Gravitationally Driven Instabilities in the Early & Late Stages of Stellar Evolution

早期重力驱动的不稳定性

• 批准号: 0407070
• 负责人: Joel Tohline
• 金额: $ 33.21万
• 依托单位: Louisiana State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-06-01 至 2008-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0407070&HistoricalAwards=false
• 关键词: Gravitationally; Driven; Instabilities; Early; &amp

Rotating stars are susceptible to a variety of global, gravitationally driven instabilities, especially during the earliest (e.g., protostellar) and latest (e.g., compact object) phases of their evolution when they are most likely to be rotating rapidly. These include, for example, a wide spectrum of nonradial pulsations. An even larger number of instabilities may be encountered by stars in binary systems through their mutual gravitational interaction, in particular, tidal and mass transferring instabilities. Any one of these instabilities may result in substantial alterations in the star's global structure and change the star's evolution. In the case of compact objects, such as neutron stars, they may give rise to measurable levels of gravitational radiation. Also, we're not likely to understand the origin of binary stars until we are able to realistically model the variety of gravitationally driven instabilities in rapidly rotating protostars and protostellar gas clouds. The Principle Investigator of this project is extending his detailed investigations of gravitationally driven instabilities in rotating stars, using fully three-dimensional, nonlinear hydrodynamical techniques to determine under what conditions certain key instabilities arise, and what the astrophysically important implications are of the nonlinear development of these instabilities. Broader Impacts. The types of high-performance computational tools that must be developed in order to further our understanding of gravitational instabilities in astrophysical systems are also used to make significant research advancements in atmospheric sciences, coastal studies, certain areas of the health sciences, and numerous subfields of engineering. This Louisiana State University researcher and his students regularly exchange ideas and computational techniques with applied mathematicians, computer scientists, and numerous colleagues who employ computational fluid dynamics tools in their research to model hurricane storm surges, fluid flow in the human eye, cooling flows in advanced gas turbine systems, coastal erosion, and reacting flows in petrochemical stirring tanks. Most of these areas of research directly influence Louisiana's environmental and economic well-being. The Principle Investigator will continue to be involved in K-12 and general public outreach projects, especially those associated with the local Highland Road Park Observatory and one secondary school in Baton Rouge where substantial efforts are being made to strengthen the early training of young women in science and mathematics.

旋转的恒星容易受到各种全球，重力驱动的不稳定性的影响，尤其是在最早的（例如原始物质）和最新的（例如，紧凑的对象）阶段的过程中，当它们最有可能迅速旋转时。这些包括例如广泛的非放射搏动。恒星在二元系统中可以通过相互的重力相互作用，尤其是潮汐和传质不稳定性来遇到更多的不稳定性。这些不稳定性中的任何一个都可能导致恒星的全球结构发生重大变化，并改变恒星的演变。 如果是紧凑的物体，例如中子星，它们可能会导致可测量的重力辐射水平。 另外，我们不太可能理解二进制恒星的起源，直到我们能够在快速旋转的质恒星和原恒星气体云中实际对重力驱动的不稳定性进行建模。该项目的主要研究者正在扩展他对旋转恒星中重力驱动的不稳定性的详细研究，该研究使用完全三维的非线性流体动力学技术来确定在哪些条件下某些关键不稳定性以及天体重要上重要的重要性的介绍是这些不稳定性的非线性发展。更广泛的影响。为了进一步了解天体物理系统中的重力不稳定性，还必须开发出高性能计算工具的类型，以在大气科学，沿海研究，健康科学的某些领域以及众多工程系方面的重大研究进步。这位路易斯安那州立大学的研究人员及其学生定期与应用数学家，计算机科学家以及众多同事交换思想和计算技术，他们在研究中使用计算流体动力学工具来模拟飓风的潮流，人眼中的流体流动，在高级气动涡轮系统，海岸侵蚀和反应的petroChem petroChem take take intrimist of the Petrocls of Petrocls of the Petrocls of the Petrocls of the Petrocls Air搅拌。这些研究领域中的大多数直接影响路易斯安那州的环境和经济福祉。原则调查员将继续参与K-12和一般公共外展项目，尤其是与当地高地公园天文台和巴吞鲁日的一所中学相关的项目，在那里正在做出大量努力，以加强对科学和数学的年轻妇女的早期培训。