Column density map of the Carina nebula. The color scale is expressed in cm^-2. The dashed boxes represent the central region around η Car (box a), the Southern Pillars region (box b), the Treasure Chest Cluster (box c), and the wave pattern (box d). These regions are analyzed in detail in Figs. 4, 5, 7, and 8. The center of the figure corresponds to the position (α_J2000, δ_J2000) = (10^h45^m21^s, −59°34′20′′).