Thermonuclear 17O(n,gamma)18O reaction rate and its astrophysical implications

Abstract

A new thermonuclear ${}^{17}$O($n$,$\gamma$)${}^{18}$O rate is derived based on a complete calculation of the direct-capture (DC) and resonant-capture contributions, for a temperature region up to 2 GK of astrophysical interest. We have firstly calculated the DC and subthreshold contributions in the energy region up to 1 MeV, and estimated the associated uncertainties by a Monte-Carlo approach. It shows that the present rate is remarkably larger than that adopted in the JINA REACLIB in the temperature region of 0.01 $\sim$ 2 GK, by up to a factor of $\sim$80. The astrophysical impacts of our rate have been examined in both $s$-process and $r$-process models. In our main $s$-process model which simulates flash-driven convective mixing in metal deficient asymptotic giant branch stars, both ${}^{18}$O and ${}^{19}$F abundances in interpulse phases are enhanced dramatically by factors of $\sim 20$--$40$ due to the new larger ${}^{17}$O($n$,$\gamma$)${}^{18}$O rate. It shows, however, that this reaction hardly affects the weak $s$-process in massive stars since the ${}^{17}$O abundance never becomes significantly large in the massive stars. For the $r$-process nucleosynthesis, we have studied impacts of our rate in both the collapsar and neutron burst models, and found that the effect can be neglected, although an interesting "loophole" effect is found owing to the enhanced new rate, which significantly changes the final nuclear abundances if fission recycling is not involved in the model, however, these significant differences are almost completely washed out if the fission recycling is considered.

27 pages, 28 figures

References in corpus (15)

• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• Modules for Experiments in Stellar Astrophysics (MESA)
• Gravitational Waves and Gamma-rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A
• Modules for Experiments in Stellar Astrophysics (MESA): Pulsating Variable Stars, Rotation, Convective Boundaries, and Energy Conservation
• Galactic Chemical Evolution and solar s-process abundances: dependence on the 13C-pocket structure
• Current Status of r-Process Nucleosynthesis
• Neutron Reactions in Astrophysics
• s-Process Nucleosynthesis in Advanced Burning Phases of Massive Stars
• Carbon-Enhanced Metal-Poor Stars. III. Main-Sequence Turn-Off Stars from the SDSS/SEGUE Sample
• Databases and tools for nuclear astrophysics applications BRUSsels Nuclear LIBrary (BRUSLIB), Nuclear Astrophysics Compilation of REactions II (NACRE II) and Nuclear NETwork GENerator (NETGEN)
• Long-Term Evolution of Slowly Rotating Collapsar in Special Relativistic Magnetohydrodynamics
• Nuclear Reaction Screening, Weak Interactions, and r-Process Nucleosynthesis in High Magnetic Fields
• Thermonuclear 42Ti(p,gamma)43V rate in type I X-ray bursts
• Progress in Nuclear Astrophysics of East and Southeast Asia
• Contribution of collapsars, supernovae, and neutron star mergers to the evolution of r-process elements in the Galaxy

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