Comparison of η Car images (fourth column) from Fig. 1 with 3D hydrodynamic simulations of LOS column density distributionsof η Car’s distorted stellar wind and WWC zone of the primary star only for the three LOS velocities of − 320, − 10, and + 320 km s⁻¹. The model images show the LOS view as seen on the sky at orbital phase ϕ = 0.014, i.e., very close to the phase of 0.0022 of the observations. Top: LOS velocity of − 320 km s⁻¹. Middle: LOSvelocity of − 10 km s⁻¹. Bottom: LOS velocity of + 320 km s⁻¹. From left to right are shown the un-shocked wind column density distribution, shocked wind column density distribution, the model sum of both (shocked plus un-shocked), and the observed images at similar LOS velocities. The FOV of all model column density maps and observed images is 60 × 60 mas or 138 × 138 au for the adopted distance of 2.3 kpc. N is up, and E is to the left.