Average emission spectra derived using the regions shown in Fig. 5. The top panel shows the K = 1, F_k = 0 trial. The black line and points indicate the average spectrum. The dashed blue curve shows the CNM emission. The thin dotted black curve shows the intrinsic WNM emission without optical-depth effects. The green curve show the WNM emission, including optical-depth effects, corresponding to gas in behind the absorber. The red curve shows the total (CNM+WNM) emission; residuals are shown in the sub-panel below. Grey lines indicate the zero and ±1σ levels in both panels. The bottom panel shows the K = 2 fit with F_k = (1.0, 0.5). Lines and symbols are as in the top panel. In addition, the orange curve shows the WNM emission in front of the absorber.