The Extraordinary Deaths of Ordinary Stars: 3D Simulations of Common Envelope Phases

Jason Nordhaus博士被授予美国国家科学基金会天文学和天体物理学博士后奖学金，在罗切斯特理工学院（RIT）计算相对论和引力中心开展研究和教育项目。诺德豪斯将使用一种新的、最先进的自适应网格细化、辐射流体动力学代码CASTRO（可压缩天体物理学）进行普通包络（CE）相位的三维数值模拟。在过去的两年中，诺德豪斯博士一直积极参与卡斯特罗在核心坍缩超新星上的发展和初步科学应用。尽管CE相对于灾难性变量、合并致密天体、Ia型超新星的祖先和低质量演化恒星很重要，但普通的包膜相从未被适当地模拟过。随着千万亿级高性能计算设备的出现，例如美国国家科学基金会资助的Blue Waters系统，现在可以用先进的多网格、多核技术模拟CE阶段。CASTRO在千万亿级水平上展示了出色的可伸缩性，从而使其成为能够有效利用千万亿级资源的少数天体物理代码之一。通过使用CASTRO来模拟各种双星类型和质量比的共同包络相位，可以在一系列天体物理系统中取得重大而持久的进展。诺德豪斯还将开设一门新的天文学和科学推理课程，教授给RIT国家聋人技术学院（NTID）的学生。诺德豪斯博士精通美国手语，NTID目前不提供任何聋人天文学课程。这门课程的题目是“通过我们的眼睛和手看宇宙：科学推理和天文学入门”。这门课程将与传统的讲座不同，在一个活跃但非语言的环境中教授通过天文学进行科学推理。期末项目将要求学生分成3-4人一组，每组为聋哑高中学生设计一个一小时的讲座，重点介绍“宇宙”课程中的一个特定主题。基于这些期末项目，诺德豪斯博士将制作一个为期一周的多媒体教学指南，供聋哑学生的高中教师在课堂上使用。诺德豪斯博士将通过NTID广泛的免费在线课程材料，将这些材料免费提供给全国的教师。

Dr. Jason Nordhaus is awarded an NSF Astronomy and Astrophysics Postdoctoral Fellowship to carry out a program of research and education at the Center for Computational Relativity and Gravitation at the Rochester Institute of Technology (RIT). Nordhaus will conduct three-dimensional numerical simulations of common envelope (CE) phases with a new, state-of-the-art adaptive mesh refinement, radiation-hydrodynamic code CASTRO (Compressible Astrophysics). For the past two years, Dr. Nordhaus has been active in the development of, and initial science applications of CASTRO to core-collapse supernovae. Despite the importance of CE phases for cataclysmic variables, merging compact objects, the progenitors of Type Ia supernovae, and low-mass evolved stars, common envelope phases have never been properly simulated. With the advent of peta-scale, high-performance computing facilities such as the NSF-funded Blue Waters system, simulating CE phases with advanced multi-grid, multi-core techniques is now possible. CASTRO has demonstrated excellent scaling at the peta-scale level, thus making it one of only a few astrophysics codes able to efficiently employ peta-scale resources. By employing CASTRO to simulate common envelope phases for various binary types and mass-ratios, significant and long-lasting progress can be made for a range of astrophysical systems.Dr. Nordhaus will also develop a new, astronomy and scientific reasoning class to be taught to students at RIT's National Technical Institute for the Deaf (NTID). Dr. Nordhaus is fluent in American Sign Language, and NTID currently does not offer any deaf astronomy classes. The course will be entitled "The Universe Through Our Eyes and Hands: An Introduction to Scientific Reasoning and Astronomy." The course will deviate from a traditional lecture to teach scientific reasoning through astronomy in an active, but non-verbal, environment. An end-of-semester project will have students break into groups of 3-4 with each group designing a one-hour lecture for deaf high school students which highlights a particular topic from "The Universe" course. Based on these end-of-course projects, Dr. Nordhaus will produce a one-week, multi-media teaching guide that high-school teachers of deaf students can use in their classrooms. Dr. Nordhaus will make the material freely available to teachers throughout the country via NTID's extensive free online course materials.