English
Related papers

Related papers: A MeerKAT view on galaxy clusters

200 papers

Non thermal emission from galaxy clusters demonstrates the existence of relativistic particles and magnetic fields in the Intra Cluster Medium (ICM). Present instruments do not allow to firmly establish the energy associated to these…

Astrophysics · Physics 2011-07-19 G. Brunetti , R. Cassano , G. Setti

We combine all available information about the spectral shape and morphology of the radio halo of the Coma cluster with the gamma-ray upper limits obtained by the Fermi-LAT and with the magnetic field strength derived from Faraday rotation…

High Energy Astrophysical Phenomena · Physics 2015-06-05 G. Brunetti , P. Blasi , O. Reimer , L. Rudnick , A. Bonafede , S. Brown

In this letter we present a morphological comparison between giant radio halos and radio mini-halos in galaxy clusters based on radio--X-ray luminosity, P_{1.4}-L_X, and radio luminosity-size, P_{1.4}-R_H, correlations. We report evidence…

Astrophysics · Physics 2009-11-13 R. Cassano , M. Gitti , G. Brunetti

Aims. To study at multiple frequencies the radio emission arising from the massive galaxy cluster MACS J0717.5+3745 (z=0.55). Known to be an extremely complex cluster merger, the system is uniquely suited for an investigation of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 A. Bonafede , L. Feretti , G. Giovannini , F. Govoni , M. Murgia , G. B. Taylor , H. Ebeling , S. Allen , G. Gentile , Y. Pihlstrom

Observations with modern radio interferometers are uncovering the intricate morphology of synchrotron sources in galaxy clusters, both those arising from the intracluster medium (ICM) and those associated with member galaxies. Moreover, in…

Astrophysics of Galaxies · Physics 2025-04-24 Andrea Botteon , Marco Balboni , Iacopo Bartalucci , Fabio Gastaldello , Reinout J. van Weeren

We report the presence of high significance diffuse radio emission from the Triangulum Australis cluster using observations made with the KAT-7 telescope and propose that this emission is a giant radio halo. We compare the radio power from…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-24 Anna M. M. Scaife , Nadeem Oozeer , Francesco de Gasperin , Marcus Brueggen , Cyril Tasse , Lindsay Magnus

Radio halos and relics are diffuse radio sources found in galaxy clusters showing significant substructure at X-ray wavelengths. These sources provide important information about non-thermal processes taking place in the ICM. Until now only…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 R. J. van Weeren , M. Bruggen , H. J. A. Rottgering , M. Hoeft , S. E. Nuza , H. T. Intema

Radio observations discovered large scale non thermal sources in the central Mpc regions of dynamically disturbed galaxy clusters (radio halos). The morphological and spectral properties of these sources suggest that the emitting electrons…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 G. Brunetti , A. Lazarian

We investigate theoretical models for the radio halo and hard X-ray (HXR) excess in the Coma galaxy cluster. Time-independent and time-dependent re-acceleration models for relativistic electrons have been carried out to study the formation…

Astrophysics · Physics 2009-11-10 Ping-Hung Kuo , Chorng-Yuan Hwang , Wing-Huen Ip

We present simulated millimeter-wavelength maps and catalogs of radio galaxies across the full sky that trace the nonlinear clustering and evolution of dark matter halos from the Websky simulation at $z<4.6$ and $M_{\rm halo}>10^{12}…

Astrophysics of Galaxies · Physics 2022-08-24 Zack Li , Giuseppe Puglisi , Mathew S. Madhavacheril , Marcelo A. Alvarez

We introduce the IllustrisTNG project, a new suite of cosmological magnetohydrodynamical simulations performed with the moving-mesh code AREPO employing an updated Illustris galaxy formation model. Here we focus on the general properties of…

We present new, high frequency radio observations of the merging galaxy clusters PLCK G287.0+32.9, Abell 2744, and Bullet. These clusters are known to host $\sim$Mpc scale sources, known as radio halos, which are formed by the acceleration…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-20 K. Rajpurohit , A. Botteon , E. O'Sullivan , W. Forman , M. Balboni , L. Bruno , R. J. van Weeren , M. Hoeft , G. Brunetti , C. Jones , A. S. Rajpurohit , S. P. Sikhosana

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…

The generation of merger shocks is a natural outcome of the hierarchical process of structure formation. As time elapses cosmic structures grow in mass and size via mergers and through the continuous accretion of material onto the potential…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-04 Sebastián E. Nuza

Studies have shown that mergers of massive galaxy clusters produce shocks and turbulence in the intra-cluster medium, the possible event that creates radio relics, as well as the radio halos. Here we present GMRT dual-band (235 and 610~MHz)…

High Energy Astrophysical Phenomena · Physics 2019-09-17 Surajit Paul , Sameer Salunkhe , Abhirup Datta , Huib T. Intema

We report the discovery of a giant radio halo in the galaxy cluster RXC J1514.9-1523 at z=0.22 with a relatively low X-ray luminosity, $L_{X \, [0.1-2.4 \rm \, kev]} \sim 7 \times 10^{44}$ erg s$^{-1}$. This faint, diffuse radio source is…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Simona Giacintucci , Daniele Dallacasa , Tiziana Venturi , Gianfranco Brunetti , Rossella Cassano , Maxim Markevitch , Ramana M. Athreya

About 1/3 of X-ray-luminous clusters show smooth, unpolarized radio emission on ~Mpc scales, known as giant radio halos. One promising model for radio halos is Fermi-II acceleration of seed relativistic electrons by turbulence of the…

High Energy Astrophysical Phenomena · Physics 2015-03-30 Anders Pinzke , S. Peng Oh , Christoph Pfrommer

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

We present evidence for the existence of shock waves caused by the formation of the large-scale structure. In some clusters of galaxies peripherally located sources of extended diffuse radio emission exist, the so-called cluster radio…

Astrophysics · Physics 2011-05-23 Torsten A. Ensslin , Peter L. Biermann , Ulrich Klein , Sven Kohle

Centrally located diffuse radio emission has been observed in both merging and non-merging galaxy clusters. Depending on their morphology and size, we distinguish between giant radio haloes, which occur predominantly in merging clusters,…