Gas distrubution and accretion during the formation and evolution of galaxies in the CLUES simulations

这个项目的目的是研究星系形成中的气体分布以及吸积模式，重点是局部群。这项提议将基于线索项目内的结构形成模拟(受限的局部宇宙模拟--见http://www.CLUES-project.org).特别是，我们感兴趣的是描述局部体积内的气体分布，以便调查其来源和空间分布。我们将研究气体是以大致均匀和球形的方式分布，还是沿着细丝分布，是否由于演化而形成了特殊的特征，如具有流入或流出通量的流，以及这些特征的特征尺度和方向是什么。另一方面，我们也有兴趣通过观察星系形成过程中的热力学历史来研究这种气体的增长方式和速率。我们打算回答的一个重要问题是，气体是否像标准图片预测的那样，在到达银河系之前受到了高温的冲击，或者，如果相反，正如最近的一些研究似乎指出的那样，它的一部分是沿着冷丝堆积而成的。使用我们的模拟要解决的另一个重要方面是，如果主要的吸积模式与时间无关，或者如果一种特定的模式在不同的红移处优于另一种模式。

The aim of this project is to study the gas distribution, as well as accretion modes, in the formation of galaxies focusing on the Local Group. This proposal will be based on the simulations of structure formation within the CLUES project (Constrained Local UniversE Simulations – see http://www.CLUES-project.org). In particular, we are interested in characterizing the gas distribution within the Local Volume in order to investigate its origin and spatial distribution. We will study whether the gas is distributed in a roughly homogeneous and spherical manner or along filaments and whether special features, such as streams, with incoming or outgoing flux, have formed as a result of the evolution, and what are the characteristic scales and orientation of these features. On the other hand, we are also interested in studying the mode and rate at which this gas accretes by looking at its thermodynamical history during the galaxy formation process. One important question we intend to answer is whether the gas was shocked to high temperatures before reaching the galaxy, as the standard picture predicts or, if on the contrary, as some recent studies seem to point out, part of it is accreted along cold filaments. Another significant aspect to address using our simulations is if the predominant accretion mode is independent of time, or if one particular mode prevails over the other at different redshifts.