Results of BeeP analysis for M 100. See the caption of Fig. 7 for a full explanation. This case is interesting because BeeP has reduced EST_QUALITY due to the extremely low uncertainties in both temperature and spectral index (Sect. 5.2), in spite of the fact that the SEDs fit the data very well. However the χ² value of the Free-model fit (middle panel) is not far from the expected unity-per-degree of freedom level, and so this is one of those exceptional cases where the very low uncertainties reflect a very good fit, rather than the fact that the sampler has not been able to explore the parameter space.