The Evolution of Carbon Burning Flames Inside Super-Asymptotic Giant Branch Stars

We explore how carbon burning impacts the bifurcation region separating stars whose final fate is a massive white dwarf from stars whose final fate is a massive star supernova. A dense grid of models with initial mass (M_ini) from 6.0M_⊙ to 11.0M_⊙ are evolved from pre main-sequence to the end of nuclear burning using the open-source toolkit, Modules for Experiments in Stellar Astrophysics (MESA). For stars between 7.0M_⊙ <= M_ini <= 9.0M_⊙, energy losses at the center of the core due to neutrino cooling causes a temperature inversion resulting in off-center ignition. First ignition occurs where the minimum temperature of 7 .10⁸ K, and a density (ρ_crit) of 2 .10⁶ g/cm³ is met. We conclude that for stars within this range, the location of first ignition decreases as a function of initial mass. Moreover, we show that there exist a unique ignition density of 2 .10⁶ g/cm³.