Related papers: Non-thermal radiation from collisions of compact o…
High resolution X-ray spectroscopy of the hot gas in galaxy clusters has shown that the gas is not cooling to low temperatures at the predicted rates of hundreds to thousands of solar masses per year. X-ray images have revealed giant…
Galactic and extragalactic relativistic jets have rich environments that are full of moving objects, such as stars and dense clumps. These objects can enter into the jets and generate shocks and non-thermal emission. We characterize the…
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…
Nonthermal radiation observed from astrophysical systems containing relativistic jets and shocks, e.g., gamma-ray bursts (GRBs), active galactic nuclei (AGNs), and Galactic microquasar systems usually have power-law emission spectra. Recent…
High-velocity clouds (HVCs) are interstellar clouds of atomic hydrogen that do not partake of the Galactic rotation and have velocities of a several hundred kilometers per second. A considerable number of these clouds are falling down…
Non-thermal TeV $\gamma$-ray emission within a multiparsec has been observed from the center region of our Galaxy. We argue that these $\gamma$-rays are the result of transient activity of the massive black hole Sgr A$^*$ that resides at…
The accretion of matter onto intermediate polar White Dwarfs (IPWDs) seems to provide attractive conditions for acceleration of particles to high energies in a strongly magnetized turbulent region at the accretion disk inner radius. We…
It was proposed that the central dense stellar cluster in the Galactic Center, containing the mass of $\sim$4 times larger than that of the central black hole, had been formed as a result of a merging of several massive globular clusters.…
It is suggested that the outflowing plasma in the jets of active galactic nuclei (AGNs) is inhomogeneous and consists of separate clouds. These clouds are strongly magnetized and move away from the central engine at relativistic speeds. The…
High-mass microquasars are binary systems consisting of a massive star and an accreting compact object from which relativistic jets are launched. There is considerable observational evidence that winds of massive stars are clumpy.…
Matter accreting onto black holes may develop shocks due to the centrifugal barrier. A part of inflowing matter in the post-shock flow is deflected along the axis in the form of jets. Post-shock flow which behaves like a Compton cloud has…
This study shows the existence of an additional thermal component found in the synchrotron emission from the M87 jet. Using Chandra, thermal bremsstrahlung is detected in four out of six fields. X-rays for the nucleus and HST-1 are well…
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…
We review the possible mechanisms for production of non-thermal electrons which are responsible for non-thermal radiation in clusters of galaxies. Our primary focus is on non-thermal Bremsstrahlung and inverse Compton scattering, that…
The nonthermal radiation observed from a handfull of clusters of galaxies (CG) is the proof that particle acceleration occurs in the intracluster medium (ICM). It is often believed that shock surfaces associated with either mergers of CG,…
The nonthermal characteristics of starburst galaxies and galaxy clusters are reviewed and the perspectives for their observation in high energy gamma rays discussed. It is argued that starburst galaxies should have physically similar and…
Non-thermal particles and high-energy radiation can play a role in the dynamical processes in star-forming regions and provide an important piece of the multiwavelength observational picture of their structure and components. Powerful…
Dense and cold clouds seem to populate the broad line region surrounding the central black hole in AGNs. These clouds could interact with the AGN jet base and this could have observational consequences. We want to study the gamma-ray…
In galactic nuclei, stellar densities are so high that stars can physically collide with each other. In this work we focus on the collision of red giants and in particular on the formation of non-thermal processes through collisions and…
Clusters of galaxies generally form by the gravitational merger of smaller clusters and groups. Major cluster mergers are the most energetic events in the Universe since the Big Bang. Mergers drive shocks into the intracluster gas, and…