相关论文: Diffuse cluster-like radio emission in poor enviro…

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…

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…

We report the discovery and investigate the nature of J1248+4826, an ORC-like source identified in the LOFAR Survey. We analyze its radio morphology, size, luminosity, and spectral properties, and study its environment and optical…

Context: Hierarchal models of large scale structure (LSS) formation predict that galaxy clusters grow via gravitational infall and mergers of (smaller) mass concentrations, such as clusters and galaxy groups. Diffuse radio emission, in the…

Diffuse radio emission in galaxy clusters is a tracer of ultra-relativistic particles and $\mu$G-level magnetic fields, and is thought to be triggered by cluster merger events. In the distant Universe (i.e. $z>0.6$), such sources have been…

We study the dynamical status of the galaxy system ZwCl 2341.1+0000, a filamentary multi-Mpc galaxy structure associated with a complex diffuse radio emission. Our analysis is mainly based on new spectroscopic data for 128 galaxies acquired…

We report radio continuum observations with the Australia Telescope Compact Array of two molecular clouds. The impetus for these observations is a search for synchrotron radiation by cosmic ray secondary electrons/positrons in a region of…

We have performed the the first census of Mpc-scale radio emission to include control fields and quantifiable upper limits for bright X-ray clusters in the range 0.03<z<0.3 . Through reprocessing radio images from the WENSS survey, we…

(Abridged) We present new, intermediate resolution spectra (~4A) of the compact radio source PKS 1345+12. Our spectra clearly show extended line emission (~20kpc) consistent with the asymmetric halo of diffuse emission observed in optical…

Diffuse radio sources associated with the intra-cluster medium are direct probes of the cosmic ray electrons and magnetic fields. We report the discovery of a diffuse radio source in the galaxy cluster RXCJ0232.2-4420 (SPT-CL J0232-4421,…

Inhomogeneities can influence the polarisation emerging from a synchrotron source. However, it is shown that the frequency distribution of circular polarisation is only marginally affected, although its magnitude may change substantially.…

We present a multi-wavelength analysis of star-forming galaxies in the massive cluster MS0451.6-0305 at z $\sim$ 0.54 to shed new light on the evolution of the far-infrared-radio relationship in distant rich clusters. We have derived total…

We report on new VLA radio observations of the distant cluster RX J1347.5-1145, which is the most luminous in X-rays. We aim at investigating the possible presence of diffuse and extended radio emission in this very peculiar system which…

The low-frequency radio sky is dominated by the diffuse synchrotron emission of our Galaxy and extragalactic radio sources related to Active Galactic Nuclei and star-forming galaxies. This foreground emission is much brighter than the…

We present Chandra observations of the X-ray environment of a sample of 6 BL Lacertae objects. The improved sensitivity of the ACIS experiment allows us to separate the core X-ray emission from the contribution of diffuse emission from the…

Investigations of the cluster environment of radio sources have not shown a correlation between radio power and degree of clustering. However, it has been demonstrated that extended X-ray luminosity and galaxy clustering do exhibit a…

By combining the REFLEX and NORAS cluster datasets with the NVSS radio catalogue, we obtain a sample of 145, z<0.3, X-ray selected clusters brighter than 3 10^(-12) erg/s/cm^2 that show a central radio emission above 3 mJy. For virial…

We report the discovery of large-scale diffuse radio emission from what appears to be a large-scale filamentary network of galaxies in the region of cluster ZwCl 2341.1+0000, and stretching over an area of at least $6 h^{-1}_{50}$ Mpc in…

A dozen of patches of polarized radio emission spanning tens of degrees in the form of coherent and stationary loops are observed at radio frequencies across the sky. Their origin is usually associated to nearby shocks, possibly arising…

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 =…