dc.creator Ruiterkamp, Richard en_US dc.creator Cox, Nick en_US dc.creator Kaper, Lex en_US dc.creator Spaans, Marco en_US dc.creator Foing, Bernard en_US dc.creator Salama, F. en_US dc.creator Ehrenfreund, Pascale en_US dc.date.accessioned 2008-01-11T21:33:54Z dc.date.available 2008-01-11T21:33:54Z dc.date.issued 2005 en_US dc.identifier 2005-FA-02 en_US dc.identifier.uri http://hdl.handle.net/1811/30244 dc.description {Ruiterkamp et al., 2005, Astronomy \& Astrophysics, In press en_US dc.description Author Institution: Leiden Observatory, Leiden, NL; Astronomical Institute, University of Amsterdam, Kruislaan 403, 1098 SJ Amsterdam, Netherlands (NL); Kapteyn Astronomical Institute, University of Groningen, Groningen, NL; ESA/SCI-SR, ESTEC, Noordwijk, NL; Space Science Division, NASA Ames Research Center, California, USA; Astronomy Institute, Radboud University, Nijmegen, NL en_US dc.description.abstract We will present our work involving the modelling of the polycyclic aromatic hydrocarbon (PAH) charge state distribution throughout diffuse/translucent clouds and the link with the unidentified diffuse interstellar bands (DIBs). As a first test case we decided to do a detailed analysis of the ubiquitously observed translucent cloud in the line of sight towards the early type star HD147889, which is situated near the $\rho$ Ophiuchus cloud. First we solved the thermal and chemical balance of this cloud, with constraints given by the observed atomic and molecular column densities. The resulting hydrogen density, incident radiation field and electron and temperature structure of the cloud subsequently determined the charge balance for the selected species. We included 70 different PAHs, belonging to five point/symmetry groups, and containing 6 to 48 carbon atoms. Together with the calculated transition wavelengths, oscillator strengths and assumed size distribution the charge state distribution can be converted to a theoretical PAH absorption spectrum for the modelled line of sight. The result can then be compared, with caution, to the spectra of the observed diffuse interstellar bands in the line of sight. Several predictions and limits on the properties of PAHs in the interstellar medium will be discussed. en_US dc.language.iso English en_US dc.publisher Ohio State University en_US dc.title PAH CHARGE STATE DISTRIBUTION AND DIB CARRIERS: IMPLICATIONS FROM THE TRANSLUCENT LINE OF SIGHT TOWARD HD147889 en_US dc.type article en_US
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