Cyanogen, cyanoacetylene, and acetonitrile in comet 67P and their relation to the cyano radical

The cyano radical (CN) is one of the most frequently remotely observed species in space, also comets. Data from high-resolution Double Focusing Mass Spectrometer (DFMS) on board Rosetta orbiter, collected inner coma comet 67P/Churyumov-Gerasimenko, revealed an unexpected chemical complexity, and, recently, more CN than expected photodissociation its likely parent hydrogen cyanide (HCN). This work dedicated to derivation abundances relative HCN three cometary nitriles (including structural isomers) DFMS data. spectrometry complex mixtures does not always allow distinction isomers. We assumed stable and abundant (in similar environments) structure our analysis, that for CHN, CH3CN C2H3N, HC3N C3HN, NCCN C2N2. For cyanoacetylene (HC3N) acetonitrile (CH3CN) complete mission timeline was evaluated, while cyanogen (NCCN) often below detection limit. By carefully selecting periods where above limit, we were able follow abundance ratio between 3.16 au inbound 3.42 outbound. These are first measurements a comet.We find neither NCCN, nor any other two nitriles, sufficiently be relevant alternative CN.