DYNAMICS AND EMISSION OF MILDLY RELATIVISTIC PLASMA

作     者：A. G. AKSENOV R. RUFFINI I. A. SIUTSOU G. V. VERESHCHAGIN 

作者机构：Institute for Computer-Aided Design Russian Academy of Sciences Vtoraya Brestskaya 19/18 Moscow 123056 Russia ICRANet p.le della Repubblica 10 65100 Pescara Italy ICRA and University of Rome Sapienza Physics Department p.le A. Moro 5 00185 Rome Italy 

出 版 物：《International Journal of Modern Physics: Conference Series》 

年 卷 期：2012年第ijmpcs卷第12期

页      面：1-9页

学科分类：07[理学] 0702[理学-物理学] 

主　　题：electron positron plasma 

摘      要：Initially optically thick (with τ = 3⋅10 7 ) spherically symmetric outflow consisting of electron-positron pairs and photons is considered. We do not assume thermal equilibrium, and include the two-body processes that occur in such plasma: Möller and Bhabha scattering of pairs, Compton scattering, two-photon pair annihilation, two-photon pair production, together with their radiative three-body variants: bremsstrahlung, double Compton scattering, and three-photon pair annihilation, with their inverse processes. We solve numerically the relativistic Boltzmann equations in spherically symmetric case for distribution functions of pairs and photons. Three epochs are considered in details: a) the thermalization, which brings initially nonequilibrium plasma to thermal equilibrium; b) the self-accelerated expansion, which we find in agreement with previous hydrodynamic studies and c) decoupling of photons from the expanding electron-positron plasma. Photon spectra are computed, and appear to be non thermal near the peak of the luminosity. In particular, the low energy part of the spectrum contain more power with respect to the black body one.