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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

Galaxy clusters are assembled via merging of smaller structures, in a process that generates shocks and turbulence in the intra cluster medium and produces radio diffuse emission in the form of halos and relics. The cluster pair A399-A401…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-17 C. D. Nunhokee , G. Bernardi , S. Manti , F. Govoni , A. Bonafede , T. Venturi , D. Dallacasa , M. Murgia , E. Orrú , R. F. Pizzo , O. M. Smirnov , V. Vacca

Deep radio observations of the galaxy cluster Abell 781 have been carried out using the Giant Metrewave Radio Telescope at 325 MHz and have been compared to previous 610 MHz observations and to archival VLA 1.4 GHz data. The radio emission…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 T. Venturi , S. Giacintucci , D. Dallacasa , G. Brunetti , R. Cassano , G. Macario , R. Athreya

Abell 1351 is a massive merging cluster that hosts a giant radio halo and a bright radio edge blended in the halo. In this paper, we present the first ever spectral analysis of this cluster using GMRT 610 MHz and VLA 1.4 GHz archival data…

High Energy Astrophysical Phenomena · Physics 2022-08-17 Swarna Chatterjee , Majidul Rahaman , Abhirup Datta , Ramij Raja

We examine the possible acceleration mechanisms of the relativistic particles responsible for the extended radio emission in Abell 520. We used new LOFAR 145 MHz, archival GMRT 323 MHz and VLA 1.5 GHz data to study the morphological and…

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

Merging galaxy clusters often host spectacular diffuse radio synchrotron sources. These sources can be explained by a non-thermal pool of relativistic electrons accelerated by shocks and turbulence in the intracluster medium. The origin of…

A number of radio observations have revealed the presence of large synchrotron-emitting sources associated with the intra-cluster medium. There is strong observational evidence that the emitting particles have been (re-)accelerated by…

We present 74 MHz and 330 MHz VLA observations of Abell 754. Diffuse, halo-like emission is detected from the center of the cluster at both frequencies. At 330 MHz the resolution of 90'' distinguishes this extended emission from previously…

Astrophysics · Physics 2009-11-06 N. E. Kassim , T. E. Clarke , T. A. Enßlin , A. S. Cohen , D. M. Neumann

Mega-parsec scale radio sources in the form of halos and relics are often detected in dynamically disturbed galaxy clusters. Although they are associated with merger-induced turbulence and shocks, respectively, their formation is not fully…

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…

Diffuse radio emission has been found in many galaxy clusters, predominantly in massive systems which are in the state of merging. The radio emission can usually be classified as relic or halo emission, which are believed to be related to…

Galaxy clusters have been found to host a range of diffuse, non-thermal emission components, generally with steep, power law spectra. In this work we report on the detection and follow-up of radio halos, relics, remnant radio galaxies, and…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-20 S. W. Duchesne , M. Johnston-Hollitt , I. Bartalucci

We present LOFAR $120-168$ MHz images of the merging galaxy cluster Abell 1240 that hosts double radio relics. In combination with the GMRT $595-629$ MHz and VLA $2-4$ GHz data, we characterised the spectral and polarimetric properties of…

Abell 3266 is a massive and complex merging galaxy cluster that exhibits significant substructure. We present new, highly sensitive radio continuum observations of Abell 3266 performed with the Australian Square Kilometre Array Pathfinder…

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

Radio halos and radio relics are diffuse synchrotron sources that extend over Mpc-scales and are found in a number of merger galaxy clusters. They are believed to form as a consequence of the energy that is dissipated by turbulence and…

We report on the detection of diffuse radio emission in the X-ray luminous and massive galaxy cluster A1351 (z=0.322) using archival Very Large Array data at 1.4 GHz. Given its central location, morphology, and Mpc-scale extent, we classify…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 S. Giacintucci , T. Venturi , R. Cassano , D. Dallacasa , G. Brunetti

We detect and characterise extended, diffuse radio emission from galaxy clusters at 168 MHz within the Epoch of Reionization 0-hour field: a $45^\circ \times 45^\circ$ region of the southern sky centred on R.~A.${}= 0^\circ$,…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-31 S. W. Duchesne , M. Johnston-Hollitt , A. R. Offringa , G. W. Pratt , Q. Zheng , S. Dehghan
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