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Related papers: The large-scale diffuse radio emission in A781

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Aims. We present the first results of an ongoing project devoted to the search of giant radio halos in galaxy clusters located in the redshift range z=0.2--0.4. One of the main goals of our study is to measure the fraction of massive galaxy…

Astrophysics · Physics 2009-11-11 T. Venturi , S. Giacintucci , G. Brunetti , R. Cassano , S. Bardelli , D. Dallacasa , G. Setti

We present newly discovered radio emission in the galaxy cluster Abell 2443 which is (1) diffuse, (2) extremely steep spectrum, (3) offset from the cluster center, (4) of irregular morphology and (5) not clearly associated with any of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Aaron Cohen , Tracy E Clarke

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

Large-scale diffuse radio emission is observed in some clusters of galaxies. There is ample of evidence that the emission has its origin in synchrotron losses of relativistic electrons, accelerated in the course of clusters mergers. In a…

Astrophysics · Physics 2009-11-13 M. Hoeft , M. Brueggen , G. Yepes , S. Gottloeber , A. Schwope

We aim to unveil their 3-dimensional geometry of Abell 2255 through WSRT observations at 18, 21, 25, 85, and 200 cm. The polarization images of the cluster were processed through rotation measure (RM) synthesis, producing three final RM…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 R. F. Pizzo , A. G. de Bruyn , G. Bernardi , M. A. Brentjens

We report the discovery of a giant radio halo in a new, hot, X-ray luminous galaxy cluster recently found by Planck, PLCKG171.9-40.7. The radio halo was found using Giant Metrewave Radio Telescope observations at 235 MHz and 610 MHz, and in…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Simona Giacintucci , Ruta Kale , Daniel R. Wik , Tiziana Venturi , Maxim Markevitch

In a recent paper we reported on the discovery of a radio halo with very steep spectrum in the merging galaxy cluster Abell 521 through observations with the Giant Metrewave Radio Telescope (GMRT). We showed that the steep spectrum of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 D. Dallacasa , G. Brunetti , S. Giacintucci , R. Cassano , T. Venturi , G. Macario , N. E. Kassim , W. Lane , G. Setti

We present a multi-wavelength analysis of the merging rich cluster of galaxies Abell 2256. We have observed A2256 at 150 MHz using the Giant Metrewave Radio Telescope and successfully detected the diffuse radio halo and the relic emission…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Kale Ruta , K. S. Dwarakanath

We present the preliminary results of 235 MHz, 327 MHz and 610 MHz observations of the galaxy cluster A3562 in the core of the Shapley Concentration. The purpose of these observations, carried out with the Giant Metrewave Radio Telescope…

Astrophysics · Physics 2009-11-10 S. Giacintucci , T. Venturi , S. Bardelli , G. Brunetti , D. Dallacasa , P. Rao , E. Zucca

The ASKAP-EMU survey is a deep wide-field radio continuum survey designed to cover the entire southern sky and a significant fraction of the northern sky up to $+30^{\circ}$. Here, we report a discovery of a radio relic in the merging…

We will discuss the properties and origins of halos and relics including estimates of the cluster magnetic fields, and present results for a few recently discovered halos and relics. The electrons in the suprathermal high energy tail of the…

Astrophysics · Physics 2007-05-23 Haida Liang

Abell 2146 ($z=0.232$) is a massive galaxy cluster currently undergoing a spectacular merger in the plane of the sky with a bullet-like morphology. It was the first system in which both the bow and upstream shock fronts were detected at…

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

Radio relics are diffuse extended synchrotron sources that originate from shock fronts induced by galaxy cluster mergers. The actual particle acceleration mechanism at the shock fronts is still under debate. The galaxy cluster 1RXS…

High Energy Astrophysical Phenomena · Physics 2020-04-15 K. Rajpurohit , M. Hoeft , F. Vazza , L. Rudnick , R. J. van Weeren , D. Wittor , A. Drabent , M. Brienza , F. Loi , E. Bonnassieux , N. Locatelli , R. Kale , C. Dumba

We identify a source (J1507+3013) with an extended diffuse radio emission around an elliptical galaxy from the Very Large Array (VLA) Faint Images of Radio Sky at Twenty-cm (FIRST) survey. J1507+3013 possesses a morphology similar to the…

Astrophysics of Galaxies · Physics 2025-06-19 Shobha Kumari , Sabyasachi Pal

We present high-sensitivity radio continuum observations with the VLA and Ryle Telescope at 1.5, 4.9, 8.4 and 15.4 GHz of the dwarf irregular galaxy NGC 1569. The radio data show an extended, irregularly-shaped halo with filamentary…

Astrophysics · Physics 2009-11-10 U. Lisenfeld , T. Wilding , G. G. Pooley , P. Alexander

The central regions of galaxy clusters are permeated by magnetic fields and filled with relativistic electrons. When clusters merge, the magnetic fields are amplified and relativistic electrons are re-accelerated by turbulence in the intra…

We present the results of a 22 cm radio survey carried out with the A3558 complex, a chain formed by the merging ACO clusters A3556-A3558-A3562 and thetwo groups SC1327-312 and SC1323-313, located in the central region of the complex, a…

Astrophysics · Physics 2009-10-31 T. Venturi , S. Bardelli , R. Morganti , R. W. Hunstead

VLA deep radio images at 1.4 GHz in total intensity and polarization reveal a diffuse non-thermal source in the interacting clusters A3411 - A3412. Moreover a small-size low power radio halo at the center of the merging cluster A3411 is…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 G. Giovannini , V. Vacca , M. Girardi , L. Feretti , F. Govoni , M. Murgia

We present the results of observations performed with the Sardinia Radio Telescope (SRT) at 1.3-1.8 GHz of the galaxy cluster CL 0217+70 and a $3^\circ \times 3^\circ$ region around it. We combine the SRT data with archival Very Large Array…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-13 P. Marchegiani , V. Vacca , F. Govoni , M. Murgia , F. Loi , L. Feretti
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