Schedule Mar 23, 2007
Type Ia Progenitor Rotation: Accretion and Simmering
Tony Piro (UC Berkeley)

Authors: Anthony Piro and Lars Bildsten

During the accretion process that grows a white dwarf (WD) toward a Chandrasekharmass, a WD gains substantial angular momentum and thus is expected to be quicklyrotating. Shear present within this rotating profile represents free energy that couldpotentially dissipate as heat. The thermal and shearing profile of a WD has importantimplications for the subsequent flame propagation during a Type Ia supernovae. Wehighlight processes that could affect the WD shear, during both accretion as well as the~1000 years of simmering that take place after carbon ignites but before a deflagrationbegins. Baroclinic instabilities and/or the growth of small magnetic fields providesufficient torque to bring the WD very close to solid body rotation during accretion.Once carbon ignites and a convective region grows at the WD's center during carbonsimmering, the redistribution of angular momentum by convection results in significantshearing.

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