暗晕子结构的数值搜寻与统计性质  

The Structure Finders and the Subhalo Population

作　　者：李昭洲 韩家信 LI Zhao-zhou;HAN Jia-xin(Key Laboratory for Research in Galaxies and Cosmology,Shanghai Astronomical Observatory,Chi-nese Academy of Sciences,Shanghai 200030,China;University of Chinese Academy of Sciences,Bei-jing 100049,China;Kavli IPMU(WPI),UTIAS,The University of Tokyo,Kashiwa,Chiba 277-8583,Japan)

机构地区：[1]中国科学院上海天文台星系与宇宙学重点实验室,上海200030 [2]中国科学院大学,北京100049 [3]Kavli IPMU(WPI),UTIAS,The University of Tokyo

出　　处：《天文学进展》2018年第3期306-324,共19页Progress In Astronomy

基　　金：国家自然科学基金(11222325;11033006;11320101002;11533006;11621303);中国科学院新兴与交叉学科布局试点项目(KJCX2-EW-J01);国家973项目(2015CB857003);上海市人才发展资金资助项目(2011069);上海市重点实验室(11DZ2260700);日本学术振兴会科研资助(JP17K14271)

摘　　要：宇宙学数值模拟预言的暗晕及其子结构的统计性质,被广泛应用于星系形成模型、近邻宇宙学、红移巡天、宇宙大尺度结构、引力透镜和暗物质搜寻等研究领域。在精确宇宙学时代,随着天文观测能力的不断增长,人们对模型精度提出了更高的要求,因此,数值模拟及其分析工具将继续起到不可替代的巨大作用。数值模拟中物质结构的性质往往与具体的搜寻算法有关,从最初通过数值模拟发现子晕到现在的20年里,结构搜寻算法有了极大的发展,新算法不断涌现。了解不同数值搜寻算法的实现及其差异,有助于分析模拟结果的系统差和不确定性,增强研究的可重复性。通过总结现代子晕数值搜寻的基本方法,并以几种典型的搜寻算法为例,探讨了它们之间的异同,及其对相关研究的影响;回顾了子晕的基本统计性质,包括质量函数、空间分布和密度轮廓等,以及这些统计结果对搜寻算法的依赖。此外,还讨论了重子物理的影响。The quantitative relations of halo and subhalo population predicted by numerical simulations are widely applied to the galaxy formation models,near-field cosmology,redshift surveys,large-scale structure,gravitational lensing and dark matter detection.In the precision cosmology era,the ever-increasing size and complexity of data coming from observations demands equally precise prediction for cosmic structures and also their substructures.The numerical simulation and relevant analysis tools will continue to play an irreplaceable role.During the past two decades since the first subhalos identified in simulation,there has been enormous progress in the art of object finding.A large number of codes based upon a vast variety of algorithm and techniques have emerged.Unfortunately,the finders may not provide the same information about the subhalos of interest,as each algorithm has its own operational definition.Knowledge about how the finders work and how they differ from each other is crucial to estimate the potential bias and uncertainty in the predictions from simulations,and to improve the reproducibility in research.Here we summarize the procedures commonly adopted in the modern subhalo finders,describe several widely used finders in detail as examples,discuss the different performance in test cases between them and the corresponding influence on the application.Then we review the basic statistics of the subhalo population,including the mass function and spatial distribution,and their dependence on the used subhalo finder,we close with a discussion of the influence of the baryon process.

关 键 词：数值模拟 结构形成 暗物质晕 暗物质晕子结构 半解析模型 统计 

分 类 号：P159.5[天文地球—天文学] P142.9