Multi-dimensional models of Type Ia supernovae

Type Ia supernovae (SNe Ia) exhibit a significant diversity in their observables suggesting that a variety of progenitor channels and/or explosion mechanisms contribute to this class of objects. Understanding the origin of the diversity is essential for applying SNe Ia as distance indicators in cosmology and for studying their role in cosmic nucleosynthesis. Multi-dimensional simulations of SN Ia explosions allow for a consistent treatment of the underlying physical mechanisms. Consequently, their predictive power enables a direct comparison with observations. This way, the validity of different explosion scenarios can be assessed. Based on a comprehensive sequence of modeling taking into account aspects of population synthesis, multi-dimensional hydrodynamic explosion simulations, nucleosynthetic postprocessing, and radiative transfer calculations, the capability of different explosion scenarios to reproduce SN Ia observations is discussed. Although traditional Chandrasekhar-mass models are promising candidates for explaining "normal" SNe Ia, the corresponding progenitors may not be numerous enough to account for their rate. Explosions of sub-Chandrasekhar mass white dwarfs provide a potential alternative. The observables predicted for violent mergers of two white dwarfs, however, resemble a class of sub-luminous SNe Ia rather than the bulk of normal events. An accurate modeling of the nucleosynthesis in SN Ia explosions is found to be critical not only for drawing conclusions on their impact on galactic chemical evolution, but also for the predicted observables.