Comparison of asymmetry amplitude A₄₀ in simulations with different dynamical parameters. Upper frame: Blue curves assume to τ_dyn = 0.5 and velocity-dependent ϵ_n with v_c = v_B, as in models of French et al. (2007), while red curves assume τ_dyn = 1, ϵ_n = 0.1. Different internal densities ρ = 650, 450, and 250 kg m⁻³ are compared. Lower frame; comparison of the τ_dyn = 1.0 and τ_dyn = 0.5 simulations for ϵ_n = 0.1 and ϵ_n = 0.5; the latter elasticity law gives practically identical results to using velocity-dependent ϵ_n with v_c = v_B. The models correspond to B = B′= 12° and the HST values are weighted averages of 10° and 15° observations (see Fig. 20 in French et al. 2007).