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Related papers: Diffuse Radio Emission in/around the Coma Cluster:…

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The Fermi-LAT collaboration recently published deep upper limits to the gamma-ray emission of the Coma cluster, a cluster that hosts the prototype of giant radio halos. In this paper we extend previous studies and use a formalism that…

High Energy Astrophysical Phenomena · Physics 2017-09-20 G. Brunetti , S. Zimmer , F. Zandanel

The upgraded Giant Metrewave Radio Telescope (GMRT) has been used to image the head-tail radio galaxy NGC 4869 in the Coma cluster with an angular resolution of 6.26 arcsec at 250-500 MHz and 2.18 arcsec at the 1050-1450 MHz bands. The…

Astrophysics of Galaxies · Physics 2020-09-16 Dharam V. Lal

We report upgraded Giant Metrewave Radio Telescope and Karl J. Jansky Very Large Array radio observations of a low-mass merging galaxy cluster PSZ2 G181.06+48.47. This exceptional galaxy cluster hosts two megaparsec-scale diffuse sources,…

We report on new VLA radio observations of the distant cluster RX J1347.5-1145, which is the most luminous in X-rays. We aim at investigating the possible presence of diffuse and extended radio emission in this very peculiar system which…

Radio halos and relics are diffuse radio sources found in galaxy clusters showing significant substructure at X-ray wavelengths. These sources provide important information about non-thermal processes taking place in the ICM. Until now only…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 R. J. van Weeren , M. Bruggen , H. J. A. Rottgering , M. Hoeft , S. E. Nuza , H. T. Intema

We report the discovery of a unique radio galaxy at z=0.137, which could possibly be the second spiral-host large radio galaxy and also the second triple-double episodic radio galaxy. The host galaxy shows signs of recent star formation in…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Ananda Hota , S. K. Sirothia , Youichi Ohyama , C. Konar , Suk Kim , Soo-Chang Rey , D. J. Saikia , J. H. Croston , Satoki Matsushita

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

Context: Hierarchal models of large scale structure (LSS) formation predict that galaxy clusters grow via gravitational infall and mergers of (smaller) mass concentrations, such as clusters and galaxy groups. Diffuse radio emission, in the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 R. J. van Weeren , H. J. A. Rottgering , J. Bagchi , S. Raychaudhury , H. T. Intema , F. Miniati , T. A. Ensslin , M. Markevitch , T. Erben

Some merging galaxy clusters host diffuse elongated radio sources, also called radio relics. It is proposed that these radio relics trace shock waves in the intracluster medium created during a cluster merger event. Within the shock waves…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 R. J. van Weeren , M. Hoeft , H. J. A. Rottgering , M. Bruggen , H. T. Intema , S. van Velzen

We combine all available information about the spectral shape and morphology of the radio halo of the Coma cluster with the gamma-ray upper limits obtained by the Fermi-LAT and with the magnetic field strength derived from Faraday rotation…

High Energy Astrophysical Phenomena · Physics 2015-06-05 G. Brunetti , P. Blasi , O. Reimer , L. Rudnick , A. Bonafede , S. Brown

Galaxy-cluster merger shocks efficiently accelerate the ambient electrons through diffusive shock acceleration and amplify magnetic field by compressing the Inter Cluster Medium. As a result, such objects produce a significant amount of…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-29 S. Paul , A. Datta , H. T. Intema

We derive the best characterization to date of the properties of radio quiescent massive galaxy clusters through a statistical analysis of their average synchrotron emissivity. We stacked 105 radio images of clusters from the 843 MHz SUMSS…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Shea Brown , Andrew Emerick , Lawrence Rudnick , Gianfranco Brunetti

A dozen of patches of polarized radio emission spanning tens of degrees in the form of coherent and stationary loops are observed at radio frequencies across the sky. Their origin is usually associated to nearby shocks, possibly arising…

Giant cluster radio relics are thought to form at shock fronts in the course of collisions between galaxy clusters. Via processes that are still poorly understood, these shocks accelerate or re-accelerate cosmic-ray electrons and might…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 A. Stroe , R. J. van Weeren , H. T. Intema , H. J. A. Röttgering , M. Brüggen , M. Hoeft

We investigate the possible presence of diffuse radio emission in the intermediate redshift, massive cluster PLCK G285.0-23.7 (z=0.39, M_500 = 8.39 x 10^(14) M_Sun). Our 16cm-band ATCA observations of PLCK G285.0-23.7 allow us to reach a…

Radio relics at the peripheries of galaxy clusters are tracers of the elusive cluster merger shocks. We report the discovery of a single radio relic in the galaxy cluster PLCK G200.9-28.2 ($z=0.22$, $M_{500} = 2.7\pm0.2 \times 10^{14}…

Radio relics are Mpc-scale diffuse radio sources at the peripheries of galaxy clusters which are thought to trace outgoing merger shocks. We present XMM-Newton and Suzaku observations of the galaxy cluster Abell 2744 (z=0.306), which reveal…

High Energy Astrophysical Phenomena · Physics 2016-07-15 Dominique Eckert , Mathilde Jauzac , Franco Vazza , Matt Owers , Jean-Paul Kneib , Celine Tchernin , Huib Intema , Kenda Knowles

The Coma cluster of galaxies hosts the brightest radio halo known and has therefore been the target of numerous searches for associated inverse Compton (IC) emission, particularly at hard X-ray energies where the IC signal must eventually…

Diffuse radio sources known as radio relics are direct tracers of shocks in the outskirts of merging galaxy clusters. PSZ2 G200.95-28.16, a low-mass merging cluster($\textrm{M}_{500} = (2.7 \pm 0.2) \times 10^{14}~\mathrm{M}_{\odot}$)…

Astrophysics of Galaxies · Physics 2024-11-26 Arpan Pal , Ruta Kale , Qian H. S. Wang , Daniel R. Wik

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