Numerical modeling of relativistic particle shock acceleration

Abstract

The shock acceleration mechanism is invoked to explain non-thermal cosmic rays in Supernova Remnants, Active Galactic Nuclei and Gamma Ray Bursts jets. Espe- cially, the importance of relativistic shock acceleration in ex- tragalactic sources is a recurring theme raising a significant interest in the research community. We will briefly overview the shock acceleration mechanism and we will address the properties of non-relativistic and relativistic shocks, particu- larly focusing on relativistic simulation studies. 1 Outline It is accepted that Super Novae Remnants (SNRs) are plau- sible environments for the acceleration of cosmic-ray parti- cles up to energies of about 10 17 eV, while for the higher en- ergies, Active Galactic Nuclei (AGN) and possibly Gamma Ray Bursts (GRBs) are favorable candidates. It is believed that the source of cosmic rays is plasma colliding at su- personic speeds, where shock waves form along with other instabilities, competing for the dissipation and acceleration mechanisms. It is until now not fully understood to which extent the astrophysical bulk flows are due to leptonic flow (electrons and positrons) or baryonic flow (electrons and ions), and by which exact mechanisms this bulk flow energy can be con- verted into cosmic ray radiation, reaching energies of TeV and beyond. Evidence in form of power-law spectra of the observed cosmic ray radiation over wide energy intervals, favors the Fermi shock acceleration mechanism (i.e. first or- der Fermi acceleration), namely diffusive shock acceleration mechanism, which raises a significant interest in the research community. In the diffusive shock acceleration mechanism