Radio-SEDs of AFGL 2591-VLA 3 and VLA 1. The SED of AFGL 2591-VLA 3 is show in black error bars, and the resolved fluxes of AFGL 2591-VLA 3 from Marengo et al. (2000) are shown as red squares. Green squares show the fluxes of VLA 1 – errors are not shown as they are smaller than the markers. The black and green solid lines show greybody fits to the SEDs of AFGL 2591-VLA 3 between 100 and 850 μm, and VLA 1 at mid-IR fluxes, respectively (see Sects. 5.2.1 and 5.2.2). The green dashed line shows the fit to the long-wavelength fluxes for VLA 1.