Supernovae as sources of cosmic rays

The enormous energy release during supernova outbursts and observations of non-thermal radio emission allowed V.L. Ginzburg and S.I. Syrovatskii to substantiate more than 60 years ago the hypothesis about the key role of supernovae as sources of the main component of galactic cosmic rays. To date, multichannel observations of supernova remnants in the entire electromagnetic wavelength range have provided a wealth of data confirming the reality of proton and electron acceleration to energies of the order of 100 TeV. Several questions remain to be solved, including the problem of the origin and search for sources of the observed high-energy cosmic rays in the range from 100 TeV to 1000 PeV. Solving the problems of efficient conversion of the kinetic energy of supernova ejecta, the rotational energy of pulsars, and the energy of anisotropic plasma flows around accreting black holes into a population of relativ„istic particles invites kinetic simulations of nonlinear mechanisms with a broad dynamic scale range. Simulations are necessary to determine the highest energies of particles accelerated by super-Alfvenic plasma flows with frozen-in magnetic fields and collisionless shock waves. The task is to reveal the physical mechanisms of strong (superadiabatic) enhancement of magnetic turbulence required for rapid particle acceleration by the Fermi mechanism. The review presents the results of kinetic simulation and analysis of nonlinear production mechanisms of strong anisotropic magnetic turbulence and celerated particle spectra. Recent observations of polarized X-ray synchrotron radiation from supernova remnants Tycho Brahe, Cassiopeia A, SN1006, etc. with the IXPE (Imaging X-ray Polarimetry Explorer) orbital observatory have made it possible to look inside cosmic particle accelerators using nonlinear models and understand the modification mechanisms of strong shock waves. Also discussed are the possibilities of acceleration of cosmic ray nuclei by powerful anisotropic plasma outflows in compact relativistic remnants of collapsed supernovae. Young pulsars in binary star systems, as well as accreting black holes—microquasars—can accelerate nuclei to energies significantly above a PeV.