Capture rate as a function of initial semimajor axis a_ini from the inner moon region of IG18 for encounters at different distances. Encounter distances are given in the top left corner of each panel and the vertical lines show the distances in R_Nep. The black thick solid lines are the rates for all captures (Table 2, Col. 3, when integrated over a_ini). The red slashed regions indicate those for survivable circularisable moons through tides [SCM (T)] while keeping Nereid safe, lower bound by tidal engulfment assuming retrograde (Table 2, Col. 6) and upper bound by prograde orbits (Col. 5). The blue slashed regions show the efficiencies for the acquirement of survivable circularisable moons though collisions+tides [SCM (C+T)] and the lower and upper bounds have the same meanings (Table 2, Cols. 9 and 10). The green checked regions present capture rates of irregular moons (IM), those uncircularisable and a > 70 R_Nep, upper bound by the circularisation model of tides only and lower by collisions+tides (Table 2, Cols. 7 and 11). SeeFig. 2 for the orbits of each type of the moon.