Astronomy and Astrophysics – Astrophysics
Scientific paper
2004-06-29
Astrophys.J. 617 (2004) L131
Astronomy and Astrophysics
Astrophysics
11 pages, 2 tables, 1 figure. Submitted to ApJ Letters
Scientific paper
10.1086/427233
We demonstrate that nucleosynthesis in rapid, high-entropy expansions of proton-rich matter from high temperature and density can result in a wider variety of abundance patterns than heretofore appreciated. In particular, such expansions can produce iron-group nuclides, p-process nuclei, or even heavy, neutron-rich isotopes. Such diversity arises because the nucleosynthesis enters a little explored regime in which the free nucleons are not in equilibrium with the abundant alpha particles. This allows nuclei significantly heavier than iron to form in t he presence of abundant free nucleons early in the expansion. As the temperature drops, nucleons increasingly assemble into alpha particles and heavier nuclei. If the assembly is efficient, the resulting depletion of free neutrons allows disintegrat ion flows to drive nuclei back down to iron and nickel. If this assembly is inefficient, then the large abundance of free nucleons prevents the disintegration flows and leaves a distribution of heavy nuclei after reaction freezeout. For cases in between, an intermediate abundance distribution, enriched in p-process isotopes, is frozen out. These last expansions may contribute to the solar system's supply of the p-process nuclides if mildly proton-rich, high-entropy matter is ejected from proto-neutron stars winds or other astrophysical sites. Also sign ificant is the fact that, because the nucleosynthesis is primary, the signature of this nucleosyn thesis may be evident in metal poor stars.
Jordan IV George C.
Meyer Bradley S.
No associations
LandOfFree
Nucleosynthesis in Fast Expansions of High-Entropy, Proton Rich Matter 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 Nucleosynthesis in Fast Expansions of High-Entropy, Proton Rich Matter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Nucleosynthesis in Fast Expansions of High-Entropy, Proton Rich Matter will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-525397