Sensitivity of Double Detonation Type Ia Supernovae Simulations to Initial Conditions and Shock Treatment

Recent observations on peculiar Type Ia supernovae are indicative of sub-Chandrasekhar mass white dwarf (WD) progenitors. One such archetype of this progenitor is the double detonation model, in which a detonation in the accreted helium layer on the WD is initiated by a shock wave that compresses and heats the matter behind it to the point of ignition, keeping the shock wave sustained as it propagates around the star and towards the carbon-oxygen core. Upon converging at the core, the pressure wave can compress the carbon to fusion ignition, leading to a supernova. Despite observational and computational research supporting double detonations across various WD and helium shell masses, discrepancies remain in the initial conditions and parameters of such simulations. As such, we use the compressible hydrodynamics codes Castro to probe the varying of these initial conditions and determine their influence on the likelihood of a double detonation. We display the impact of spatial resolution on resolving the convergence of the pressure wave in the WD core and the efficiency of Castro when compared to the previously published literature. Additionally, we present the sensitivity of simulation results to the treatment of nuclear reactions in numerically broadened shock zones. Lastly, we demonstrate how the behavior of the initial helium detonation is extremely dependent on the chemical composition and temperature gradient present at the carbon-helium WD-accretion interface.