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Related papers: Spectral Index Studies of the Diffuse Radio Emissi…

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The Westerbork Northern Sky Survey (WENSS) and the NRAO/VLA Sky Survey (NVSS) were used to determine an upper limit to the diffuse radio flux from the nearby cluster Abell 2199. For the entire cluster, this limit is <3.25 Jy at 327 MHz from…

Astrophysics · Physics 2009-10-31 Joshua C. Kempner , Craig L. Sarazin

Context. Abell 1213, a low-richness galaxy system, is known to host an anomalous radio halo detected in data of the VLA. It is an outlier with regard to the relation between the radio halo power and the X-ray luminosity of the parent…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-26 W. Boschin , M. Girardi , S. De Grandi , G. Riva , L. Feretti , G. Giovannini , F. Govoni , V. Vacca

We present a numerical model for the extended steep-spectrum radio sources and the elongated X-ray structure in A3667 based on new 3-dimensional MHD/N-body simulations. The X-ray and optical analyses of A3667 indicate that it has undergone…

Astrophysics · Physics 2009-10-31 K. Roettiger , J. O. Burns , J. M. Stone

In some clusters of galaxies, a diffuse non-thermal emission is present, not obviously associated with any individual galaxy. These sources have been identified as relics, mini-halos, and halos according to their properties and position…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 G. Giovannini , A. Bonafede , L. Feretti , F. Govoni , M. Murgia

Massive, merging galaxy clusters often host giant, diffuse radio sources that arise from shocks and turbulence; hence, radio observations can be useful for determining the merger state of a cluster. In preparation for a larger study, we…

Radio halos are extended and diffuse non-thermal radio sources present at the cluster center, not obviously associated with any individual galaxy. A strong correlation has been found between the cluster X-ray luminosity and the halo radio…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 G. Giovannini , L. Feretti , M. Girardi , F. Govoni , M. Murgia , V. Vacca , J. Bagchi

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

We explore the internal dynamics of Abell 2254, which has been shown to host a very clumpy and irregular radio halo. Our analysis is mainly based on redshift data for 128 galaxies acquired at the TNG. We also use new g',r',i' photometric…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 M. Girardi , S. Bardelli , R. Barrena , W. Boschin , F. Gastaldello , M. Nonino

We report new observations of Abell 2256 with the Karl G. Jansky Very Large Array (VLA) at frequencies between 1 and 8 GHz. These observations take advantage of the 2:1 bandwidths available for a single observation to study the spectral…

Astrophysics of Galaxies · Physics 2015-06-22 Frazer Owen , Lawrence Rudnick , Jean Eilek , Urvashi Rau , Sanjay Bhatnagar , Leonid Kogan

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

We present results based on new Chandra and multi-frequency radio observations of the disturbed cool core cluster Abell 133. The diffuse gas has a complex bird-like morphology, with a plume of emission extending from two symmetric wing-like…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 S. W. Randall , T. E. Clarke , P. E. J. Nulsen , M. S. Owers , C. L. Sarazin , W. R. Forman , S. S. Murray

New multi-wavelength (radio, optical & X-rays) observational evidences are presented which show that the nearby (z=0.046), rich cluster of galaxies Abell 3376 is experiencing a major event of binary subcluster merger. The key evidence is…

Astrophysics · Physics 2007-05-23 Joydeep Bagchi

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

Abell 1033 is a merging galaxy cluster of moderate mass ($M_{500}=3.2\times10^{14} \mathrm{M}_\odot$). It hosts a broad variety of diffuse radio sources linked to different astrophysical phenomena. The most peculiar one is an elongated…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-28 H. W. Edler , F. de Gasperin , G. Brunetti , A. Botteon , V. Cuciti , R. J. van Weeren , R. Cassano , T. W. Shimwell , M. Brüggen , A. Drabent

We present radio observations of the galaxy cluster Abell S1136 at 888 MHz, using the Australian Square Kilometre Array Pathfinder radio telescope, as part of the Evolutionary Map of the Universe Early Science program. We compare these…

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 Chandra observation of the merging cluster of galaxies Abell 2744. The cluster shows strong evidence for an ongoing major merger which we believe to be responsible for the radio halo. X-ray emission and temperature maps of the…

Astrophysics · Physics 2009-11-10 Joshua C. Kempner , Laurence P. David

We have detected a radio bridge of unpolarized synchrotron emission connecting the NW relic of the galaxy cluster Abell 3667 to its central regions. We used data at 2.3 GHz from the S-band Polarization All Sky Survey (S-PASS) and at 3.3 GHz…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 E. Carretti , S. Brown , L. Staveley-Smith , J. M. Malarecki , G. Bernardi , B. M. Gaensler , M. Haverkorn , M. J. Kesteven , S. Poppi

Double radio relics in galaxy clusters are rare phenomena that trace shocks in the outskirts of merging galaxy clusters. We have carried out a spectral and polarization study of the spectacular double relics in the galaxy cluster A3376…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Ruta Kale , K. S. Dwarakanath , Joydeep Bagchi , Surajit Paul

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…

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