1999ApJ...514L..43W

We used the IRAM interferometer to obtain subarcsecond resolution observations of the high-mass star-forming region W3(OH) and its surroundings at a frequency of 220 GHz. With the improved angular resolution, we distinguish three peaks in the thermal dust continuum emission originating from the hot core region ~6" (0.06 pc) east of W3(OH). The dust emission peaks are coincident with known radio continuum sources, one of which is of nonthermal nature. The latter source is also at the center of expansion of a powerful bipolar outflow observed in H₂O maser emission. We determine the hot core mass to be 15 M_☉ based on the integrated dust continuum emission. Simultaneously, many molecular lines are detected, allowing the analysis of the temperature structure and the distribution of complex organic molecules in the hot core. From HNCO lines spanning a wide range of excitation, two 200 K temperature peaks are found coincident with dust continuum emission peaks, suggesting embedded heating sources within them.