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arXiv 2203.07526astro-ph.COgr-qc
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星系是如何在极端密度的环境中形成晕圈的?SDSS中晕占据分布的分析

How do galaxies populate halos in extreme density environments? An analysis of the Halo Occupation Distribution in SDSS

Ignacio G. Alfaro, Facundo Rodriguez, Andrés N. Ruiz, Heliana E. Luparello, Diego Garcia Lambas

摘要:

最近的工作表明,暗物质晕中星系群的性质随大尺度环境而变化。这些结果表明,在极端密度环境中的晕占据分布(HOD)的变化。为了分析这些影响,我们确定宇宙空洞和未来的维里化结构(FVS)的SDSS-DR 12和估计HOD在这些超结构使用组目录作为暗物质晕代理。我们的目标是使用观测星系数据来描述HOD内的空隙和FVS,探索这些星系人口的不同属性,并将它们与这些超结构外的一般结果进行比较。使用星系群目录,我们计算的HOD在这两种类型的超结构。我们还研究了结果对主空洞和FVS属性的依赖性。我们还分析了这些区域内星系的平均恒星年龄。在所有情况下,我们都将结果与来自Field示例的结果进行比较。内部空隙,我们发现一个强烈的减少HOD有关的字段的结果。卫星的平均数量下降到50%。在FVS内部,HOD显示出对场的显著增加,卫星的平均数量超过40%。在这两个区域中,对于密度环境的极端值,场的差异增加。我们没有得到与空隙和FVS的固有特性相关的变化的迹象。我们发现,中央星系恒星平均年龄的累积分布在这些地区也有所不同。最后,我们探索了25%最年轻(最古老)星系的HOD。我们发现,对于低质量的群体,最年轻的星系只存在于空洞内。另一方面,对于高质量的群体,FVS环境显示出同样的增加,在HOD有关的领域。我们发现宇宙空洞缺乏最古老的星系。

英文摘要:

Recent works have shown that the properties of galaxy populations in dark matter halos vary with large-scale environments. These results suggest a variation in the halo occupation distribution (HOD) in extreme density environments. To analyse these effects, we identify cosmic voids and future virialised structures (FVS) in the SDSS-DR12 and estimate the HOD within these superstructures using group catalogues as dark matter halo proxies. Our goal is to use observational galaxy data to characterise the HOD within voids and FVS, explore the different properties of these galaxies populations and compare them with the general results outside these superstructures. Using a galaxy group catalogue we compute the HOD within both types of superstructures. We also study the dependence on the results on the main void and FVS properties. We also analysed the mean stellar age of the galaxies inside these regions. In all cases, we compare the results with those derived from the Field sample. Inside voids, we find a strong decrease in HOD concerning the Field results. The mean number of satellites fall to 50%. Inside FVS, the HOD shows a significant increase to the Field, with a 40% excess in the mean number of satellites. In both regions, the differences with respect to the Field increases for the extreme values of the density environments. We obtain no signs of variations related to intrinsic characteristics of voids and FVS. We find that the cumulative distribution of the mean age of stars of the central galaxy also varies in these regions. Finally, we explore the HOD for the 25% youngest (oldest) galaxies. We find that for the low-mass groups the youngest galaxies are only present inside voids. On the other hand, for the high-mass groups the FVS environments show the same increase in the HOD concerning the Field. We find that cosmic voids lack of oldest galaxies.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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