We present an interferometric and single dish study of small organic species toward Comets C/1995 O1 ( Hale-Bopp ) and C/2002 T7 ( LINEAR ) using the BIMA interferometer at 3 mm and the ARO 12m telescope at 2 mm .
For Comet Hale-Bopp , both the single-dish and interferometer observations of CH _ { 3 } OH indicate an excitation temperature of 105 \pm 5 K and an average production rate ratio Q ( CH _ { 3 } OH ) / Q ( H _ { 2 } O ) \sim 1.3 % at \sim 1 AU .
Additionally , the aperture synthesis observations of CH _ { 3 } OH suggest a distribution well described by a spherical outflow and no evidence of significant extended emission .
Single-dish observations of CH _ { 3 } CN in Comet Hale-Bopp indicate an excitation temperature of 200 \pm 10 K and a production rate ratio of Q ( CH _ { 3 } CN ) / Q ( H _ { 2 } O ) \sim 0.017 % at \sim 1 AU .
The non-detection of a previously claimed transition of cometary ( CH _ { 2 } OH ) _ { 2 } toward Comet Hale-Bopp with the 12m telescope indicates a compact distribution of emission , D < 9 ^ { \prime \prime } ( < 8500 km ) .
For the single-dish observations of Comet T7 LINEAR , we find an excitation temperature of CH _ { 3 } OH of 35 \pm 5 K and a CH _ { 3 } OH production rate ratio of Q ( CH _ { 3 } OH ) / Q ( H _ { 2 } O ) \sim 1.5 % at \sim 0.3 AU .
Our data support current chemical models that CH _ { 3 } OH , CH _ { 3 } CN and ( CH _ { 2 } OH ) _ { 2 } are parent nuclear species distributed into the coma via direct sublimation off cometary ices from the nucleus with no evidence of significant production in the outer coma .