Abstract:
We refine our previously introduced parameterized model for explosive carbon–oxygen fusion during
thermonuclear Type Ia supernovae (SNe Ia) by adding corrections to post-processing of recorded Lagrangian
fluid-element histories to obtain more accurate isotopic yields. Deflagration and detonation products are verified for
propagation in a medium of uniform density. A new method is introduced for reconstructing the temperature–
density history within the artificially thick model deflagration front. We obtain better than 5% consistency between
the electron capture computed by the burning model and yields from post-processing. For detonations, we compare
to a benchmark calculation of the structure of driven steady-state planar detonations performed with a large nuclear
reaction network and error-controlled integration. We verify that, for steady-state planar detonations down to a
density of 5 × 106 g cm−3
, our post-processing matches the major abundances in the benchmark solution typically
to better than 10% for times greater than 0.01 s after the passage of the shock front. As a test case to demonstrate
the method, presented here with post-processing for the first time, we perform a two-dimensional simulation of a
SN Ia in the scenario of a Chandrasekhar-mass deflagration–detonation transition (DDT). We find that
reconstruction of deflagration tracks leads to slightly more complete silicon burning than without
reconstruction. The resulting abundance structure of the ejecta is consistent with inferences from spectroscopic
studies of observed SNe Ia. We confirm the absence of a central region of stable Fe-group material for the multidimensional
DDT scenario. Detailed isotopic yields are tabulated and change only modestly when using
deflagration reconstruction.
