On the Systematics of Core-Collapse Explosions
  Recent observations of supernovae, supernova remnants, and radio pulsars suggest that there are correlations between pulsar kicks and spins, infrared and gamma-ray line profiles, supernova polarizations, and ejecta debris fields. A framework is emerging in which explosion asymmetries play a central role. The new perspective meshes recent multi-dimensional theoretical investigations of the explosion mechanism with trends in $^{56}$Ni yields and explosion kinetic energies. These trends imply that the mass above which black holes form after collapse is $\sim$30 M$_{\odot}$ and that supernova explosion energies may vary by as much as a factor of four. In addition, new neutrino-matter opacity calculations reveal that the inner cores of protoneutron stars are more transparent than hitherto suspected. This may have consequences for the delayed neutrino-driven mechanism of explosion itself. 
Adam Burrows