X射线源计数的最近邻统计Ⅰ.方法
The nearest neighbor statistics for X-ray source counts I.The method
摘要：
大多数X射线背景（XRB）由离散的X射线源产生。这是可能的，仍然未解决的部分XRB是由人口的弱源低于目前的检测阈值和一个真正的扩散组件。这是一个讨论的问题，这些薄弱的来源的性质。本文的目的是探讨光子分布的最近邻统计量（NNST）的有效性的调查非常微弱的源的数目计数。所有产生至少两个计数的源，每个源引起计数的非随机分布。该分布通过NNST进行分析。利用基本概率方程，导出了源数N（S）与NNST之间的关系。结果表明，该方法产生的N（S）的关系低于规则的离散源检测阈值的约束。NNST应用于中深钱德拉指向，以评估仅在非常深的曝光下才能达到的通量水平下的源计数N（S）。计算结果与基于Chandra深场（CDF）的直接源计数结果吻合较好。在本系列的下一篇文章中，NNST将应用于CDF，以评估低于当前通量限制的源计数。
英文摘要：
Most of the X-ray background (XRB) is generated by discrete X-ray sources. It is likely that still unresolved fraction of the XRB is composed from a population of the weak sources below the present detection thresholds and a truly diffuse component. It is a matter of discussion a nature of these weak sources. The goal of the present paper is to explore the effectiveness of the nearest neighbor statistics (NNST) of the photon distribution for the investigation of the number counts of the very weak sources. All the sources generating at least two counts each induce a nonrandom distribution of counts. This distribution is analyzed by means of the NNST. Using the basic probability equations, the relationships between the source number counts N(S) and the NNST are derived. It is shown that the method yields constraints on the N(S) relationship below the regular discrete source detection threshold. The NNST was applied to the medium deep Chandra pointing to assess the source counts N(S) at flux levels attainable only with the very deep exposures. The results are in good agreement with the direct source counts based in the Chandra Deep Fields (CDF). In the next paper of this series the NNST will be applied to the the CDF to assess the source counts below the present flux limits.
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。
