511 keV line flux in the bulge, dependent on the disk size (analogous to Fig. 6). Shown are the lines of equal flux touching the (2Δlog (L) = 1)-, and (2Δlog (L) = 4)-contours, respectively, marked by the blue dots. These tangents correspond to the 1 and 2σ uncertainties of the line flux in the bulge with respect to the disk size (longitude and latitude extent). The star symbol is marking the point with the largest likelihood at 0.961 × 10^-3 ph cm^-2 s^-1. The resulting 1 and 2σ-uncertainties are (0.961 ± 0.009) × 10^-3 ph cm^-2 s^-1, and , respectively.