Publications

New attempts to understand nanodiamond stardust

Author(s)

Ulrich Ott, A. Besmehn, K. Farouqi, O. Hallmann, P. Hoppe, K.-L. Kratz, Klaus Melber, Anton Wallner

Abstract

We report on a concerted effort aimed at understanding the origin and

history of the pre-solar nanodiamonds in meteorites including the

astrophysical sources of the observed isotopic abundance signatures.

This includes measurement of light elements by secondary ion mass

spectrometry (SIMS), analysis of additional heavy trace elements by

accelerator mass spectrometry (AMS) and dynamic calculations of

r-process nucleosynthesis with updated nuclear properties. Results

obtained indicate that: (i) there is no evidence for the former presence

of now-extinct ²⁶Al and ⁴⁴Ti in our diamond

samples other than what can be attributed to silicon carbide and other

‘impurities’, and this does not offer support for a supernova (SN)

origin but neither does it negate it; (ii) analysis by AMS of platinum

in ‘bulk diamond’ yields an overabundance of r-only ¹⁹⁸Pt

that at face value seems more consistent with the neutron burst than

with the separation model for the origin of heavy trace elements in the

diamonds, although this conclusion is not firm given analytical

uncertainties; (iii) if the Xe–H pattern was established by an

unadulterated r-process, it must have been a strong variant of the main

r-process, which possibly could also account for the new observations in

platinum.

Organisation(s)

Isotope Physics

External organisation(s)

Max-Planck-Institut für Chemie (Otto-Hahn-Institut), University of West Hungary

Journal

Publications of the Astronomical Society of Australia

Volume

Pages

90-97

No. of pages

ISSN

1323-3580

DOI

https://doi.org/10.1071/AS11064

Publication date

2012

Peer reviewed

Yes

Austrian Fields of Science 2012

103005 Atomic physics

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