1. Evaluation of the $^{13}$N($\alpha$,p)$^{16}$O thermonuclear reaction rate and its impact on the isotopic composition of supernova grains
- Author
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Meyer, A., de Séréville, N., Laird, A. M., Hammache, F., Longland, R., Lawson, T., Pignatari, M., Audouin, L., Beaumel, D., Fortier, S., Kiener, J., Lefebvre-Schuhl, A., Pellegriti, M. G., Stanoiu, M., Tatischeff, V., Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), and Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM)
- Subjects
Astrophysics - Solar and Stellar Astrophysics ,Nuclear Astrophysics ,[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex] ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,Nuclear Experiment - Abstract
International audience; Background: It has been recently suggested that hydrogen ingestion into the helium shell of massive stars could lead to high C13 and N15 excesses when the shock of a core-collapse supernova passes through its helium shell. This prediction questions the origin of extremely high C13 and N15 abundances observed in rare presolar SiC grains which is usually attributed to classical novae. In this context the N13(α,p)O16 reaction plays an important role since it is in competition with N13β+ decay to C13. Purpose: The N13(α,p)O16 reaction rate used in stellar evolution calculations comes from the Caughlan and Fowler compilation with very scarce information on the origin of this rate and with no associated uncertainty. The goal of this work is to provide a recommended N13(α,p)O16 reaction rate, based on available experimental data, with a meaningful statistical uncertainty. Method: Unbound nuclear states in the F17 compound nucleus were studied using the spectroscopic information of the analog states in O17 nucleus that were measured at the Tandem-Alto facility using the C13(Li7,t)O17 α-particle-transfer reaction. The α-particle spectroscopic factors were derived using a finite-range distorted-wave Born approximation analysis. This spectroscopic information was used to calculate a recommended N13(α,p)O16 reaction rate with meaningful uncertainty using a Monte Carlo approach. Results: The N13(α,p)O16 reaction rate from the present work is found to be within a factor of two of the previous evaluation in the temperature range of interest, with a typical uncertainty of a factor ≈2–3. The source of this uncertainty has been identified to come from the three main contributing resonances at Erc.m.=221, 741, and 959 keV. This new error estimation translates to an overall uncertainty in the C13 production of a factor of 50 when using the lower and upper reaction rates in the conditions relevant for the N13(α,p)O16 activation. Conclusions: The main source of uncertainty on the re-evaluated N13(α,p)O16 reaction rate currently comes from the uncertain α-particle width of relevant F17 states.
- Published
- 2020