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

要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物质的形成，即富含钙铝的包裹体（CAIs）。cai包含在原始陨石中，它们可以用来研究太阳系发展最早阶段的形成和演化。cai大约在45.67亿年前形成于年轻的太阳附近，形成时间相对较短（<5万年），然后被远端运送到大块陨石形成区域。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运输过程至关重要。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上那个阶段的组成部分的性质。因此，CAI是本奖学金申请的重点，我将专门使用它们来更好地理解：1)超新星和/或多种核合成源如何/是否为早期太阳系贡献物质2)CAI形成区域特定元素的前太阳系载体3)CAI和后来形成的太阳系材料（例如地球）如何相关。与之前的研究不同，这些研究已经检查了代表平均CAI成分的批量CAI。首先，我将确定cai中包含的各个组件的构建块。这将利用一种完善的连续酸浸技术来完成，这种技术以前曾用于识别大块陨石中的单个成分。将对多个cai进行酸浸，并在渗滤液馏分上测量多种元素（Mg, Si, Fe, Ti, Hf）的同位素组成。此外，将在扫描电子显微镜下分析来自一个CAI的每个渗滤液分数的一部分，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，这将意味着这些元素被寄主在相同的前太阳载体中，并且来自相同的恒星来源，例如超新星。相反，如果没有观察到相关性，这就告诉我们，cai形成区域在短时间内与来自不同恒星环境的前太阳物质很好地混合在一起。此外，通过在浸出馏分中使用Mg、Si、Fe和Ti同位素，还将获得cai后续历史的信息，如冷凝和蒸发事件。这些数据将与目前太阳系早期发生的此类事件的模型进行比较。因此，确定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物质的演变，并将为太阳系最早时期发生的物质和事件提供新的线索。

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.