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Related papers: A study of halo and relic radio emission in mergin…

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We present the results of a survey for low frequency radio emission from 17 known exoplanetary systems with the Murchison Widefield Array. This sample includes 13 systems that have not previously been targeted with radio observations. We…

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

Diffuse, non-thermal emission in galaxy clusters is increasingly being detected in low-frequency radio surveys and images. We present a new diffuse, steep-spectrum, non-thermal radio source within the cluster Abell 1127 found in survey data…

Astrophysics of Galaxies · Physics 2020-07-31 Stefan W. Duchesne , Melanie Johnston-Hollitt , Zhenghao Zhu , Randall B. Wayth , Jack L. B. Line

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

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

We present low-frequency spectral energy distributions of 60 known radio pulsars observed with the Murchison Widefield Array (MWA) telescope. We searched the GaLactic and Extragalactic All-sky MWA (GLEAM) survey images for 200-MHz continuum…

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

Radio halos are synchrotron diffuse sources at the centre of a fraction of galaxy clusters. The study of large samples of clusters with adequate radio and X-ray data is necessary to investigate the origin of radio halos and their connection…

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

Detecting diffuse radio emission, such as from halos, in galaxy clusters is crucial for understanding large-scale structure formation in the universe. Traditional methods, which rely on X-ray and Sunyaev-Zeldovich (SZ) cluster…

Astrophysics of Galaxies · Physics 2025-06-04 Ashutosh K. Mishra , Emma Tolley , Shreyam Parth Krishna , Jean-Paul Kneib

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

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

Radio halos are diffuse synchrotron sources observed in dynamically unrelaxed galaxy clusters. Current observations and models suggest that halos trace turbulent regions in the intra-cluster medium where mildly relativistic particles are…

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…

Recent X-ray and Sunyaev-Zel'dovich (SZ) observations have dramatically increased the number of known distant galaxy clusters. In some merging, low-redshift (z<0.4) clusters, centrally-located, diffuse, extended radio emission (called radio…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-27 R. J. van Weeren , H. T. Intema , D. V. Lal , A. Bonafede , C. Jones , W. R. Forman , H. J. A. Röttgering , M. Brüggen , A. Stroe , M. Hoeft , S. E. Nuza , F. de Gasperin

Studies have shown that mergers of massive galaxy clusters produce shocks and turbulence in the intra-cluster medium, the possible event that creates radio relics, as well as the radio halos. Here we present GMRT dual-band (235 and 610~MHz)…

High Energy Astrophysical Phenomena · Physics 2019-09-17 Surajit Paul , Sameer Salunkhe , Abhirup Datta , Huib T. Intema

New images of 7 radio halos and relics, obtained with the Very Large Array at 20 or 90 cm, are presented here. The existence of a cluster-wide radio halo in the clusters A 665 and CL 0016+16 is confirmed. Both these clusters share the…

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

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

Centrally located diffuse radio emission has been observed in both merging and non-merging galaxy clusters. Depending on their morphology and size, we distinguish between giant radio haloes, which occur predominantly in merging clusters,…

We present the first deep low frequency radio observations of the massive and highly disturbed galaxy cluster Abell 2744 using the upgraded Giant Metrewave Radio Telescope (uGMRT). The cluster is experiencing a very complex multiple merger…

A very important aspect of the radio emission from galaxy clusters is represented by the diffuse radio sources associated with the intracluster medium: radio halos and relics. These radio sources indicate the existence of large scale…

Astrophysics · Physics 2007-05-23 Luigina Feretti