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相关论文: A giant radio halo in the cool core cluster CL1821…

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Abell 2146 ($z=0.232$) is a massive galaxy cluster currently undergoing a spectacular merger in the plane of the sky with a bullet-like morphology. It was the first system in which both the bow and upstream shock fronts were detected at…

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…

高能天体物理现象 · 物理学 2022-08-17 Swarna Chatterjee , Majidul Rahaman , Abhirup Datta , Ramij Raja

A521 is an interacting galaxy cluster located at z=0.247, hosting a low frequency radio halo connected to an eastern radio relic. Previous Chandra observations hinted at the presence of an X-ray brightness edge at the position of the relic,…

宇宙学与河外天体物理 · 物理学 2013-02-05 H. Bourdin , P. Mazzotta , M. Markevitch , Giacintucci , G. Brunetti

We present a new radio-selected cluster of galaxies, 0217+70, using observations from the Very Large Array and archival optical and X-ray data. The new cluster is one of only seven known that has candidate double peripheral radio relics,…

宇宙学与河外天体物理 · 物理学 2015-05-20 Shea Brown , Jon Duesterhoeft , Lawrence Rudnick

We examine the possible acceleration mechanisms of the relativistic particles responsible for the extended radio emission in Abell 520. We used new LOFAR 145 MHz, archival GMRT 323 MHz and VLA 1.5 GHz data to study the morphological and…

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…

星系天体物理 · 物理学 2015-06-19 R. Barrena , M. Girardi , W. Boschin , S. De Grandi , M. Rossetti

We recently performed a study of a sample of relaxed, cooling core galaxy clusters with deep Very Large Array observations at 1.4 GHz. We find that in the central regions of A1835, A2029, and Ophiuchus the dominant radio galaxy is…

宇宙学与河外天体物理 · 物理学 2015-05-13 M. Murgia , F. Govoni , M. Markevitch , L. Feretti , G. Giovannini , G. B. Taylor , E. Carretti

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…

Non-thermal radio emission from cosmic ray electrons in the vicinity of merging galaxy clusters is an important tracer of cluster merger activity, and is the result of complex physical processes that involve magnetic fields, particle…

宇宙学与河外天体物理 · 物理学 2015-06-12 Samuel W. Skillman , Hao Xu , Eric J. Hallman , Brian W. O'Shea , Jack O. Burns , Hui Li , David C. Collins , Michael L. Norman

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…

宇宙学与河外天体物理 · 物理学 2015-05-13 D. Dallacasa , G. Brunetti , S. Giacintucci , R. Cassano , T. Venturi , G. Macario , N. E. Kassim , W. Lane , G. Setti

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…

宇宙学与河外天体物理 · 物理学 2015-06-17 Damon Farnsworth , Lawrence Rudnick , Shea Brown , Gianfranco Brunetti

Giant radio halos are the most relevant examples of diffuse synchrotron emission from galaxy clusters. A number of these sources have very steep spectrum, with spectral index $\alpha \geq 1.5-1.6$ ($F(\nu) \propto \nu^{-\alpha}$), and are…

高能天体物理现象 · 物理学 2015-05-14 G. Brunetti

We investigate the occurrence of radio minihalos --- diffuse radio sources of unknown origin observed in the cores of some galaxy clusters --- in a statistical sample of 58 clusters drawn from the Planck Sunyaev-Zel'dovich cluster catalog…

高能天体物理现象 · 物理学 2017-05-31 Simona Giacintucci , Maxim Markevitch , Rossella Cassano , Tiziana Venturi , Tracy E. Clarke , Gianfranco Brunetti

Cluster-central gigahertz peak and compact steep spectrum (CSS) sources offer an opportunity to study the earliest phases of AGN feedback, but few have yet been examined in detail. We present results from radio and X-ray observations of…

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…

In the current paradigm, high redshift radio halos are expected to be scarce due to inverse Compton energy losses and redshift dimming, which cause them to be intrinsically faint. This low occurrence fraction is predicted by cosmic ray…

Merging galaxy clusters leave long-lasting signatures on the baryonic and non-baryonic cluster constituents, including shock fronts, cold fronts, X-ray substructure, radio halos, and offsets between the dark matter and the gas components.…

Diffuse, low surface-brightness radio emission in merging galaxy clusters provides insights into cosmic structure formation, the growth of magnetic fields, and turbulence. This paper reports a search for diffuse radio emission in a pilot…

In this paper we present a detailed study of the giant radio halo in the galaxy cluster Abell 697, with the aim to constrain its origin and connection with the cluster dynamics. We performed high sensitivity GMRT observations at 325 MHz,…

We have investigated evolution of non-thermal emission from relativistic electrons accelerated at around the shock fronts during merger of clusters of galaxies. We estimate synchrotron radio emission and inverse Compton scattering of cosmic…

天体物理学 · 物理学 2009-10-31 Motokazu Takizawa , Tsuguya Naito