Selection functions for the compact (left) and extended (right) model emitters shown in Fig. 1. The color of each flux-wavelength point on the grid indicates its f_C, the detection completeness fraction estimated by the model for UDF-Mosaic. The black and white curves show lines of f_C = 0.85 and f_C = 0.15. The model in the left column represents a relatively compact LAH, with a halo flux fraction f_H = 0.5, a halo scale length r_sH = 1.6 kpc, a spectral line width 126 km/s, and a skew parameter γ = 3. The model in the right column is more extended, with a halo flux fraction f_H = 0.9, a halo scale length r_sH = 5.0 kpc, a spectral line width 316 km/s, and a skew parameter γ = 0. Vertical red lines near the top of the panels indicate the wavelengths where models were inserted into LSDCat. The selection functions predict that these changes will have a substantial effect on the detectability, with the more compact model achieving f_C = 1 down to much fainter line fluxes.