Related papers: Cosmic rays in galaxy clusters and their non-therm…
The interaction of magnetic turbulence and relativistic particles is a important process for understanding particles propagation and acceleration in many astrophysical environments. Large-scale turbulence can be generated in the…
Clusters of galaxies, as the largest virialized systems in the Universe, are ideal laboratories to study the formation and evolution of cosmic structures...(abridged)... Most of the detailed knowledge of galaxy clusters has been obtained in…
The presence of non-thermal components in galaxy clusters is now clearly established. Diffuse radio emission from the Intra Cluster Medium (ICM) of several galaxy clusters is revealed in the form of radio halos and relics. These emissions…
The main component of the intracluster medium (ICM) in clusters of galaxies is represented by the X-ray emitting thermal plasma. In addition, the presence of relativistic electrons and large-scale magnetic fields in a fraction of galaxy…
The existence and extent of non-thermal phenomena in galaxy clusters is now well established. A key question in our understanding of these phenomena is the origin of the relativistic electrons which may be constrained by the modelling of…
Acceleration of cosmic-ray electrons (CRe) in the intra-cluster-medium (ICM) is probed by radio observations that detect diffuse, Mpc-scale, synchrotron sources in a fraction of galaxy clusters. Giant radio halos are the most spectacular…
The role of cosmic rays (CR) in the formation and evolution of clusters of galaxies has been much debated. It may well be related to other fundamental questions, such as the mechanism which heats and virializes the intracluster medium…
Recent observations of high energy (> 20 keV) X-ray emission in a few clusters of galaxies broaden our knowledge of physical phenomena in the intracluster space. This emission is likely to be nonthermal, probably resulting from Compton…
The existence of cosmic rays and weak magnetic fields in the intracluster volume has been well proven by deep radio observations of galaxy clusters. However a detailed physical characterization of the non-thermal component of large…
The discovery of diffuse synchrotron radio emission and, more recently, of the hard X-ray (HXR) tails have triggered a growing interest about non-thermal phenomena in galaxy clusters. After a brief review of the most important evidences for…
This Chapter provides a brief tutorial on some aspects of plasma physics that are fundamental to understanding the dynamics and energetics of the intracluster medium (ICM). The tutorial is split into two parts: one that focuses on the…
Clusters of galaxies are sites of acceleration of charged particles and sources of non-thermal radiation. We report on new constraints on the population of cosmic rays in the Intra Cluster Medium (ICM) obtained via radio observations of a…
There is now firm evidence that the ICM consists of a mixture of hot plasma, magnetic fields and relativistic particles. The most important evidences for non-thermal phenomena in galaxy clusters comes from the diffuse Mpc-scale synchrotron…
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…
The presence of magnetic fields in the intra-cluster medium of galaxy clusters is now well estabilished. It is directly revealed by the presence of cluster-wide radio sources: radio halos and radio relics. In the last years increasing…
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…
The most spectacular aspect of cluster radio emission is represented by the large-scale diffuse radio sources, which cannot be obviously associated with any individual galaxy. These sources demonstrate the existence of relativistic…
Recent observations of galaxy clusters in radio and X-ray indicate that cosmic rays and magnetic fields may be energetically important in the intracluster medium. According to the estimates based on theses observational studies, the…
Observations of giant radio halos provide unambiguous evidence for the existence of cosmic ray (CR) electrons and magnetic fields in galaxy clusters. The physical mechanism generating radio halos is still heavily debated. We critically…
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…