Schematic representation of the position of the slits when the surface brightness profiles were extracted for the galaxy UGC 01040. Note that the slits were resized for each galaxy taking into account the corresponding galaxy size in order to analyse equivalent regions. Left: vertical slits used to extract the central vertical surface brightness profiles (central slit) and the shifted vertical profiles (two slits on the sides). Right: radial slits for obtaining the central radial surface brightness profile (central slit) and the shifted radial profiles (two slits above and below).