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Related papers: Diffuse radio emission in the complex merging gala…

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With Low-Frequency Array (LOFAR) observations, we have discovered a diverse assembly of steep spectrum emission that is apparently associated with the intra cluster medium (ICM) of the merging galaxy cluster Abell 2034. Such a rich variety…

We conduct an intensive study of the rich, X-ray luminous galaxy cluster A773 at z=0.22 containing a diffuse radio halo to determine its dynamical status. Our analysis is based on new spectroscopic data obtained at the TNG telescope for 107…

Astrophysics · Physics 2009-11-13 R. Barrena , W. Boschin , M. Girardi , M. Spolaor

Abell 1995 is a puzzling galaxy cluster hosting a powerful radio halo, but it has not yet been recognized as a obvious cluster merger, as usually expected for clusters with diffuse radio emission. We aim at an exhaustive analysis of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 W. Boschin , M. Girardi , R. Barrena

We have performed the the first census of Mpc-scale radio emission to include control fields and quantifiable upper limits for bright X-ray clusters in the range 0.03<z<0.3 . Through reprocessing radio images from the WENSS survey, we…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-15 Lawrence Rudnick , Jeffrey Lemmerman

The number of diffuse radio halos in clusters of galaxies has grown in recent years, making it possible to derive statistical properties of these sources and of the hosting clusters. We show that diffuse sources are associated with X-ray…

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

We present LOFAR $120-168$ MHz images of the merging galaxy cluster Abell 1240 that hosts double radio relics. In combination with the GMRT $595-629$ MHz and VLA $2-4$ GHz data, we characterised the spectral and polarimetric properties of…

Radio halos and radio relics are diffuse synchrotron sources that extend over Mpc-scales and are found in a number of merger galaxy clusters. They are believed to form as a consequence of the energy that is dissipated by turbulence and…

The hot plasma within merging galaxy clusters is predicted to be filled with shocks and turbulence that may convert part of their kinetic energy into relativistic electrons and magnetic fields generating synchrotron radiation. Analyzing Low…

We present the results of deep Chandra and XMM-Newton X-ray imaging and spatially-resolved spectroscopy of Abell 2256, a nearby (z=0.058) galaxy cluster experiencing multiple mergers and displaying a rich radio morphology dominated by a…

High Energy Astrophysical Phenomena · Physics 2020-06-10 J. P. Breuer , N. Werner , F. Mernier , T. Mroczkowski , A. Simionescu , T. E. Clarke , J. A. ZuHone , L. Di Mascolo

We present the first detailed analysis of the radio halo in the merging galaxy cluster Abell 2256 using the LOFAR, uGMRT, and VLA. These observations combined with archival X-ray data allowed us to study the halo emission with unprecedented…

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

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

We analyze the dynamical state of Abell 1914, a merging cluster hosting a radio halo, quite unusual for its structure. Our study considers spectroscopic data for 119 galaxies obtained with the Italian Telescopio Nazionale Galileo. We select…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 R. Barrena , M. Girardi , W. Boschin

Abell 2256 is a nearby (z~0.06), rich cluster of galaxies with fascinating observed properties across a range of wavelengths. Long believed to represent a cluster merger, recent X-ray and optical results have suggested that in addition to…

Astrophysics · Physics 2009-11-07 Neal Miller , Frazer Owen , John Hill

Diffuse radio sources, known as mini-halos and halos, are detected at the centres of galaxy clusters. These centralized diffuse sources are typically observed individually, with both appearing together only in rare cases. The origin of the…

High Energy Astrophysical Phenomena · Physics 2025-03-26 D. N. Hoang , M. Brüggen , A. Bonafede , P. M. Koch , G. Brunetti , E. Bulbul , G. Di Gennaro , A. Liu , C. J. Riseley , H. J. A. Röttgering , R. J. van Weeren

We present 74 MHz and 330 MHz VLA observations of Abell 754. Diffuse, halo-like emission is detected from the center of the cluster at both frequencies. At 330 MHz the resolution of 90'' distinguishes this extended emission from previously…

Astrophysics · Physics 2009-11-06 N. E. Kassim , T. E. Clarke , T. A. Enßlin , A. S. Cohen , D. M. Neumann

We aim to review the internal structure and dynamics of the Abell 1351 cluster, shown to host a radio halo with a quite irregular shape. Our analysis is based on radial velocity data for 135 galaxies obtained at the Telescopio Nazionale…

Astrophysics of Galaxies · Physics 2015-06-19 R. Barrena , M. Girardi , W. Boschin , S. De Grandi , M. Rossetti

Diffuse synchrotron radio emission from cosmic-ray electrons is observed at the center of a number of galaxy clusters. These sources can be classified either as giant radio halos, which occur in merging clusters, or as mini halos, which are…

We seek to explore the internal dynamics of the cluster Abell 1758N, which has been shown to host a radio halo and two relics, and is known to be a merging bimodal cluster. Our analysis is mainly based on new redshift data for 137 galaxies…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 W. Boschin , M. Girardi , R. Barrena , M. Nonino

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