1999ApJ...523..683L

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 H₂, 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.