Comparison plot of grating spectra. Examples of the SSa class: comparison of high-resolution X-ray spectra of the two CNe KT Eri and V4743 Sgr. No scaling is necessary to fit both spectra in the same graph with the same units. In this figure as well as in Figs. 3, 4, 7, and 9, the top panel shows the entire wavelength range and legends with average error bars for each observation (left) and line/fill styles belonging to the corresponding target names (right) where the days in brackets are days after t₀ in Table 2. The panels below show details, with some overlap spectral ranges. Prominent bound-bound transitions are marked with vertical lines at their rest wavelengths, and a label on top of each line gives the corresponding element/ion descriptor.