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arXiv 0809.4003astro-ph
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第一次俄歇数据后的全球自相关研究:对UHECR源数密度的影响

A global autocorrelation study after the first Auger data: impact on the number density of UHECR sources

A. Cuoco, S. Hannestad, T. Haugboelle, M. Kachelriess, P. D. Serpico

摘要:

我们执行的俄歇数据的自相关研究的目的是约束数密度n_s的超高能宇宙线(UHECR)源,估计在同一时间的$n_s$的系统能量尺度的不确定性和分布的UHECR的影响。使用全局分析的优点在于,通过先验地选择单个角度尺度,在n_s中或在相关误差条中不引入偏差。连续均匀分布源的情况在99% C. L.处通常不受欢迎。如果源遵循宇宙中物质的大尺度结构,则拟合度会提高。得到的质子源数密度的最佳拟合值在n_s ~ 10^{-4}/Mpc ^3附近的~2倍范围内,并且主要取决于俄歇能量校准标度,如果电流标度正确,则优选较低的密度。数据显示,在小于几度的尺度上没有显著的小规模聚集。这可以被解释为具有可比尺寸的磁拖尾的特征,与来自互相关结果的~3度磁偏转的指示可比。文中还讨论了某些近似对上述结果的影响。

英文摘要:

We perform an autocorrelation study of the Auger data with the aim to constrain the number density n_s of ultrahigh energy cosmic ray (UHECR) sources, estimating at the same time the effect on $n_s$ of the systematic energy scale uncertainty and of the distribution of UHECR. The use of global analysis has the advantage that no biases are introduced, either in n_s or in the related error bar, by the a priori choice of a single angular scale. The case of continuous, uniformly distributed sources is nominally disfavored at 99% C.L. and the fit improves if the sources follow the large-scale structure of matter in the universe. The best fit values obtained for the number density of proton sources are within a factor ~2 around n_s ~ 10^{-4}/Mpc^3 and depend mainly on the Auger energy calibration scale, with lower densities being preferred if the current scale is correct. The data show no significant small-scale clustering on scales smaller than a few degrees. This might be interpreted as a signature of magnetic smearing of comparable size, comparable with the indication of a ~3 degrees magnetic deflection coming from cross-correlation results. The effects on the above results of some approximations done is also discussed.

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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