Flame fronts in Supernovae Ia and their pulsational stability

TL;DR

This paper investigates the structure and stability of deflagration flames in Type Ia supernovae, finding that these flames are stable against pulsations due to their low Zeldovich number, with implications for supernova modeling.

Contribution

It provides new calculations of flame parameters and analyzes pulsational stability considering hydrodynamics and realistic conditions.

Findings

Flame velocity and thickness are consistent with previous studies.

Pulsation instability occurs only at artificially increased Zeldovich numbers.

Type Ia supernova flames are stable against pulsations under realistic conditions.

Abstract

The structure of the deflagration burning front in type Ia supernovae is considered. The parameters of the flame are obtained: its normal velocity and thickness. The results are in good agreement with the previous works of different authors. The problem of pulsation instability of the flame, subject to plane perturbations, is studied. First, with the artificial system with switched-off hydrodynamics the possibility of secondary reactions to stabilize the front is shown. Second, with account of hydrodynamics, realistic EOS and thermal conduction we can obtain pulsations when Zeldovich number was artificially increased. The critical Zeldovich numbers are presented. These results show the stability of the flame in type Ia supernovae against pulsations because its effective Zeldovich number is small.