Subarcsecond Submillimeter Continuum Observations of Orion KL

We present the first 865 mu continuum image with sub-arcsecond resolutionobtained with the Submillimeter Array. These data resolve the Orion-KL regioninto the hot core, the nearby radio source I, the sub-mm counterpart to theinfrared source n (radio source L), and new sub-mm continuum sources. The radioto submillimeter emission from source I may be modeled as either the result ofproton-electron free-free emission that is optically thick to ~100 GHz plusdust emission that accounts for the majority of the submillimeter flux, or H-free-free emission that gives rise to a power-law spectrum with power-law indexof ~1.6. The latter model would indicate similar physical conditions as foundin the inner circumstellar environment of Mira variable stars. Futuresub-arcsecond observations at shorter sub-mm wavelengths should easilydiscriminate between these two possibilities. The sub-mm continuum emissiontoward source n can be interpreted in the framework of emission from anaccretion disk.Comment: 4 pages, 2 figures, 1 table, accepted for the Astrophysical Journal Letter