Exploring the Efficacy and Limitations of Shock-cooling Models: New Analysis of Type II Supernovae Observed by the Kepler Mission

Modern transient surveys have begun discovering and following supernovae (SNe) shortly after first light - providing systematic measurements of the rise of Type II SNe. We explore how analytic models of early shock-cooling emission from core-collapse SNe can constrain the progenitor's radius, explosion velocity, and local host extinction. We simulate synthetic photometry in several realistic observing scenarios; assuming the models describe the typical explosions well, we find that ultraviolet observations can constrain the progenitor's radius to a statistical uncertainty of ±10%-15%, with a systematic uncertainty of ±20%. With these observations the local host extinction (A _V) can be constrained to a factor of two and the shock velocity to ±5% with a systematic uncertainty of ±10%. We also reanalyze the SN light curves presented by Garnavich et al. (2016) and find that KSN 2011a can be fit by a blue supergiant model with a progenitor radius of R_s < 7.7 + 8.8 (sat) + 1.9 (sys)R, while KSN 2011d can be fit with a red supergiant model with a progenitor radius of R_s=111 _-21(stat)^+89(stat)_-1(sys)^-49(sys) R. Our results do not agree with those of Garnavich et al. Moreover, we re-evaluate their claims and find that there is no statistically significant evidence for a shock-breakout flare in the light curve of KSN 2011d.