International Research Fellow Awards Program: Development of a State-of-the-art Three-dimensional Cosmological Gas Dynamics and Radiation Dynamics Code

00003682Iliev国际研究员奖励计划使美国科学家和工程师能够在国外进行三到二十四个月的研究。 该计划的奖项提供了联合研究的机会，以及使用独特或互补的设施，专业知识和国外的实验条件。伊利耶夫与支持六个月的工作与博士亚历杭德罗C。Raga在墨西哥城的墨西哥国立自治大学。这个项目由美国国家科学基金会的数学和物理科学理事会的多学科活动办公室共同资助。在宇宙只有100万年的重组时期和10亿年或更长时间后第一批类星体出现之间的某个时候，宇宙中的大多数物质再次电离。 通过使用数值模拟来模拟这个再电离时期，PI将致力于回答这样的问题：什么样的物体在什么时候再电离了宇宙？ 第一个物体（恒星、原星系）是何时以及如何形成的？ 光致电离紫外线背景是如何演变的？ 这种背景对后来形成的物体有什么影响？ 该项目要求开发最先进的三维宇宙气体动力学和辐射动力学代码，以详细研究我们今天看到的宇宙结构的起源和演变的重要问题。 他们期望对宇宙再电离过程以及反馈和辐射传输对宇宙结构形成的影响进行深入研究。 这一领域的宇宙学关注的是理解我们所看到的宇宙中的所有结构是如何形成和演化的。拉加博士和他的合作者已经开发了一个星际气体和辐射动力学代码，该代码将进一步发展，以包括自引力的影响，使其适用于宇宙学模拟。

00003682IlievThe International Research Fellow Awards Program enables U.S. scientists and engineers to conduct three to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will provide Dr. Ilian T. Iliev with support for six months to work with Dr. Alejandro C. Raga at Universidad Nacional Autonoma de Mexico in Mexico City, Mexico. This project is being co-funded by NSF's Directorate for Mathematical and Physical Sciences' Office of Multidisciplinary Activities.Sometime between the recombination epoch when the universe was only a million years old, and the appearance of the first quasars a billion years or more later, most matter in the universe became ionized again. By using numerical simulations to model this reionization epoch the PIs will work to answer the questions: What kind of objects reionized the universe and when? When and how did the first objects (stars, protogalaxies) form? How did the photoionizing ultraviolet background evolve? What was the impact of this background on the objects forming later? The project calls for development of state-of-the-art three-dimensional cosmological gas dynamics and radiation dynamics code to study in detail these important questions about the origin and evolution of the cosmic structures we see today. They expect to conduct an in-depth study of the processes during the reionization of the universe and the effects of feedback and radiative transfer on the formation of cosmic structures. This area of cosmology is concerned with understanding how all the structures in the universe we see are formed and evolved.Dr. Raga and his collaborators have developed an interstellar gas-and radiation dynamics code, which will be further developed to include the effects of self-gravity, adapting it for cosmological simulations.