相关论文: The large-scale diffuse radio emission in A781

In a growing number of galaxy clusters diffuse extended radio sources have been found. These sources are not directly associated with individual cluster galaxies. The radio emission reveal the presence of cosmic rays and magnetic fields in…

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…

The goal of the present study is to extend our current knowledge of the diffuse radio source (halo and relic) populations to $z$ $>$ 0.3. Here we report GMRT and EVLA radio observations of six galaxy clusters taken from the MAssive Cluster…

Diffuse synchrotron radio emission from cosmic-ray electrons is observed at the center of a number of galaxy clusters. These sources can be classified either as giant radio halos, which occur in merging clusters, or as mini halos, which are…

Spectral index studies of halos, relics, and radio galaxies provide useful information on their origin and connection with merger processes. We present WSRT multi-wavelength observations of the galaxy cluster Abell 2255 at 25 cm, 85 cm, and…

Large-scale magnetic fields reveal themselves through diffuse synchrotron sources observed in galaxy clusters such as radio halos. Total intensity filaments of these sources have been observed in polarization as well, but only in three…

Synchrotron radio emission is being detected from an increasing number of galaxy clusters. Spectral index images are a powerful tool to investigate the origin, nature, and connection of these sources with the dynamical state of the cluster.…

We present radio observations of the galaxy cluster PLCK G004.5-19.5 ($z=0.52$) using the Giant Metrewave Radio Telescope at 150~MHz, 325~MHz, and 610~MHz. We find an unusual arrangement of diffuse radio emission in the center and periphery…

Radio halos are synchrotron diffuse sources at the centre of a fraction of galaxy clusters. The study of large samples of clusters with adequate radio and X-ray data is necessary to investigate the origin of radio halos and their connection…

Radio halos and radio relics are diffuse synchrotron sources that extend over Mpc-scales and are found in a number of merger galaxy clusters. They are believed to form as a consequence of the energy that is dissipated by turbulence and…

We present deep 1.1-3.1 GHz Australia Telescope Compact Array observations of the radio halo of the bullet cluster, 1E 0657-55.8. In comparison to existing images of this radio halo the detection in our images is at higher significance. The…

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…

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 present new measurements of the diffuse radio emission from the Coma cluster of galaxies at 1.4 GHz using the Effelsberg 100-m-telescope. The halo source Coma C has an extent down to noise of about 80 arcmin corresponding to 3 Mpc (H_0 =…

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…

We report the discovery of a luminous, mini radio halo of ~240 kpc dimension at the center of a distant cluster of galaxies at redshift z = 0.131. Our optical and multi-wavelength GMRT and VLA observations reveal a highly unusual structure…

A fraction of galaxy clusters host diffuse radio sources whose origins are investigated through multi-wavelength studies of cluster samples. We investigate the presence of diffuse radio emission in a sample of seven galaxy clusters in the…

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…

We report the detection of a diffuse radio halo source in the hottest known cluster of galaxies 1E0658-56 (RXJ0658-5557). The radio halo has a morphology similar to the X-ray emission from the hot intracluster medium. The detection of such…

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…