Rapid proton capture on accreting neutron stars -effects of uncertainty in the nuclear process

The rapid proton capture process on accreting neutron stars is investigated with the use of the current nuclear data and extended nuclear reaction networks. A simple but crucial model is adopted to investigate the detailed nucleosynthesis during the burst: the plane parallel (one zone) model. Compared with the results of Hanawa et al. (1983), significant differences are found. The peak temperature becomes higher due to the rapid break out from the hot CNO cycle. The amount of the fuel left after the burst depends on the still uncertain Q-values of (p, γ) reactions for nuclei like ⁶⁸Se. It is also demonstrated that the uncertainties in the nuclear data should influence significantly the profile of the light curve in the burst models.