The stellar velocity dispersion of the central group galaxy versus the optical emission line widths from the MUSE sample. The central velocity dispersion of the ionized gas is shown with circles, while the different structures, such as filaments, clumps, rings, and off-central regions, are shown with stars. The gray dashed line represents the one-to-one relation, while the black dashed line corresponds to half of the stellar velocity dispersion. Filaments and rotating disks are color-coded with blue and orange color symbols, respectively.