Galaxy Formation, Alignments and Lensing Contamination

像太阳这样的恒星位于由数十亿颗恒星组成的星系中，与其他星系隔着遥远的距离。这些星系可以有多种形式，从像我们银河系一样的扁平旋转盘，到位于星系团中心的巨大的近球形星系。我们想知道这些形状是如何产生的，以及自旋是从哪里来的。我们知道星系可能是由早期宇宙中气体云的引力坍缩形成的。原则上，我们现在看到的星系形状和旋转的模式保留了最初发生的信息。今天正在进行的对数百万个星系的大规模新调查将使我们能够非常精确地测量这些模式。这个项目将使用星系形成的计算机模型来探索这些非常早期的条件是如何决定我们今天在我们周围的宇宙中所看到的。特别是，它试图研究星系是如何形成的，它们是如何形成形状的，以及它们为什么旋转。它还将检查这些计算是否显示了邻近星系的形状和自旋之间的相关性。星系形状和自旋相关的可能性对其他试图通过这些星系的引力场（称为引力透镜）测量光的弯曲的项目具有重要意义。＊＊＊

AST 0205978Croft Stars such as the Sun lie in galaxies that are collections of billions of stars, separated from other galaxies by vast distances. These galaxies can take many forms, from flat, spinning disks like our own Milky Way, to giant nearly spherical galaxies that lie at the center of galaxy clusters. We would like to know how these shapes arise, and where the spins came from. We know that galaxies probably formed from the gravitational collapse of clouds of gas in the early Universe. In principle, the patterns of galaxy shapes and spins that we see nowadays has preserved information about what happened at the very beginning. Enormous new surveys of millions of galaxies that are being carried out today will enable us to measure these patterns very precisely.This project will use computer models of galaxy formation to explore how the conditions at these very early times dictated what we see in the Universe around us today. In particular, it seeks to investigate how galaxies form, how they get their shapes and why they spin. It will also examine whether these calculations show correlations between the shapes and spins of neighboring galaxies. The possibility that galaxy shapes and spins are correlated has important implications for other projects that try to measure the bending of light by the gravitational fields of these galaxies (known as gravitational lensing). ***