Slices of density in units of ﹩{\rho }_{\infty }﹩ (top panels) and Mach number (bottom panels) through the orbital (x–y) plane, for a fixed mass ratio q_r and varying upstream Mach number ﹩{{ \mathcal M }}_{\infty }﹩, for the simulation suite (Γ_s, γ) = (5/3, 5/3). The simulations use q_r = 0.1 and ﹩{{ \mathcal M }}_{\infty }﹩ 5.0, 3.48, 2.84, 2.20, 1.69, and 1.15, corresponding to density gradients ϵ_ρ of 4.132, 2.0, 1.33, 0.8, 0.47, and 0.218, respectively. The slices compare the state of the flow at simulation time ﹩t=30{R}_{{\rm{a}}}/{v}_{\infty }﹩. Moving from the highest to the lowest ﹩{{ \mathcal M }}_{\infty }﹩, the slices show the pattern of the flow around the embedded companion object as it inspirals from the outer to the inner regions of the primary star’s envelope.