CAREER: Understanding Stellar Forges: The Properties and the Physics of Formation of Cosmic Dust

尘埃是星际介质中的次要成分，但在宇宙的演化和我们观察宇宙的能力方面发挥着重要作用。拉扎蒂博士和他的团队将结合分析和数值技术来研究各种大小的尘埃颗粒，从最小的大分子和团簇到微米大小的结晶和非晶态固体。在项目的第一部分，将用密度泛函理论技术计算微小尘埃颗粒的结构和光学性质。我们将研究最多1000个原子的原子和分子团簇。在第二部分中，尘埃成核模型将通过发展包含真实原子结构的动力学理论来改进，放松热平衡假设，并包括能量交换的量子化。最后，将计算恒星大气、风、超新星和活动星系核流出的尘埃产生量。该项目将更清楚地描绘宇宙尘埃形成的图景，并有可能提供弥散星际带和2175埃星云特征的载流子的识别。由于烟尘和碳质宇宙尘埃有许多相似之处，尘埃团的光学性质将成为星系、恒星形成甚至大气研究中辐射传输模型的宝贵组成部分。研究结果将通过PI和北卡罗来纳州自然科学博物馆的合作向公众传播。拉扎蒂博士和博物馆工作人员将为K-12学生和普通公众开发互动英语和西班牙语课程，介绍宇宙中元素和尘埃的演变。这些节目最终将被转换成视频，可以在全国各地的博物馆和学校放映。将为教育工作者和教师开发配套的教学材料。将利用这些活动的双语特点，促进拉美裔/拉丁裔社区更广泛地参与STEM职业。来自贫困家庭的高中生和本科生也将加入PI的暑期研究项目小组。

Dust is a minor component of the interstellar medium but plays a major role in the evolution of the universe and on our capability to observe it. Dr. Lazzati and his group will combine analytical and numerical techniques to study dust particles of all sizes, from the smallest macromolecules and clusters up to micron-sized crystalline and amorphous solids. In the first part of the project structural and optical properties of small dust grains will be computed with density functional theory techniques. Atomic and molecular clusters with up to 1000 atoms will be studied. In the second part models of dust nucleation will be improved by developing a kinetic theory that includes realistic atomic structures, relaxes the assumption of thermal equilibrium, and includes quantization of energy exchanges. Finally, dust yields from stellar atmospheres and winds, supernovae, and AGN outflows will be computed. This project will paint a clearer picture of cosmic dust formation and has the potential to provide the identification of the carriers of the diffuse interstellar bands and of the 2175 Angstrom feature. The optical properties of dust clusters will be an invaluable ingredient for radiation transfer models in galaxies, star formation, and even for atmospheric studies, since soot and carbonaceous cosmic dust share many similarities.The results of the research will be disseminated to the public through a collaboration between the PI and the North Carolina Museum of Natural Sciences. Dr. Lazzati and museum staff will develop interactive English and Spanish programs for K-12 students and the general public on the evolution of elements and dust in the universe. The programs will eventually be converted into videos that can be shown in museums and schools around the country. Accompanying instructional materials for educators and teachers will be developed. The bilingual character of the activities will be exploited to foster a broader participation of the Hispanic/Latino community in STEM careers. High-school and undergraduate students from underprivileged backgrounds will also join the PI's group for summer research projects.