A simple model for electron plasma heating in supernova remnants. (Research Note)

Max-Planck-Institut fu¨r Kernphysik, Saupfercheckweg 1,69117 Heidelberg, GermanyABSTRACTContext.Multiwavelength observations of supernova remnants can be explained within the framework of diffusive shock accelerationtheory, which allows effective conversion of the explosion energy into cosmic rays. Although the models of nonlinear shocks describereasonably well the nonthermal component of emission, certain issues, including the heating of the thermal electron plasma and therelated X-ray emission, still remain open.Aims. Study of electron heating in supernova remnants in the Sedov phase due to Coulomb exchange between protons and electrons.Methods. Numerical solution of the equations of the Chevalier model for supernova remnant evolution, coupled with Coulombscattering heating of the electrons.Results. The electron temperature and the X-ray thermal Bremsstrahlung emission from supernova remnants have been calculatedas functions of the relevant parameters. Since only the Coulomb mechanism was considered for electron heating, the values obtainedfor the electron temperatures should be treated as lower limits. Results from this work can be useful to constrain model parametersfor observed SNRs.