Kinematic properties of neutral gas. Left panel: Velocity shifts for neutral gas measured from Ca II vs. Na I. Error bars correspond to the 16^th and the 84^th percentile of the probability distribution function from emcee. The red line represents the best-fit linear relation of the measurements weighted by their errors, while the orange shadow is the 1σ error of the best-fit line. Right panel: Velocity dispersions of neutral gas inferred from Ca II vs. Na I. The dashed green line represents the 1:1 relation. The velocity dispersion of Ca II lines of COSMOS-18668 is only an upper limit represented by an arrow.