Photoprocessing of large PAH cations

Gabi Wenzel (1) , Sarah Rodriguez Castillo (1) , Giacomo Mulas (2, 1) , Ming-Chao Ji (1) , Anthony Bonnamy (1) , Hassan Sabbah (1) , Alexandre Giuliani (3, 4) , Laurent Nahon (4) , Christine Joblin (1)

1 IRAP - Institut de recherche en astrophysique et planétologie
2 OAC - INAF - Osservatorio Astronomico di Cagliari
3 CEPIA - Département Caractérisation et Elaboration des Produits Issus de l'Agriculture
4 SSOLEIL - Synchrotron SOLEIL

In cosmic environments, polycyclic aromatic hydrocarbons (PAHs) strongly interact with vacuum ultraviolet (VUV) photons emitted by young stars. Trapped PAH cations ranging in size from 30 to 48 carbon atoms were irradiated by tunable synchrotron light (DESIRS beamline at SOLEIL). Their ionization and dissociation cross sections were determined and compared with TD-DFT computed photoabsorption cross sections. Evidence for radiative cooling is reported.

Keywords: Astrochemistry; ISM: molecules; methods: laboratory; ultraviolet: ISM

Domains: Physics [physics]; Astrophysics [astro-ph]; Physics [physics]; Physics [physics]; Chemical Physics [physics.chem-ph]

Gabi Wenzel, Sarah Rodriguez Castillo, Giacomo Mulas, Ming-Chao Ji, Anthony Bonnamy, et al.. Photoprocessing of large PAH cations. Proceedings of the International Astronomical Union, 2019, 15 (S350), pp.388-389. ⟨10.1017/S1743921319007063⟩. ⟨hal-03090504⟩