Maps of projected stellar surface brightness and GW progenitor merger surface density events for the BBH, BHNS, and BNS channels (clockwise from the right, as indicated in the figure). The maps are centered on the most massive FoF halo of the MTNG740 run and have a side length of 5 Mpc. The stellar map was obtained by mapping the g, r, and z photometric bands to the blue, green, and red channels of the figure, respectively, with intensities linearly scaled over the interval [20, 30] mag arcsec⁻². For the GW progenitor merger rate events, only compact binary mergers occurring at z < 0.1 are considered. The values are logarithmically scaled over the interval [10⁻⁸, 10⁻²] pc⁻².