CAREER: Understanding Stellar Overflows

9702484摘要-弗兰克双极外流和高度准直的喷流几乎是与恒星质量损失有关的普遍特征。从年轻恒星天体(YSO)到发光蓝变星(LBV)和行星星云(PNE)--恒星的摇篮到坟墓--存在着以狭窄的高速流或扩展的双极叶的形式存在的准直气体流动的明显证据。在YSO中，观测到LBV和PNE准直的高超音速外流从中央恒星输送了大量的能量和动量。流出和喷流在母星的演化过程中肯定扮演着重要的动力学角色。赫茨斯普龙格-罗素(H-R)图上喷流和双极外流的相似性肯定会告诉我们一些关于恒星演化的本质以及恒星与其环境的相互作用的基本和非常普遍的信息。有一个高分辨率观测的大型数据库，包括来自哈勃太空望远镜(HST)的观测。一套通用的、经过充分测试的理论用于解释外流的准直和传播，可以作为一个强大的诊断工具，将外流与它们经常被掩盖的来源联系起来。这可能会在现代天文学面临的两个最基本的问题上取得实质性进展：理解恒星诞生和恒星死亡的必要性。这个项目的研究目标雄心勃勃，但是可以实现的。首先，通过详细阐述驱动准直过程的基本物理，发展和提炼这样一个准直恒星流出的一般理论。第二，扩展我们对流出的准直和传播的理解，以包括更真实的物理，如微物理过程和磁场的影响。这项研究集中在两个主要的调查。这项研究的一个目标是使用PNE和PPNe形态来确定像太阳这样的恒星从巨星阶段演化到矮星阶段所遵循的路线。第二个项目是对年轻星体喷流的辐射-气体动力学和磁气动力学准直的长程研究。这项研究的最终产品将是一套经过充分测试的工具，可以弥合理论和现实之间的差距，允许恢复单个物体和物体类别的历史。该项目的教育和推广目标同样雄心勃勃：利用数值模拟(即图形和动画)固有的可访问性以及真实和“合成”的两极流出观测的视觉力量，作为课程开发、互动天文馆展示和中学推广工作的一系列创新计划的核心。作为一名“受欢迎的”科学作家，作为《发现》杂志和《天文学》杂志的定期撰稿人，这些努力为向更广泛的受众介绍科学的有效战略提供了经验。这些技能和研究成果将被整合到教育倡议中，向天文馆参观者、大学生和中学生介绍恒星天文学以及整个科学工作中更广泛的问题。

AST-9702484 Abstract - A Frank Bipolar outflows and highly collimated jets are nearly ubiquitous features associated with stellar mass loss. From Young Stellar Objects (YSOs) to Luminous Blue Variables (LBVs) and Planetary Nebulae (PNe) - the stellar cradle to the grave - there exists clear evidence for collimated gaseous flows in the form of narrow high velocity streams or extended bipolar lobes. In YSOs, LBVs and PNe collimated highly supersonic outflows are observed to be transporting prodigious amounts of energy and momentum from a central star . Outflows and jets must play a significant dynamical role in the evolution of the parent stars. The similarity of jets and bipolar outflows across the Hertzsprung- Russell (H-R) diagram must tell us something fundamental and quite general about the nature of stellar evolution, as well as the interaction of stars with their environments. A large database of high resolution observations , including observations from the Hubble Space Telescope (HST)) are available. A general, well tested suite of theory for explaining outflow collimation and propagation could serve as a powerful diagnostic tool linking the outflows to their often obscured sources. This could initiate substantial progress in two of the most fundamental issues facing modern astronomy: the need to understand stellar birth and stellar death. The research goals of this project are ambitious but attainable. First, to develop and refine such a general theory of collimated stellar outflows by detailing the basic physics which drives the collimation process. Second, to extend our understanding of the collimation and propagation of the outflows to include more realistic physics such as the effect of microphysical processes and magnetic fields. The research focuses on two major investigations. One goal of this study is to use PNe and PPNe morphologies to determine the route which stars like the sun follow as they evolve from the Giant to the Dwarf stage. The second project is a long range study of radiation-gasdynamic and magneto-gasdynamic collimation of jets from Young Stellar Objects. The final products of the research will be a suite of well tested tools which can bridge the gap between the theory and reality, allowing the histories of individual objects and classes of objects to be recovered. The educational and outreach goals of the project are equally ambitious: to use the accessibility inherent to numerical simulations (i.e. graphics and animations) along with the visual power of real and "synthetic" bipolar outflow observations as the core of a series of innovative programs in curriculum development, interactive planetarium displays and middle school outreach efforts. The efforts as a "popular" science writer and as a regular contributer to both DISCOVER and ASTRONOMY magazines have provided experiences in effective strategies for bringing science to wider audiences. These skills, and the fruits of the research, will be integrated into education initiatives which will introduce Planetarium visitors, college and middle school students to stellar astronomy as well as to wider issues in the workings of science as a whole.