Cosmic-ray proton and electron spectra. Left panel: CR proton spectrum as a function of the energy for three low-energy spectral slopes: α = 0.1 (labelled as model ), α = −0.8 (labelled as model ), and α = −1.2. Right panel: CR electron spectrum as a function of the energy. Data are from Voyager 1 (black circles; Cummings et al. 2016); Voyager 2 (orange diamonds; Stone et al. 2019); Fermi-LAT (upward-pointing magenta triangles; Ackermann et al. 2010); Pamela (downward-pointing pink triangles; Adriani et al. 2011); and AMS-02 (cyan squares; Aguilar et al. 2014, 2015).