Top panel: dependence of the number (blue squares) and energy (red circles) fractions contained in the high-energy tail of the electron distribution, averaged for ct/L ∈ [9:10], on the mean hot magnetization value. Bottom panel: dependence of the maximum Lorentz factor measured at the level of u²N(u) = 10⁻³ for normalized electron distributions, averaged for ct/L ∈ [9:10]. The point size indicates the simulation domain size L.