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Related papers: The Curious Case of Abell 2256

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Turbulence introduced into the intra-cluster medium (ICM) through cluster merger events transfers energy to non-thermal components, and can trigger the formation of diffuse synchrotron radio sources. Typical diffuse sources in the forms of…

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 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

Deep polarimetric Westerbork observations of the galaxy cluster Abell 2256 are presented, covering a frequency range of 325-377 MHz. The central halo source has a diameter of the order of 1.2 Mpc (18'), which is somewhat larger than at 1.4…

Astrophysics · Physics 2009-11-13 M. A. Brentjens

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

We present a multi-band study of the diffuse emission in the galaxy cluster Abell 3558, located in the core of the Shapley Supercluster. Using new MeerKAT UHF-Band and uGMRT Band-3 observations, and published MeerKAT L-band and ASKAP 887…

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

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

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 present results on 12 X-ray bright clusters observed at 1.4 GHz with the Green Bank Telescope. After subtraction of point sources, we reach a median (best) 1-sigma noise level of 0.01 (0.006) microJy/sq. arcsec, and find a significant…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Damon Farnsworth , Lawrence Rudnick , Shea Brown , Gianfranco Brunetti

Deep radio observations of the galaxy cluster Abell 781 have been carried out using the Giant Metrewave Radio Telescope at 325 MHz and have been compared to previous 610 MHz observations and to archival VLA 1.4 GHz data. The radio emission…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 T. Venturi , S. Giacintucci , D. Dallacasa , G. Brunetti , R. Cassano , G. Macario , R. Athreya

Here we analyze radio, optical, and X-ray data for a peculiar cluster Abell 578. This cluster is not fully relaxed and consists of two merging sub-systems. The brightest cluster galaxy, CGPG 0719.8+6704, is a pair of interacting ellipticals…

High Energy Astrophysical Phenomena · Physics 2015-06-03 K. Hagino , L. Stawarz , A. Siemiginowska , C. C. Cheung , D. Koziel-Wierzbowska , A. Szostek , G. Madejski , D. E. Harris , A. Simionescu , T. Takahashi

Deep (103 ks) \chandra\ observations of Abell 665 have revealed rich structures in this merging galaxy cluster, including a strong shock and two cold fronts. The newly discovered shock has a Mach number of $M$ = 3.0 $\pm$ 0.6, propagating…

Radio halos and relics are Mpc-scale diffuse radio sources in galaxy clusters, with a steep spectral index $\alpha>1$ ($S\propto \nu^{-\alpha}$). It has been proposed that they arise from particle acceleration induced by turbulence and weak…

Recent advances in high-sensitivity radio observations have uncovered a population of faint, ultra-steep-spectrum sources in galaxy clusters, commonly known as radio phoenixes. However, their observational classification remains poorly…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-28 Nasmi S Anand , Swarna Chatterjee , Ramij Raja , Majidul Rahaman , Abhirup Datta

Galaxy clusters with signs for a recent merger show in many cases extended diffuse radio features. This emission originates from relativistic electrons which suffer synchrotron losses due to the intra-cluster magnetic field. The mechanisms…

Astrophysics of Galaxies · Physics 2015-02-11 A. Drabent , M. Hoeft , R. F. Pizzo , A. Bonafede , R. J. van Weeren , U. Klein

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…

We report on the detection of diffuse radio emission in the X-ray luminous and massive galaxy cluster A1351 (z=0.322) using archival Very Large Array data at 1.4 GHz. Given its central location, morphology, and Mpc-scale extent, we classify…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 S. Giacintucci , T. Venturi , R. Cassano , D. Dallacasa , G. Brunetti

We aim to obtain new insights into the internal dynamics of the cluster Abell 1240, showing the presence of two roughly symmetric radio relics, separated by ~2 h_70^-1 Mpc. Our analysis is mainly based on redshift data for 145 galaxies and…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 R. Barrena , M. Girardi , W. Boschin , M. Dasi

Giant radio haloes are diffuse synchrotron sources typically found in merging galaxy clusters, while smaller mini-haloes occur in cool-core clusters. Both trace cosmic-ray electrons in the intracluster medium, though recent observations…