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Related papers: The Coma Cluster at gamma-ray energies: multifrequ…

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Relativistic electrons, seen in the large diffuse radio halo of the Coma cluster of galaxies, should scatter background photons to higher energies. We calculate the inverse Compton contributions from the microwave background, from the local…

Astrophysics · Physics 2011-05-23 Torsten A. Ensslin , Peter L. Biermann

We calculate the flux of radio, hard X-ray and UV radiation from clusters of galaxies as produced by synchrotron emission and Inverse Compton Scattering of electrons generated as secondaries in cosmic ray interactions in the intracluster…

Astrophysics · Physics 2011-08-09 P. Blasi , S. Colafrancesco

Observations of diffuse, non-thermal radio emission spanning several megaparsecs have been documented in over 100 galaxy clusters. This emission, classified as giant radio halos (GHs), mini halos, and radio relics based mainly on their…

High Energy Astrophysical Phenomena · Physics 2024-04-23 Doron Kushnir , Uri Keshet , Eli Waxman

We use the results from a constrained, cosmological MHD simulation of the Local Universe to predict the radio halo and the gamma-ray flux from the Coma cluster and compare it to current observations. The simulated magnetic field within the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 J. Donnert , K. Dolag , G. Brunetti , R. Cassano , A. Bonafede

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

Many galaxy clusters have giant halos of non-thermal radio emission, indicating the presence of relativistic electrons in the clusters. Relativistic protons may also be accelerated by merger and/or accretion shocks in galaxy clusters. These…

High Energy Astrophysical Phenomena · Physics 2018-09-19 Shao-Qiang Xi , Xiang-Yu Wang , Yun-Feng Liang , Fang-Kun Peng , Rui-Zhi Yang , Ruo-Yu Liu

Observations of radio halos and relics in galaxy clusters indicate efficient electron acceleration. Protons should likewise be accelerated, suggesting that clusters may also be sources of very high-energy (VHE; E>100 GeV) gamma-ray…

We present results of X-ray observations of the Coma cluster with multiple instruments over a broad energy band. Using the data from INTEGRAL, RXTE and ROSAT observatories, we find that the Coma spectrum in the 0.5-107 keV energy band can…

Astrophysics · Physics 2009-11-13 A. A. Lutovinov , A. Vikhlinin , E. M. Churazov , M. G. Revnivtsev , R. A. Sunyaev

We study the origin of the non-thermal emission from the intracluster medium, including the excess hard X-ray emission and cluster-wide radio haloes, through fitting two representative models to the Coma cluster. If the synchrotron emitting…

Astrophysics · Physics 2009-11-07 H. Liang , V. Dogiel , M. Birkinshaw

The RXTE satellite observed the Coma cluster for 177 ksec during November and December 2000, a second observation motivated by the intriguing results from the first 87 ksec observation in 1996. Analysis of the new dataset confirms that…

Astrophysics · Physics 2009-11-07 Yoel Rephaeli , Duane Gruber

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

The brightest cluster radio halo known resides in the Coma cluster of galaxies. The relativistic electrons producing this diffuse synchrotron emission should also produce inverse Compton emission that becomes competitive with thermal…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 Daniel R. Wik , Craig L. Sarazin , Alexis Finoguenov , Kyoko Matsushita , Kazuhiro Nakazawa , Tracy E. Clarke

We present results from {\gamma}-ray observations of the Coma cluster incorporating 6 years of Fermi-LAT data and the newly released {\emph{Pass 8}} event-level analysis. Our analysis of the region reveals low-significance residual…

High Energy Astrophysical Phenomena · Physics 2016-03-10 LAT Collaboration , Y. Rephaeli

We calculate the fluxes of radio, hard X-rays and gamma-ray emission from clusters of galaxies, in the context of a secondary electron model (SEM). In the SEM the radiating electrons are produced by the decay of charged pions in cosmic ray…

Astrophysics · Physics 2007-05-23 P. Blasi , S. Colafrancesco

The inverse Compton (IC) interpretation of the excess EUV emission, that was recently reported from several clusters of galaxies, suggests that the amount of relativistic electrons in the intracluster medium is highly significant,…

Astrophysics · Physics 2009-10-31 A. M. Atoyan , H. J. Voelk

Several deep PSPC observations of the Coma cluster reveal a very large-scale halo of soft X-ray emission, substantially in excess of the well known radiation from the hot intra-cluster medium. The excess emission, previously reported in the…

Astrophysics · Physics 2009-11-07 M. Bonamente , M. K. Joy , R. Lieu

The radio spectral index map of the Coma halo shows a progressive steepening of the spectral index with increasing radius. Such a steepening cannot be simply justified by models involving continuous injection of fresh particles in the Coma…

Astrophysics · Physics 2009-10-31 G. Brunetti , G. Setti , L. Feretti , G. Giovannini

We have used the upgraded Giant Metrewave Radio Telescope to map the Coma cluster of galaxies at 250-500 MHz and 1050-1450 MHz bands. These 6.26 arcsec and 2.18 arcsec resolutions observations allow detailed radio structures to be…

Astrophysics of Galaxies · Physics 2021-06-01 Dharam V. Lal

The radio spectral index map of the Coma halo shows a progressive steepening of the spectral index with increasing radius. Such a steepening cannot be simply justified by models involving continuous injection of fresh particles in the Coma…

Astrophysics · Physics 2007-05-23 G. Brunetti , L. Feretti , G. Giovannini , G. Setti

We examine whether nonthermal protons energized during a cluster merger are simultaneously responsible for the Coma cluster's diffuse radio flux (via secondary decay) and the departure of its intra-cluster medium (ICM) from a thermal…

Astrophysics · Physics 2018-09-26 Brandon Wolfe , Fulvio Melia
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