Dresden 2014 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 62: Posters: Surface Reactions and Dynamics, Nanostructures
O 62.1: Poster
Mittwoch, 2. April 2014, 17:30–21:00, P1
Formation of superhydrogenated PAHs through interaction with atomic hydrogen and hydrogenated carbonaceous grains — •John Thrower1,2, Emil Friis1, Anders Skov1, Bjarke Jørgensen1, Louis Nilsson1, Saoud Baouche1, Richard Balog1, and Liv Hornekaer1 — 1Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark — 2Present Address: Physikalisches Institut, Westfälische Wilhelms-Universität Münster, Germany
Processes occurring on dust grain surfaces play a crucial role in interstellar chemical evolution. In particular, H2, the most abundant molecule, is only formed efficiently through surface reactions. Polycyclic aromatic hydrocarbon (PAH) molecules account for up to 10% of the total carbon budget. It has been suggested that in warmer environments, e.g. photodissociation regions (PDRs), PAHs are involved in H2 formation [1]. Building on previous DFT calculations [2], we present mass spectrometric investigations of the formation of superhydrogenated PAH molecules through H-atom addition to coronene (C24H12) which reveal abstraction reactions that release H2 [3]. Furthermore, we demonstrate that hydrogenated graphitic surfaces can act as an addition source of H-atoms that can react with physisorbed PAH molecules, potentially releasing H and H2 from the grain surface.
[1] E. Habart, F. Boulanger, L. Verstraete, et al., Astron. Astrophys., 414, 531 (2004).
[2] E. Rauls and L. Hornekær, Astrophys. J., 679, 531 (2008).
[3] J. D. Thrower, B. Jørgensen, E. E. Friis, et al., Astrophys. J., 752, 3 (2012).