Extended Data Fig. 10: Co-added INMS ice grain spike spectrum from three plume encounters. | Nature

Extended Data Fig. 10: Co-added INMS ice grain spike spectrum from three plume encounters.

From: Macromolecular organic compounds from the depths of Enceladus

Extended Data Fig. 10

See Methods section ‘INMS ice grain spectrum’ for details on how the spectrum was composed and analysed. Error bars (1 s.d.) are derived from the dispersion of the count rate from the three separate measurements of the individual encounters. The spectrum suggests the presence of CO fragments (blue circles) as an oxygen-bearing species. N2 has very low abundance and contributes less than ~10% of the 28 u signal. CO2 and C2H4 collectively contribute less than ~10% of the 28 u signal. CO (blue circles) is required to fit the rest of the 28 u signal and the entire 29 u signal and matches its other dissociative peaks (C at 12 u and CO++ at 14 u) well. The spectrum also indicates the presence of nitrogen-bearing species: the ‘stair step’ pattern around 41 u matches best to the C2H3N spectrum (red circles).