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

• Published in: The Astrophysical journal Vol. 656; no. 1; pp. 313 - 332
• Main Authors: Calder, A. C, Townsley, D. M, Seitenzahl, I. R, Peng, F, Messer, O. E. B, Vladimirova, N, Brown, E. F, Truran, J. W, Lamb, D. Q
• Format: Journal Article
• Language: English
• Published: Chicago, IL IOP Publishing 10.02.2007; University of Chicago Press
• Subjects: Astronomy; Earth, ocean, space; Exact sciences and technology; Energetics; Type I supernova; White dwarf stars; nuclear reactions, nucleosynthesis, abundances; white dwarfs; Nucleosynthesis; Abundance; Neutronization; hydrodynamics; supemovae: general
• ISSN: 0004-637X; 1538-4357
• DOI: 10.1086/510709

We develop and calibrate a realistic model flame for hydrodynamic simulations of deflagrations in white dwarf (Type Ia) supernovae. Our flame model builds on the advection-diffusion-reaction model of Khokhlov and includes electron screening and Coulomb corrections to the equation of state in a self-consistent way. We calibrate this model flame--its energetics and timescales for energy release and neutronization--with self-heating reaction network calculations that include both these Coulomb effects and up-to-date weak interactions. The burned material evolves postflame due to both weak interactions and hydrodynamic changes in density and temperature. We develop a scheme to follow the evolution, including neutronization, of the NSE state subsequent to the passage of the flame front. As a result, our model flame is suitable for deflagration simulations over a wide range of initial central densities and can track the temperature and electron fraction of the burned material through the explosion and into the expansion of the ejecta.