Simulating radiation and kinetic processes in relativistic plasmas
Résumé
Modelling the emission properties of compact high energy sources such asX-ray binaries, AGN or gamma-ray bursts represents a complex problem.Contributions of numerous processes participate non linearly to produce theobserved spectra: particle-particle, particle-photon and particle-waveinteractions. In the past decades, numerical simulations have been widely usedto address the key properties of the high energy plasmas present in thesesources. This article presents a code that has been designed to investigatethese questions. It includes most of the relevant processes needed to simulatethe emission of high energy sources. This code solves the time-dependentkinetic equations for homogeneous, isotropic distributions of photons,electrons and positrons. No assumption is made on the shape of thesedistributions. Have been included so far: syn- chrotron self-absorbedradiation, Compton scattering, pair production/annihilation, e-e and e-pCoulomb collisions and some prescriptions for additional particle heating andacceleration. We also present comparisons with earlier works and some examplesto illustrate the code computational capacities. Previous results arereproduced qualitatively but some differences are often found in the details ofthe particle As a first application of the code, we investigate acceleration bysecond order Fermi-like processes and we find that the energy threshold foracceleration has a crucial influence on the particle distribution and theemitted spectrum.