Dust Driven Multiphase Hydrodynamics in Planetary Nebulae

行星状星云中尘埃驱动的多相流体动力学

• 批准号: 1812946
• 负责人: Jacob McFarland
• 金额: $ 37.47万
• 依托单位: University of Missouri-Columbia
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2020-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1812946&HistoricalAwards=false
• 关键词: Dust; Driven; Multiphase; Hydrodynamics; Planetary

Average stars, like the sun, eventually use up all their fuel and die. They leave behind beautiful corpses in the form large glowing clouds of gas and dust known as planetary nebulae. These nebulae are stunning and colorful with diverse and distinctive shapes, earning them names like cat?s eye, helix, and dumbbell. While a nebula is born from a round star, different effects in the life of stars result in nebulae with these distinctive shapes, for unknown reasons. These nebulae are also important sources of cosmic dust; it is this dust from which our planet and we were made. The role of dust in the shaping and aging of these nebulae is not well understood. The investigators study how the shapes of planetary nebulae can be explained by the interactions of gas flows, light, and dust particles that come from the star, just prior to its death. The shaping of these planetary nebulae occurs over thousands of years and at distances of many trillions of miles, making it difficult to experiment with them. Instead, the investigators will create super-computer simulations of planetary nebulae. These models run in hours instead of thousands of years. These models give a better understanding of the interactions of dust, light, and gas. The investigators will compare their model results to observations of real planetary nebulae. This project combines knowledge from both astrophysics and engineering. This interdisciplinary approach will also apply to training graduate students and conducting K-12 outreach, using both engineering and astrophysics. The investigators will create classroom activities that help K-12 students understand the interactions of light and matter. The primary objective of this work is to determine the role of dust in the formation of observed small-scale (cometary knots) and large-scale (bipolar axisymmetric ejecta) hydrodynamic features found in planetary nebulae. The investigators hypothesize that these events are driven by multiphase coupling of dust and gas in shock and radiation driven hydrodynamics arising from perturbed, heterogeneous, initial conditions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

普通恒星，比如太阳，最终会耗尽所有的燃料而死亡。它们留下美丽的尸体，以巨大的发光气体和尘埃云的形式，被称为行星状星云。这些星云是惊人的和丰富多彩的不同和独特的形状，赢得他们的名字像猫？的眼睛，螺旋，和哑铃。虽然星云是从一颗圆形的星星中诞生的，但恒星生命中的不同影响导致了这些独特形状的星云，原因不明。这些星云也是宇宙尘埃的重要来源;正是这些尘埃造就了我们的星球和我们。尘埃在这些星云的形成和老化中所起的作用还没有得到很好的理解。研究人员研究如何通过来自星星的气流、光和尘埃颗粒在其死亡之前的相互作用来解释行星状星云的形状。这些行星状星云的形成经历了数千年的时间，距离有数万亿英里，因此很难对它们进行实验。相反，研究人员将创建行星状星云的超级计算机模拟。 这些模型以小时为单位运行，而不是数千年。这些模型可以更好地理解尘埃、光和气体的相互作用。研究人员将把他们的模型结果与真实的行星状星云的观测结果进行比较。这个项目结合了天体物理学和工程学的知识。这种跨学科的方法也将适用于培训研究生和进行K-12推广，使用工程和天体物理学。研究人员将创建课堂活动，帮助K-12学生了解光和物质的相互作用。 这项工作的主要目标是确定尘埃在行星状星云中观察到的小尺度（彗星结）和大尺度（双极轴对称喷出物）流体动力学特征形成中的作用。研究人员假设，这些事件是由多相耦合的灰尘和气体在冲击和辐射驱动的流体动力学所产生的扰动，异质，初始conditions.This奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。