Simulating the formation and evolution of galaxies and cosmic structure

我们的宇宙包含了一系列惊人的可见结构，大小不等，从行星到恒星，再到星系和星系团。我们也可以看得很远，因此回到过去，看到现在结构的早期混乱的祖先。最终，在最遥远的地方，我们只能看到大爆炸余辉中的微小涟漪，它们是所有当前结构的种子。这种进化是如何发生的？该项目将宇宙放入计算机，使我们能够实验宇宙结构如何形成，相互作用和演化;在几小时或几天内，我们可以模拟140亿年的宇宙历史。 在许多方面，我们现在了解了宇宙结构在最大尺度上的分布，数千万光年甚至更大，但对星系本身的详细了解仍然难以捉摸。然而，星系是宇宙的关键发光标记，了解它们的起源和历史是宇宙后期宇宙学的中心目标;这是我研究的重点。 我们必须模拟几个过程的复杂相互作用。万有引力作用于所有物质：看不见的暗物质、气体、尘埃和恒星。气体受到流体动力的作用。恒星形成于气态的星际介质，在其生命期内通过电离辐射和恒星风为周围环境提供能量，在其死亡时，富含重元素的气体通过剧烈爆炸返回到星际介质中。我们正在开发这些过程的越来越精确的计算机模拟，最终目标是提供星系群及其形成和演化的详细模型。这项研究为天文学家现在从地面和太空观测站收集和预测的大量观测数据提供了理论上的对应。它是加拿大数字建模专业知识的关键驱动力，也是国际公认的加拿大揭示我们宇宙起源的努力的一部分。

Our universe contains an astonishing array of visible structures ranging in size from planets, to stars, to galaxies and clusters of galaxies. We can also look to great distances, and hence back in time, and see the early, chaotic progenitors of current structure. Eventually, at the furthest distances we see just the small ripples in the afterglow of the Big Bang that are the seeds for all current structure. How did this evolution happen? This project puts the universe into a computer, allowing us to experiment with how cosmic structures form, interact and evolve; in hours or days we can model what has taken 14 billion years of cosmic history. In many respects we now understand the distribution of cosmic structures on the largest scales, tens of millions of light years and greater, but a detailed understanding of galaxies themselves remains elusive. Yet galaxies are the key luminous markers of the universe, and understanding their origins and histories stands as a central goal of late-universe cosmology; this is the focus of my research. Galaxies result from the complex interplay of several processes which we must model. Gravity acts on all matter: invisible dark matter, gas, dust and stars. Gas is subject to hydrodynamic forces. Stars form out of the gaseous inter-stellar medium, energize their surroundings with ionizing radiation and winds during their lives, and, at their deaths, return gas enriched with heavy elements to the inter-stellar medium in violent explosions. We are developing increasingly accurate computer simulations of these processes with the ultimate aim of providing detailed models of galaxy populations and their formation and evolution. The research provides the theoretical counterpart to the wealth of observational data that astronomers are now gathering and anticipating from ground- and space-based observatories. It is a key driver of numerical modelling expertise in Canada and forms part of the internationally recognized Canadian endeavour to uncover our cosmic origins.