Sensitivity of ${^{44}}$Ti and ${^{56}}$Ni production in CCSN shock-driven nucleosynthesis to reaction rates

TL;DR

This study investigates how uncertainties in nuclear reaction rates affect the production of ${^{44}}$Ti and ${^{56}}$Ni in core-collapse supernova models, highlighting key reactions and the need for further sensitivity analyses.

Contribution

It identifies specific nuclear reactions that significantly influence ${^{44}}$Ti and ${^{56}}$Ni synthesis in supernova models, expanding on previous sensitivity studies.

Findings

Certain reactions strongly impact nucleosynthesis, especially in lower-mass progenitors.

The list of influential reactions from prior studies is likely incomplete.

Reaction rate uncertainties can alter predicted isotope yields.

Abstract

Recent observational advances have enabled high resolution mapping of ${^{44}}$Ti in core-collapse supernova (CCSN) remnants. Comparisons between observations and models provide stringent constraints on the CCSN mechanism. However, past work has identified several uncertain nuclear reaction rates that influence ${^{44}}$Ti and ${^{56}}$Ni production in post-processing model calculations. We evolved one dimensional models of $15~M_{\odot}$, $18~M_{\odot}$, $22~M_{\odot}$ and $25~M_{\odot}$ stars from zero-age main sequence through CCSN using {\tt MESA} (Modules for Experiments in Stellar Astrophysics) and investigated the previously identified reaction rate sensitivities of ${^{44}}$Ti and ${^{56}}$Ni production. We tested the robustness of our results by making various assumptions about the CCSN explosion energy and mass-cut. We found a number of reactions that have a significant impact on the nucleosynthesis of ${^{44}}$Ti and ${^{56}}$Ni, particularly for lower progenitor masses. Notably, the reaction rates $^{13}{\rm N}(\alpha,p)^{16}{\rm O}$, $^{17}{\rm F}(\alpha,p)^{20}{\rm Ne}$, $^{52}{\rm Fe}(\alpha,p)^{55}{\rm Co}$, $^{56}{\rm Ni}(\alpha,p)^{59}{\rm Cu}$, $^{57}{\rm Ni}(n,p)^{57}{\rm Co}$, $^{56}{\rm Co}(p,n)^{56}{\rm Ni}$, $^{39}{\rm K}(p,\gamma)^{40}{\rm Ca}$, $^{47}{\rm V}(p,\gamma)^{48}{\rm Cr}$, $^{52}{\rm Mn}(p,\gamma)^{53}{\rm Fe}$, $^{57}{\rm Co}(p,\gamma)^{58}{\rm Ni}$, and $^{39}{\rm K}(p,\alpha)^{36}{\rm Ar}$ are influential for a large number of model conditions. Furthermore, we found the list of influential reactions identified by previous post-processing studies of CCSN shock-driven nucleosynthesis is likely incomplete, motivating future larger-scale sensitivity studies.