Postdoctoral Fellowship: AAPF: All Shook Up: Understanding the Chemistry, Dynamics, and Kinematics of the Diffuse Interstellar Medium

Daniel Rybarczyk被授予NSF天文学和天体物理学奖学金，以在威斯康星大学麦迪逊分校开展一项研究和教育计划。Rybarczyk将利用对原子氢(HI)和各种分子物种的无线电/毫米观测来研究激波在塑造扩散星际介质(ISM)结构和化学方面的作用。Rybarczyk将在分子形成刚刚开始的区域测量这些关键ISM组分的丰度，以了解分子云形成过程的第一步，分子云形成在恒星形成和星系演化中起着关键作用。Rybarczyk还将开展一项外展计划，接待公立学校访问威斯康星大学麦迪逊分校的天文系，包括天文馆和沃什伯恩天文台(包括天文馆和沃什伯恩天文台)(重点关注那些学生来自STEM领域历史上代表性较低的群体的学校)。最近的研究表明，激波对弥漫的ISM的物理和化学演化至关重要，在恒星形成过程的最初阶段发挥着至关重要的作用，但在这些环境中直接观察到激波示踪器的情况很少见。Rybarczyk将通过观测扩散ISM中的SiO分子--通常被认为是星际冲击波的明确示踪物--大约是现有漫反射视线样本的三倍，目标方向是间接示踪剂或丝状结构暗示的激波化学。这些测量和与非平衡化学模型预测的比较将检验我们对低密度区域中激波化学的理解，这在现有文献中基本上没有被探索过。对HCO+和CO分子的进一步观察将补充SIO测量，探测扩散ISM的分子气体含量，并测试我们使用不同示踪剂探测扩散分子气体的能力。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Daniel Rybarczyk is awarded an NSF Astronomy and Astrophysics Fellowship to carry out a program of research and education at the University of Wisconsin–Madison. Rybarczyk will use radio/millimeter observations of atomic hydrogen (HI) and various molecular species to study the role of shocks in shaping the structure and chemistry of the diffuse interstellar medium (ISM). Rybarczyk will measure the abundances of these key ISM constituents in regions where molecule formation is just getting under way to understand the first steps in the process of molecular cloud formation, which plays a critical role in star formation and galaxy evolution. Rybarczyk will also conduct an outreach program hosting public school visits (with a focus on schools with students from groups historically underrepresented in STEM fields) to the University of Wisconsin–Madison's Astronomy Department, including its planetarium and Washburn Observatory.Recent work has argued that shocks are crucial to the physical and chemical evolution of the diffuse ISM, playing a vital role in the very first stages of the star formation process, but direct observations of shock tracers in these environments are rare. Rybarczyk will roughly triple the existing sample of diffuse sightlines with observations of the molecule SiO — generally believed to be an unambiguous tracer of interstellar shocks — in the diffuse ISM, targeting directions where shock chemistry is implied by indirect tracers or filamentary structure. These measurements and a comparison to non-equilibrium chemical model predictions will test our understanding of shock chemistry in a low-density regime largely unexplored in the existing literature. Further observations of the molecules HCO+ and CO will complement the SiO measurements, probing the molecular gas content of the diffuse ISM and testing our ability to detect diffuse molecular gas using different tracers.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.