a) Virial parameter α = M_vir(r₁)/M_CO as a function of M_CO = 3.9   L_CO, for KOSMA-data. Data in Table 5. The numbers in the circles identify the clumps. In the absence of external pressure and magnetic fields, virial equilibrium is represented by α = 1. b) As a), but for SEST-data. Data in Table 6. For display purposes, clump 22 is not drawn at its real position, which is indicated with an arrow.