Light-Element Reaction Flow and the Conditions for r-Process Nucleosynthesis
Abstract
We deduce new constraints on the entropy per baryon (s/k), dynamical timescale (τdyn), and electron fraction (Ye) consistent with heavy-element nucleosynthesis in the r-process. We show that the previously neglected reaction flow through the reaction sequence 4He(t, γ)7Li(n, γ)8Li(α, n)11B significantly enhances the production of seed nuclei. We analyze the r-process nucleosynthesis in the context of a schematic exponential wind model. We show that fewer neutrons per seed nucleus implies that the entropy per baryon required for successful r-process nucleosynthesis must be more than a factor of 2 higher than previous estimates. This places new constraints on dynamical models for the r-process.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 2006
- DOI:
- 10.1086/504507
- arXiv:
- arXiv:astro-ph/0507393
- Bibcode:
- 2006ApJ...645.1345S
- Keywords:
-
- Nuclear Reactions;
- Nucleosynthesis;
- Abundances;
- Stars: Supernovae: General;
- Astrophysics
- E-Print:
- submitted to ApJ, 14pages, 2figures