New fission fragment distributions and r-process origin of the rare-earth elements.
Phys Rev Lett
; 111(24): 242502, 2013 Dec 13.
Article
in En
| MEDLINE
| ID: mdl-24483647
ABSTRACT
Neutron star (NS) merger ejecta offer a viable site for the production of heavy r-process elements with nuclear mass numbers Aâ³140. The crucial role of fission recycling is responsible for the robustness of this site against many astrophysical uncertainties, but calculations sensitively depend on nuclear physics. In particular, the fission fragment yields determine the creation of 110â²Aâ²170 nuclei. Here, we apply a new scission-point model, called SPY, to derive the fission fragment distribution (FFD) of all relevant neutron-rich, fissioning nuclei. The model predicts a doubly asymmetric FFD in the abundant A≃278 mass region that is responsible for the final recycling of the fissioning material. Using ejecta conditions based on relativistic NS merger calculations, we show that this specific FFD leads to a production of the A≃165 rare-earth peak that is nicely compatible with the abundance patterns in the Sun and metal-poor stars. This new finding further strengthens the case of NS mergers as possible dominant origin of r nuclei with Aâ³140.
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Collection:
01-internacional
Database:
MEDLINE
Type of study:
Prognostic_studies
Language:
En
Journal:
Phys Rev Lett
Year:
2013
Document type:
Article
Affiliation country:
Belgium