Dust Driven Multiphase Hydrodynamics in Planetary Nebulae

点击翻译按钮获取中文摘要

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.