Velocity of the preshock gas (left axes) and cumulative Hα luminosity (right axes) for the shock at the surface at the planet (left panel) and of the CPD (right) for 2 M_J (5 M_J) top (bottom) row. We set Σ ≈ 0.02 g cm⁻² and f_cent ≈ 0.03 to match the ﹩{\dot{M}}_{{\rm{Hill}},\,{\rm{net}}}﹩ and ﹩{\dot{M}}_{{\rm{p}},\,{\rm{direct}}}﹩ of the detailed simulations (see Section 2.4.3). With this, the ballistic model of this paper (colored lines) reproduces excellently the radiation-hydrodynamical simulations of MKBM23 (gray points).