The Cosmic Web and its impact on galaxy formation and alignment

星系是宇宙最基本的组成部分。观测表明，它们不是随机分布在整个宇宙中，而是以一种复杂的模式组织起来：宇宙网。这是星系获得气体、角动量并与较小卫星星系合并的阶段。因此，它们表现出不同程度的几何和运动学对齐。在我们所在的宇宙中，银河系的卫星星系（以及我们的邻居仙女座星系M31和半人马座A）位于薄的，共同旋转的平面上。这样的空间结构在目前的“λ冷暗物质”宇宙学中很难获得。 这种结盟是如何产生的？它们是对我们关于结构和星系如何形成的范式的挑战吗？在更大的尺度上，整个宇宙网络中的星系相互对齐。越来越多的证据表明星系和宇宙网之间存在着密切的关系。在这个项目中，我们打算使用本地约束模拟和半解析模型来研究宇宙网对星系排列的影响。这样的研究将有助于我们了解在本地卷中看到的卫星的特殊配置是否是唯一的，以及在不同尺度上的对齐的洞察力。我们专业知识的互补性将推动项目向前发展：中国方面带来了星系建模的专业知识，德国方面带来了模拟当地体积的经验。我们还致力于加强现有的中德合作，培养下一代星系天体物理学家。

Galaxies are the most fundamental building blocks of the Universe. Observations have shown that they are not randomly distributed throughout the cosmos, but are organised in a complex filamentary pattern: the Cosmic Web. This is the stage on which galaxies gain their gas, angular momentum and merge with smaller satellites galaxies. Accordingly, they exhibit different levels of geometric and kinematic alignment. In our local universe, the satellite galaxies of the Milky Way (and our neighbours the Andromeda galaxy M31 and Centaurus A) sit on thin, co-rotating planes. Such a spatial configuration is difficult to obtain in the current 'Lambda Cold Dark Matter' cosmology. How did such alignment originate? Are they a challenge to our paradigm of how structures and galaxies form? On even larger scales, galaxies throughout the cosmic web are mutually aligned with each other. Increasing evidence points to an intimate relationship between galaxies and the cosmic web. In this project we intend to use both local constrained simulations and semi-analytical models to examine the impact of the cosmic web on galaxy alignment. Such a study will help us understand if the peculiar configuration of satellites seen in the local volume is unique as well as gain insight into the alignment on various scales. The complementarity of our expertise will drive the project forwards: while the Chinese side brings expertise of galaxy modelling the German side brings experience in simulating the local volume. Together we also aim to enhance our existing sino-german collaboration and to train the next generation of galaxy astrophysicists.