Convection and neutrino emission in the late stages of massive star evolution

It is argued that the treatment of convection, particularly the choice of mixing length, is a large source of uncertainty in the last stages of nuclear burning and thus in the development of iron cores for Type II supernovae. This sensitivity is the result of the delicate competition between convective energy transport and neutrino emission processes which become large during and after core carbon burning in stars with mass larger than ∼10 M ○. . The role of the mixing length in standard treatments of convection is discussed, followed by demonstrations of how convection and neutrino emission affect the size of convective regions. The evidence for these effects can be seen in calculations of the core carbon burning phase by several groups