Spectral fits to the HCO⁺ and HCN-vib J = 4 − 3 lines in the two galaxies IRAS 05189–2524 and IRAS 12224–0624. The solid black histograms represent the data and the solid magenta lines indicate the best fits to the data. The velocity scale is set relative to the frequency of the HCO⁺J = 4 − 3 line. Dashed vertical lines indicate the expected positions of the HCO⁺ and HCN-vib J = 4 − 3 lines given the adopted redshifts. The dotted lines in the plot for IRAS 05189–2524 indicate the expected positions given the redshift adopted by Veilleux et al. (2013).