Solving the Puzzle of the Galactic Bar

解开银河酒吧之谜

• 批准号: 1203017
• 负责人: Gail Zasowski
• 金额: $ 8.9万
• 依托单位: Zasowski Gail
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1203017&HistoricalAwards=false
• 关键词: Solving; Puzzle; Galactic; Bar

Dr. Gail Zasowski is awarded an NSF Astronomy and Astrophysics Postdoctoral Fellowship to carry out a program of research and education at The Ohio State University (OSU). One of the greatest unresolved puzzles of our Milky Way Galaxy (MW) is the nature of the long central bar: its structure, dynamics, and stellar chemical composition. The bar is expected to have a significant impact on mass and abundance distributions in the inner Galaxy, which are used to characterize the MW's global properties and their relation to those of other galaxies. This characterization is crucial for understanding not only the MW but also general galactic evolution because the proximity and accessibility of the MW makes it the most powerful resource that investigators have to develop models of galaxy formation and aging. Unfortunately, a thorough understanding of the MW's fundamental properties has been precluded as its inner regions, where most of the stellar mass is located, are behind the thick dust of the midplane. New infrared (IR) data from multiple photometric and spectroscopic surveys are providing a way to probe these inner regions at a level never before possible. The fellow plans a comprehensive analysis of the inner MW that focuses on the spatial, dynamical, and chemical properties of the influential but poorly-understood long bar. This project will take advantage of the unprecedented availability of both photometric and spectroscopic infrared observations of the inner MW midplane, including unique high resolution IR spectra from the Sloan Digital Sky Survey III's Apache Point Observatory Galactic Evolution Experiment (APOGEE).The fellow will combine near- and mid-IR photometry to produce an extinction-corrected catalogue of stars spanning the long bar and outer bulge, and she will use this catalogue to make the first stellar density map of these regions that is capable of measuring the long bar's position, axial ratios, and structural coherence. She will collect radial velocities with APOGEE for a large sample of red clump (RC) giants in the long bar and compare them to kinematical predictions from N-body and stellar dynamics models to measure the bar's systematic velocity, dispersion, and dynamical coherence. Of particular interest are the kinematics of the "transition regions" where resonances influence the bar-bulge and bar-disk relationships. Finally, the fellow will use the APOGEE-derived metallicities and abundances of the RC sample to measure the metallicity distribution along the bar, including the presence of multiple stellar populations. The result will be a complete picture of the long bar's spatial, dynamical, and chemical distributions, which can be used to establish the bar's properties compared to external galactic bars, along with its stellar properties and mixing efficiency.The broader impacts of this project include a significant educational component. The fellow will leverage OSU's partnership with Ohio's 4-H program to demonstrate to children and the general public that science and scientific inquiry are fun, relevant to their lives, and perhaps most importantly, accessible to all. In partnership with the Ohio 4-H state office, the fellow will contribute to two projects teaching scientific concepts through interactive activities, with an emphasis on those that can be easily done in the home. First, she will develop astronomy-themed activities for an annual summer Space Camp targeted at middle-school students. Second, she will combine astronomy-themed activities with suitable background information and evaluation metrics into a Space Science Project Book for 4-H's Project Book series, which encourages students to select, design, and evaluate their own learning experiences beyond the classroom. The close association of 4-H with rural and often economically disadvantaged schools means that the materials that she develops will impact the scientific literacy of these underserved communities.

Gail Zasowski博士被授予NSF天文学和天体物理学博士后研究金，以在俄亥俄州立大学（OSU）进行研究和教育计划。 我们银河系（MW）的最伟大的未解决的难题之一是长中央条的本质：其结构，动力学和恒星化学成分。 预计该条将对内星系中的质量和丰度分布产生重大影响，该棒用于表征MW的全球特性及其与其他星系的关系。 这种表征不仅对于理解MW，而且还要理解一般银河进化至关重要，因为MW的接近性和可及性使其成为研究人员必须开发银河形成和老化模型的最强大资源。 不幸的是，对MW的基本特性的透彻理解被排除在其内部区域（大多数恒星质量所在的内部区域）位于中平面的厚灰尘后面。 来自多个光度法和光谱调查的新红外（IR）数据正在提供一种以前从未做出的水平探测这些内部区域的方法。 同胞对内部MW进行了全面分析，该内部MW着重于有影响力但不足的长条的空间，动力和化学性质。 该项目将利用光度和光谱的红外线观察的前所未有的可用性，包括Sloan Digital Sky Survey III的Apache点观测点银河系进化实验（APOGEE）的独特的高分辨率IR光谱，以结合近距离和Mid-Mid-ir光度范围。她将使用此目录来制作这些区域的第一个恒星密度图，该区域能够测量长条的位置，轴向比率和结构相干性。 她将在长杆中收集带有高等的红色团（RC）巨头样本的径向速度，并将它们与N-Body和Stellar Dynamics模型的运动学预测进行比较，以测量条形的系统速度，分散体和动态连贯性。 特别令人感兴趣的是“过渡区域”的运动学，其中共鸣会影响杠铃和钢丝关系。 最后，该研究员将使用RC样品的顶源性金属和丰度来测量沿条沿标准的金属分布，包括存在多个恒星种群。 结果将是Long bar的空间，动力学和化学分布的完整图片，该图案可用于建立与外部银河棒的棒性特性以及其出色的特性和混合效率。该项目的更广泛影响包括重要的教育组成部分。 该研究员将利用OSU与俄亥俄州4-H计划的合作伙伴关系向儿童和公众展示科学和科学探究很有趣，与他们的生活有关，也许最重要的是，所有人都可以访问。 与俄亥俄州4-H州办公室合作，该研究员将通过互动活动为教授科学概念的两个项目做出贡献，重点是在家庭中很容易完成的项目。 首先，她将针对针对中学学生的年度夏季空间营进行以天文学为主题的活动。 其次，她将将以天文学为主题的活动与适当的背景信息和评估指标相结合到4-H的项目书籍系列的太空科学项目书中，该计划鼓励学生选择，设计和评估课堂以外的学习经验。 4-H与农村和经济不利的学校的密切关联意味着她开发的材料将影响这些服务不足的社区的科学素养。