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Characterization, Quantification and Compound-specific Isotopic Analysis of Pyrogenic Carbon Using Benzene Polycarboxylic Acids (BPCA)
Published on: May 16, 2016
Polycyclic aromatic hydrocarbons, carbon nanoparticles and the diffuse interstellar bands.
1Physics Department, University of Waterloo, Ontario, Canada N2L 3G1. wwduley@uwaterloo.ca
Faraday Discussions
|December 29, 2006
Summary
Large carbon molecules and nanoparticles may explain diffuse interstellar bands (DIBs). Their abundance and properties constrain formation and destruction rates, suggesting decomposition from larger particles for strong DIBs.
Area of Science:
- Astrochemistry
- Interstellar Medium Physics
- Materials Science
Background:
- Diffuse interstellar bands (DIBs) are observed spectral features in the interstellar medium.
- The exact carriers of DIBs remain unidentified, hindering understanding of interstellar chemistry.
Purpose of the Study:
- To review observational data of DIBs.
- To evaluate a model proposing large carbon molecules and nanoparticles as DIB carriers.
- To constrain the formation and destruction rates of these proposed carriers.
Main Methods:
- Review of observational data on DIB appearance and properties.
- Analysis of a theoretical model involving carbonaceous species (30-hundreds of carbon atoms).
- Integration of molecular and condensed matter physics principles.
Main Results:
- Carrier abundance estimates from DIB strengths constrain formation/destruction rates.
- Strongest DIBs, like the 4428 Å band, may arise from larger carbon particle decomposition.
- Proposed carriers are mixed sp2 and sp3 carbon particles, bridging molecular and solid-state physics.
Conclusions:
- Large carbon molecules and nanoparticles are plausible carriers for DIBs.
- The 2175 Å extinction feature may be linked to the same particle population.
- Further experimental and theoretical data are needed to confirm these findings.
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