VLT/MUSE mean stacked normalised spectra of 14, 6, 17, and 27 member galaxies of A2744, AS1063, M0416, and M1149, respectively, with σ > 180 km s⁻¹ and S/N > 15. The shaded regions are the standard deviation of each spectral pixel. The spectra are smoothed with a Gaussian kernel with a standard deviation of 3.75 Å. The red dashed vertical lines locate the absorption features detected in the spectra. For clearer visualisation, the normalised flux values from AS1063, M0416, and M1149 have been increased by 1, 2, and 3, respectively.