Position‐velocity plot of the H¹³CN ﹩J=1\rightarrow 0﹩ emission along the disk plane at ﹩\mathrm{P.A.}\,=60\fdg 0﹩. Positive offsets are to the northeast. The velocity gradient is seen in all three hyperfine lines. The velocity scale is relative to the strongest hyperfine component, ﹩F=2{\mbox{--}} 1﹩, centered at a systemic velocity of ~−56 km s﹩^{-1}﹩. The line drawing at the bottom of the plot shows the position of three hyperfine components and their relative intensity. The disk emission is redshifted to the southwest and blueshifted to the northeast (see text).