Top panel: column density map of the molecular cloud derived from ¹³CO emission (see Sect. 3.2.1). Middle panel: column density map of the CNM derived from HISA, assuming T_S = 40 K, p = 0.9 and using a second order polynomial to estimate the background temperature T_off. Bottom panel: optical depth corrected column density map of atomic hydrogen derived from H I emission. The contours indicate column density threshold used for the N-PDFs (see Sect. 4.5). For the H₂, HISA, and HI emission they have levels of 6 × 10²⁰, 1.5 × 10²⁰, and 1.7 × 10²¹ cm⁻², respectively. The red and green polygons mark the region for the mass estimates and the column density PDF measurements shown in Figs. 20 and 22, respectively.