Occupation fraction of nuclear star clusters and active galactic nuclei versus host galaxy stellar mass (log₁₀ ). We combine the eRASS:4 data with the data from Baldassare et al. (2022) to gain statistical significance (green line). Literature data for NSCs & AGN come from Seth et al. (2008, gray line). In addition, we show the occupation fractions of AGN from the observational studies of Miller et al. (2015a) and Ohlson et al. (2023, blue and purple lines, respectively), and the computational results of Tremmel et al. (2023, red line).