Long-Term Multidimensional Models of Core-Collapse Supernovae: Progress and Challenges

Self-consistent, multidimensional core-collapse (CC) supernova (SN) simulations, especially in three dimensions, have achieved tremendous progress over the past 10 years. They are now able to follow the entire evolution from CC through bounce, neutrino-triggered shock revival, and shock breakout at the stellar surface to the electromagnetic SN outburst and the subsequent SN remnant phase. Thus they provide general support for the neutrino-driven explosion mechanism by reproducing observed SN energies, neutron star (NS) kicks, and diagnostically relevant radioactive isotope yields. They also allow prediction of neutrino and gravitational wave signals for many seconds of proto-NS cooling, confirm correlations between explosion and progenitor or remnant properties already expected from previous spherically symmetric (one-dimensional) and two-dimensional models, and carve out various scenarios for stellar-mass black hole (BH) formation. Despite these successes, it is currently unclear which stars explode or form BHs because different modeling approaches disagree and suggest the possible importance of the three-dimensional nature of the progenitors and of magnetic fields. The role of neutrino flavor conversion in SN cores needs to be better understood, the nuclear equation of state (including potential phase transitions) implies major uncertainties, the SN 1987A neutrino measurements raise new puzzles, and tracing a possible correlation of NS spins and kicks requires still more refined SN simulations.