On Type Ia Supernovae From The Collisions of Two White Dwarfs
  We explore collisions between two white dwarfs as a pathway for making Type
Ia Supernovae (SNIa). White dwarf number densities in globular clusters allow
10-100 redshift <1 collisions per year, and observations by (Chomiuk et al.
2008) of globular clusters in the nearby S0 galaxy NGC 7457 have detected what
is likely to be a SNIa remnant. We carry out simulations of the collision
between two 0.6 solar mass white dwarfs at various impact parameters and mass
resolutions. For impact parameters less than half the radius of the white
dwarf, we find such collisions produce approximately 0.4 solar masses of Ni56,
making such events potential candidates for underluminous SNIa or a new class
of transients between Novae and SNIa.
