Top: HCN rovibrational spectra (v₂ = 1 J = 3− 2 e∕f) observed with ALMA. The spectra are extracted from the inner 1″ region with red and blue denoting the e and f vibronic angular momentum quantum number, respectively. The black spectrum shows the stacked spectrum of the two lines, allowing a more stringent upper limit on the transition. Bottom: fundamental v = 1− 0 CO vibrational spectra taken with the VLT/CRIRES (Herczeg et al. 2011). The shown ¹²CO spectrum is the co-added rotational line profiles from R(3) to P(9), while the ¹³CO spectrum includes co-added R(10) to P(9). The green vertical solid line is the systemic velocity of the system, while the red horizontal dashed line indicates the baseline.