| Autor: |
Korth, A., Marconi, M. L., Mendis, D. A., Krueger, F. R., Richter, A. K., Lin, R. P., Mitchell, D. L., Anderson, K. A., Carlson, C. W., Rème, H., Sauvaud, J. A., d'Uston, C. |
| Zdroj: |
Nature; January 1989, Vol. 337 Issue: 6202 p53-55, 3p |
| Abstrakt: |
The heavy-ion analyser PICCA1,2on the Giotto spacecraft was used to determine the composition and energy distribution of positively charged ions in the coma of comet Halley. Here we argue that the distinct peak observed at mass 39 AMU is due to the aromatic cation C3H3+(cyclopropenyl). Laboratory mass spec-troscopy of unsaturated hydrocarbon-chain molecules and aromatics yields large intensities of mass-to-charge ratio (m/z) 39; the spectra of the aromatic molecules also indicate the presence of C4H3+(m/z =51) and C5H5+(m/z =65). These latter products are not seen in the PICCA data, suggesting that in the cometary environment unsaturated hydrocarbon chains predominate over aromatics. We suggest that the progenitor of the hydrocarbon chains (which are apparently the parents of the C3H3+ion) are the 'CHON' dust particles observed around the comet3; the C3H3+ion may also be one of the parent molecules of C3, which is a common feature of cometary spectra4, although its origin has remained obscure. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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