Illustration of the migration vector definition (${\overrightarrow{m}}_{\mathrm{\Delta }t}$). The output SFH from CIGALE provides the SFRs and stellar masses (M_⋆) of the galaxy between the times t₂ and t₁, allowing its placement on the M_⋆ − SFR plane at that epoch. The migration vector is defined by the angle Φ_Δt (Eq. 1) between the line connecting the galaxy’s position and the horizontal line representing a constant SFR. The quantity r_Δt × Δt (Eq. 2) represents the norm of the vector connecting the galaxy’s position, where r_Δt is the rate of change of the galaxy’s position on the M_⋆ − SFR plane over time interval Δt.