Spitzer MIPS 24 μm Detection of Photoevaporating Protoplanetary Disks

Abstract

We present 24 μm 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 μm 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.