CAREER: Complex organic molecules in cold interstellar clouds-- A laboratory kinetics study

复杂的有机分子是地球上生命的最终组成部分，它们在银河系中无处不在。它们被发现的更令人惊讶的地方之一是在寒冷，致密的前恒星核心。目前最先进的化学模型无法准确地再现几乎所有复杂有机分子的观测丰度，也无法预测它们在星前核中的存在。Crabtree博士和他的学生将研究在星际介质和前恒星核心中发现的温度下形成这些分子的化学过程。 在如此低温下的高形成率可能意味着生命前化学在整个宇宙中无处不在，这可能对寻找生命具有重要意义。这项工作将导致至少三个博士论文，本科生将通过加州大学戴维斯分校的CURE夏季研究计划参与这个项目。该团队将使用一种强大的新仪器进行实验，该仪器基于均匀超声膨胀，耦合到啁啾脉冲傅里叶变换微波光谱仪，以收集羟基和硫烷基反应的速率数据和化学产物，其中包括小O-，N-，和含硫分子。这些数据对于建立天体化学模型和将它们与阿尔马观测的星星形成区域进行比较至关重要。该实验工作将为加州大学戴维斯分校的研究生创造论文机会，为本科生创造暑期研究机会。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Complex organic molecules are the ultimate building blocks of life on Earth, and they are ubiquitous throughout the Galaxy. One of the more surprising places they are found is in cold, dense pre-stellar cores. Current state-of-the-art chemical models fail to accurately reproduce the observed abundances of nearly all complex organic molecules or to predict their presence in pre-stellar cores. Dr. Crabtree and his students will examine chemical processes that form these molecules at the temperatures found in the interstellar medium and in pre-stellar cores. High formation rates at these low temperatures could imply that prebiotic chemistry is ubiquitous throughout the Universe, which could have important implications on the search for life. This work will lead to a minimum of three PhD theses, and undergraduate students will participate this project through UC Davis’s CURE Summer Research Program.The team will conduct experiments with a powerful new instrument based on a uniform supersonic expansion coupled to a chirped-pulse Fourier transform microwave spectrometer to gather rate data and chemical products of hydroxyl and sulfanyl reactions with small O-, N-, and S- bearing molecules. These data will be crucial in forming astrochemical models and comparing them to ALMA observations of star forming regions. The experimental work will create thesis opportunities for graduate students and summer research opportunities for undergraduate students at UC Davis.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.