The structure, formation and evolution of galaxies in the local universe

虽然结构形成的宇宙学模型现在与最大空间尺度上的观测结果非常吻合，但在星系和更小的尺度上仍然存在严重的差异。不幸的是，要想详细了解星系形成目前状态的机制，最终取决于我们仍然知之甚少的天体物理过程：即气体冷却、恒星形成、恒星和活动星系核的反馈。

While cosmological models of structure formation now show excellent agreement with observations on the largest spatial scales, there remain serious discrepancies on the scales of galaxies and smaller. Unfortunately, a detailed understanding of the mechanisms by which galaxies were assembled into their present state ultimately hinges on astrophysical processes that are still poorly understood: i.e., gas cooling, star formation, and feedback from stars and active galactic nuclei.