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.

普通的恒星，就像太阳一样，最终会耗尽所有的燃料而死亡。它们留下了美丽的尸体，形成巨大的发光气体和尘埃云，称为行星状星云。这些星云令人惊叹，色彩缤纷，形状多样且独特，因此被称为“猫眼”、“螺旋”和“哑铃”等。虽然星云是由圆形恒星诞生的，但由于未知的原因，恒星生命中的不同影响导致了具有这些独特形状的星云。这些星云也是宇宙尘埃的重要来源。我们的星球和我们就是由这些尘埃构成的。尘埃在这些星云的形成和老化中的作用尚不清楚。研究人员研究了如何通过恒星死亡前的气流、光和尘埃粒子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需要数千年的时间，距离数万亿英里，因此很难对其进行实验。相反，研究人员将创建行星状星云的超级计算机模拟。 这些模型在数小时内运行，而不是数千年。这些模型可以更好地理解灰尘、光和气体的相互作用。研究人员将他们的模型结果与真实行星状星云的观测结果进行比较。该项目结合了天体物理学和工程学的知识。这种跨学科方法也将适用于利用工程学和天体物理学来培训研究生和开展 K-12 外展活动。研究人员将创建课堂活动，帮助 K-12 学生了解光与物质的相互作用。 这项工作的主要目标是确定尘埃在行星状星云中发现的小规模（彗星结）和大规模（双极轴对称喷射物）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扰动、异质、初始条件引起的冲击和辐射驱动的流体动力学中尘埃和气体的多相耦合驱动的。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值进行评估，被认为值得支持以及更广泛的影响审查标准。