Upper: sub-mm to cm SED structure of the parametric model (n = 3.0). The red crosses correspond to the observed fluxes from APEX (870 μm), JCMT (1.1 mm), CARMA (3.265 mm), and VLA (2 cm). The plotted parametric model (with n = 3.0) SEDs (black solid lines) are for R_out/R_e = 10; 20; 25; 30; 35; 40; 45; 50; 60; 70; 80; 90, and 100 from bottom to top. Lower: reduced χ² dependence on R_out for APEX (solid), CARMA (dotted) and VLA (dashed). The combined χ² for all four observations is plotted as a red solid line.