Proto-Planetary Disk Chemistry Recorded by D-Rich Organic Radicals in Carbonaceous Chondrites
Abstract
Insoluble organic matter (IOM) in primitive carbonaceous meteorites has preserved its chemical composition and isotopic heterogeneity since the solar system formed ~4.567 billion years ago. We have identified the carrier moieties of isotopically anomalous hydrogen in IOM isolated from the Orgueil carbonaceous chondrite. Data from high spatial resolution, quantitative isotopic NanoSIMS mapping of Orgueil IOM combined with data from electron paramagnetic resonance spectroscopy reveals that organic radicals hold all the deuterium excess (relative to the bulk IOM) in distinct, micrometer-sized, D-rich hotspots. Taken together with previous work, the results indicate that an isotopic exchange reaction took place between pre-existing organic compounds characterized by low D/H ratios and D-rich gaseous molecules, such as H_2D^+ or HD_2^+. This exchange reaction most likely took place in the diffuse outer regions of the proto-planetary disk around the young Sun, offering a model that reconciles meteoritic and cometary isotopic compositions of organic molecules.
Additional Information
© 2009 The American Astronomical Society. Received 2008 May 6; accepted 2009 April 6; published 2009 June 8. The NanoSIMS facility at the Museum National d'Histoire Naturelle in Paris was established through funds from CNRS, Region Ile de France, the French Ministry for Research and Museum National d'Histoire Naturelle. This work was supported by the Agence Nationale de la Recherche (ANR).We are grateful to the anonymous referee for his comments that improved this paper. John Eiler is also thanked for helpful discussions on this manuscript.Attached Files
Published - Remusat2009p4606Astrophys_J.pdf
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Additional details
- Eprint ID
- 15675
- Resolver ID
- CaltechAUTHORS:20090908-135050339
- Centre National de la Recherche Scientifique (CNRS)
- Agence Nationale de la Recherche (ANR)
- Created
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2009-09-15Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field