Capturing the Fire: Flame Energetics and Neutronization for Type Ia Supernova Simulations

We develop and calibrate a realistic model flame for hydrodynamicalsimulations of deflagrations in white dwarf (Type Ia) supernovae. Our flamemodel builds on the advection-diffusion-reaction model of Khokhlov and includeselectron screening and Coulomb corrections to the equation of state in aself-consistent way. We calibrate this model flame--its energetics andtimescales for energy release and neutronization--with self-heating reactionnetwork calculations that include both these Coulomb effects and up-to-dateweak interactions. The burned material evolves post-flame due to both weakinteractions and hydrodynamic changes in density and temperature. We develop ascheme to follow the evolution, including neutronization, of the NSE statesubsequent to the passage of the flame front. As a result, our model flame issuitable for deflagration simulations over a wide range of initial centraldensities and can track the temperature and electron fraction of the burnedmaterial through the explosion and into the expansion of the ejecta.Comment: 21 pages, 24 figures, to appear in Ap