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Abstract In order to better connect core-collapse supernova (CCSN) theory with its observational signatures, we have developed a simulation pipeline from the onset of the core collapse to beyond shock breakout from the stellar envelope. Using this framework, we present a 3D simulation study from 5 s to over 5 days following the evolution of a 17M_⊙progenitor, exploding with ∼10⁵¹erg of energy and ∼0.1M_⊙of⁵⁶Ni ejecta. The early explosion is highly asymmetric, expanding most prominently along the southern hemisphere. This early asymmetry is preserved to shock breakout, ∼1 day later. Breakout itself evinces strong angle-dependence, with as much as 1 day delay in the shock breakout by direction. The nickel ejecta closely tail the forward shock, with velocities at the breakout as high as ∼7000 km s⁻¹. A delayed reverse shock forming at the H/He interface on hour timescales leads to the formation of Rayleigh–Taylor instabilities, fast-moving nickel bullets, and almost complete mixing of the metal core into the hydrogen envelope. For the first time, we illustrate the angle-dependent emergent broadband and bolometric light curves from simulations evolved in 3D in entirety, continuing through hydrodynamic shock breakout from a CCSN model of a massive stellar progenitor evolved with detailed, late-time neutrino microphysics and transport. Our case study of a single progenitor underscores that 3D simulations generically produce the cornucopia of observed asymmetries and features in CCSNe observations, while establishing the methodology to study this problem in breadth. 

Abstract The two-moment method is widely used to approximate the full neutrino transport equation in core-collapse supernova (CCSN) simulations, and different closures lead to subtle differences in the simulation results. In this paper, we compare the effects of closure choices on various physical quantities in 1D and 2D time-dependent CCSN simulations with our multigroup radiation hydrodynamics code Fornax. We find that choices of the third-order closure relations influence the time-dependent simulations only slightly. Choices of the second-order closure relation have larger consequences than choices of the third-order closure, but these are still small compared to the remaining variations due to ambiguities in some physical inputs such as the nuclear equation of state. We also find that deviations in Eddington factors are not monotonically related to deviations in physical quantities, which means that simply comparing the Eddington factors does not inform one concerning which closure is better. 

Abstract Calibrating with detailed 2D core-collapse supernova (CCSN) simulations, we derive a simple CCSN explosion condition based solely upon the terminal density profiles of state-of-the-art stellar evolution calculations of the progenitor massive stars. This condition captures the vast majority of the behaviour of the one hundred 2D state-of-the-art models we performed to gauge its usefulness. The goal is to predict, without resort to detailed simulation, the explodability of a given massive star. We find that the simple maximum fractional ram pressure jump discriminant we define works well ∼90 per cent of the time and we speculate on the origin of the few false positives and false negatives we witness. The maximum ram pressure jump generally occurs at the time of accretion of the silicon/oxygen interface, but not always. Our results depend upon the fidelity with which the current implementation of our code F ornax adheres to Nature and issues concerning the neutrino–matter interaction, the nuclear equation of state, the possible effects of neutrino oscillations, grid resolution, the possible role of rotation and magnetic fields, and the accuracy of the numerical algorithms employed remain to be resolved. Nevertheless, the explodability condition we obtain is simple to implement, shows promise that it might be further generalized while still employing data from only the unstable Chandrasekhar progenitors, and is a more credible and robust simple explosion predictor than can currently be found in the literature.