|
| 04/29/02
| |
maurin david |
lapth |
| Chemin de bellevue | PCHE- |
|
74941 |
Annecy le vieux, france |
Presentation 1 : Oral
Heavy Nuclei Enrichment of the Galactic Cosmic Rays at High Energy: Astrophysical Interpretation (PCHE)
D. Maurin, E. Flam & M. Casse
A substantial increase of the mean logarithmic mass of galactic
cosmic rays vs energy has been observed . We study three effects that
could explain this trend i) different source spectra for protons and
heavy nuclei ii) a selective nuclear destruction in flight of heavies
iii) a gradient of the source number and chemical composition in the
galactic disk. Pure geometrical effects are less determining than the
diffusion coefficient spectral index and a difference in source spectra.
Subsequently, we conclude that the physics of cosmic ray confinement
is the essential cause of the heavy nuclei enrichment until ~10^{15} eV.