Figure caption for Figure 17 a:
Fragment showing the basic structural and molecular character of a carbonaceous, interstellar dust grain in the diffuse interstellar medium. The molecular details have been deduced from the spectroscopic constraints as discussed in sections 5 and 6. The specific geometries of the aromatic plates and aliphatic components simply represent what is likely. The structure is somewhat splayed out to reveal the molecular structural details; we envision the actual structure somewhat more closed in. For the interconnected species (not the free floating entities), the relative numbers of aromatic and aliphatic carbon-hydrogen bonds, as well as their sub-classification within type, are all consistent with the observed spectrum described here. The latter includes the aliphatic -CH₃ to -CH₂-ratio, and the relative numbers of aromatic solo, duo, trio, and quartet hydrogens deduced from the interstellar IR emission bands as described in Hony et al. 2001. The approximate volume of this fragment is on the order of 10-19 cm³ ). Thus, a typical 0.1 micron DISM carbonaceous dust grain would comprise approximately 104 of these fragments.

To view this figure you need the MDL Chemscape CHIME plug-in whch you can download for free. Here is an example of CHIME properly configured for Netscape.

Additional information about this paper can be found here.

Please direct comments about the science here.

Please direct comments about this site here.