Radial-intensity profile along the direction to the east in the models with the density contrast, β = 5 (dashed-dotted line), 3 (dashed line), and 2 (solid line). The y-axis gives the normalised intensity averaged over 0.2′′ -wide rings within a 10° circle sector. The red and green rectangles are the same as Fig. A.2. The inset plot shows a zoom-in of the region around the rectangles.