Spectra of HCN (black), H¹³CN (red, ×5), and HC¹⁵N (green, ×10) averaged within each Keplerian velocity channel (see, e.g., Table B.1) and within annuli of constant thickness 5 au, centered at 30, 40, and 50 au (from top to bottom). The specific intensity scale is K using K/(Jy beam⁻¹) conversion factors of 178.7, 188.1, and 189.0 for HCN, H¹³CN, and HC¹⁵N, respectively. The spectra are shifted vertically for the sake of legibility.