Specific mass corresponding to each energy (Eq. (7) with α = ϵ/ϵ_max) for Schuster-Plummer and NFW potentials. Top panel: log-linear representation. Bottom panel: log-log representation. Note that the specific mass diverges for low energies as a power-law of exponent −2.5, for the Schuster-Plummer potential, and around −2.81, for the NFW potential (the dashed lines labeled in the inset of the bottom panel).