Subarcsecond resolution observations of Sagittarius B2 at 85 GHz

We present 3 mm continuum and spectral line observations of vinyl cyanide (C2H3CN) and ethyl cyanide (C2H5CN) toward the Sgr B2 region carried out by the BIMA Array at subarcsecond resolution. These are the highest angular resolution observations ever reported for C2H3CN and C2H5CN. With an angular resolution of 0."8, we were able to probe physical scales only one-tenth the size of the Oort cloud. Toward Sgr B2(N-LMH), the continuum emission is dominated by the K2 source, where dust emission contributes more than 60% of the 3 mm flux. The C2H3CN and C2H5CN emission reveals outflows in the dense molecular gas around K2, while C2H5CN exists in the ambient component as well. The distribution difference appears to indicate that C2H5CN is processed into C2H3CN in shock regions presumably caused by outflows. Column densities of C2H3CN and C2H5CN are found to be at least 3 times higher than previously reported. Inferred high H-2, C2H3CN, and C2H5CN column densities indicate that K2 can be the heating source for dust mantle evaporation at Sgr B2(N-LMH), the primary site of complex molecules.