Theoretical Studies in Star Formation

在这个项目中，麦基博士将对磁场及其在恒星形成中的作用进行理论研究。磁场从形成恒星的气体中提取角动量，从而确定气体云是形成单颗恒星还是双星。恒星形成时发出的辐射可以抑制碎裂，从而使在没有热反馈的情况下会形成许多恒星的区域中只形成一颗或两颗恒星。频率相关的辐射传输将首次用于研究低质量恒星形成中热反馈的影响。先前的理论研究表明，与第一批恒星相关的电离区域特别重要，因为它们决定了这些恒星的质量。此外，该项目还将探索恒星群和星团的形成。大多数恒星形成于星团中，事实上，太阳很可能形成于一个包含大质量恒星以及像太阳这样的低质量恒星的大星团中。星团的形成受到伴随恒星形成的强大反馈机制的影响，包括原恒星流出，以及对于大质量恒星来说，光电离和辐射压力。半解析理论和模拟都将用于研究大质量星团的形成。结果将与银河系中的星团和其他星系中的超级星团的观测结果进行比较。银河尺度上的恒星形成是由银河系星际介质的特性决定的。恒星形成是当代天体物理学的核心。作为气体转变为恒星的过程，它决定了星系的结构和演化。通过利用大爆炸留下的气体中的核能，它可以确定星系的光度，并且很可能导致宇宙的再电离。大多数元素，包括构成我们周围世界的元素，都是在恒星中形成的。最后，恒星形成的过程与行星系统的形成和早期演化有着千丝万缕的联系。恒星形成理论必须解决单个恒星的形成和恒星系统（从星团到星系）的形成。这笔赠款将资助一名或多名研究生的教育，他们将为教育做出贡献并增加科学劳动力的多样性。计算方法的进展将被发布以供社区使用。

In this project, Dr. McKee will undertake a theoretical study of magnetic fields and their role in star formation. Magnetic fields extract angular momentum from the gas that forms a star, thereby determining whether a gas cloud forms a single star or a binary. The radiation emitted by stars as they form can suppress fragmentation, thereby enabling just one or two stars to form in a region that would have formed many in the absence of thermal feedback. For the first time, frequency-dependent radiative transfer will be used to study the effects of thermal feedback in the formation of low-mass stars. Previous theoretical research has shown that ionized regions associated with the first stars are of particular importance since they determine the masses of these stars. In addition, this project will explore the formation of stars in groups and clusters. Most stars form in clusters, and indeed it is likely that the Sun formed in a large cluster that contained high-mass stars as well as low-mass stars like the Sun. The formation of star clusters is affected by the powerful feedback mechanisms that accompany star formation, including protostellar outflows and, for massive stars, photoionization and radiation pressure. Both semi-analytic theory and simulation will be used to investigate the formation of clusters of high-mass stars. The results will be compared with observations of star clusters in the Galaxy and of super star clusters in other galaxies. Star formation on galactic scales is determined by the properties of the interstellar medium of the galaxy. Star formation is central to contemporary astrophysics. As the process by which gas is transformed into stars, it determines the structure and evolution of galaxies. By tapping the nuclear energy in the gas left over from the Big Bang, it determines the luminosity of galaxies and, quite possibly, leads to the reionization of the universe. Most of the elements, including those that make up the world around us, are formed in stars. Finally, the process of star formation is inextricably tied up with the formation and early evolution of planetary systems. A theory of star formation must address both the formation of individual stars and the formation of systems of stars, ranging from clusters to galaxies. This grant will fund the education of one or more graduate students who will contribute to education and add to the diversity of the scientific work force. Developments in computational methodology will be published for use by the community.