Continuum-subtracted CO line profiles in the two nuclei. Note the deep absorption features at the centers of the eastern nucleus and western nucleus. High-velocity outflows seen in ¹²CO J = 3 → 2 are highlighted in yellow. The line profiles were extracted at the center of the continuum emission at 427.8 GHz (i.e., 15:34:57.292, +23.30.11.33 and 15:34:57.223, +23.30.11.49) for the eastern and western nuclei, respectively. This is because each fitted continuum center location is different by one to two pixels, with the 427.8 GHz continuum having the median center location of the three data sets. The assumed rest frequency of ¹²CO J = 3 → 2 is 345.796 GHz and ¹³CO J = 4 → 3 is 440.765 GHz. ¹²CO J = 6 → 5 observations are from Rangwala et al. (2015). For ¹²CO J = 3 → 2, 1 Jy/beam = 248 K, for ¹³CO J = 4 → 3, 1 Jy/beam = 294.5 K, and for ¹²CO J = 6 → 5, 1 Jy/beam = 30 K. The systemic velocity of the CO lines is shown as vertical dashed black lines. The systemic velocity of the other lines is shown by the corresponding colored vertical dashed lines. In addition, the systemic velocity of the H¹³CN J = 4 → 3 line that may contaminate some of the CO J = 3 → 2 emission and the H¹³CO + J = 4 → 3 line that may contaminate some of the SiO J = 8 → 7 absorption are shown.