New insights into galaxy formation and evolution

埋藏在我们银河系后院的是关于我们的银河系是如何形成和进化的信息的宝库。“星系考古学”领域致力于揭示和破译这一信息对我们的星系和整个星系形成的影响。在接下来的十年里，银河系考古学即将经历一场革命，因为欧洲航天局的盖亚任务将提供对超过10亿颗恒星的恒星位置和数千万颗恒星的真实运动的精密新观测。结合即将到来的对恒星化学特征的调查(具有相似化学特征的恒星可能是一起形成的)，我们将能够拼凑出它们在时间上的演化。我的研究计划的第一部分概述了一系列在并行计算机上的模拟，这些模拟将为我们的银河系考古研究带来新的保真度，并使我们能够以极高的精度模拟即将到来的盖亚调查(和其他调查)的数据。我将逐步增加物理复杂性，以便最终包括银河系中存在的所有主要物理过程。研究计划的第二部分将重点放在黑洞如何实际上直接决定最大星系的演化。黑洞曾经被认为在星系形成过程中基本上是无关的。由于黑洞周围存在吸积盘，黑洞实际上释放了大量能量，并将其返回到周围的星系。但描述这一过程是极其困难的。即使是质量是太阳数千万倍的超大质量黑洞，与星系的整体大小相比也微不足道--这一比例类似于一粒沙子和整个地球。这项提议中概述的研究将通过增加更大的物理复杂性来改进我们对这一过程的建模，并使我们能够跟踪从黑洞流出的能量到大半径，在那里它与星系的其他部分相互作用。

Buried within our galactic backyard is a treasure trove of information about how our galaxy, the Milky Way, formed and evolved. The field of "galactic archaeology" sets out to uncover and decipher the implications of this information both for our galaxy and galaxy formation in general. In the next decade, galactic archaeology is about to undergo a revolution as the European Space Agency's Gaia mission will provide exquisite new observations of the stellar positions of over a billion stars and true motions of tens of millions. Combined with upcoming surveys of the chemical signatures of stars (stars with similar chemical signatures were likely formed together) we will then be able to piece together their evolution back in time. The first part of my research program outlines a series of simulations on parallel computers that will introduce new levels of fidelity into our studies of galactic archaeology, and enable us to model upcoming data from the Gaia survey (and others) with great precision. Step-by-step I will increase physical complexity so as to eventually include all the dominant physical processes present in the Milky Way.The second part of the research program will focus on how black holes, once thought to be largely irrelevant in the process of galaxy formation, can actually directly determine the evolution of the largest galaxies. Due to the presence of an accretion disk around them, black holes actually liberate and return vast amounts of energy to their surrounding galaxy. But describing this process is immensely difficult. Even supermassive black holes, with masses tens of millions of times that of the Sun, are tiny compared to the overall size of a galaxy - the ratio is akin to a grain of sand and the entire Earth. The research outlined in this proposal will improve our modelling of this process by adding greater physical complexity and also allowing us to follow the energy that flows out from black holes to large radii where it interacts with the rest of the galaxy.