The elemental and isotopic composition of galactic cosmic ray nuclei

Abstract

Galactic cosmic rays represent a directly accessible sample of matter that originates outside the solar system. The elemental and isotopic composition of this sample of high‐energy matter contains a record of nucleosynthesis in other regions of the galaxy, and of subsequent nuclear and electromagnetic interactions that have altered its composition. There have recently been significant new advances in reading this record, brought about in large part by the launch of new high‐resolution instrumentation. In particular, measurements of the abundances of individual elements have now been extended into the upper 2/3 of the periodic table, and the individual isotopes of a number of heavy cosmic ray nuclei have recently been resolved.

Lithium–beryllium–boron: origin and evolution

“…It is worth noting that in the early Galaxy, supernovae play a leading role since at very low metallicity stellar winds are unsignificant. Table 1 shows a sample of compositions used by different authors: solar system (SS) for comparison ([72] from [1]), cosmic ray source (CRS) ( [72] from [115]), wind of massive stars (W40) ( [68] from [116]), composition of grain products (GR) ( [72] and [60]), 40 Mo supernova at Z = 10 −4 Zo from [97] , 35 Mo supernova of solar metallicity ( [72] from [124]). The two supernovae, though at different metallicities, (SN40 at low metallicity and SN35 at solar metallicity), give similar yields due to the fact that metallicity dependent mass loss has not been taken into account in the stellar models.…”

Gamma-ray lines from the Orion complex

“…We assume that the composition of the ambient medium is that of the solar photosphere given in column 2 of this table. The cosmic ray source composition (CRS) is from Mewaldt (1983) except 1 4 H for which we took the solar value relative to He. The SN15M and SN25M composi-¯tions represent the ejecta of the 15M and 25M supernovae given by Weaver & Woosley ¯(1 993).…”

Near-Earth Space Radiation Models

“…The ions from lithium through the iron-nickel group (atomic number 28) account for most of the remaining 1%. Elements above iron-nickel (up to atomic number of 92) are present, but they account for only 0.00003% of the GCRs [36]. Fig.…”