登录 | 注册

STARDUST INVESTIGATION INTO THE CR CHONDRITE GROVE MOUNTAIN 021710

上传时间:2016-07-18 18:48

【发表年份】2013

【作  者】Xuchao Zhao1, Christine Floss2, Yangting Lin1,4, and Maitrayee Bose3

【提交单位】中科院地质与地球物理研究所

【摘  要】We report the presolar grain inventory of the CR chondrite Grove Mountain 021710. A total of 35 C-anomalous grains (∼236 ppm) and 112 O-anomalous grains (∼189 ppm) were identified in situ using NanoSIMS ion imaging.Of 35 C-anomalous grains, 28 were determined to be SiC grains by Auger spectroscopy. Seven of the SiC grains were subsequently measured for N and Si isotopes, allowing classification as one nova grain, one Y grain, one Z grain, and four mainstream grains. Eighty-nine out of 112 O-anomalous grains belong to Group 1, indicating origins in low-to-intermediate-mass red giant and asymptotic giant branch stars. Twenty-one are Group 4 grains and have origins in supernovae. Auger spectroscopic elemental measurements of 35 O-anomalous grains show that 33 of them are ferromagnesian silicates. They have higher Mg/(Mg+Fe) ratios than those reported in other meteorites, suggesting a lower degree of alteration in the nebula and/or asteroid parent bodies. Only two oxide grains were identified, with stoichiometric compositions of MgAl2O4 and SiO2, respectively. The presolar silicate/oxide ratio of GRV 021710 is comparable with those of the CR3 chondrites (QUE 99177 and MET 00426) and primitive interplanetary dust particles. In order to search for presolar sulfides, the meteorite was also mapped for S isotopes. However, no presolar sulfides were found, suggesting a maximum abundance of 2 ppm. The scarcity of presolar sulfides may be due to their much faster sputtering rate by cosmic rays compared to silicates.

【关键词 】astrochemistry – circumstellar matter – novae, cataclysmic variables – nuclear reactions, nucleosynthesis, abundances – stars: winds, outflows – supernovae: general Online-only material: color figures

原文下载
原文预览
版权所有 © 2007-2019 All Rights Reserved.    |    中国极地研究中心 www.pric.org.cn    |    极地标本资源共享平台 birds.chinare.org.cn
地址:上海浦东金桥路451号    |    联系电话:021-58717576    |    邮政编码:200136    |    邮箱:connect@pric.org.cn
技术支持:上海橙智信息科技有限公司
沪ICP备05021913号