Related papers: Structure Shocks as a Source of Cosmic Rays in Clu…
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…
We present a spherically symmetric model for the origin and evolution of the temperature profiles in the hot plasma filling galaxy groups and clusters. We find that the gas in clusters is generically not isothermal, and that the temperature…
The non-thermal particle spectra responsible for the emission from many astrophysical systems are thought to originate from shocks via a first order Fermi process otherwise known as diffusive shock acceleration. The same mechanism is also…
Cosmic rays (CRs) are an important energy source in the circum-galactic medium (CGM) that impact the multi-phase gas structure and dynamics. We perform two-dimensional CR-magnetohydrodynamic simulations to investigate the role of CRs in…
Context: Cosmic ray acceleration in galaxy clusters is still an ongoing puzzle, with relativistic electrons forming radio relics at merger shocks and emitting synchrotron radiation. In the present work we perform hybrid-kinetic simulations…
Accelerated particles are ubiquitous in the Cosmos and play a fundamental role in many processes governing the evolution of the Universe at all scales, from the sub-AU ones relevant for the formation and evolution of stars and planets to…
The formation of collisionless shock fronts is an ubiquitous phenomenon in space plasma environments. In the solar wind shocks might accompany coronal mass ejections, while even more violent events, such as supernovae, produce shock fronts…
We have developed a numerical model for the temporal evolution of particle and photon spectra resulting from nonthermal processes at the shock fronts formed in merging clusters of galaxies. Fermi acceleration is approximated by injecting…
Cosmic rays (CRs) are a plausible mechanism for launching winds of cool material from the discs of star-forming galaxies. However, there is no consensus on what types of galaxies likely host CR-driven winds, or what role these winds might…
In the Milky Way, cosmic rays (CRs) are dynamically important in the interstellar medium, contribute to hydrostatic balance, and may help regulate star formation. However, we know far less about the importance of CRs in galaxies whose gas…
The acceleration of charged particles at astrophysical collisionless shock waves is one of the best studied processes for the energization of particles to ultrarelativistic energies, required by multifrequency observations in a variety of…
Within the standard framework of structure formation, where clusters and groups of galaxies are built up from the merging of smaller systems, the physical properties of the intracluster medium, such as the gas temperature and the total…
Although the origin of cosmic rays (CRs) remains an open question, collisionless magnetized shock waves are widely regarded as key sites for particle acceleration. Recent theories further suggest that shock-shock collisions in stellar…
Our Galaxy is the largest nuclear interaction experiment which we know, because of the interaction between cosmic ray particles and the interstellar material. Cosmic rays are particles, which have been accelerated in the Galaxy or in…
The nonthermal source abundances of elements play a crucial role in the understanding of cosmic ray (CR) phenomena from a few GeV up to several tens of EeV. We present a first systematic approach to describe the change of the abundances…
Large-scale diffuse radio emission is observed in some clusters of galaxies. There is ample of evidence that the emission has its origin in synchrotron losses of relativistic electrons, accelerated in the course of clusters mergers. In a…
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…
FERMI (formely GLAST) will shortly provide crucial information on relativistic particles in galaxy clusters. We discuss non-thermal emission in the context of general calculations in which relativistic particles (protons and secondary…
The X-ray emission from clusters of galaxies enables them to be used as good cosmological probes and as an example for massive galaxy formation. The gas mass fraction in clusters should be a universal standard which by means of Chandra…
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…