Level structure of S-30: Implications for the astrophysical P-29(p, gamma)S-30 reaction rate in ONe novae and x-ray bursts

A gamma-ray spectroscopy study of S-30 is presented. Excitation energies have been determined with improved precision over previous studies and firm spin-parity assignments have been made for key P-29 + p resonant states. An evaluation of the P-29(p, gamma)S-30 reaction for T = 0.08-2.5 GK shows that the 3(+) and 2(+) resonant states located at E-r = 289(3) and 410(3) keV, respectively, dominate the P-29(p, gamma)S-30 reaction rate in ONe novae, while the 410-keV resonance is expected to govern the rate in x-ray burster environments. These new, precise resonance energy measurements and firm spin-parity assignments have significantly reduced uncertainties in the P-29(p, gamma)S-30 reaction in ONe novae and x-ray bursts. In particular, the reaction rate is now specified precisely enough for calculations of isotopic abundances in ONe novae ejecta.