Effect of $^{12}C+$ $^{12}C$ Reaction & Convective Mixing on the Progenitor Mass of ONe White Dwarfs

TL;DR

This paper examines how the $^{12}C+^{12}C$ fusion reaction rate and convective mixing influence the critical stellar mass ($M_{up}$) that determines whether stars develop into ONe white dwarfs or undergo supernovae, using detailed stellar models.

Contribution

It provides new insights into the sensitivity of the transition mass $M_{up}$ to recent nuclear reaction rates and convective mixing treatments in stellar evolution models.

Findings

The $^{12}C+^{12}C$ fusion rate significantly affects $M_{up}$.

Convective core extension during hydrogen and helium burning alters $M_{up}$.

Detailed stellar models illustrate the impact of nuclear physics uncertainties on stellar evolution outcomes.

Abstract

Stars in the mass range ~8 - 12 $M_{\odot }$ are the most numerous massive stars. This mass range is critical because it may lead to supernova (SN) explosion, so it is important for the production of heavy elements and the chemical evolution of the galaxy. We investigate the critical transition mass ($M_{up}$), which is the minimum initial stellar mass that attains the conditions for hydrostatic carbon burning. Stars of masses < $M_{up}$ evolve to the Asymptotic Giant Branch and then develop CO White Dwarfs, while stars of masses $\geqslant $ $M_{up}$ ignite carbon in a partially degenerate CO core and form electron degenerate ONe cores. These stars evolve to the Super AGB (SAGB) phase and either become progenitors of ONe White Dwarfs or eventually explode as electron-capture SN (EC-SN). We study the sensitivity of $M_{up}$ to the C-burning reaction rate and to the treatment of convective mixing. In particular, we show the effect of a recent determination of the $^{12}C+$ $^{12}C$ fusion rate, as well as the extension of the convective core during hydrogen and helium burning on $M_{up}$ in solar metallicity stars. We choose the 9$M_{\odot }$ model to show the detailed characteristics of the evolution with the new C-burning rate.