Cosmic-ray electrons lose their energy by synchrotron and inverse Compton processes during their propagation through the Galaxy. It has been recognized that the spectrum of electrons will bring us unique information about the propagation and acceleration of cosmic-rays. First, we review the past observations of high energy primary electrons beyond 100 GeV, and discuss the inherent technical difficulties in the direct observations of electrons in this high energy region. Next, discussion is made on the observations and their astrophysical significance to the electron spectrum in the TeV region. By these observations, it is promising to find the major contributing sources and to determine the parameters in models of propagation of cosmic-rays. Astrophysical importance is emphasized in the observations of electrons with more statistical significance in TeV region.
ASJC Scopus subject areas