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Related papers: Diffuse Radio Emission in Abell 754

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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 present a long BeppoSAX observation of Abell 754 that reports a nonthermal excess with respect to the thermal emission at energies greater than ~45 keV. A VLA radio observation at 1.4 GHz definitely confirms the existence of diffuse…

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

In this paper we present new high sensitivity 153 MHz Giant Meterwave Radio Telescope follow-up observations of the diffuse steep spectrum cluster radio sources in the galaxy clusters Abell 521, Abell 697, Abell 1682. Abell 521 hosts a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 G. Macario , T. Venturi , H. T. Intema , D. Dallacasa , G. Brunetti , R. Cassano , S. Giacintucci , C. Ferrari , C. H. Ishwara-Chandra , R. Athreya

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

We present new Chandra X-ray and Giant Meterwave Radio Telescope (GMRT) radio observations of the nearby merging galaxy cluster Abell 754. Our X-ray data confirm the presence of a shock front by obtaining the first direct measurement of a…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Giulia Macario , Maxim Markevitch , Simona Giacintucci , Gianfranco Brunetti , Tiziana Venturi , Stephen S. Murray

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

The knowledge of the origin and statistical properties of diffuse radio emission in galaxy clusters has appreciably improved thanks to the GMRT Radio Halo Survey, a project based on 610 MHz observations of clusters belonging to a…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-10 Simona Giacintucci

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

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

The galaxy cluster Abell 523 (A523) hosts an extended diffuse synchrotron source historically classified as a radio halo. Its radio power at 1.4 GHz makes it one of the most significant outliers in the scaling relations between observables…

We report a discovery of a 1.3 Mpc diffuse radio source with extremely steep spectrum fading radio structures in the vicinity of the Abell 449 cluster of galaxies. Its extended diffuse lobes are bright only at low radio frequencies and…

Astrophysics of Galaxies · Physics 2016-02-11 D. Hunik , M. Jamrozy

We detect and characterise extended, diffuse radio emission from galaxy clusters at 168 MHz within the Epoch of Reionization 0-hour field: a $45^\circ \times 45^\circ$ region of the southern sky centred on R.~A.${}= 0^\circ$,…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-31 S. W. Duchesne , M. Johnston-Hollitt , A. R. Offringa , G. W. Pratt , Q. Zheng , S. Dehghan

We present newly discovered radio emission in the galaxy cluster Abell 2443 which is (1) diffuse, (2) extremely steep spectrum, (3) offset from the cluster center, (4) of irregular morphology and (5) not clearly associated with any of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Aaron Cohen , Tracy E Clarke

Diffuse radio emission has been found in many galaxy clusters, predominantly in massive systems which are in the state of merging. The radio emission can usually be classified as relic or halo emission, which are believed to be related to…

We present a multi-wavelength analysis of the merging rich cluster of galaxies Abell 2256. We have observed A2256 at 150 MHz using the Giant Metrewave Radio Telescope and successfully detected the diffuse radio halo and the relic emission…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Kale Ruta , K. S. Dwarakanath

We report the discovery of a putative radio relic, 830 kpc in length and found toward the outskirts of galaxy cluster Abell 1697 ($z=0.181$), using the LOFAR Two Meter Sky Survey (LoTSS) at 144 MHz. With an X-ray-inferred mass of…

Astrophysics of Galaxies · Physics 2020-01-15 Surajit Paul , Sameer Salunkhe , Satish Sonkamble , Prateek Gupta , Tony Mroczkowski , Somak Raychaudhury

Abell 1351 is a massive merging cluster that hosts a giant radio halo and a bright radio edge blended in the halo. In this paper, we present the first ever spectral analysis of this cluster using GMRT 610 MHz and VLA 1.4 GHz archival data…

High Energy Astrophysical Phenomena · Physics 2022-08-17 Swarna Chatterjee , Majidul Rahaman , Abhirup Datta , Ramij Raja

Radio halos are megaparsec-scale diffuse, non-thermal radio sources located at the centers of galaxy clusters, tracing relativistic particles and magnetic fields in the intra-cluster medium. Their origin is generally attributed to cluster…

The relation between giant radio halos and mini-halos in galaxy clusters is not understood. The former are usually associated with merging clusters, the latter are found in relaxed systems. In the last years, the advent of low-frequency…

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