Details of the model for the HVC shown in Fig. 10 with light-blue curves; note that higher velocities correspond to lower distances to the far-IR exciting source in a decelerating field. a) Column density of H nuclei (assuming X_OH = 2.5 × 10^-6) in intervals of 100 km s^-1 as a function of the radial velocity for R_out/R_int = 1.3, N_OH = 1.6 × 10¹⁷ cm^-2, v_int = 1700 km s^-1, and v_out = 100 km s^-1. b) Rotational temperature of the Π_3/2 J = 7/2 level (the lower level of the OH65 transition) relative to the ground state, as a function of the radial velocity. c) OH84 and OH65 optical depths along a ray passing through the center, and d) covering factor of the continuum, both as a function of the line-of-sight velocity. At low projected velocities (<400 km s^-1), the covering factor exceeds unity, which generates reemission from the limb of the outflow.