Cosmic rays constitute high-energy protons and atomic nuclei that originate from stars (both within our galaxy and from other galaxies) and are accelerated by supernovae and other high-energy astrophysical objects.
October 3, 2022
Cosmic rays constitute high-energy protons and atomic nuclei that originate from stars (both within our galaxy and from other galaxies) and are accelerated by supernovae and other high-energy astrophysical objects.
Our current understanding of the Galactic cosmic ray energy spectrum suggests that it follows a power-law dependence, in that the spectral index of protons detected within a certain energy range goes down by power law as energy increases.
But recent observations made using magnetic spectrometers for low energy levels and calorimeters for high energy levels has hinted at a deviation from this power-law variation, with the spectral index of protons becoming larger around an energy of few hundred GeV at energies up to 10 TeV. Following this « spectral hardening, » characterized by a smaller absolute value of the spectral index, a « spectral softening » has been detected above 10 TeV using the CALorimetric Electron Telescope (CALET), a space telescope installed at the International Space Station.
However, better measurements with high statistics and low uncertainty need to be performed over a broad energy spectrum for the confirmation of these spectral structures.
