The composition of galactic cosmic rays and solar energetic particles

Abstract

Galactic cosmic rays and solar energetic particles constitute two high energy particle populations which originate from different astrophysical reservoirs, and yet which we may study directly at earth. Since galactic cosmic rays stay in the galactic disk for only about 10 million years, they may carry information about recent nucleosynthetic activity in the galaxy. On the other hand, solar energetic particles originate in the corona, whose composition has probably remained essentially unchanged for several billion years, and thus they carry information concerning the origin of the solar system. Details of the composition of these high energy particles carry information of vital importance to other diverse topics as well, such as dynamical processes in the solar corona and in supernovae shocks, and the propagation and transport of particles in the interplanetary and interstellar space. Copyright 1987 by the American Geophysical Union.