The Laminar Flame Speedup by Neon-22 Enrichment in White Dwarf Supernovae

We explore how the thermonuclear burning in a type Ia supernovae is influenced by the composition of the progenitor white dwarf. Type Ia supernovae are one of the premier tools for measuring cosmological properties. Recent observations have suggested that there may be more than one population of progenitor, and the peak luminosity may depend on the composition of the white dwarf. Of particular interest is ²²Ne, which is formed during core He burning on the horizontal branch and reflects the CNO abundance of the progenitor main-sequence star. Our focus here is on how the addition of ²²Ne affects the rate of carbon burning. We find that the laminar flame speed of a C/O mixture is enhanced when it is enriched with small amounts of ²²Ne. This Increase in the laminar flame speed is most important in two regimes, just after ignition near the center of the white dwarf, where the laminar flame speed dominates over the rising of buoyant hot ash, and in regions of lower density 10⁷ g cm^-3 where a transition to distributed burning is conjectured to occur.