Final continuous resonance index k (Eq. (18)) of two equal-mass planets as a function of the surface density Σ₀ at 1 AU and the planet mass m_p. The inner planet is fixed at the inner disk edge (0.1 AU), while the outer planet migrates from 0.2 AU. Systems that do not satisfy 0 < Δ < 0.03 are considered not in resonance and are plotted in red. Hill-unstable systems are removed and are plotted in white. The dashed line indicates the transition mass (Eq. (14)) to the regime of type II migration. The accretion rate displayed on the right axis is computed from Eq. (4) assuming a viscous parameter α = 10⁻².