2008/11/30 by H. M. Boechat-Roberty, H. M. Boechat‐Roberty, Rafael Felipe Coelho Neves +4
Chemistry · Physics and Astronomy · #Advanced Chemical Physics Studies #Astrophysics and Star Formation Studies #Atomic and Molecular Physics #Atomic physics #Chemistry #Dissociation (chemistry) #Ion #Ionization #Molecule #Photochemistry #Photodissociation #Photoionization #Physical chemistry #Physics #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2008.14368.x
The paper contains 8 pages, 9 figures and 4 tables. Accepted to be published on MNRAS on 2008 November 26
arxiv created 2008/11/30 · openalex publication_date 2009/02/18 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Benzene molecules, present in the proto-planetary nebula CRL 618, are ionized and dissociated by ultraviolet (UV) and X-ray photons originated from the hot central star and by its fast wind. Ionic species and free radicals produced by these processes can lead to the formation of new organic molecules. The aim of this work is to study the photoionization and photodissociation processes of the benzene molecule, using synchrotron radiation and time-of-flight mass spectrometry. Mass spectra were recorded at different energies corresponding to the vacuum UV (21.21 eV) and soft X-ray (282–310 eV) spectral regions. The production of ions from the benzene dissociative photoionization is here quantified, indicating that C6H6 is more efficiently fragmented by soft X-ray than UV radiation, where 50 per cent of the ionized benzene molecules survive to UV dissociation while only about 4 per cent resist to X-rays. Partial ion yields of H+ and small hydrocarbons, such as C2H+2, C3H+3, C4H+2, are determined as a function of photon energy. Absolute photoionization and dissociative photoionization cross-sections have also been determined. From these values, half-life of benzene molecule due to UV and X-ray photon fluxes in CRL 618 was obtained.