کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8910988 1637936 2018 28 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Iron and nickel isotope compositions of presolar silicon carbide grains from supernovae
ترجمه فارسی عنوان
ترکیبات ایزوتوپ آهن و نیکل از دانه های سیلیکون کاربید از ابرنواختر
کلمات کلیدی
هسته سنتز، ایزوتوپهای آهن، ایزوتوپهای نیکل، ابرنواختر، ابزار شیکاگو برای یونیزاسیون لیزر،
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات ژئوشیمی و پترولوژی
چکیده انگلیسی
We report the carbon, silicon, iron, and nickel isotope compositions of twenty-five presolar SiC grains of mostly supernova (SN) origin. The iron and nickel isotope compositions were measured with the new Chicago Instrument for Laser Ionization, CHILI, which allows the analysis of all iron and nickel isotopes without the isobaric interferences that plagued previous measurements with the NanoSIMS. Despite terrestrial iron and nickel contamination, significant isotopic anomalies in 54Fe/56Fe, 57Fe/56Fe, 60Ni/58Ni, 61Ni/58Ni, 62Ni/58Ni, and 64Ni/58Ni were detected in nine SN grains (of type X). Combined multi-isotope data of three grains with the largest nickel isotope anomalies (>100‰ or <−100‰ in at least one isotope ratio, when expressed as deviation from the solar value) are compared with the predictions of two SN models, one with and one without hydrogen ingestion in the He shell prior to SN explosion. One grain's carbon-silicon-iron-nickel isotope composition is consistent with the prediction of the model without hydrogen ingestion, whereas the other two grains' isotope anomalies could not be reproduced using either SN models. The discrepancies between the measured isotope compositions and model predictions may indicate element fractionation in the SN ejecta prior to or during grain condensation, and reiterate the need for three-dimensional SN models.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Geochimica et Cosmochimica Acta - Volume 221, 15 January 2018, Pages 127-144
نویسندگان
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