Absorption spectra of para H₂O at 244.330 GHz in R Hya, S Pav and RAql (blue profiles) and, emission/absorption spectra of the υ = 1 transition of CO(2−1) at 228.439 GHz in the same sources (red profiles). The spectra are converted from the observed frequency to the LSR systemic velocity using the H₂O line 5 (Table 2) and υ = 1, CO(2−1) rest frequencies. All spectra are extracted from the high resolution data cubes for an aperture diameter of 0.′′08. The vertical black dotted lines indicate the adopted new LSR systemic velocities (see Table 1).