Sequence of DEM distributions (left panels) and observed and calculated spectra (right) taken at five selected time intervals. Black and orange colours are related to the 1D-HD model and RESIK DEMs, respectively. The dots correspond to the values of average temperature and total emission measure (see the text) calculated from the DEM distributions. Right panels: RESIK measured spectra with uncertainties are shown in light orange. The synthetic spectra calculated based on DEM distributions (from left panel) are plotted in black and dark orange lines.