Distribution of CO, C¹⁸O and H₂ gas. (a) CO (J = 1−0) integrated intensity map, W_co, is overlaid with the C¹⁸O (J= 1−0) integrated intensity contours. The integrated velocity ranges are [1.3, 6.1] km s⁻¹ for CO (J = 1−0) and [2.5, 4.2] km s⁻¹ for C¹⁸O (J= 1−0). The color bar represents the CO (J = 1−0) integrated intensity in units of Κ km s⁻¹, while the contours start at 0.54 Κ km s⁻¹ and increase by 0.54 Κ km s⁻¹. (b) C¹⁸O (J = 1−0) integrated intensity map, is overlaid with the H₂ column density black contours from the near infrared extinction map (Juvela & Montillaud b2016). The color bar represents the C¹⁸O (J = 1−0) integrated intensity in units of Κ km s⁻¹. The black contours start at 3 × 10²¹ cm^-2 and increase by 3 × 10²¹ cm^-2, (c) Extinction-based H₂ column density map. In each panel, the beam size is shown in the lower right corner, and the two Planck cold clumps are indicated by the two blue open circles.