2011MNRAS.413L..20L

Modelling of molecular emission spectra from interstellar clouds requires the calculation of rates for excitation by collisions with the most-abundant species. We calculate hyperfine structure resolved excitation rate coefficients of the cyano radical (CN) by He. State-to-state rate coefficients between the 37 lowest hyperfine levels of CN were calculated for low temperatures in the range 5-30 K. The new rate coefficients will help significantly in the interpretation of the CN emission lines observed with current and future telescopes, and enable this molecule to become a powerful astrophysical tool.