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Related papers: The beautiful mess in Abell 2255

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With Low-Frequency Array (LOFAR) observations, we have discovered a diverse assembly of steep spectrum emission that is apparently associated with the intra cluster medium (ICM) of the merging galaxy cluster Abell 2034. Such a rich variety…

High sensitivity of modern interferometers is revealing a plethora of filaments surrounding radio galaxies, especially in galaxy cluster environments. The morphology and spectral characteristics of these thin structures require the…

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…

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

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…

Nonthermal emission observed in galaxy clusters provides a direct probe into the plasma physics of the intra-cluster medium (ICM) under extreme conditions. We report the first detailed analysis of the giant radio halo in the merging galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-01 Ramananda Santra , Ruta Kale , Simona Giacintucci , Herve Bourdin , Rashi Jain , Andrea Botteon , Gianfranco Brunetti

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…

A number of merging galaxy clusters show the presence of large-scale radio emission associated with the intra-cluster medium (ICM). These synchrotron sources are generally classified as radio haloes and radio relics. Whilst it is commonly…

New radio and X-ray data are reported for the rich cluster Abell 2255. The cluster radio emission is characterized by the presence of a diffuse halo source, located at the cluster center, and a more peripheral ridge of radio emission which…

Astrophysics · Physics 2007-05-23 L. Feretti , H. Boehringer , G. Giovannini , D. Neumann

Abell 2256 is a rich, nearby (z=0.0594) galaxy cluster that has significant evidence of merger activity. We present new radio and X-ray observations of this system. The low-frequency radio images trace the diffuse synchrotron emission of…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-01 Tracy E. Clarke , Torsten Enßlin , Alexis Finoguenov , Huib Intema , Christoph Pfrommer , Reinout van Weeren , Huub Röttgering , Raymond Oonk

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 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…

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…

Turbulence introduced into the intra-cluster medium (ICM) through cluster merger events transfers energy to non-thermal components, and can trigger the formation of diffuse synchrotron radio sources. Typical diffuse sources in the forms of…

Diffuse synchrotron emission in the form of radio halos and radio relics probe the existence of relativistic electrons and magnetic fields in galaxy clusters. These nonthermal components are generated from the dissipation of kinetic energy…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-24 Andrea Botteon

Some galaxy clusters contain non-thermal synchrotron emitting plasma permeating the intracluster medium (ICM). The spectral properties of this radio emission are not well characterized at decameter wavelengths ({\nu} < 30 MHz), primarily…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-10 C. Groeneveld , R. J. van Weeren , A. Botteon , R. Cassano , F. de Gasperin , E. Osinga , G. Brunetti , H. J. A. Röttgering

We aim to review the internal structure and dynamics of the Abell 1351 cluster, shown to host a radio halo with a quite irregular shape. Our analysis is based on radial velocity data for 135 galaxies obtained at the Telescopio Nazionale…

Astrophysics of Galaxies · Physics 2015-06-19 R. Barrena , M. Girardi , W. Boschin , S. De Grandi , M. Rossetti

Radio halos and relics are Mpc-scale diffuse radio sources in galaxy clusters, with a steep spectral index $\alpha>1$ ($S\propto \nu^{-\alpha}$). It has been proposed that they arise from particle acceleration induced by turbulence and weak…

Clusters of galaxies are turbulent environments, whether merging systems with a turbulent intracluster medium (ICM) or relaxed systems sloshing within the potential well. In many such clusters, diffuse radio sources associated with the ICM…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-29 C. J. Riseley , A. Bonafede , L. Bruno , A. Botteon , M. Rossetti , N. Biava , E. Bonnassieux , F. Loi , T. Vernstrom , M. Balboni

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
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