High resolution mid-infrared imaging of W3(OH)

Abstract

We present results of our diffraction-limited mid-infrared imaging of the massive star-forming region W3(OH) with SpectroCam-10 on the 5-m Hale telescope at wavelengths of 8.8, 11.7, and 17.9 μm. The thermal emission from heated dust grains associated with the ultracompact HII region W3(OH) is resolved and has a spatial extent of ∼2″ in the N band. We did not detect the hot core source W3(H2O) which implies the presence of at least 12 mag of extinction at 11.7 μm towards this source. These results together with other data were used to constrain the properties of W3(OH) and W3(H2O) and their envelopes by modelling the thermal dust emission.