Recent numerical models for SNR evolution are presented, including first-order Fermi acceleration with injection of suprathermal particles at the shock wave, heating due to dissipation of Alfven waves in the precursor region and radiative cooling of the thermal plasma. The X-ray fluxes obtained from these SNR models show significant differences depending on the acceleration efficiency of cosmic rays. gamma-ray fluxes are calculated originating from pi(0)-decay of pions generated by collisions of the high-energy particles with the thermal plasma. Cooling of the thermal plasma and dissipation of Alfven waves in the precursor are important to determine the final amount of the explosion energy E(SN) which is transferred into cosmic rays.
机构:
NASA,GODDARD SPACE FLIGHT CTR,THEORET STUDIES BRANCH,LAB SPACE PHYS,GREENBELT,MD 20770NASA,GODDARD SPACE FLIGHT CTR,THEORET STUDIES BRANCH,LAB SPACE PHYS,GREENBELT,MD 20770
机构:
NASA,GODDARD SPACE FLIGHT CTR,THEORET STUDIES BRANCH,LAB SPACE PHYS,GREENBELT,MD 20770NASA,GODDARD SPACE FLIGHT CTR,THEORET STUDIES BRANCH,LAB SPACE PHYS,GREENBELT,MD 20770