Mass-accretion efficiency for the non-rotating models. Colours represent equivalent mass ratios. Circles correspond to models where v_∞ = 15.1 km s⁻¹, triangles to models where v_∞ = 10.9 km s⁻¹, and squares to models where v_∞ = 6 km s⁻¹. The dotted lines correspond to the values predicted by BHL as given by Eq. (10) assuming α_BHL = 0.75. Continuous lines correspond to the fit given by Eq. (11).