English
Related papers

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

200 papers

We present radio observations of the galaxy cluster PLCK G004.5-19.5 ($z=0.52$) using the Giant Metrewave Radio Telescope at 150~MHz, 325~MHz, and 610~MHz. We find an unusual arrangement of diffuse radio emission in the center and periphery…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-01 J. G. Albert , C. Sifón , A. Stroe , F. Mernier , H. T. Intema , H. J. A. Röttgering , G. Brunetti

In a growing number of galaxy clusters diffuse extended radio sources have been found. These sources are not directly associated with individual cluster galaxies. The radio emission reveal the presence of cosmic rays and magnetic fields in…

High Energy Astrophysical Phenomena · Physics 2019-02-13 R. J. van Weeren , F. de Gasperin , H. Akamatsu , M. Brüggen , L. Feretti , H. Kang , A. Stroe , F. Zandanel

The goal of the present study is to extend our current knowledge of the diffuse radio source (halo and relic) populations to $z$ $>$ 0.3. Here we report GMRT and EVLA radio observations of six galaxy clusters taken from the MAssive Cluster…

Astrophysics of Galaxies · Physics 2016-11-23 Viral Parekh , K. S. Dwarakanath , Ruta Kale , Huib Intema

Deep Very Large Array radio observations are presented for the REFLEX clusters RXCJ0437.1+0043 and RXCJ1314.4-2515. They are at similar distance and show similar X-ray luminosity, but they are quite different in X-ray structure. Indeed…

Astrophysics · Physics 2009-11-11 L. Feretti , P. Schuecker , H. Boehringer , F. Govoni , G. Giovannini

With Australia Telescope Compact Array observations, we detect a highly elongated Mpc-scale diffuse radio source on the eastern periphery of the Bullet cluster 1E0657-55.8, which we argue has the positional, spectral and polarimetric…

High Energy Astrophysical Phenomena · Physics 2016-03-23 Timothy W. Shimwell , Maxim Markevitch , Shea Brown , Luigina Feretti , B. M. Gaensler , M. Johnston-Hollitt , Craig Lage , Raghav Srinivasan

We present the results of a deep (1.1 Ms) observation of the Coma cluster of galaxies in the 18-30 keV band with the IBIS/ISGRI imager on board the INTEGRAL satellite. We show that the source extension in the North-East to South-West (SW)…

Astrophysics · Physics 2007-10-25 D. Eckert , N. Produit , A. Neronov , T. J. -L. Courvoisier

Low-frequency radio observations of galaxy clusters are the key to detecting the diffuse extended emission associated with them. The presence and properties of such radio sources in galaxy clusters reveal the existence of magnetic fields on…

Astrophysics · Physics 2009-11-13 R. F. Pizzo , A. G. de Bruyn , L. Feretti , F. Govoni

Hierarchical models of structure formation predict that galaxy clusters grow via mergers of smaller clusters and galaxy groups, as well as through continuous accretion of gas. MACS J0717.5+3745 is an X-ray luminous and complex merging…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 R. J. van Weeren , H. J. A. Rottgering , M. Bruggen , A. Cohen

We performed GMRT low frequency observations of the radio halos, relics and new candidates belonging to the GMRT Radio Halo Cluster Sample first observed at 610 MHz. High sensitivity imaging was performed using the GMRT at 325 MHz and 240…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Tiziana Venturi , Simona Giacintucci , Daniele Dallacasa , Rossella Cassano , Gianfranco Brunetti , Giulia Macario , Ramana Athreya

Enhanced inverse Compton (IC) losses at high redshift steepen diffuse radio spectra in galaxy clusters, making low-frequency (~100 MHz) observations favorable. However, low-frequency studies often lack the resolution needed to locate…

We investigate theoretical models for the radio halo and hard X-ray (HXR) excess in the Coma galaxy cluster. Time-independent and time-dependent re-acceleration models for relativistic electrons have been carried out to study the formation…

Astrophysics · Physics 2009-11-10 Ping-Hung Kuo , Chorng-Yuan Hwang , Wing-Huen Ip

We report the discovery of a radio halo in the massive merging cluster MACSJ2243.3-0935, as well as a new radio relic candidate, using the Giant Meterwave Radio Telescope and the KAT-7 telescope. The radio halo is coincident with the…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-09 T. M. Cantwell , A. M. M. Scaife , N. Oozeer , Z. L. Wen , J. L. Han

Radio relics are diffuse, extended synchrotron sources that originate from shock fronts generated during cluster mergers. The massive merging galaxy cluster MACS J0717.5+3745 hosts one of the more complex relics known to date. We present…

We study diffuse radio emission in the galaxy cluster A1550, with the aim of constraining particle re-acceleration in the intra-cluster medium. We exploit observations at four different frequencies: 54, 144, 400 and 1400 MHz. To complement…

We present a deep, 8$\degr$ diameter, 0.4 GHz radio image using a first time combination of the NAIC Arecibo 305-m telescope in Puerto Rico, and the wide-angle interferometer at the Dominion Radio Astrophysical Observatory at Penticton,…

Astrophysics · Physics 2010-11-05 P. P. Kronberg , R. Kothes , C. J. Salter , P. Perillat

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

We have performed 323 MHz observations with the Giant Metrewave Radio Telescope of the most promising candidates selected from the MACS catalog. The aim of the work is to extend our knowledge of the radio halo and relic populations to…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 A. Bonafede , M Brueggen , R. van Weeren , F. Vazza , G. Giovannini , H. Ebeling , A. C. Edge , M. Hoeft , U. Klein

A fraction of galaxy clusters host diffuse radio sources whose origins are investigated through multi-wavelength studies of cluster samples. We investigate the presence of diffuse radio emission in a sample of seven galaxy clusters in the…

We report the first detection of an inverse Compton X-ray emission, spatially correlated with a very steep spectrum radio source (VSSRS), 0038-096, without any detected optical counterpart, in cluster Abell 85. The ROSAT PSPC data and its…

Astrophysics · Physics 2009-10-30 J. Bagchi , V. Pislar , G. B. Lima Neto

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…