Sketch of the model considered. The position of the CD is represented by a black solid line, while the orange and blue regions represent the FS and the RS, respectively. The solid lines with arrows represent different streamlines in each shock, injected in different positions separated by an angle Δθ. We also show the orientation of perpendicular and tangential vectors to the shocks in different positions, alongside v_w and V_ISM = −V_⋆, and the angle α between them. Adapted from del Palacio et al. (2018).