A Simple Approach to the Supernova Progenitor-Explosion Connection
(18.02.2016)Zusammenfassung
We present a new approach to understand the landscape of supernova explosion
energies, ejected nickel masses, and neutron star birth masses. In contrast to
other recent parametric approaches, our model predicts the properties of
neutrino-driven explosions based on the pre-collapse stellar structure without
the need for hydrodynamic simulations. The model is based on physically
motivated scaling laws and simple differential equations describing the shock
propagation, the contraction of the neutron star, the neutrino emission, the
heating conditions, and the explosion energetics. Using model parameters
compatible with multi-D simulations and a fine grid of thousands of supernova
progenitors, we obtain a variegated landscape of neutron star and black hole
formation similar to other parameterised approaches and find good agreement
with semi-empirical measures for the "explodability" of massive stars. Our
predicted explosion properties largely conform to observed correlations between
the nickel mass and explosion energy. Accounting for the coexistence of
outflows and downflows during the explosion phase, we naturally obtain a
positive correlation between explosion energy and ejecta mass. These
correlations are relatively robust against parameter variations, but our
results suggest that there is considerable leeway in parametric models to widen
or narrow the mass ranges for black hole and neutron star formation and to
scale explosion energies up or down. Our model is currently limited to an
all-or-nothing treatment of fallback and there remain some minor discrepancies
between model predictions and observational constraints.