comparable with observations. In fact, in the literature the observed samples usually provide a single-value galaxy velocity dispersion for each object, which is obtained from the broadening of distinct spectral features due to the internal motions of the stars. This measure is an integrated quantity over a galactocentric radius generally determined by telescope aperture or detection limit. The model on the other hand outputs intrinsic, physical galaxy properties, thus the comparison with the observed spectral line dispersion requires *1)* the definition of a ’model aperture radius’ inside which to compute the velocity dispersion, and *2)* the definition of an integrated velocity dispersion inside this radius.

In defining such a radius, there are two factors to consider: *1)* the galaxy dynamics becomes increasingly dark matter-dominated at larger galactocentric distances, but *2)* the only visible tracers of the galaxy velocity dispersion are the stars in the bulge, since the disk is modeled as completely rotation-supported. Therefore, if we were to ’observe’ a model galaxy, the entirety of the velocity dispersion signal in the spectral features would come from the stars in the bulge. For this reason, we assume that the ’model aperture radius’ corresponds to the bulge outer limit. The latter is 