A simple approach to the supernova progenitor–explosion connection

Abstract

We present a new approach to understand the landscape of supernova explosion\nenergies, ejected nickel masses, and neutron star birth masses. In contrast to\nother recent parametric approaches, our model predicts the properties of\nneutrino-driven explosions based on the pre-collapse stellar structure without\nthe need for hydrodynamic simulations. The model is based on physically\nmotivated scaling laws and simple differential equations describing the shock\npropagation, the contraction of the neutron star, the neutrino emission, the\nheating conditions, and the explosion energetics. Using model parameters\ncompatible with multi-D simulations and a fine grid of thousands of supernova\nprogenitors, we obtain a variegated landscape of neutron star and black hole\nformation similar to other parameterised approaches and find good agreement\nwith semi-empirical measures for the "explodability" of massive stars. Our\npredicted explosion properties largely conform to observed correlations between\nthe nickel mass and explosion energy. Accounting for the coexistence of\noutflows and downflows during the explosion phase, we naturally obtain a\npositive correlation between explosion energy and ejecta mass. These\ncorrelations are relatively robust against parameter variations, but our\nresults suggest that there is considerable leeway in parametric models to widen\nor narrow the mass ranges for black hole and neutron star formation and to\nscale explosion energies up or down. Our model is currently limited to an\nall-or-nothing treatment of fallback and there remain some minor discrepancies\nbetween model predictions and observational constraints.\n