New Views of Warm Molecular Gas in Nearby Galaxies

Julia Kamenetzky博士被授予美国国家科学基金会天文学和天体物理学博士后奖学金，在亚利桑那大学开展研究和教育项目。她将研究整个星系中的分子气体，这种气体是恒星形成的原材料；这种气体足够冷，原子可以结合在一起形成分子。这项研究将结合阿塔卡马大毫米阵列(ALMA)的高分辨率分子气体地图来查看几个星系的精致细节，并结合对许多星系的低分辨率观测来在大样本中寻找模式。通过比较不同类型星系的气体条件，她将增加我们对哪些物理过程对恒星形成的增加和减少最重要的理解。恒星的诞生和消亡显著影响星系的能量和化学组成；这个项目的目标是利用天文学家现在才能获得的新技术，研究恒星形成的原材料--分子气体。此外，Kamenetzky博士将与天文学教育中心(CAE)共同开发和分发新的以研究为基础、以学生为中心的射电天文学课程。来自Herschel的新数据表明，更高能量的CO旋转线(例如，CO J=6-5)是从温暖的分子气体发出的，而不同于由例如CO J=1-0跟踪的研究较好的较冷分子气体。Kamenetzky博士建议用ALMA高分辨率测量这种温暖的CO气体的尚不清楚的形态和运动学，以了解它与研究得很好的星系成分的关系，并揭示其激发机制。此外，将使用亚利桑那州射电天文台对低J-CO线进行新的单盘观测，将其与来自赫歇尔尖顶的高J线相结合，以便同时对多达300个星系的大型参考样本中的气体冷/暖成分进行建模。类似的方法将被应用于最近发现的超新星1987A残骸中的CO和SiO分子的新的ALMA 3D多普勒层析成像图。新的射电天文课程将通过天文教育中心(CAE)广泛分发，CAE是公认的研究型教育材料和研讨会的提供者。

Dr. Julia Kamenetzky is awarded an NSF Astronomy and Astrophysics Postdoctoral Fellowship to carry out a program of research and education at the University of Arizona. She will study the molecular gas throughout galaxies that is the raw material for star formation; this gas is cold enough that atoms can bind together into molecules. This study will occur with a combination of high-resolution maps of molecular gas from the Atacama Large Millimeter Array (ALMA) to see exquisite detail in a few galaxies, and low-resolution observations of many galaxies to search for patterns in a large sample. By comparing the conditions of the gas in different types of galaxies, she will add to our understanding of which physical processes are most important for increasing and decreasing star formation. The birth and death of stars significantly impact the energetic and chemical composition of galaxies; the goal of this project is to study the raw material of star formation, molecular gas, using new technology that has only now become available to astronomers. Additionally, Dr. Kamenetzky will develop and distribute new research-based, student-focused radio astronomy curriculum with the Center for Astronomy Education (CAE).New data from Herschel indicates that higher-energy CO rotational lines (e.g. CO J=6-5) are emitted from warm molecular gas that is distinct from the well-studied cooler molecular gas traced by e.g. CO J=1-0. Dr. Kamenetzky proposes to measure the yet-unknown morphology and kinematics of this warm CO gas in high resolution with ALMA to understand its relation to well-studied galaxy components and reveal its excitation mechanisms. Additionally, new single-dish observations of low-J CO lines will be obtained using the Arizona Radio Observatory, to be combined with high-J lines from Herschel SPIRE, in order to simultaneously model the cool/warm components of gas in a large reference sample of up to 300 galaxies. Similar methods will be applied to new ALMA 3D Doppler tomography maps of recently discovered molecular CO and SiO in the remnant of Supernova 1987A. New radio astronomy curriculum will be widely distributed via the Center for Astronomy Education (CAE), a recognized provider of research-based educational materials and workshops.