High angular resolution submillimeter observations of Sagittarius B2

Continuum observations of the Sgr B2 molecular cloud have been carried out. The data offer the first detailed description of the submillimeter radiation from this complex source. The emission is dominated by the middle and northern compact sources, but the far-infrared radiation associated with the Northeast H II region L and from the southern H II region/molecular maser source H have been detected for the first time. The data, together with existing infrared measurements, indicate that the optical depth within Sgr B2(N) is significantly greater than that of Sgr B2(M) and that it has a noticeable effect for lambda = 800 microns or less. The envelope of Sgr B2(M) becomes optically thick for the radiation from Sgr B2(N), located within it, for wavelengths 100 microns or less. From radiative transfer modeling, a luminosity of 10 million solar is obtained for the middle source and 2 million solar for the northern source. 30 refs.