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arXiv 1111.4867astro-ph.HE
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限制超高能宇宙射线偏转角尺度和源密度的扩展聚类分析

Extended clustering analyses to constrain the deflection angular scale and source density of the ultra-high-energy cosmic rays

Guillaume Decerprit, Nicolas G. Busca, Etienne Parizot

摘要:

在超高能宇宙射线(UHECR)的到达方向上搜索聚类信号是评估所调查数据集各向异性水平的标准方法。在这里,我们首先展示了如何量化的灵敏度的UHECR探测器的各向异性的检测,然后提出了一种新的方法,推动了两点自动关联函数的研究,使之能够把天体物理学上有意义的约束的有效UHECR源密度和角偏转,这些带电粒子遭受,而他们通过银河系和星系际磁场传播。我们将该方法应用于各种天体物理条件下获得的模拟数据集,并显示如何输入模型参数可以通过我们的分析估计,引入“聚类相似性”的概念(数据集之间),我们给一个精确的统计意义。我们还研究了该方法的约束能力如何受到调查中的数据集的大小,它被应用到的UHECRs的最小能量,以及有关基本源分布的先验假设的影响。我们还表明,这种方法是特别适合的数据集组成的几十到几百个事件,这对应于当前和不久的将来的观测情况在该领域的UHECRs。

英文摘要:

The search of a clustering signal in the arrival directions of ultra-high-energy cosmic rays (UHECRs) is a standard method to assess the level of anisotropy of the data sets under investigation. Here, we first show how to quantify the sensitivity of a UHECR detector to the detection of anisotropy, and then propose a new method that pushes forward the study of the two-point auto-correlation function, enabling one to put astrophysically meaningful constraints on both the effective UHECR source density and the angular deflections that these charged particles suffer while they propagate through the galactic and intergalactic magnetic fields. We apply the method to simulated data sets obtained under various astrophysical conditions, and show how the input model parameters can be estimated through our analysis, introducing the notion of "clustering similarity" (between data sets), to which we give a precise statistical meaning. We also study how the constraining power of the method is influenced by the size of the data set under investigation, the minimum energy of the UHECRs to which it is applied, and a prior assumption about the underlying source distribution. We also show that this method is particularly adapted to data sets consisting of a few tens to a few hundreds of events, which corresponds to the current and near-future observational situation in the field of UHECRs.

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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