Nishimura (西村信哉), N, Rauscher, T, Hirschi, R, Cescutti, G, Murphy, ASJ and Fröhlich, C (2019) Uncertainties in νp-process nucleosynthesis from Monte Carlo variation of reaction rates. Monthly Notices of the Royal Astronomical Society, 489 (1). pp. 1379-1396. ISSN 0035-8711

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It has been suggested that a νp process can occur when hot, dense, and proton-rich matter is expanding within a strong flux of anti-neutrinos. In such an environment, proton-rich nuclides can be produced in sequences of proton captures and (n, p) reactions, where the free neutrons are created in situ by $øverlineν _\mathrme+\mathrmp \rightarrow \mathrmn+\mathrme^+$ reactions. The detailed hydrodynamic evolution determines where the nucleosynthesis path turns off from N = Z line and how far up the nuclear chart it runs. In this work, the uncertainties on the final isotopic abundances stemming from uncertainties in the nuclear reaction rates were investigated in a large-scale Monte Carlo approach, simultaneously varying ten thousand reactions. A large range of model conditions was investigated because a definitive astrophysical site for the νp process has not yet been identified. The present parameter study provides, for each model, identification of the key nuclear reactions dominating the uncertainty for a given nuclide abundance. As all rates appearing in the νp process involve unstable nuclei, and thus only theoretical rates are available, the final abundance uncertainties are larger than those for nucleosynthesis processes closer to stability. Nevertheless, most uncertainties remain below a factor of three in trajectories with robust nucleosynthesis. More extreme conditions allow production of heavier nuclides but show larger uncertainties because of the accumulation of the uncertainties in many rates and because the termination of nucleosynthesis is not at equilibrium conditions. It is also found that the solar ratio of the abundances of 92Mo and 94Mo could be reproduced within uncertainties.

Item Type: Article
Additional Information: This article has been accepted for publication in the Monthly Notices of the Royal Astronomical Society © 2019, published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
Uncontrolled Keywords: nuclear reactions, nucleosynthesis, abundances – stars: abundances – supernovae: general
Subjects: Q Science > QB Astronomy > QB460 Astrophysics
Q Science > QB Astronomy > QB799 Stars
Divisions: Faculty of Natural Sciences > School of Chemical and Physical Sciences
Depositing User: Symplectic
Date Deposited: 09 Aug 2019 08:22
Last Modified: 23 Mar 2021 10:41

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