Constructing high-fidelity halo merger trees in abacussummit
Constructing high-fidelity halo merger trees in abacussummit
复制标题
在 abacussummit 中构建高保真 halo 合并树
DOI：
10.1093/mnras/stac555
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发表时间：
2022
影响因子：
4.8
通讯作者：
Bose S
中科院分区：
文献类型：
--
作者：
Bose S
追踪暗物质晕的形成和演化是任何宇宙学 N 体模拟分析的一个关键方面。特别是，光晕及其祖先的质量组装，封装在其合并树的形式中，作为构建星系形成的半解析模型的基本输入，更一般地说，用于构建模拟星系巡天的模拟目录。我们提出了一种从abacussummit构建晕合并树的算法，这是迄今为止执行的最大的宇宙学N体模拟套件，由近60万亿个粒子组成，其设计是为了满足暗能量光谱仪器（DESI）调查的宇宙学模拟要求。我们的方法跟踪光环的核心，以确定跨多个时间片的对象之间的关联，为整个套件中识别的数百亿个光环生成光环祖先和后代的列表。我们提出了这些合并树的应用，作为通过标记和“合并”被认为表现出非单调的过去合并历史的光环来增强算盘目录保真度的方法。我们表明，这种清洁技术可以识别由于光环探测器所做的选择而被破坏的光环群体的部分，但它们可能是更大的聚合系统的一部分。我们证明，通过在此后处理步骤中清理光环目录，我们删除了默认光环目录中潜在的非物理特征，留下了更强大的光环群体，可用于从算盘峰会创建高度准确的模拟星系实现。
Tracking the formation and evolution of dark matter haloes is a critical aspect of any analysis of cosmologicalN-body simulations. In particular, the mass assembly of a halo and its progenitors, encapsulated in the form of its merger tree, serves as a fundamental input for constructing semi-analytic models of galaxy formation and, more generally, for building mock catalogues that emulate galaxy surveys. We present an algorithm for constructing halo merger trees fromabacussummit, the largest suite of cosmologicalN-body simulations performed to date consisting of nearly 60 trillion particles, and which has been designed to meet the Cosmological Simulation Requirements of the Dark Energy Spectroscopic Instrument (DESI) survey. Our method tracks the cores of haloes to determine associations between objects across multiple time slices, yielding lists of halo progenitors and descendants for the several tens of billions of haloes identified across the entire suite. We present an application of these merger trees as a means to enhance the fidelity ofabacussummithalo catalogues by flagging and ‘merging’ haloes deemed to exhibit non-monotonic past merger histories. We show that this cleaning technique identifies portions of the halo population that have been deblended due to choices made by the halo finder, but which could have feasibly been part of larger aggregate systems. We demonstrate that by cleaning halo catalogues in this post-processing step, we remove potentially unphysical features in the default halo catalogues, leaving behind a more robust halo population that can be used to create highly accurate mock galaxy realizations fromabacussummit.