Related papers: Non-thermal phenomena in galaxies clusters
We revisit the phenomenon of elements diffusion in the intergalactic medium (IGM) in clusters of galaxies. The diffusion is driven by gravity, concentration and temperature gradients. The latter cause thermal diffusion, which has been so…
Clusters of galaxies and the large scale filaments that connect neighboring clusters are expected to be sites of acceleration of charged particles and sources of non-thermal radiation from radio frequencies to gamma rays. Gamma rays are…
Multiwavelength observations suggest that clusters are reservoirs of vast amounts relativistic electrons and positrons that are either injected into and accelerated directly in the intra-cluster medium, or produced as secondary pairs by…
It is generally argued that most clusters of galaxies host cooling flows in which radiative cooling in the centre causes a slow inflow. However, recent observations by Chandra and XMM conflict with the predicted cooling flow rates. It has…
Recent multifrequency observations contribute to derive a comprehensive picture of the origin and evolution of relativistic particles in galaxy clusters. In this review I briefly discuss theoretical aspects and open problems of this…
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…
Cosmology models predict that external accretion shocks form in the outer region of galaxy clusters due to supersonic gas infall from filaments and voids in the cosmic web. They are characterized by high sonic and Alfv\'enic Mach numbers,…
The spatial clustering of galaxies in galaxy clusters implies that the background of infrared (IR) light in the intracluster medium (ICM) may exceed the universal background. Cosmic rays injected within the ICM propagate diffusively and at…
We present a new model for the X-ray properties of the intracluster medium that explicitly includes heating of the gas by the energy released during the evolution of cluster galaxies. We calculate the evolution of clusters by combining the…
Clusters of galaxies are believed to contain a significant population of cosmic rays. From the radio and probably hard X-ray bands it is known that clusters are the spatially most extended emitters of non-thermal radiation in the Universe.…
The spectra of active galactic nuclei exhibit broad-emission lines that presumably originate in the Broad-Line Region (BLR) with gaseous-dusty clouds in a predominantly Keplerian motion around the central black hole. Signatures of both…
Non-thermal emission from clusters of galaxies at the high-energy X-ray regime has been searched with various instruments, but the detection significance of this emission has yet been found to be either marginal or controversial. Taking…
Clusters of galaxies as the largest clearly defined objects in our Universe are ideal laboratories to study the distribution of the most abundant chemical elements heavier than hydrogen and helium and the history of their production. The…
Galaxy clusters host the largest particle accelerators in the Universe: Shock waves in the intracluster medium (ICM), a hot and ionised plasma, that accelerate particles to high energies. Radio observations pick up synchrotron emission in…
We investigate the spatial behaviour of the total comptonization parameter $y_{tot}$ evaluated for a galaxy cluster containing two population of electrons: the thermal population, with energy around some KeV and whose trace is evident in…
The detections of high-energy gamma-ray emission from the nearby starburst galaxies M82 & NGC253, and other local group galaxies, broaden our knowledge of star-driven nonthermal processes and phenomena in non-AGN star-forming galaxies. We…
Radio galaxies in clusters of galaxies are prominent reservoirs of magnetic fields and of non-thermal particles, which get mixed with the intracluster medium. We review the observational and theoretical knowledge of the role of these…
Galaxy clusters (GCs) are the largest and most massive gravitationally bound objects in the large-scale structure of the Universe. Due to keV temperatures of virialized gas in the intracluster medium (ICM) and presence of cosmic rays (CRs),…
The intra-cluster medium of several galaxy clusters hosts large-scale regions of diffuse synchrotron radio emission, known as radio halos and relics, which demonstrate the presence of magnetic fields and relativistic electrons in clusters.…
We review observations of extended regions of radio emission in clusters; these include diffuse emission in `relics', and the large central regions commonly referred to as `halos'. The spectral observations, as well as Faraday rotation…