|Abstract: We model shock-cooling emission in the first hours and days of core-collapse supernovae (SNe). A decade of fitting the observed emission to analytic models has shed light on the properties of the progenitor star, but despite its potential, fitting has also led to some inconsistent results, at times in disagreement with other measurement methods.
We provide a frequency-dependent analytic formula for the spectral energy distribution (SED), derived from first principles, and carefully calibrated to multigroup numerical simulations with realistic opacity. We choose a simplified system with few free parameters. We span a large parameter space and show insensitivity to deviations from idealized ‘polytropic’ stellar structure.
Recently in a systematic analysis of dozens of SNe, our model was used to show that ~70% of type II SNe are well described by simple shock-cooling, with progenitor radii consistent with observed RSG’s in the field. Apart from being a new scientific claim about the state of the progenitors, this result provides confidence in early-time emission fitting and in our method.