A Holistic Approach to Modeling Galaxy Groups and Clusters

星系群和星系团是非凡的系统。这些系统的质量从相当于10万亿个太阳到令人难以置信的百万亿个太阳不等，是宇宙中最大、最大的引力束缚物体。它们以明亮星系的丰富浓度脱颖而出，是宇宙中最明亮的X射线源之一。 因此，它们很容易在很远的地方被识别出来。它们也是最年轻的宇宙结构，因此仍然带有导致其形成的条件的印记。 由于所有这些因素，这些系统中质量最大的已经被确定为潜在的强大的宇宙几何和膨胀探测器。 然而，将星系团用作宇宙学探测器，关键取决于我们对局部宇宙中的星系团和星系团为什么看起来像这样的理解程度，以及这些系统在更早的时代会是什么样子。 我的研究集中在这两个问题上。 我正在开发现实的预测模型来详细描述群体和集群是如何形成的，以及它们是如何随着时间的推移而变化的。 建模涉及使用最先进的计算机模拟，在强大的超级计算机上进行，以“虚拟”复制宇宙137亿年的历史，并确定导致我们今天观察到的系统的条件。随着时间的推移，群体和集群受到一个令人难以置信的复杂过程网络的影响，这些过程都相互影响，例如那些控制恒星诞生，生命和死亡的过程，那些塑造收敛暗物质流的潮起潮落的过程，这些过程随着时间的推移而产生越来越大的宇宙结构，以及那些控制超大质量黑洞从周围捕获和吸入气体时的反应。 现实的数值模拟是解开这张网的唯一途径，也是理解星系团和星系团的观测性质是如何出现的唯一途径。

Galaxy groups and clusters are remarkable systems. With masses ranging from an equivalent of 10,000 billion suns to a mind-boggling million billion suns, these systems are the largest, most massive gravitationally bound objects in the Universe. They stand out as rich concentrations of bright galaxies and are among the most luminous X-ray sources in the universe. As a result, they are easy to identify out to vast distances. They are also the youngest of the cosmic structures to have formed and as such, still bear the imprints of the conditions that led to their formation. Because of all these factors, the most massive of these systems have been identified as potentially powerful probes of the geometry and the expansion of the universe. However, the use of clusters as cosmological probes depends critically on how well we understand why groups and clusters in the local universe look the way they do, and what these systems would have looked like at an earlier epoch. My research focuses on these two issues. I am developing realistic predictive models to describe, in detail, how groups and clusters formed and how they have changed over time. The modeling involves using state-of-the-art computer simulations, carried out on powerful supercomputers, to replicate "virtually" the universe's 13.7 billion year history and identify the conditions that led to the systems we observe today. Over the course of time, groups and clusters are influenced by an incredibly complex web of processes all influencing one another, processes such as those that govern the birth, life and death of stars, those that shape the ebb and flow of convergent dark matter flows that give rise to increasingly larger cosmic structures with time, and those that govern the response of supermassive black holes as they capture and draw in gas from their surroundings. Realistic numerical simulations are the only way of unraveling this web and making sense of how the observed properties of galaxy groups and clusters emerged.