Off-center Collisions of two White Dwarfs: A Type Ia Supernova Progenitor Scenario.

We present 3D simulations of off-center collisions between two white dwarfs (WD) to explore the possibility of such events being part of the overall Type Ia Supernovae (SNIa) population. In particular, we investigate collisions of carbon-oxygen white dwarfs of various mass combinations and impact parameters using a combination of Lagrangian and Eulerian computational techniques. Pre-collision, the white dwarfs are evolved using SNSPH, an implementation of Smooth Particle Hydrodynamics (SPH), which ensures that the angular momentum of the system is conserved. At the point of contact between the WDs, the results are mapped onto FLASH, an Eulerian adaptive-grid code which is adept at capturing shock structures. Preliminary results indicate 0.0 - 0.5 solar masses of 56Ni and 0.1 - 0.3 solar masses of unburned carbon and oxygen, making such collisions a candidate for producing sub-luminous supernovae, such as SN 1991bg, SN 1992K, and SN 2005bl.