Spitzer MIPS 24 μm detection of photoevaporating protoplanetary disks

We present 24 mm images of three protoplanetary disks being photoevaporated around high-mass O-type stars. These objects have cometary structure where the dust pulled away from the disk by the photoevaporating flow is forced away from the O star by photon pressure on the dust and heating and ionization of the gas. Models of the 24 and 8 mm brightness profiles agree with this hypothesis. These models show that the mass-loss rate needed to sustain such a configuration is in agreement with or somewhat less than the theoretical predictions for the photoevaporation process.