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We present results from an X-ray and radio study of the merging galaxy cluster Abell 115. We use the full set of 5 Chandra observations taken of A115 to date (360 ks total integration) to construct high-fidelity temperature and surface…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-06 Eric J. Hallman , Brian Alden , David Rapetti , Abhirup Datta , Jack O. Burns

Radio phoenices are complex and filamentary diffuse radio sources found in both merging and relaxed clusters. The formation of these sources was proposed to be due to adiabatic compression of old Active Galactic Nucleus (AGN) plasma in…

High Energy Astrophysical Phenomena · Physics 2024-08-30 Ramij Raja , Majidul Rahaman , Abhirup Datta , Oleg M. Smirnov

The largest galaxy clusters are observed still to be forming through major cluster-cluster mergers, often showing observational signatures such as radio relics and giant radio haloes. Using LOFAR Two-meter Sky Survey data, we present new…

We present new high sensitivity observations of the radio relic in A521 carried out with the Giant Metrewave Radio Telescope at 327 MHz and with the Very Large Array at 4.9 and 8.5 GHz. We imaged the relic at these frequencies and carried…

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

We present a Chandra X-ray observation and VLA radio observations of the nearby (z=0.11) galaxy cluster Abell 562 and the wide angle tail (WAT) radio source 0647+693. The cluster displays signatures of an ongoing merger leading to the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 E. M. Douglass , Elizabeth L. Blanton , T. E. Clarke , Scott W. Randall , Joshua D. Wing

A fraction of galaxy clusters host diffuse radio sources called radio halos, radio relics and mini-halos. We present the sample and first results from the Extended GMRT Radio Halo Survey (EGRHS)- an extension of the GMRT Radio Halo Survey…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 R. Kale , T. Venturi , S. Giacintucci , D. Dallacasa , R. Cassano , G. Brunetti , G. Macario , R. Athreya

Radio relics are diffuse, extended synchrotron sources that originate from shock fronts generated during cluster mergers. The massive merging galaxy cluster MACS J0717.5+3745 hosts one of the more complex relics known to date. We present…

Abell 754 is a rich galaxy cluster at $z=0.0543$ and is considered the prototype of a major cluster merger. Like many dynamically unrelaxed systems, it hosts diffuse radio emission on Mpc-scales. Extended synchrotron sources in the…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-16 A. Botteon , R. J. van Weeren , D. Eckert , F. Gastaldello , M. Markevitch , S. Giacintucci , G. Brunetti , R. Kale , T. Venturi

We report the discovery of large-scale diffuse radio emission in the galaxy cluster MACS J1752.0+4440 (z=0.366). Using Westerbork Synthesis Radio Telescope (WSRT) observations we find that the cluster hosts a double radio relic system as…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 R. J. van Weeren , A. Bonafede , H. Ebeling , A. C. Edge , M. Bruggen , G. Giovannini , M. Hoeft , H. J. A. Rottgering

An 8.3 hour observation of the Abell 2256 galaxy cluster using the Rossi X-ray Timing Explorer proportional counter array produced a high quality spectrum in the 2 - 30 keV range. Joint fitting with the 0.7 - 11 keV spectrum obtained with…

Astrophysics · Physics 2009-10-31 M. Henriksen

Radio halos are faint radio sources usually located at the center of merging clusters of galaxies. These diffuse radio sources are rare, having so far been found only in about 30 clusters of galaxies, suggesting that particular conditions…

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

We present a multi-frequency study of radio relics associated with the galaxy clusters A4038, A1664 and A786. Radio images, integrated spectra, spectral index maps and fits to the integrated spectra in the framework of the adiabatic…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Ruta Kale , K. S. Dwarakanath

Clusters of galaxies may contain cluster-wide, centrally located, diffuse radio sources, called halos. They have been found to show morphologies similar to those of the X-ray emission. To quantify this qualitative statement we performed a…

Astrophysics · Physics 2009-11-06 F. Govoni , T. A. Ensslin , L. Feretti , G. Giovannini

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 present spectroscopy of 880 galaxies within a 2-degree field around the massive, merging cluster Abell 3266. This sample, which includes 704 new measurements, was combined with the existing redshifts measurements to generate a sample of…

Astrophysics of Galaxies · Physics 2017-05-03 Siamak Dehghan , Melanie Johnston-Hollitt , Matthew Colless , Rowan Miller

We report on the detection of diffuse radio emission with peculiar morphology in the central region of the galaxy cluster Abell 2657. The most striking feature identified in our 144 MHz LOFAR image is a bifurcated radio arc that extends for…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-27 A. Botteon , F. Gastaldello , J. A. ZuHone , M. Balboni , I. Bartalucci , G. Brunetti , A. Bonafede , M. Brüggen , T. W. Shimwell , R. J. van Weeren

High sensitivity of modern interferometers is revealing a plethora of filaments surrounding radio galaxies, especially in galaxy cluster environments. The morphology and spectral characteristics of these thin structures require the…

The goal of this work is to constrain the strength and structure of the magnetic field in the nearby cluster of galaxies A2255. At radio wavelengths A2255 is characterized by the presence of a polarized radio halo at the cluster center, a…

Astrophysics · Physics 2009-11-11 F. Govoni , M. Murgia , L. Feretti , G. Giovannini , K. Dolag , G. B. Taylor

Diffuse radio sources known as radio relics are direct tracers of shocks in the outskirts of merging galaxy clusters. PSZ2 G200.95-28.16, a low-mass merging cluster($\textrm{M}_{500} = (2.7 \pm 0.2) \times 10^{14}~\mathrm{M}_{\odot}$)…

Astrophysics of Galaxies · Physics 2024-11-26 Arpan Pal , Ruta Kale , Qian H. S. Wang , Daniel R. Wik