We present zero impact parameter 3D collisions of white dwarfs using the Eulerian adaptive grid code FLASH for 0.64-0.64 M⊙ (henceforth 2x0.64) and 0.81-0.81 M⊙ (henceforth 2x0.81) pairings spanning a range of maximum spatial resolution from 5.2E7 to 1.2E7 cm. We find that the 2x0.64 head-on collision produces 0.32 M⊙ of Ni-56, and the 2x0.81 head-on collision produces 0.39 M⊙ of Ni-56. Both simulations also yield 0.2 M⊙ of unburned C-12+O-16, and their nucleosynthetic yields are consistent with those in subluminous supernova Type Ia. A parallel study carried out using a Lagrangian particle code SNSPH for the same configurations show larger Ni-56 production, 0.48 M⊙ of Ni-56 for the 2x0.64 collision and 0.84 M⊙ of Ni-56 for the 2x0.81 collision, and we apply a new SNSPH-to-FLASH mapping tool to compare the results. We find the Ni-56 yields from these models are similar to our initial simulations - 0.26 M⊙ of Ni-56 for the 2x0.64 collision and 0.36 M⊙ of Ni-56 for the 2x0.81 collision - indicating that the differences in 56Ni yields are not due to differences in pre-collision conditions. Instead, we attribute the differences in 56Ni production to differences in the pre-detonation pressure and temperature profiles. We explore the possible causes for these profile differences, and conclude that a higher pre-detonation peak temperature in SNSPH is the most likely cause.
American Astronomical Society Meeting Abstracts #219
- Pub Date:
- January 2012