Abstract
To understand better the early Galactic production of Li, Be, and B by cosmic-ray spallation and fusion reactions, the dependence of these production rates on cosmic-ray models and model parameters is examined. The sensitivity of elemental and isotopic production to the cosmic-ray path length magnitude and energy dependence, source spectrum, spallation kinematics, and cross section uncertainties is studied. Changes in these model features, particularly those features related to confinement, are shown to alter the Be- and B-versus-Fe slopes from a naive quadratic relation. The implications of our results for the diffuse γ-ray back-ground are examined, and the role of chemical evolution and its relation to our results is noted. It is also noted that the unmeasured high-energy behavior of α + α fusion can lead to effects as large as a factor of 2 in the resultant yields. Future data should enable Population II Li, Be, and B abundances to constrain cosmicray models for the early Galaxy.
Original language | English (US) |
---|---|
Pages (from-to) | 185-202 |
Number of pages | 18 |
Journal | Astrophysical Journal |
Volume | 435 |
Issue number | 1 |
DOIs | |
State | Published - Nov 1 1994 |
Externally published | Yes |
Keywords
- Cosmic rays
- Galaxy : evolution
- Nuclear reactions, nucleosynthesis, abundances
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science