2007ApJ...654L.147D

The mid-infrared emission at the center of IRAS 21026+4104 is not that of a simple compact source, as one would expect from an isolated high-mass protostellar object. Furthermore, the central thermal infrared emission does not appear to be coming directly from a circumstellar disk as has been recently hypothesized from near-infrared observations. The mid-infrared structure is complex, but with the help of multiple-wavelength information two plausible scenarios to explain the emission in the region are advanced. The first is that there is a tight cluster of young stellar objects here. The second is that the mid-infrared emission and masers are delineating the walls of the outflow cavities of a massive stellar source located in the center of the near- and mid-infrared dark lane.