radiation-hyrodynamic simulations of @mueller2012 to test the validity of the general principles inferred from the parametric models. The @mueller2012 models follow the evolution of a star of mass $8.1M_\odot$ and metallicity $Z=10^{-4}$ (A. Heger 2013, private communication), and a $27M_\odot$ star of solar metallicity [@woosley02]. The code employed is VERTEX-CoCoNuT [@mueller2010], which treats multi-group neutrino transport using the ‘ray-by-ray-plus’ approach [@rampp02; @bruenn2006; @buras06a].

These two successfully exploding models follow very different paths on their way to runaway expansion. The $8.1M_\odot$ progenitor (model u8.1) becomes dominated by convection shortly after the shock stalls, and remains so until runaway sets in. In contrast, the $27M_\odot$ model (s27) develops a strong SASI throughout the evolution.

Results {#s:results}
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Transition to Explosion
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We first concentrate on the differences in the transition to explosion introduced by the initial dominance of the SASI or convection. To this end, we focus the discussion on models that bracket the critical heating rate for explosion (Table \[t:models\]). We then discuss the effect of different initial perturbations on exploding models.

![Time-series diagnostics for SASI-dominated models below and above the threshold for explosion (p0B08L1 and p0B10L1, respectively). The $\ell=1$ SASI mode is excited with an overdense shell. The top panels 