GALACTIC AND SOLAR COSMIC RAYS

The aspects of Cosmic Ray (CR) origin are reviewed. Recent observational evidence on the spatial patterns of non-thermal X-ray radiation from Supernovae Remnants (SNR) support long waiting expectations of proton and nuclei acceleration up to PeV energies. We add new arguments based on the experimental data from surface arrays measuring Extensive Air Showers (EAS) and on data from solar accelerators available now from space born X-ray and gamma-ray spectrometers. Energy spectra of primary nuclei with atomic Number from from Z=1 to Z=26 can provide useful information on the validity of models of cosmic ray acceleration. By estimating the threshold energy of the onset of the suppression of the different nuclei flux, the so called spectral “knee ” energy, we can directly check the hypothesis of rigidity dependent acceleration of the hadrons in SNR sites. Unfortunately, information from the EAS experiments does not provide enough clues for such “spectroscopy ” of the “knee region. ” Nonetheless, by grouping the primary nuclei in 2 or 3 broad mass groups (light, intermediate and heavy) we can obtain useful information on energy spectra of the primaries. Recently, using multidimensional classification methods on MAKET-ANI experimental data, we categorized the “all-particle ” spectra into 2 distinct primary mass groups. From the spectra analysis, we come to the conclusion that the SNR based particle acceleration model is valid and presents evidence that there exists a nearby source of cosmic rays, which provides a significant portion of the CR flux