Left panel: velocity dispersion of the narrow component in the cores, shells-1 and shells-2. Shells-1 and shells-2 are defined as two consecutive shells of width equal to one beam around the respective coherent cores. The black-dotted line shows the velocity dispersion with at typical core temperature of T_K = 10 K. Right panel:same, but for the broad component. We note that as we do not consider the two-component fit to shell-1 of SR3 (see Sect. 5.5), the values for the core and shell-2 are connected by a dashed line.