Zoom into the MEG spectrum (at HWHM resolution) at the energies of the Mg xi and Si xiii triplets when modeled with the addition of a thermal emission model (blue dotted line). The upper panel shows the Mg xi region, where the mekal component can reproduce the entire profile with no need of an additional Gaussian emission line component. The lower panel shows that to reproduce the Si xiii triplet, we need to include a strong emission line component (magenta line) to account for the residual emission at the energy of the forbidden line. In both panels the red line shows the best-fit model where we included a mekal component (see Sect. 4.1.1).