Astronomy and Astrophysics – Astrophysics
Scientific paper
1998-09-22
Astronomy and Astrophysics
Astrophysics
25 pages, latex, 8 ps figures, figure 1 corrected
Scientific paper
10.1086/307145
Because of the roughly linear correlation between Be/H and Fe/H in low metallicity halo stars, it has been argued that a ``primary'' component in the nucleosynthesis of Be must be present in addition to the ``secondary'' component from standard Galactic cosmic ray nucleosynthesis. In this paper we critically re-evaluate the evidence for the primary versus secondary character of Li, Be, and B evolution, analyzing both in the observations and in Galactic chemical evolution models. While it appears that [Be/H] versus [Fe/H] has a logarithmic slope near 1, it is rather the Be-O trend that directly arises from the physics of spallation production. Using new abundances for oxygen in halo stars based on UV OH lines, we find that the Be-O slope has a large uncertainty due to systematic effects, rendering it difficult to distinguish from the data between the secondary slope of 2 and the primary slope of 1. The possible difference between the Be-Fe and Be-O slopes is a consequence of the variation in O/Fe versus Fe: recent data suggests a negative slope rather than zero (i.e., Fe $\propto$ O) as is often assumed. In addition to a phenomenological analysis of Be and B evolution, we have also examined the predicted LiBeB, O, and Fe trends in Galactic chemical evolution models which include outflow. Based on our results, it is possible that a good fit to the LiBeB evolution requires only traditional the Galactic cosmic ray spallation, and the (primary) neutrino-process contribution to B11. We thus suggest that these two processes might be sufficient to explain Li6, Be, and B evolution in the Galaxy, without the need for an additional primary source of Be and B.
Fields Brian D.
Olive Keith A.
No associations
LandOfFree
The Revival of Galactic Cosmic Ray Nucleosynthesis? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The Revival of Galactic Cosmic Ray Nucleosynthesis?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Revival of Galactic Cosmic Ray Nucleosynthesis? will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-193914