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Related papers: Imaging results from the legacy GMRT Galaxy Cluste…

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In this Letter, we report the discovery of a radio halo in the high-redshift galaxy cluster PSZ2 G099.86+58.45 ($z=0.616$) with the LOw Frequency ARray (LOFAR) at 120-168 MHz. This is one of the most distant radio halos discovered so far.…

In the current paradigm, high redshift radio halos are expected to be scarce due to inverse Compton energy losses and redshift dimming, which cause them to be intrinsically faint. This low occurrence fraction is predicted by cosmic ray…

High Energy Astrophysical Phenomena · Physics 2025-06-11 S. P. Sikhosana , M. Hilton , G. Bernardi , K. Kesebonye , D. Y. Klutse , K. Knowles , K. Moodley , T. Mroczkowski , B. Partridge , C. Sifón , C. Vargas , E. Wollack

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

We present the results of a search for diffuse radio emission in a uniformly selected sample of 30 of the most massive Sunyaev-Zel'dovich selected galaxy clusters at $z > 1$, providing the first statistical constraints on the evolution of…

Non-thermal properties of galaxy clusters have been studied with detailed and deep radio images in comparison with X-ray data. While much progress has been made, most of the studied clusters are at a relatively low redshift (z < 0.3). We…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-26 G. Giovannini , M. Cau , A. Bonafede , H. Ebeling , L. Feretti , M. Girardi , M. Gitti , F. Govoni , A. Ignesti , M. Murgia , G. B. Taylor , V. Vacca

We examine the clustering properties of low-power radio galaxies at redshift 0.4<z<0.8, using data from the 2SLAQ Luminous Red Galaxy (LRG) survey. We find that radio-detected LRGs (with optical luminosities of 3-5L* and 1.4GHz radio powers…

Astrophysics · Physics 2009-11-13 David A. Wake , Scott M. Croom , Elaine M. Sadler , Helen M. Johnston

The Intra-Cluster Medium is characterized by thermal emission, and by the presence of large scale magnetic fields. In some clusters of galaxies a diffuse non-thermal emission is also present, located at the cluster center and named radio…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 G. Giovannini , A. Bonafede , L. Feretti , F. Govoni , M. Murgia , F. Ferrari , G. Monti

Many galaxy clusters host Mpc scale diffuse radio sources called radio halos. Their origin is connected to the processes that lead to the formation of clusters themselves. In order to unveil this connection, statistical studies of radio…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-10 V. Cuciti , R. Cassano , G. Brunetti , D. Dallacasa , F. de Gasperin , S. Ettori , S. Giacintucci , R. Kale , G. W. Pratt , R. J. van Weeren , T. Venturi

Radio halos are synchrotron radio sources detected in some massive galaxy clusters. Their Mpc-size indicates that (re)acceleration processes are taking place in the host cluster. X-ray catalogues of galaxy clusters have been used in the…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-28 A. Bonafede , H. T. Intema , M. Brüggen , F. Vazza , K. Basu , M. Sommer , H. Ebeling , F. de Gasperin , H. J. A. Röttgering , R. J. van Weeren , R. Cassano

We have studied radio haloes and relics in nine merging galaxy clusters using the Murchison Widefield Array (MWA). The images used for this study were obtained from the GaLactic and Extragalactic All-sky MWA (GLEAM) Survey which was carried…

Many galaxy clusters host Megaparsec-scale radio halos, generated by ultrarelativistic electrons in the magnetized intracluster medium. Correlations between the power of radio halos and the thermal properties of the hosting clusters were…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 R. Cassano , S. Ettori , G. Brunetti , S. Giacintucci , G. W. Pratt , T. Venturi , R. Kale , K. Dolag , M. Markevitch

Low-mass ($M_{\rm{500}}<5\times10^{14}{\rm{M_\odot}}$) galaxy clusters have been largely unexplored in radio observations, due to the inadequate sensitivity of existing telescopes. However, the upgraded GMRT (uGMRT) and the Low Frequency…

Almost two decades of observations of radio emission in galaxy clusters have proven the existence of relativistic particles and magnetic fields that generate extended synchrotron emission in the form of radio halos. In the current scenario,…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-28 G. Bernardi , T. Venturi , R. Cassano , G. Brunetti , D. Dallacasa , B. Fanaroff , B. Hugo , S. Makhatini , N. Oozeer , O. M. Smirnov , J. T. L. Zwart

Clusters of galaxies are sites of acceleration of charged particles and sources of non-thermal radiation. We report on new constraints on the population of cosmic rays in the Intra Cluster Medium (ICM) obtained via radio observations of a…

Astrophysics · Physics 2009-11-13 G. Brunetti , T. Venturi , D. Dallacasa , R. Cassano , K. Dolag , S. Giacintucci , G. Setti

We present the first multi-frequency analysis of the candidate ultra-steep spectrum radio halo in the galaxy cluster PLCKESZ G171.94$-$40.65, using the upgraded Giant Metrewave Radio telescope (uGMRT; 400 MHz), and Karl G. Jansky Very Large…

We report the discovery of extended radio emission in the Phoenix cluster (SPT-CL J2344-4243, z=0.596) with the GMRT at 610 MHz. The diffuse emission extends over a region of at least 400-500 kpc and surrounds the central radio source of…

Some galaxy clusters show diffuse radio emission in the form of giant halos (GHs) on Mpc scales or minihalos (MHs) on smaller scales. Comparing VLA and XMM radial profiles of several such clusters, we find a universal linear correlation…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Uri Keshet , Abraham Loeb

The frequently observed association between giant radio halos and merging galaxy clusters has driven present theoretical models of non-thermal emission from galaxy clusters, which are based on the idea that the energy dissipated during…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-09 R. Cassano , S. Ettori , S. Giacintucci , G. Brunetti , M. Markevitch , T. Venturi , M. Gitti

Diffuse radio emission from galaxy clusters in the form of radio halos and relics are tracers of the shocks and turbulence in the intra-cluster medium. The imprints of the physical processes that govern their origin and evolution can be…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-08 Ruta Kale

Giant radio halos (RH) are diffuse Mpc-scale synchrotron sources detected in a fraction of massive and merging galaxy clusters. An unbiased study of the statistical properties of RHs is crucial to constrain their origin and evolution. We…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-12 V. Cuciti , R. Cassano , G. Brunetti , D. Dallacasa , R. Kale , S. Ettori , T. Venturi