Evolution of the Early Solar Nebula: Isotopic Fractionation and Dynamical Processes

天文学中最有趣的问题之一是了解行星系统形成的条件。年轻恒星周围的尘埃和气体原行星盘被认为是行星系统的诞生地。它们类似于我们几百万年前的太阳系。需要对这些天体的分子谱线和尘埃热发射进行观测，再加上对陨石和彗星样本的分析和建模，以揭示行星形成边缘的初始条件和化学复杂性。这种连贯的研究方法是基于天体化学，天体物理学和宇宙化学数据。为了更好地理解太阳星云的物理学、化学和动力学，必须严格地重新评估和调整盘模型。在接下来的两年里，我将：1）利用我们先进的热化学盘模型耦合到气体颗粒化学研究氘分馏与核自旋态过程中的湍流太阳星云和其他原行星盘，2）通过添加同位素分馏的C和O的化学盘模型，3）验证模型的预测与阿塔卡马大型毫米波阵列（阿尔马）。该项目的主要方向是：（1）研究演化中的太阳星云中分子和复杂冰的演化，（2）研究太阳星云中同位素分馏及其与热/辐射历史的关系，（3）研究和比较太阳星云化学与其他原行星盘中的同位素化学。

One of the most interesting questions in astronomy is to understand the conditions under which planetary systems form. Protoplanetary disks of dust and gas around young stars are believed to be birthplaces of planetary systems. They resemble our Solar system at the age of several million years. Observations of these objects in molecular lines and dust thermal emission, coupled to analysis and modeling of meteoritic and cometary samples, are needed to unravel the initial conditions and chemical complexity at the verge of planet formation. This coherent research approach is based upon astrochemical, astrophysical, and cosmochemistry data. To better understand the Solar nebula physics, chemistry and dynamics, disk models will have to be critically re-evaluated and adjusted. Over the next two years I will: 1) utilize our advanced thermochemical disk model coupled to gas- grain chemistry to study deuterium fractionation with nuclear spin-state processes in the turbulent Solar nebula and other protoplanetary disks, 2) extend the chemical disk model by adding isotopic fractionation for C and O, 3) verify the model predictions with the Atacama Large Millimeter Array (ALMA). The main directions of the project will be: (1) the study of the evolution of molecules and complex ices in the evolving Solar nebula, (2) the study of the isotopic fractionation and its relevance to the thermal/irradiation history in the Solar nebula, 3) the study and comparison of the Solar nebula chemistry with the isotopic chemistry in other protoplanetary disks.