Observations of ¹²CO (2−1) emission in the DL Tau disk. Shown are the channel map of the observed line brightness distribution (left), the moment-zero map (top right), and the integrated spectrum (bottom right). The channel map shows 16 velocity channels with a step of 0.5 km s⁻¹ in the [−4.5, +4.5] km s⁻¹ range around the systemic velocity. The contour lines start at 2 K, with a step of 2 K. The color bar shows line brightness temperatures (K). The contour lines in the moment-zero plot start at 3, 6, and 9σ, with a step of 6σ afterward. The 1σ rms noise (mJy km s⁻¹) is shown in the upper left corner of the moment-zero plot, and the synthesized beam is depicted by the dark ellipse in the left bottom corner.