More Interstellar Exposure Ages of Large Presolar Sic Grains from the Murchison Meteorite
نویسندگان
چکیده
MURCHISON METEORITE. F. Gyngard 1 , J. N. Ávila 2,3 , T. R. Ireland 2,3 , and E. Zinner 1 , 1 Laboratory for Space Sciences and Department of Physics, [email protected], Washington University, St. Louis, MO 63130, USA, 2 Research School of Earth Sciences, The Australian National University, Canberra ACT 0200, Australia, 3 Planetary Science Institute, The Australian National University, Canberra ACT 0200, Australia.
منابع مشابه
Infrared spectra of meteoritic SiC grains
We present here the first infrared spectra of meteoritic SiC grains. The mid-infrared transmission spectra of meteoritic SiC grains isolated from the Murchison meteorite were measured in the wavelength range 2.5–16.5 μm, in order to make available the optical properties of presolar SiC grains. These grains are most likely stellar condensates with an origin predominately in carbon stars. Measure...
متن کاملComprehensive Analyses of Gentle Separated Presolar Sic-grains
Introduction: Presolar grains undergo a long jour ney through interstellar space before being incorporat ed into primitive meteorites from which they are recov ered [1]. During this journey they are exposed to parti cle impacts and UV-radiation which might lead to al teration, accretion or sputtering effects leading to changes in structure and formation of coatings on the original refracto...
متن کاملs-PROCESS Sr ISOTOPIC COMPOSITIONS IN PRESOLAR SiC FROM THE MURCHISON METEORITE
We have used thermal ionization mass spectrometry to measure the isotopic compositions of Sr in size-sorted samples (the KJ series) of interstellar SiC separated from the Murchison meteorite. The Sr compositions are radically anomalous in comparison to those in normal solar system materials. As for other heavy elements in presolar SiC, the anomalies can be understood to represent enrichment of ...
متن کاملCoordinated Micro-raman and Nanosims Analysis of Micron- to Submicron- Sized Presolar Sic Grains from Murchison
Introduction: Transmission electron microscopy (TEM) studies of sub-μm presolar SiC grains showed that 3C-SiC is the dominant polytype (~80%) [1]. Although TEM is the most effective technique to determine the crystal structure and disorder, TEM is destructive and time-consuming, and may not be representative of the bulk sample. On the other hand, Raman spectrometry investigates matter at the sc...
متن کاملPresolar Grains from the Qingzhen (eh3) Meteorite
A 28 g sample of the Qingzhen enstatite (EH3) chondrite was subjected to chemical and physical separation procedures to yield several grain-size residues. Ion mapping of isotopes of Si, O, and C in the ion microprobe of two size fractions (QZR4: 0.4–0.8 lm; QZR5: 0.8–2 lm) identified 55 30Si-depleted candidates out of 37,917 Si-rich grains and six 18O-depleted grains out of 54,410 oxides. Subse...
متن کامل