CH3CO+ discovery in space and in laboratory

The lines have been seen towards the cold dense cores TMC-1, L483, L1527, and L1544. High level of theory ab initio calculations indicate that the best possible candidate is the acetyl cation, CH_3_CO^+^, which is the most stable product resulting from the protonation of ketene.

We have produced this species in the laboratory and observed its rotational transitions Ju=10 up to Ju=27. Hence, we report the discovery of CH_3_CO^+^ in space based on our observations, theoretical calculations, and laboratory experiments. The derived rotational and distortion constants allow us to predict the spectrum of CH_3_CO^+^ with high accuracy up to 500GHz.