X-ray spectroscopy. Background-subtracted STIX count spectra (black) and best fit (green) from the sum of an isothermal (blue) and a thick target (red) component for November 10, 2022 for four time intervals during the flare evolution (indicated in Fig. 7). Gray vertical lines on the data points indicate the error bars of the count rate. The gray dashed line shows the preflare background spectrum. The red vertical lines show the considered energy range.