Integrated PN J = 2−1 spectrum extracted from the hot core. The upper panel shows the spectrum extracted from the 3 mm continuum contour shown in Fig. 1. The lower panel shows the spectrum extracted from a beam around the intensity peak of the 3 mm continuum. The red vertical lines indicate the expected velocities of the hyperfine components, and their length is proportional to the relative intensity of the components. The horizontal lines illustrate the 3σ rms level.