Ultrahigh energy cosmic ray probes of large scale structure and magnetic fields
Ultrahigh energy cosmic ray probes of large scale structure and magnetic fields
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DOI：
10.1103/physrevd.70.043007
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发表时间：
2004-01
影响因子：
5
通讯作者：
G. Sigl;F. Miniati;T. Ensslin
中科院分区：
文献类型：
--
作者：
G. Sigl;F. Miniati;T. Ensslin
我们研究了结构化宇宙在多极矩、自相关函数和原子团统计中的特征，这些特征是能量在10 ^{19} eV以上的宇宙射线。我们比较的情况下，源分布均匀，或根据重子密度分布从宇宙学大尺度结构模拟。河外磁场的影响进行了研究，通过比较的情况下，可忽略的领域，预计将产生沿着大规模的冲击与观测一致的最大强度的字段。我们证实，强磁化观测者将预测相当大的各向异性在大尺度上，这已经与目前的数据相冲突。在最佳拟合的情况下，只有源被强磁化，尽管偏转仍然可以是相当大的，从20\ifmmode\circ\else\textdegree\fi {}$到${10}^{20}\mathrm{eV}，$，并且预测了明显的GZK截止。然后，我们讨论了未来的大型全天空探测器，如皮埃尔俄歇和EUSO项目的签名。只有当磁场不显著影响传播时，自相关才对源密度敏感。相反，对于弱磁化观测者，低于一定水平的度标度自相关表明磁化离散源。即使是下一代实验也很难区分结构化和非结构化源分布。
We study signatures of a structured universe in the multi-pole moments, auto-correlation function, and cluster statistics of ultrahigh energy cosmic rays above ${10}^{19}\mathrm{eV}.$ We compare scenarios where the sources are distributed homogeneously or according to the baryon density distribution obtained from a cosmological large scale structure simulation. The influence of extragalactic magnetic fields is studied by comparing the case of negligible fields with fields expected to be produced along large scale shocks with a maximal strength consistent with observations. We confirm that strongly magnetized observers would predict considerable anisotropy on large scales, which is already in conflict with current data. In the best fit scenario only the sources are strongly magnetized, although deflection can still be considerable, of order $20\ifmmode^\circ\else\textdegree\fi{}$ up to ${10}^{20}\mathrm{eV},$ and a pronounced GZK cutoff is predicted. We then discuss signatures for future large scale full-sky detectors such as the Pierre Auger and EUSO projects. Auto-correlations are sensitive to the source density only if magnetic fields do not significantly affect propagation. In contrast, for a weakly magnetized observer, degree scale auto-correlations below a certain level indicate magnetized discrete sources. It may be difficult even for next generation experiments to distinguish between structured and unstructured source distributions.