Electron acceleration at the Earth's bow shock, solar flares and interplanetary shocks

Solar flares and interplanetary shocks (IPSs) generate power-law energy distributions of electrons, but parameter dependence of electron acceleration has not been clarified from both theories and observations. Making use of in-situ data obtained by Geotail at the Earth's bow shock, we studied power-law formation of electron energy spectra with respect to the Alfven Mach number M-A and shock angle theta(Bn). We found that the spectral index Gamma of electron energy spectrum f (E) proportional to E-(Gamma) is regulated by the whistler critical Mach number. sub-critical regime while Gamma were concentrated between 3.0 and 3.5 in the super-critical regime. Electron acceleration at solar flares and interplanetary shocks are discussed based on the results.