The Physics and End-Products of Merging CO WD Binaries

The merger of two carbon-oxygen white dwarfs has long been theorized to lead to a massive carbon-oxygen or oxygen-neon white dwarf, accretion-induced collapse to a neutron star, or a type Ia supernova. Determining which mergers lead to a particular outcome requires hydrodynamic simulations of the merging process. I give a brief overview of the current understanding of mergers and their end-products derived from simulations, and show how temperature, rather than density or mass, most strongly determines a merging binary's subsequent evolution. I then describe recent simulations that show mergers generate strong magnetic fields that could help drive a merger remnant to ignition.