal emission is also present, located at the cluster center and named radio…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 G. Giovannini , A. Bonafede , L. Feretti , F. Govoni , M. Murgia , F. Ferrari , G. Monti

We aim to unveil their 3-dimensional geometry of Abell 2255 through WSRT observations at 18, 21, 25, 85, and 200 cm. The polarization images of the cluster were processed through rotation measure (RM) synthesis, producing three final RM…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 R. F. Pizzo , A. G. de Bruyn , G. Bernardi , M. A. Brentjens

We present the first detailed analysis of the radio halo in the merging galaxy cluster Abell 2256 using the LOFAR, uGMRT, and VLA. These observations combined with archival X-ray data allowed us to study the halo emission with unprecedented…

VLA observations at 1477 MHz revealed the presence of a radio mini-halo surrounding the faint central point-like radio source in the Ophiuchus cluster of galaxies. In this work we present a study of the radio emission from this cluster of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 M. Murgia , D. Eckert , F. Govoni , C. Ferrari , M. Pandey-Pommier , J. Nevalainen , S. Paltani

We report on a spectral study at radio frequencies of the giant radio halo in A2142 (z=0.0909), which we performed to explore its nature and origin. A2142 is not a major merger and the presence of a giant radio halo is somewhat surprising.…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-26 T. Venturi , M. Rossetti , G. Brunetti , D. Farnsworth , F. Gastaldello , S. Giacintucci , D. V. Lal , L. Rudnick , T. W. Shimwell , D. Eckert , S. Molendi , M. Owers

The galaxy cluster Abell 523 (A523) hosts an extended diffuse synchrotron source historically classified as a radio halo. Its radio power at 1.4 GHz makes it one of the most significant outliers in the scaling relations between observables…

We present deep VLA observations of the galaxy clusters Abell 2256 and Abell 754, both of which appear to be in the violent stage of major cluster merger events. The complex nature of Abell 2256 is revealed through radio images which, in…

Astrophysics · Physics 2007-05-23 T. E. Clarke , T. A. Ensslin

Context: Hierarchical galaxy formation models indicate that during their lifetime galaxy clusters undergo several mergers. Here we report on the discovery of three diffuse radio sources in the periphery of Abell 2256, using the GMRT. Aims:…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 R. J. van Weeren , H. T. Intema , J. B. R. Oonk , H. J. A. Rottgering , T. E. Clarke

Abell 2256 is one of the best known examples of a galaxy cluster hosting large-scale diffuse radio emission that is unrelated to individual galaxies. It contains both a giant radio halo and a relic, as well as a number of head-tail sources…

We present deep VLA observations of the merging galaxy cluster Abell 2256. This cluster is known to possess diffuse steep spectrum radio relic emission in the peripheral regions. Our new observations provide the first detailed image of the…

Astrophysics · Physics 2008-11-26 Tracy E. Clarke , Torsten A. Ensslin
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