SRG/eROSITA best-fit spectra of one of the sources included in the sample (4FGL J0543.9–5531). The black data points show the observations, and the solid red line corresponds to the best-fit model including the IGM component. The bottom panels show the data-model ratio for the models without and with the IGM component (see Sect. 3 for further details). All cameras were grouped for illustration purposes.