Dresden 2014 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 62: Posters: Surface Reactions and Dynamics, Nanostructures
O 62.2: Poster
Mittwoch, 2. April 2014, 17:30–21:00, P1
Thermal desorption spectroscopy of astrophysically relevant molecules on olivine and single crystal forsterite — •Tushar Suhasaria1,2, Nadine Heming1, Robert Frigge1, Björn Siemer1, and Helmut Zacharias1,2 — 1Physikalisches Institut, University of Münster, Germany — 2Graduate School of Chemistry, University of Münster, Germany
Chemical surface reactions on dust grains are a possible way of molecule formation in the Interstellar Medium (ISM). These grains typically consist of graphitic and silicate materials. At low temperatures in molecular clouds (T < 20 K) atoms and molecules freeze out and form ices around the dust grains [1].Temperature programmed desorption (TPD) spectroscopy is an established method to define the binding energies between molecules and surfaces of astronomical interest. We have performed TPD measurements on several molecules like D2, CO, CH4, CO2 and NH3 adsorbed on single crystal forsterite (MgSiO4) and olivine (Mgx Fe1−x SiO4) surfaces. We determine the average binding energies, order and pre-exponential factors for such molecules on silicate surfaces and present a comparison of such properties on two silicate surfaces.
1] Tielens A. G. G. M., 2005, the physics and chemistry of the interstellar medium, Cambridge University Press.