Speaker
Description
O-C shell mergers in massive stars have been proposed as a potential site for the production of p-process isotopes. These mergers provide a convective-reactive environment where the timescales for the nucleosynthesis of C-shell ashes such as $^{20}\mathrm{Ne}$ and convective mixing of species are of the same order. However, the nucleosynthetic pathways of these convective-reactive processes remain largely unexplored. In this study, we use the $15 M_\odot$, $Z=0.02$ model from the NuGrid stellar data set II (Ritter et al., 2018) to create a detailed post-processed model of an O-C shell merger event. Three preliminary experiments were conducted by varying the reaction rates of $^{20}\mathrm{Ne}(\gamma,\mathrm{p})^{16}\mathrm{O}$, the $(\gamma,\mathrm{p})$ rates for the odd-Z isotopes $^{31}\mathrm{P}$, $^{35}\mathrm{Cl}$, $^{39}\mathrm{K}$, $^{45}\mathrm{Sc}$, and all $(\mathrm{p},\gamma)$ rates by a factor of 10 up and down from their default values. The results show that altering the $^{20}\mathrm{Ne}(\gamma,\mathrm{p})^{16}\mathrm{O}$ rate has the strongest effect on the production of p-nuclei, notably $^{115}\mathrm{Sn}$, $^{138}\mathrm{La}$, $^{162}\mathrm{Er}$, $^{168}\mathrm{Yb}$, and $^{180}\mathrm{Ta}$. The other two experiments show a smaller impact on all isotopes. We will present the results of a full multizone Monte Carlo analysis of the impact from varying all reaction rates.
| Length of presentation requested | Oral presentation: 8 min + 2 min questions (Poster-type talk) |
|---|---|
| Please select a keyword related to your abstract | Stellar Models and Galactic Chemical Evolution |
