Position-velocity diagram of the CH₃OH 5_0,5–4_0,4 E transition in OB cluster forming region G10.6-0.4 (contour; see Fig. 3 of Liu et al. 2011 for the comparisons with other CH₃OH excitation levels and the NH₃ (3, 3) hyperfine lines), and the model PV curve (red curve). The pv cut is centered at the coordinates of RA = 18^h10^m28.64^s and Dec = −19°55′49.22′′ with position angle PA = 140°. Positive angular offsets are southeast of the center. Contour levels are 0.36 Jy beam^-1 × [ 1, 2, 3, 4, 5, 6, 7]. The resolution of this CH₃OH observation is 1.̋5 × 1.̋3, and the rms noise level is 0.06 Jy beam^-1. The dashed line marks the cloud systemic velocity of −3 km s^-1. The face-on view of the model filamentary spiral structure is also plotted on the same physical scale (blue curve; assuming observers are viewing this structure from the left, and assuming the same spatial scales in the horizontal and vertical directions).