Constituents of living or synthetic active matter have access to a local energy supply that serves to keep the system out of thermal equilibrium. The statistical properties of such fluctuating active systems differ from those of their equilibrium counterparts. Using the actin filament gliding assay as a model, we studied how nonthermal distributions emerge in active matter. We found that the ba...

Possibility to model the high energy synchrotron emission (in Xand γ-rays) from supernova remnants (SNRs) is an important task for modern astronomy and astrophysics, because it may be responsible for the nonthermal X-rays and TeV γrays observed recently from a number of SNRs. This emission allows as to look in the processes of particle acceleration on SNR shocks and generation of cosmic rays. I...

We show that the collapsar model of gamma-ray bursts results in a series of successive shocks and rarefaction waves propagating in the ‘‘ cork ’’ of stellar material being pushed ahead of the jet, as it emerges from the massive stellar progenitor. Our results are derived from analytical calculations assuming a hot, ultrarelativistic one-dimensional flowwith an initial Lorentz factor j 100. The ...

The rapid variability of the VHE emission reported for some TeV blazars implies Doppler factors well in excess of those inferred from superluminal motions and unification schemes. We propose that those extreme flares may result from radiative deceleration of blobs on scales where local dissipation occurs. The minimum jet power estimated from the resolved synchrotron emission on VLBI scales appe...

A region about 10◦ around the galactic center (G.C.) has been studied in surveys available between 19.7 and 408 MHz. The maps show a trough near the G.C. sided by two intense emission peaks. Interpreting the observations as produced by an HII region that absorbs the radiation from bright nonthermal sources we propose a model consisting of four sources concentric with the G.C. and embedded in a ...

We present the first comparison between radio images of high–energy electrons accelerated by a solar flare and images of hard X–rays produced by the same electrons at photon energies above 100 keV. The radio and hard X–ray light curves match each other well and both light curves and spectra are quantitatively consistent with an origin in a single population of nonthermal electrons with a power ...

We have calculated nonthermal bremsstrahlung (NTB) models for the hard X-ray (HXR) tails recently observed by BeppoSAX in clusters of galaxies. In these models, the HXR emission is due to suprathermal electrons with energies of ∼10–200 keV. We consider models in which these transrelativistic suprathermal particles are the low energy end of a population of electrons which are being accelerated t...