Stardust Interstellar Preliminary Examination VI: Quantitative elemental analysis by synchrotron X-ray fluorescence nanoimaging of eight impact features in aerogel

Autor: Christine Floss, R. Lettieri, Hans A. Bechtel, Ralf Srama, Nabil Bassim, Scott A. Sandford, Ryan Doll, Akira Tsuchiyama, Joachim Huth, Peter Tsou, Carlton Allen, Naomi Wordsworth, Rhonda M. Stroud, Geert Silversmit, Hugues Leroux, Anna L. Butterworth, Joshua Von Korff, Janet Borg, Laszlo Vincze, Sylvia Schmitz, Ron K. Bastien, George J. Flynn, Thomas Stephan, Vicente A. Solé, Frank Postberg, Mario Trieloff, Larry R. Nittler, Steven Sutton, Peter Hoppe, William Marchant, Andrew M. Davis, David Anderson, Zack Gainsforth, Jan Leitner, Daniel Zevin, Juan-Angel Sans Tresseras, Eberhard Grün, Tom Schoonjans, Julien Stodolna, Tolek Tyliszczak, Mark J. Burchell, Hitesh Changela, Mark C. Price, Brit Hvide, Manfred Burghammer, Bruce Hudson, Ryan C. Ogliore, Bart Vekemans, Ariel Leonard, Asna Ansari, Peter Cloetens, Laurence Lemelle, Michael E. Zolensky, Veerle Sterken, John Bridges, Philipp R. Heck, Anton T. Kearsley, D. Frank, Jon K. Hillier, Ashley J. King, Saša Bajt, Wei Ja Ong, Donald E. Brownlee, Frank E. Brenker, Frank J. Stadermann, Barry Lai, Andrew J. Westphal, Alexandre Simionovici
Přispěvatelé: Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS)
Jazyk: angličtina
Rok vydání: 2014
Předmět:
Zdroj: Meteoritics and Planetary Science
Meteoritics and Planetary Science, Wiley, 2014, 49 (9, SI), pp.1612--1625. ⟨10.1111/maps.12208⟩
Meteoritics and Planetary Science, 2014, 49 (9, SI), pp.1612--1625. ⟨10.1111/maps.12208⟩
ISSN: 1086-9379
1945-5100
Popis: Hard X-ray, quantitative, fluorescence elemental imaging was performed on the ID22NI nanoprobe and ID22 microprobe beam lines of the European Synchrotron Research facility (ESRF) in Grenoble, France, on eight interstellar candidate impact features in the framework of the NASA Stardust Interstellar Preliminary Examination (ISPE). Three features were unambiguous tracks, and the other five were identified as possible, but not definite, impact features. Overall, we produced an absolute quantification of elemental abundances in the 15 ? Z ? 30 range by means of corrections of the beam parameters, reference materials, and fundamental atomic parameters. Seven features were ruled out as interstellar dust candidates (ISDC) based on compositional arguments. One of the three tracks, I1043,1,30,0,0, contained, at the time of our analysis, two physically separated, micrometer-sized terminal particles, the most promising ISDCs, Orion and Sirius. We found that the Sirius particle was a fairly homogenous Ni-bearing particle and contained about 33 fg of distributed high-Z elements (Z > 12). Orion was a highly heterogeneous Fe-bearing particle and contained about 59 fg of heavy elements located in hundred nanometer phases, forming an irregular mantle that surrounded a low-Z core. X-ray diffraction (XRD) measurements revealed Sirius to be amorphous, whereas Orion contained partially crystalline material (Gainsforth et al. 2014). Within the mantle, one grain was relatively Fe-Ni-Mn-rich; other zones were relatively Mn-Cr-Ti-rich and may correspond to different spinel populations. For absolute quantification purposes, Orion was assigned to a mineralogical assemblage of forsterite, spinel, and an unknown Fe-bearing phase, while Sirius was most likely composed of an amorphous Mg-bearing material with minor Ni and Fe. Owing to its nearly chondritic abundances of the nonvolatile elements Ca, Ti, Co, and Ni with respect to Fe, in combination with the presence of olivine and spinel as inferred from XRD measurements, Orion had a high probability of being extraterrestrial in origin.
Databáze: OpenAIRE
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