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，像太阳一样，最终消耗了所有的燃料并死亡。他们留下了美丽的尸体，形式是大量发光的气体和尘埃，称为行星星云。这些星云令人叹为观止，色彩缤纷，形状多样，呈独特的形状，赢得了猫的眼睛，螺旋和哑铃等名称。星云是从圆星诞生的，但由于未知原因，恒星生活中的不同影响带来了这些独特形状的星云。这些星云也是宇宙尘埃的重要来源。正是我们的星球和我们制造的尘埃。尘埃在这些星云的塑形和衰老中的作用尚不清楚。研究人员研究了行星星云的形状如何通过恒星死前的气体流，光和灰尘颗粒的相互作用来解释。这些行星星云的塑造发生在数千年的时间内，并且在数万亿英里的距离上发生，因此很难与它们进行试验。相反，研究人员将对行星星云进行超级计算机模拟。 这些模型在数小时而不是数千年的时间内运行。这些模型可以更好地了解灰尘，光和气体的相互作用。研究人员将将其模型结果与对真实行星星云的观察进行比较。该项目结合了天体物理学和工程学的知识。这种跨学科方法还将适用于培训研究生，并使用工程学和天体物理学进行K-12外展。调查人员将创建课堂活动，以帮助K-12学生了解光与物质的互动。 这项工作的主要目的是确定灰尘在观察到的小规模（彗星结）和大尺度（双极轴对称性喷射）流体动力学特征中的作用。研究人员假设这些事件是由尘埃和气体在冲击和辐射驱动的流体动力学中的多相耦合所驱动的，这是由扰动，异质性的初始条件引起的。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识功能和广泛的影响来评估的。