Identification of presolar components in the Solar System's oldest dated solids

太阳系最古老固体中太阳前成分的识别

• 批准号: 440227108
• 负责人: Dr. Quinn Shollenberger
• 金额: --
• 依托单位: Department of Earth, Planetary and Space Sciences
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/440227108?language=en
• 关键词: Identification; presolar; components; Solar; System

To decipher the events in the early Solar System that eventually lead to the formation of Earth, we must understand the formation of the earliest solid materials, which are calcium-aluminum-rich inclusions (CAIs). CAIs are contained within primitive meteorites and they can be used to study the formation and evolution of the earliest phase of Solar System development. CAIs formed about 4.567 billion years ago near the young sun within a relatively short amount of time (<50,000 years) before they were transported distally to the bulk meteorite forming regions. As such, understanding the formation and evolution of CAIs is imperative to assess the mixing and transport processes that occurred in the early Solar System. Specifically, measuring the isotopic compositions of CAIs allows researchers to understand the nature of the building blocks during that phase of the Solar System’s history. Therefore, CAIs are the focus of this fellowship application, and I will use them specifically to better understand:1) How/if supernova and/or multiple nucleosynthetic sources contributed material to the early Solar System2) Presolar carriers of specific elements in the region where CAIs formed3) How CAIs and later-formed Solar System materials (e.g., Earth) are relatedUnlike previous studies that have examined bulk CAIs, which represent an average CAI composition, in the proposed work, the first of its kind, I will identify the building blocks of the individual components contained within CAIs. This will be done utilizing a well-established sequential acid leaching technique, which has been used previously to identify individual components within bulk meteorites. Acid leaching will be performed on multiple CAIs and the isotopic composition of multiple elements (Mg, Si, Fe, Ti, Hf) will be measured on the leachate fractions. Also, a portion of each leachate fraction from one CAI will be analyzed under a scanning electron microscope to characterize the individual parts and interpret the isotopic results. If correlations exist for the isotopic compositions of the elements, this would mean these elements are hosted in the same presolar carrier and are derived from the same stellar source, such as a supernova. Conversely, if no correlations are observed, this informs us that the CAI-forming region was well mixed with presolar matter from diverse stellar environments in a short amount of time. Additionally, through the use of Mg, Si, Fe, and Ti isotopes in the leaching fractions, information will also be obtained on the subsequent history of the CAIs such as condensation and evaporation events. This data will be compared with current models for such events occurring in the early Solar System. As such, identifying the components of CAIs and their subsequent history will help us understand the evolution of early formed solid material and will shed new light on the material and events that took place in the earliest epoch of the Solar System.

为了破译早期太阳系中最终导致地球形成的事件，我们必须了解最早的固体材料的形成，即富含钙铝的夹杂物（CAI）。 CAI 包含在原始陨石中，可用于研究太阳系发展最早阶段的形成和演化。 CAI 形成于大约 45.67 亿年前，在相对较短的时间内（<50,000 年）在年轻太阳附近形成，然后被传送到远端的大块陨石形成区域。因此，了解 CAI 的形成和演化对于评估早期太阳系中发生的混合和传输过程至关重要。具体来说，测量 CAI 的同位素组成可以让研究人员了解太阳系历史这一阶段的组成部分的性质。因此，CAI 是本次奖学金申请的重点，我将专门使用它们来更好地理解：1）超新星和/或多种核合成来源如何/是否为早期太阳系贡献了材料2）CAI 形成区域中特定元素的前太阳载体3）CAI 和后来形成的太阳系材料（例如地球）如何相关与之前检查散装 CAI 的研究不同，这些研究代表了平均 CAI 在拟议的工作中，我将确定 CAI 中包含的各个组件的构建块。这将利用成熟的连续酸浸技术来完成，该技术之前已用于识别块状陨石中的各个成分。将对多种 CAI 进行酸浸，并对浸出液部分的多种元素（Mg、Si、Fe、Ti、Hf）的同位素组成进行测量。此外，将在扫描电子显微镜下分析来自一种 CAI 的每种渗滤液部分的一部分，以表征各个部分并解释同位素结果。如果元素的同位素组成存在相关性，则意味着这些元素位于相同的前太阳载体中，并且源自相同的恒星源，例如超新星。相反，如果没有观察到相关性，这告诉我们 CAI 形成区域在短时间内与来自不同恒星环境的太阳前物质充分混合。此外，通过在浸出部分中使用镁、硅、铁和钛同位素，还将获得有关 CAI 随后历史的信息，例如冷凝和蒸发事件。该数据将与早期太阳系中发生的此类事件的当前模型进行比较。因此，识别 CAI 的组成部分及其随后的历史将有助于我们了解早期形成的固体材料的演化，并将为了解太阳系最早时期发生的材料和事件提供新的线索。