Covering fraction of X-ray emission from satellite circumgalactic media in TNG-Cluster. We measure the projected covering fraction of satellites soft X-ray (0.5−2.0 keV) emission to total for the 352 clusters at z = 0 for two cases: above a given fixed satellite surface brightness threshold (left panel) and above a given satellite-to-total fractional local threshold (right panel). The fiducial threshold choices are shown for varying cluster-centric apertures. Thick curves are the medians across all clusters, shaded regions enclose the 16th and 84th percentiles, and points are the individual clusters, where we manually place clusters with satellite covering fractions < 10⁻² between 10⁻² and 10^−2.5. In both panels when varying the minimum threshold we use the fiducial aperture of < 1.0 R_200c, and when varying the aperture we use the intermediate threshold (> 10³⁵ erg s⁻¹ kpc⁻² in the left panel; > 10% contribution in the right panel). The collection of satellite CGM can contribute to a significant portion of the cluster’s projected area, and at larger surface brightness or satellite-to-total fractional thresholds there is more halo to halo variation.