Distribution of heavier secondary species produced in the disintegration of Fe nuclei at boost γ = 3.5 ⋅ 10⁹ after propagating for 30 Mpc. Top: Marginal distributions of mass number (left) and charge number (right) obtained with Monte Carlo (using CRPropa, green solid) versus Analytical (using CRISP, purple lines). Down: Relative differences, in percentages, of Monte Carlo and Analytical probabilities for each secondary species with a probability larger than 1%.