Simulated two-temperature spectrum and best fitting one-temperature model. The simulated spectrum and its components are plotted in red, the 1.8 keV and 3.6 keV components are shown as a dotted and dashed line, respectively, while the total spectrum is shown as a solid line. The best fitting one-temperature model is shown as a solid black line. Both the simulation and the fit were performed in a broad energy band, 0.5–10.0 keV; however, here we show only the 0.7–4.0 keV range. The one-temperature model does an adequate job of reproducing the shape of the L-shell blend arising from the two-temperature spectrum (for a more detailed discussion see text and Gastaldello et al. 2010). Given the didactic nature of this simulation, background components have not been included; these contributions will make attempts to discriminate between different spectral models even more arduous.