First Imaging Survey of Rapid Rotators and Be Stars with Long-Baseline Interferometry

这个项目是由干涉光学和红外望远镜的最新结果推动的，这些望远镜已经开始解析快速旋转的恒星的表面。最近的恒星模型表明，自转的影响远远不能忽略不计，并且可以影响快速自转恒星的寿命、表面亮度、表面丰度和演化轨迹。在这里，研究人员将利用一种新的仪器-密歇根红外组合器(MIRC)，该仪器于去年在佐治亚州立大学高角分辨率天文中心的6望远镜光学干涉仪上投入使用。有了它，他们将测量快速自转恒星的表面，直接绘制重力变暗与纬度的关系图，并测试冯·泽佩尔-罗奇模型对这些恒星的影响。通过对谱线轮廓、光谱能量分布和干涉可见度/闭合相位的详细模拟，将建立恒星光球扁率和重力暗化规律的定量模型。这项工作将首次与最近的模型进行比较，以约束热恒星中差异旋转的内部结构和性质。最后，Be星盘的连续发射也将被成像，当结合发射线测量和光谱能量分布时，将允许建立迄今为止最准确的盘模型。目标是确定圆盘的温度结构和密度，并将这些性质与形成机制联系起来。这里的工作将形成一名研究生的博士论文，他将接受使用最前沿天文仪器的培训。通用分析工具和成像算法将公开供其他研究人员使用。还将开展一项以红外成像技术为中心的教育和公共推广计划，包括通过安娜堡动手博物馆组织的一系列巡回展览。

This project is motivated by recent results from interferometric optical and infrared telescopes that have begun to resolve the surfaces of rapidly rotating stars. Recent stellar models have demonstrated that the effects of rotation are far from negligible and can influence the lifetimes, surface brightnesses, surface abundances, and evolutionary tracks of rapidly rotating stars. Here, the investigators will take advantage of a new instrument, the Michigan Infrared Combiner (MIRC), which was commissioned last year at the Georgia State University Center for High Angular Resolution Astronomy's 6-telescope optical interferometer. With it, they will survey the surfaces of fast rotating stars, directly mapping the latitude-dependence of gravity darkening and testing the von Zeipel-Roche model for such stars. Through detailed modeling of the line profiles, spectral energy distributions, and interferometry visibilities/closure phases, quantitative models of the stellar photospheres' oblateness and gravity darkening laws will be developed. This work will be compared to the recent models to constrain the internal structure and nature of differential rotation in hot stars for the first time. Finally, the continuum emission of Be star disks will also be imaged, which when combined with emission line measurements and the spectral energy distribution, will allow the construction of the most accurate disk models to date. The goal is to determine the temperature structure and density of the disks and to link these properties back to the formation mechanism.The work here will form the Ph.D. thesis of a graduate student who will be trained in the use of forefront astronomical instrumentation. The general purpose analysis tools and imaging algorithms will be made publicly available for use by other researchers. An education and public outreach program will also be undertaken which will center around infrared imaging technology, including a series of traveling exhibits organized through the Ann Arbor Hands-on Museum.