A New Model for the Thermal X-ray Composites and the Neutral Pion Decay Gamma-Rays from Supernova Remnants
Abstract
Recent nonthermal X-ray and gamma-ray observations, attributed to electron emission processes, for the first time give an experimental confirmation that electrons are accelerated on SNR shocks up to the energy 10^{14} eV. We have no direct observational confirmations about proton acceleration by SNR. Different models of gamma-emission from SNRs predict different emission mechanisms as dominating. Only decays of neutral pion created in proton-nucleon interactions allow us to look inside the CR nuclear component acceleration processes. A new model for the thermal X-ray composites strongly suggest that thermal X-ray peak inside the radio shell of SNR tells us about entering of one part of SNR shock into a denser medium compared with other parts of the shell. This makes a TXCs promising sites for gamma-ray generation via neutral pion decays. Detailed consideration of SNR-cloud interaction allows to increase an expected proton induced gamma-ray flux from SNR at least on an order of magnitude, that allows to adjust the theoretical proton origin gamma-luminosities with observed fluxes at least for a few SNRs even for low density (n=10-100 cm^{-3}) cloud.