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Related papers: Radial Profiles of Radio Halos in Massive Galaxy C…

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Radio halos are diffuse synchrotron sources on scales of ~1 Mpc that are found in merging clusters of galaxies, and are believed to be powered by electrons re-accelerated by the merger-driven turbulence. We present measurements of extended…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-18 Martin W. Sommer , Kaustuv Basu , Huib Intema , Florian Pacaud , Annalisa Bonafede , Arif Babul , Frank Bertoldi

Radio halos are elusive sources located at the center of merging galaxy clusters. To date, only about 40 radio halos are known, thus the discovery of new halos provide important insights on this class of sources. To improve the statistics…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 F. Govoni , C. Ferrari , L. Feretti , V. Vacca , M. Murgia , G. Giovannini , R. Perley , C. Benoist

Radio halos are synchrotron radio sources detected in some massive galaxy clusters. Their Mpc-size indicates that (re)acceleration processes are taking place in the host cluster. X-ray catalogues of galaxy clusters have been used in the…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-28 A. Bonafede , H. T. Intema , M. Brüggen , F. Vazza , K. Basu , M. Sommer , H. Ebeling , F. de Gasperin , H. J. A. Röttgering , R. J. van Weeren , R. Cassano

A fraction of galaxy clusters host diffuse radio sources called radio halos, radio relics and mini-halos. We present the sample and first results from the Extended GMRT Radio Halo Survey (EGRHS)- an extension of the GMRT Radio Halo Survey…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 R. Kale , T. Venturi , S. Giacintucci , D. Dallacasa , R. Cassano , G. Brunetti , G. Macario , R. Athreya

Many galaxy clusters host Mpc scale diffuse radio sources called radio halos. Their origin is connected to the processes that lead to the formation of clusters themselves. In order to unveil this connection, statistical studies of radio…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-10 V. Cuciti , R. Cassano , G. Brunetti , D. Dallacasa , F. de Gasperin , S. Ettori , S. Giacintucci , R. Kale , G. W. Pratt , R. J. van Weeren , T. Venturi

Radio halos are megaparsec-scale diffuse, non-thermal radio sources located at the centers of galaxy clusters, tracing relativistic particles and magnetic fields in the intra-cluster medium. Their origin is generally attributed to cluster…

The aim of this work is to analyse the radio properties of the massive and dynamical disturbed clusters Abell 1451 and Zwcl 0634.1+4750, especially focusing on the possible presence of diffuse emission. We present new GMRT 320 MHz and JVLA…

Astrophysics of Galaxies · Physics 2018-01-10 V. Cuciti , G. Brunetti , R. van Weeren , A. Bonafede , D. Dallacasa , R. Cassano , T. Venturi , R. Kale

Radio halos are synchrotron diffuse sources at the centre of a fraction of galaxy clusters. The study of large samples of clusters with adequate radio and X-ray data is necessary to investigate the origin of radio halos and their connection…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-10 V. Cuciti , R. Cassano , G. Brunetti , D. Dallacasa , R. J. van Weeren , S. Giacintucci , A. Bonafede , F. de Gasperin , S. Ettori , R. Kale , G. W. Pratt , T. Venturi

Previously it has been recognized that radio halos in galaxy clusters are preferentially associated with merging systems as indicated by substructure in the X-ray images and temperature maps. Since, however, many clusters without radio…

Astrophysics · Physics 2009-11-06 David A. Buote

Massive merging galaxy clusters often host diffuse Mpc-scale radio synchrotron emission. This emission originates from relativistic electrons in the ionized intracluster medium (ICM). An important question is how these synchrotron emitting…

Clusters of galaxies are the largest gravitationally bound objects in the Universe, containing about 10^15 solar masses of hot (10^8 K) gas, galaxies and dark matter in a typical volume of about 10 Mpc^3. Magnetic fields and relativistic…

The presence of megaparsec-scale radio halos in galaxy clusters has already been established by many observations over the last two decades. The emerging explanation for the formation of these giant sources of diffuse synchrotron radio…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-15 G. Bernardi , T. Venturi , R. Cassano , D. Dallacasa , G. Brunetti , V. Cuciti , M. Johnston-Hollitt , N. Oozeer , V. Parekh , O. M. Smirnov

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

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

Radio halos are extended and diffuse non-thermal radio sources present at the cluster center, not obviously associated with any individual galaxy. A strong correlation has been found between the cluster X-ray luminosity and the halo radio…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 G. Giovannini , L. Feretti , M. Girardi , F. Govoni , M. Murgia , V. Vacca , J. Bagchi

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…

We have performed the the first census of Mpc-scale radio emission to include control fields and quantifiable upper limits for bright X-ray clusters in the range 0.03<z<0.3 . Through reprocessing radio images from the WENSS survey, we…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-15 Lawrence Rudnick , Jeffrey Lemmerman

Abell 2146 ($z=0.232$) is a massive galaxy cluster currently undergoing a spectacular merger in the plane of the sky with a bullet-like morphology. It was the first system in which both the bow and upstream shock fronts were detected at…

We report the discovery of a giant radio halo in the galaxy cluster RXC J1514.9-1523 at z=0.22 with a relatively low X-ray luminosity, $L_{X \, [0.1-2.4 \rm \, kev]} \sim 7 \times 10^{44}$ erg s$^{-1}$. This faint, diffuse radio source is…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Simona Giacintucci , Daniele Dallacasa , Tiziana Venturi , Gianfranco Brunetti , Rossella Cassano , Maxim Markevitch , Ramana M. Athreya

Radio observations discovered large scale non thermal sources in the central Mpc regions of dynamically disturbed galaxy clusters (radio halos). The morphological and spectral properties of these sources suggest that the emitting electrons…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-05 G. Brunetti , R. Cassano
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