THERMAL INFRARED IMAGING OF SUBARCSECOND STRUCTURE IN THE TRAPEZIUM NEBULA

We present 11.7 and 8.8 mum images of the central region of the Ney-Al len Nebula in Orion which reveal mid-infrared counterparts to the ioni zed globules previously discovered by optical and radio observations. The 0.5'' FWHM resolution images also reveal several arc-shaped struct ures which are associated with the compact sources. Each of the arcs p oints toward theta1 Ori C, providing further evidence for the strong e ffects of the intense radiation and wind from this star on the central Orion Nebula. Low-resolution spectra of a few of these condensations and arcs are similar to spectra of the diffuse, optically thin silicat e dust observed throughout the region. Photometry of one of the conden sations, however, indicates that it is cooler than the others. Simple momentum-balance arguments indicate that dust in the arcs could origin ate in the outflow from the compact sources and flow outward until sto pped by the stellar wind and radiation pressure from theta1 Ori C.