Cosmic Rays Report from the Structure of Space

Figure 5

Proton flux versus energy compiled from many measurements, available from Database of Charged Cosmic Rays [79] (see text for references), displays the low-energy spectrum about the flux maximum that is governed by the proton rest energy ≈ 10⁹ eV. The computed line (orange line) has been scaled in energy to match the data to reveal that the proton flux with decreasing energy originates from more and more distant sources in the expanding part of the Universe.