Impacts of Nuclear Reaction Rate Uncertainties on Sub-Chandrasekhar-Mass White Dwarf Detonations

TL;DR

This study examines how uncertainties in nuclear reaction rates affect the nucleosynthesis outcomes of sub-Chandrasekhar-mass white dwarf detonations, finding that iron-group element yields are relatively unaffected.

Contribution

It provides the first detailed analysis of the impact of nuclear reaction rate uncertainties on nucleosynthesis in sub-Chandrasekhar-mass white dwarf detonations.

Findings

Iron-group element yields are insensitive to reaction rate uncertainties.

Identifies key nuclear reactions influencing nucleosynthesis.

Supports the robustness of sub-Chandrasekhar SN Ia models.

Abstract

The precise nature of Type Ia supernova (SN Ia) progenitors remains a mystery, but the detonation of a sub-Chandrasekhar-mass white dwarf (WD) has become a promising candidate. There is a growing body of work suggesting that the carbon core detonation of a sub-Chandrasekhar-mass WD can be triggered by the detonation of a helium shell accreted from a companion WD, through either inward shock convergence near the center or direct edge-lit detonation. This "double-detonation" SN Ia can be triggered by a small helium shell and is therefore well approximated by the detonation of a bare carbon-oxygen white dwarf (C/O WD). The impacts of uncertainties in experimentally and theoretically determined nuclear reaction rates on nucleosynthesis in the detonations of sub-Chandrasekhar-mass WDs have not yet been fully explored. We investigate the sensitivity of this model to nuclear reaction rate uncertainties to better constrain the nucleosynthetic yields resulting from these phenomena and identify the nuclear reaction rates whose uncertainties have the most significant impacts on nucleosynthesis. We find that the chemical abundances, and in particular those of the iron-group elements, are relatively insensitive to these nuclear reaction rate uncertainties.