Examining Clumpy Cyanide Chemistry in the Inner Envelope of IRC+10216

In recent years, many questions have arisen regarding gas phase chemistry of CN-bearing molecules in the carbon-rich winds of evolved stars. To address them, there is a need for high angular resolution interferometric work covering many emission lines which trace different regions of these objects. We used archival band 7 ALMA observations to image high-J transitions of several cyanide species in the inner envelope (<8”) of the carbon star IRC+10216. The emission maps of HC3N, CH3CN, and NaCN show compact morphologies comprising various arcs and loops, with significant enhancement in dense clumps at an angular distance of ~3” (350 AU) from the star. Considering the proposed formation mechanisms of these molecules, our results are consistent with the theory that anisotropic photochemistry is occurring in warm (~200 K) knots present in the inner regions of this circumstellar envelope.