  It has been suggested that whether a star explodes or not, and what kind of
explosion properties it shows, is strongly dependent on the progenitor's core
structure. We present the results from 101 axisymmetric core-collapse supernova
simulations performed with progenitors spanning initial masses in the range
from 10.8 to 75 solar masses, and focus on their connections to the compactness
of the progenitor's core. Our simulations confirm a correlation between the
neutrinos emitted during the accretion phase and the progenitor's compactness.
We suggest that the ratio of observed neutrino events during the first hundreds
of milliseconds can be used to infer the progenitor's inner mass density
structure.
