摘要：We report the first extragalactic detection of the fluoromethylidynium ion CF+ in the z = 0.89 absorber toward PKS 1830−211. We estimate an abundance of ~3 × 10-10 relative to H2 and that ~1% of fluorine is captured in CF+. The absorption line profile of CF+ is found to be markedly different from that of other species observed within the same tuning, and is notably anticorrelated with CH3OH. On the other hand, the CF+ profile resembles that of [C I]. Our results are consistent with expected fluorine chemistry and point to chemical differentiation in the column of absorbing gas.
