2D maps showing the column densities of C IV. Panel 3a shows the projections for R32-AL simulation along the y-axis for down-the-barrel images (top) and along the x-axis for edge-on (bottom). The same for the model R32-TR in panel 3b. From left to right, the plots display C IV column densities at t = 0.2, 1.2, 2.2 and 3.2 Myr (or t/t_cc = 0.2, 0.9, 1.7, 2.5) respectively. We notice that C IV follows a more extended volume of cloud material than C II (which mainly tracks the core), including both the cloud core and the tail. As for C II, also the C IV column density morphology is affected by the different orientation of B, maintaining an extension smaller that 10 pc along the x-axis in R32-TR due to draping.