Visible absorptions of potential diffuse ISM hydrocarbons: C${}_9$H${}_9$ and C${}_9$H${}_5$ radicals

Abstract

The laboratory detection of previously unobserved resonance-stabilized C${}_9$H${}_5$ and C${}_9$H${}_9$ radicals in the supersonic expansion of a hydrocarbon discharge source is reported. The radicals are tentatively assigned as acetylenic-substituted cyclopentadienyl C${}_9$H${}_5$ and vinyl-substituted benzyl C${}_9$H${}_9$ species. They are found to feature visible absorption bands that coincide with a few very weak diffuse interstellar bands toward HD183143 and HD204827.

arXiv comment5 figures, 3 tables

References in corpus (6)

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• Studies of the Diffuse Interstellar Bands. III. HD 183143
• Identification of more interstellar C60+ bands
• The abundances of hydrocarbon functional groups in the interstellar medium inferred from laboratory spectra of hydrogenated and methylated polycyclic aromatic hydrocarbons
• Electronic spectra of linear HC${}_5$H and cumulene carbene H${}_2$C${}_5$
• Constraining the size of the carrier of the $\lambda$5797.1 diffuse interstellar band