Parameter recovery for an injected mock light curve from the Gaussian AFTERGLOWPY jet model. The corner plot shows the posterior contours at 68 and 95% credibility. Parameters correspond to the symbols in Table 1, σ_sys is the freely sampled systematic uncertainty. Different colors compare posteriors obtained with different sampling methods. The posterior in red is based on likelihood evaluations from the proper AFTERGLOWPY model with the NMMA sampler. The purple posterior relies on the FIESTA surrogate for the likelihood evaluation but uses the NMMA sampler. The light blue posterior uses the FIESTA surrogate as well but is sampled within FIESTA’s own inference framework that relies on FLOWMC. The injection parameters used to generate the mock light curve data are indicated by the orange lines. The insets on the upper right side show the injection data across the photometric filters and the best-fit light curve (i.e., highest likelihood) of the FIESTA posterior (lightblue) and the actual AFTERGLOWPY light curve used to generate the mock data (red). The latter lies almost completely underneath the former.