Effective ICM emissivity ϵ_c in terms of the 0.4–2 keV count rate per SRG/eROSITA telescope module (with the FOV-averaged effective area) as a function of the ICM temperature. The assumed spectral shape is given by the APEC model at redshifts z = 0 (black), 0.5 (blue), 1(cyan), 1.5 (green), 2 (red) with the metals abundance varying from Z∕Z_⊙ = 0.3 (long-dashed) to Z∕Z_⊙ = 0.6 (solid) to Z∕Z_⊙ = 1 (short-dashed) with respect to the Solar metallicity Z_⊙. The applied foreground absorption column density equals to N_H = 10²⁰ cm⁻².