Virial mass M_vir of the seven identified peaks, as in Table 3, vs. the total mass M_tot as in Table 1. We show both the virial mass computed only with our spectroscopic sample (red dots, Col. 6 of Table 3) and how it would change if we add to our sample other spectroscopic sources found in the literature (black crosses, Col. 9 of Table 3). Only peaks [1], [3], [4], and [5] have this second estimate of M_vir. The dotted line is the bisector, as a reference.