The Local Interstellar Spectrum of Cosmic Ray Electrons

摘要

The local interstellar spectrum of cosmic ray electrons and positrons from 0.8 GeV to 2 TeV is derived by demodulating the measured spectra by balloon and satellite experiments.It can be well represented by a single power law in kinetic energy with spectral index 3.4 over the whole energy range,pushing for the idea that it is not representative of the galactic average.Instead,the spectrum has to reflect the nature of our local bubble,being mostly sensitive to the last nearby supernova.The most favored sites for cosmic ray(CR)acceleration are the shock fronts generated by supernova(SN)explosions: the SN emitted power and their estimated rate are compatible with the CR energy density in the Galaxy(of the order of 1 eV cm~(-3))if the acceleration mechanism has an efficiency of few percent,while the Fermi model of the acceleration by magnetic irregularities naturally produces a power-law spectrum in momentum.