ALMA spectra (continuum subtracted) of Arp220W (left panel) and IRAS 17208-0014 (centre and right panels). The systemic velocities of HCN, HCO⁺ and HCN-VIB J = 4–3 and the H₂S lines are marked with dashed vertical lines. The self- and continuum absorption leads to double-peaked HCN and HCO⁺ν = 0 spectra while the HCN-VIB and H₂S lines are single-peaked close to systemic velocity (see Sect. 4.2). Half of the HCN-VIB is blended with the HCO⁺ line. Note that part of the HCO⁺ line is outside the band for Arp220W. We also detect lines of HC₃N and HC¹³CCN. Fluxes are in mJy beam^-1.