Example of spectra and 2D slices from the four toy-model data sets. The ground truth $\widehat{Z}$ is shown in black, and the two data sets in purple and orange: X with the higher spatial resolution, and Y with the higher spectral resolution. (a) Gaussian model between 0.5 and 1.4 keV, (b) Gaussian model between 6.2 and 6.9 keV, (c) Gaussian model with rebinning between 0.5 and 1.4 keV, and (d) the Realistic model between 0.5 and 1.4 keV.