Spectral line profiles. Lines in the first row (detected) are integrated over three rings at different radii: 0′′ –0.2′′ (the inner hole), 0.5′′–2.0′′ (the main region), and 3.5′′–4.5′′ (the outer region). The shaded region highlights the profile from the inner hole. Arrows on the CN line profile denote the presence of blended lines. For lines in the second row (undetected) only the profile over the main region is shown. For these lines, the profile is obtained by averaging all available lines for that species. The vertical line indicates the systemic velocity of the source (6.4 km s⁻¹).