H₂CO 3_1,2 − 2_1,1, CS 5− 4, and CN 2−1 spectra integrated over a 0′′.33–0′′.75 ring area (top panels) and over a 3′′ circular area (bottom panels). The vertical dashed lines indicate the systemic velocity, V_sys = + 6.24 km s⁻¹. For CN 2−1, the velocity scale corresponds to the brightest of the three hyperfine components at 226.87 GHz reported in Table 1 (N = 2−1, J = 5∕2−3∕2, F = 7∕2−3∕2), and the position of the two fainter components is indicated by the vertical dashed lines.