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Related papers: Revived Fossil Plasma Sources in Galaxy Clusters

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Non-thermal radio emission from cosmic ray electrons in the vicinity of merging galaxy clusters is an important tracer of cluster merger activity, and is the result of complex physical processes that involve magnetic fields, particle…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Samuel W. Skillman , Hao Xu , Eric J. Hallman , Brian W. O'Shea , Jack O. Burns , Hui Li , David C. Collins , Michael L. Norman

Diffuse radio sources in galaxy clusters are unique signposts of cluster assembly in the Universe. Our knowledge of their observational properties has considerably improved over the past decade, and the long standing questions concerning…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-18 Tiziana Venturi , INAF , Istituto di Radioastronomia

Observations of galaxy clusters show radio emission extended over almost the system scale, necessitating mechanisms for particle acceleration. Previous models for acceleration such as diffusive shock acceleration and that due to turbulence…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-30 Subham Ghosh , Pallavi Bhat

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…

The study of diffuse radio sources is essential to our knowledge of the physical conditions in clusters of galaxies and of the role that large scale magnetic fields play in the propagation of the relativistic particles in the intracluster…

High Energy Astrophysical Phenomena · Physics 2013-09-30 Nonis , Stavros , Gizani , Nectaria A. B

Radio galaxies play an important role in the seeding of cosmic rays and magnetic fields in galaxy clusters. Here, we simulate the evolution of relativistic electrons injected into the intracluster medium by radio galaxies. Using passive…

High Energy Astrophysical Phenomena · Physics 2021-09-15 F. Vazza , D. Wittor , G. Brunetti , M. Brüggen

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…

Radio relics in galaxy clusters are extended synchrotron sources produced by cosmic-ray electrons in the $\mu$G magnetic field. Many relics are found in the cluster periphery and have a cluster-centric, narrow arc-like shape, which suggests…

High Energy Astrophysical Phenomena · Physics 2021-06-23 John A. ZuHone , Maxim Markevitch , Rainer Weinberger , Paul Nulsen , Kristian Ehlert

We present evidence for the existence of shock waves caused by the formation of the large-scale structure. In some clusters of galaxies peripherally located sources of extended diffuse radio emission exist, the so-called cluster radio…

Astrophysics · Physics 2011-05-23 Torsten A. Ensslin , Peter L. Biermann , Ulrich Klein , Sven Kohle

The main component of the intracluster medium (ICM) in clusters of galaxies is represented by the X-ray emitting thermal plasma. In addition, the presence of relativistic electrons and large-scale magnetic fields in a fraction of galaxy…

Astrophysics · Physics 2007-05-23 L. Feretti

Most of the Universe's populations of low energy cosmic ray electrons in the energy range of 1-100 MeV still manage to elude from detection by our instruments, since their synchrotron emission is at too low frequencies. We investigate a…

Astrophysics · Physics 2009-11-06 Torsten A. Ensslin , Rashid A. Sunyaev

Context. It is well-established that shock waves in the intracluster medium launched by galaxy cluster mergers can produce synchrotron emission, which is visible to us at radio frequencies as radio relics. However, the particle acceleration…

Extended steep-spectrum radio emission in a galaxy cluster is usually associated with a recent merger. However, given the complex scenario of galaxy cluster mergers, many of the discovered sources hardly fit into the strict boundaries of a…

Astrophysics of Galaxies · Physics 2015-06-23 F. de Gasperin , G. A. Ogrean , R. J. van Weeren , W. A. Dawson , M. Brüggen , A. Bonafede , A. Simionescu

According to structure formation simulations, weak shocks with typical Mach number, $M_{\rm s}\lesssim 3$, are expected to form in merging galaxy clusters. The presence of such shocks has been indicated by X-ray and radio observations of…

High Energy Astrophysical Phenomena · Physics 2017-07-26 Hyesung Kang , Dongsu Ryu , T. W. Jones

The acceleration of electrons at shock fronts is thought to be responsible for radio relics, extended radio features in the vicinity of merging galaxy clusters. By combining high resolution Adaptive Mesh Refinement Hydro/N-body cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Jack O. Burns , Samuel W. Skillman

Radio relics are Mpc-sized synchrotron sources located in the peripheral regions of galaxy clusters. Models based on the diffuse shock acceleration (DSA) scenario have been widely accepted to explain the formation of radio relics. However,…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-05 Yihao Zhou , Haiguang Xu , Zhenghao Zhu , Yuanyuan Zhao , Shida Fan , Chenxi Shan , Yongkai Zhu , Lei Hao , Li Ji , Zhongli Zhang , Xianzhong Zheng

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 investigate the possibility that patches of old radio plasma (`radio ghosts') of former radio galaxies form a second distinct phase of the inter-galactic medium (IGM), not mixed with the thermal gas. The separation of this phase from the…

Astrophysics · Physics 2007-05-23 Torsten A. Ensslin

Recent radio observations have identified a class of structures, so-called radio relics, in clusters of galaxies. The radio emission from these sources is interpreted as synchrotron radiation from GeV electrons gyrating in microG-level…

High Energy Astrophysical Phenomena · Physics 2015-06-05 Hyesung Kang , Dongsu Ryu , T. W. Jones

Radio relics are diffuse radio sources observed in galaxy clusters, probably produced by shock acceleration during cluster-cluster mergers. Their large size, of the order of 1 Mpc, indicates that the emitting electrons need to be…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 A. Bonafede , H. T. Intema , M. Brüggen , M. Girardi , M. Nonino , N. Kantharia , R. J. van Weeren , H. J. A. Röttgering