Projected rest-frame X-ray events from the TNG300 ligthcone in the 0.5−2.0 keV band for a telescope with energy-independent collecting area 1000 cm² and exposure time of 1000 ks. The events are generated using the hot gas cells within the TNG300 lightcone at redshifts 0.03−0.3 using pyXsim (ZuHone & Hallman 2016). The centre for the projection onto the sky is chosen as RA, Dec ≡ (0., 0.) degrees. The contours represent the two X-ray surface brightness levels of 5×10⁻¹⁴ erg s⁻¹ cm⁻² arcmin⁻² and 2×10⁻¹⁶ erg s⁻¹ cm⁻² arcmin⁻².