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Abstract No.: TuP-102
Session: Gas Phase Ion Chemistry
Presentation date: Tue, Aug 29, 2006
Presentation time: 14:30 – 16:00

Study of Gas-grain Interactions with Pirenea : C24Hn+ + H2O

Natacha Bruneleau1, Christine Joblin1, Aude Simon1, Michel Armengaud1, Patrick Frabel1, Loic Nogues1

1 CESR, Toulouse, France

Correspondence address: Natacha Bruneleau, CESR, 31, 9 avenue du Colonel Roche, Toulouse, 31028 France.

Keywords: Fourier Transform ICR; Polycyclic Aromatic Hydrocarbons; Rate Constants; Reaction, Ion/Molecule.

Novel aspect: Studying the (catalylic) role of PAHs in the formation of new molecules in the interstellar medium.

 

Gas-grain interactions play an important role in interstellar chemistry, both in UV- irradiated regions and in the more embedded regions of molecular clouds. To address experimentally this question, laboratory set-ups have been built to approach the physical conditions that prevail in space (very low density and temperature). The PIRENEA experiment, Piege a Ions pour la Recherche et l’Etude de Nouvelles Especes Astrochimiques, was developed according to these specifications : it combines the trapping capabilities of an ion cyclotron resonance (ICR) cell with cryogenic shielding. It is also equipped with several photon sources and a gas inlet interface. Our aim is to study the interaction of molecules such as H2, H2O, NH3 with the smallest grains of interstellar interest which are made of polycyclic aromatic hydrocarbon (PAH) macromolecules and various types of nanograins (PAH clusters, Fe-PAH complexes, silicate nanoparticles). We report here the results obtained on the reactivity of the PAH species C24Hn+ (n=12-1) with H2O via radiative association and at two temperatures (300 K, 40 K).

Acknowledgements : The authors acknowledge the financial support of the PIRENEA set-up by the Programme National de Physique et Chimie du Milieu Interstellaire and by the Region Midi-Pyrenees. N. Bruneleau acknowledges the financial support by the Fonds Social Europeen.