A New17F(p, γ)18Ne Reaction Rate and Its Implications for Nova Nucleosynthesis

Abstract

Proton capture by 17F plays an important role in the synthesis of nuclei in nova explosions. A revised rate for this reaction, based on a measurement of the 1H(17F, p)17F excitation function using a radioactive 17F beam at Oak Ridge National Laboratory's Holifield Radioactive Ion Beam Facility, is used to calculate the nucleosynthesis in nova outbursts on the surfaces of 1.25 and 1.35 M☉ ONeMg white dwarfs and a 1.00 M☉ CO white dwarf. We find that the new 17F (p, γ)18Ne reaction rate changes the abundances of some nuclides (e.g., 17O) synthesized in the hottest zones of an explosion on a 1.35 M☉ white dwarf by more than a factor of 104 compared to calculations using some previous estimates for this reaction rate, and by more than a factor of 3 when the entire exploding envelope is considered. In a 1.25 M☉ white dwarf nova explosion, this new rate changes the abundances of some nuclides synthesized in the hottest zones by more than a factor of 600, and by more than a factor of 2 when the entire exploding envelope is considered. Calculations for the 1.00 M☉ white dwarf nova show that this new rate changes the abundance of 18Ne by 21% but has negligible effect on all other nuclides. Comparison of model predictions with observations is also discussed.