Related papers: Discovering the most elusive radio relic in the sk…
Galaxy clusters are the most massive gravitationally bound structures in the Universe. They grow by accreting smaller structures in a merging process that produces shocks and turbulence in the intra-cluster gas. We observed a ridge of radio…
Extended steep-spectrum radio emission in a galaxy cluster is usually associated with a recent merger. However, given the complex scenario of galaxy cluster mergers, many of the discovered sources hardly fit into the strict boundaries of a…
Abell 2256 is a nearby (z~0.06), rich cluster of galaxies with fascinating observed properties across a range of wavelengths. Long believed to represent a cluster merger, recent X-ray and optical results have suggested that in addition to…
Previous studies have shown that CIZA J2242.8+5301 (the 'Sausage' cluster, $z=0.192$) is a massive merging galaxy cluster that hosts a radio halo and multiple relics. In this paper we present deep, high fidelity, low-frequency images made…
We describe multiwavelength optical, X-ray and radio evidences of energetic mergers in southern galaxy cluster Abell 3376 (A3376, redshift z=0.046, X-ray luminosity $ \rm L_{X}(0.1-2.4 keV)= 2.48 \times 10^{44} erg s^{-1}$). Here we report…
We present new high sensitivity observations of the radio relic in A521 carried out with the Giant Metrewave Radio Telescope at 327 MHz and with the Very Large Array at 4.9 and 8.5 GHz. We imaged the relic at these frequencies and carried…
At very low frequencies, the new pan-European radio telescope LOFAR is opening the last unexplored window of the electromagnetic spectrum for astrophysical studies. The revolutionary APERTIF phased arrays that are about to be installed on…
Despite progress in understanding radio relics, there are still open questions regarding the underlying particle acceleration mechanisms. In this paper we present deep 1--4 GHz VLA observations of CIZA\,J2242.8+5301 ($z=0.1921$), a double…
We present deep VLA observations of the merging galaxy cluster Abell 2256. This cluster is known to possess diffuse steep spectrum radio relic emission in the peripheral regions. Our new observations provide the first detailed image of the…
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.${}= 0^\circ$,…
We present a low frequency study of the diffuse radio emission in the galaxy cluster A754. We present new 150 MHz image of the galaxy cluster A754 made with the Giant Metrewave Radio Telescope (GMRT) and discuss the detection of 4 diffuse…
A joint hadronic model is shown to quantitatively explain the observations of diffuse radio emission from galaxy clusters in the form of minihalos, giant halos, relics, and their hybrid, transitional stages. Cosmic-ray diffusion of order…
Radio relics are sites of electron (re)acceleration in merging galaxy clusters but the mechanism of acceleration and the topology of the magnetic field in and near relics are yet to be understood. We are carrying out an observational…
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…
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…
The largest galaxy clusters are observed still to be forming through major cluster-cluster mergers, often showing observational signatures such as radio relics and giant radio haloes. Using LOFAR Two-meter Sky Survey data, we present new…
A number of merging galaxy clusters show the presence of large-scale radio emission associated with the intra-cluster medium (ICM). These synchrotron sources are generally classified as radio haloes and radio relics. Whilst it is commonly…
Radio halos are diffuse synchrotron sources on scales of ~1 Mpc that are found in merging clusters of galaxies, and are believed to be powered by electrons re-accelerated by the merger-driven turbulence. We present measurements of extended…
Clusters of galaxies host spectacular diffuse radio sources, extending over scales from 100 kpc to several Mpcs. These sources, with extremely faint surface brightness ($\mu$Jy/arcsec$^2$ level), are not tied to individual galaxies but…
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…