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dc.contributor.authorIshii, H. A.
dc.contributor.authorBrennan, S.
dc.contributor.authorBradley, J. P.
dc.contributor.authorLuening, K.
dc.contributor.authorIgnatyev, K.
dc.contributor.authorPianetta, P.
dc.date.accessioned2021-02-12T22:30:38Z
dc.date.available2021-02-12T22:30:38Z
dc.date.issued2008-01-01
dc.identifier.citationIshii, H. A., Brennan, S., Bradley, J. P., Luening, K., Ignatyev, K., & Pianetta, P. (2008). Recovering the elemental composition of comet Wild 2 dust in five Stardust impact tracks and terminal particles in aerogel. Meteoritics & Planetary Science, 43(1‐2), 215-231.
dc.identifier.issn1945-5100
dc.identifier.doi10.1111/j.1945-5100.2008.tb00618.x
dc.identifier.urihttp://hdl.handle.net/10150/656390
dc.description.abstractThe elemental (non-volatile) composition of five Stardust impact tracks and terminal particles left from capture of comet 81P/Wild 2 dust were mapped in a synchrotron X-ray scanning microprobe with full fluorescence spectra at each pixel. Because aerogel includes background levels of several elements of interest, we employ a novel "dual threshold" approach to discriminate against background contaminants: an upper threshold, above which a spectrum contains cometary material plus aerogel and a lower threshold below which it contains only aerogel. The difference between normalized cometary-plus-background and background-only spectra is attributable to cometary material. The few spectra in-between are discarded since misallocation is detrimental: cometary material incorrectly placed in the background spectrum is later subtracted from the cometary spectrum, doubling the loss of reportable cometary material. This approach improves accuracy of composition quantification. We present the refined whole impact track and terminal particle elemental abundances for the five impact tracks. One track shows mass increases in Cr and Mn (1.4x), Cu, As and K (2x), Zn (4x), and total mass (13%) by dual thresholds compared to a single threshold. Major elements Fe and Ni are not significantly affected. The additional Cr arises from cometary material containing little Fe. We exclude Au intermixed with cometary material because it is found to be a localized surface contaminant carried by comet dust into an impact track. The dual threshold technique can be used in other situations where elements of interest in a small sample embedded in a matrix are also present in the matrix itself.
dc.language.isoen
dc.publisherThe Meteoritical Society
dc.relation.urlhttps://meteoritical.org/
dc.rightsCopyright © The Meteoritical Society
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/
dc.subjecttrace elements
dc.subjectchemical composition of comets
dc.subjectcometary dust
dc.subjectStardust Mission
dc.titleRecovering the elemental composition of comet Wild 2 dust in five Stardust impact tracks and terminal particles in aerogel
dc.typeArticle
dc.typetext
dc.identifier.journalMeteoritics & Planetary Science
dc.description.collectioninformationThe Meteoritics & Planetary Science archives are made available by the Meteoritical Society and the University of Arizona Libraries. Contact lbry-journals@email.arizona.edu for further information.
dc.eprint.versionFinal published version
dc.description.admin-noteMigrated from OJS platform February 2021
dc.source.volume43
dc.source.issue1-2
dc.source.beginpage215
dc.source.endpage231
refterms.dateFOA2021-02-12T22:30:38Z


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