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MS: Fachverband Massenspektrometrie
MS 3: Ion Trap and FT-ICR-MS, Molecules, Clusters and Reactions
MS 3.5: Vortrag
Montag, 18. März 2013, 17:45–18:00, F 442
Destruction and creation of interstellar hydrocarbon chain anions — •Eric Endres, Thorsten Best, Daniel Hauser, Olga Lakhmanskaya, and Roland Wester — Universtität Innsbruck, Institut für Ionenphysik und Angewandte Physik, Österreich
In the interstellar medium (ISM), ion-molecule reactions are believed to play a key role in the formation of complex molecules. The detection of the first interstellar anion [1] has raised new interest in the quantitative composition of the ISM and the underlying reaction network. To date, six anions have been detected, three of which are unsaturated hydrocarbon chains, namely C4H−, C6H− and C8H−.
Characteristics of these carbon chain anions have been investigated via photodetachment measurements [2] and via reactions with atomic partners H, N and O at room temperature [3]. Reactions with molecular hydrogen are assumed to take place slowly [3]. However, because of the abundance of H2 in the ISM, a precise knowledge of the reaction rates are still important.
A cryogenic 22-pol radio frequency ion trap is the ideal tool to observe rare reactions. Furthermore, measurements over a large temperature scale are possible. This allows us to simulate the conditions of the ISM and analyse possible reactions. Temperature dependent measurements of the reaction rates of hydrocarbon chain anions with H2 will be presented. Furthermore, the status of the investigation concerning possible chain elongation of the anions will be reported.
[1] McCarthy et al. Ap.J. 652:L141 (2006); [2] Best et al. Ap.J. 742:63 (2011); [3] Eichelberger et al. Ap.J. 667:1283 (2007)