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arXiv 1702.02620astro-ph.GAastro-ph.CO
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nIFTy宇宙学:星系形成模型的聚类一致性

nIFTy Cosmology: the clustering consistency of galaxy formation models

Arnau Pujol, Ramin A. Skibba, Enrique Gaztañaga, Andrew Benson, Jeremy Blaizot, Richard Bower, Jorge Carretero, Francisco J. Castander, Andrea Cattaneo, Sofia A… 展开作者

Arnau Pujol, Ramin A. Skibba, Enrique Gaztañaga, Andrew Benson, Jeremy Blaizot, Richard Bower, Jorge Carretero, Francisco J. Castander, Andrea Cattaneo, Sofia A. Cora, Darren J. Croton, Weiguang Cui, Daniel Cunnama, Gabriella De Lucia, Julien E. Devriendt, Pascal J. Elahi, Andreea Font, Fabio Fontanot, Juan Garcia-Bellido, Ignacio D. Gargiulo, Violeta Gonzalez-Perez, John Helly, Bruno M. B. Henriques, Michaela Hirschmann, Alexander Knebe, Jaehyun Lee, Gary A. Mamon, Pierluigi Monaco, Julian Onions, Nelson D. Padilla, Frazer R. Pearce, Chris Power, Rachel S. Somerville, Chaichalit Srisawat, Peter A. Thomas, Edouard Tollet, Cristian A. Vega-Martínez, Sukyoung K. Yi

摘要:

我们提出了一个聚类比较的12个星系形成模型(包括半解析模型(SAMs)和Halo Occupation Distribution(HOD)模型),所有运行的晕目录和合并树提取从一个单一的ΛCDM N体模拟。我们比较了平均晕占据数、晕中星系径向分布和两点关联函数(2 PCF)的测量结果。我们还研究了不同的治疗孤儿(星系不分配到任何暗物质subhalo)和非孤儿星系在这些测量的影响。我们的主要结果是,星系形成模型一般同意在他们的聚类预测,但他们不同意显着HOD和SAM的孤儿卫星。虽然在中央星系的2 PCF模型之间有很好的一致性,但当包括孤儿卫星时,模型之间的散射可以大于2倍,尺度小于1 Mpc/h。我们还表明,星系形成模型,不包括孤儿卫星星系有一个显着较低的2 PCF在小尺度上,与以前的研究一致。最后,我们表明孤儿卫星的2 PCF之间的SAM和HOD模型是显着不同的。孤立卫星在SAM中呈现出比HOD模型更高的聚类,因为它们往往占据更大的晕。我们的结论是,孤儿卫星有一个重要的作用,星系聚类和他们之间的差异的主要原因HOD模型和SAM。

英文摘要:

We present a clustering comparison of 12 galaxy formation models (including Semi-Analytic Models (SAMs) and Halo Occupation Distribution (HOD) models) all run on halo catalogues and merger trees extracted from a single ΛCDM N-body simulation. We compare the results of the measurements of the mean halo occupation numbers, the radial distribution of galaxies in haloes and the 2-Point Correlation Functions (2PCF). We also study the implications of the different treatments of orphan (galaxies not assigned to any dark matter subhalo) and non-orphan galaxies in these measurements. Our main result is that the galaxy formation models generally agree in their clustering predictions but they disagree significantly between HOD and SAMs for the orphan satellites. Although there is a very good agreement between the models on the 2PCF of central galaxies, the scatter between the models when orphan satellites are included can be larger than a factor of 2 for scales smaller than 1 Mpc/h. We also show that galaxy formation models that do not include orphan satellite galaxies have a significantly lower 2PCF on small scales, consistent with previous studies. Finally, we show that the 2PCF of orphan satellites is remarkably different between SAMs and HOD models. Orphan satellites in SAMs present a higher clustering than in HOD models because they tend to occupy more massive haloes. We conclude that orphan satellites have an important role on galaxy clustering and they are the main cause of the differences in the clustering between HOD models and SAMs.

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