标题： XXL巡天：VI. 1000个最亮的X射线点源 显示英文标题

标题： The XXL Survey: VI. The 1000 brightest X-ray point sources

摘要： X射线河外巡天是研究活动星系核（AGN）演化和聚集的理想实验室。 XXL巡天覆盖了两个区域，总观测面积为50 $deg^2$，并用XMM-Newton进行了超过6Ms的观测，占据了深度巡天和非常宽区域巡天之间的参数空间；同时它受益于大量辅助数据。 本文标志着在2-10 keV能量带中选择的XXL点源目录的首次发布，其极限流量为 $F_{2-10keV}=4.8\cdot10^{-14}\rm{erg\,s^{-1}\,cm^{-2}}$。 我们使用公开和专有数据集来识别X射线点源的对应体，并通过应用一种随机森林分类器来改进AGN的光度红移确定，该分类器被训练以针对每个物体识别最佳的光度红移模型库。 我们还为每个源分配一个可能是恒星或异常值的概率。 我们通过贝叶斯分析对X射线谱进行建模，假设存在一个幂律模型和吸收介质。 我们发现平均未吸收光子指数为 $\Gamma=1.85$，平均氢柱密度为 $\log{N_{H}}=21.07 cm^{-2}$。 我们发现 $\Gamma$或 $N_H$随红移没有趋势，且有26%的吸收源（$\log N_{H}>22$）。 我们展示了XXL-1000-AGN的数量计数扩展了COSMOS巡天的计数到更高的流量，并与欧几里得预期完全一致。 我们在2-10 keV能量带内限制了AGN的固有光度函数，其中未吸收X射线流量从X射线光谱拟合估计到z=3。 最后，我们证明在红移0.14处存在一个超团尺度结构，这是通过XXL-1000-AGN样本的渗透分析识别出来的。 XXL巡天达到中等流量极限并覆盖广泛区域，是在当前深度场和计划中的宽区域巡天之间的一个重要步骤。 显示英文摘要

摘要： X-ray extragalactic surveys are ideal laboratories for the study of the evolution and clustering of active galactic nuclei (AGN). The XXL Survey spans two fields of a combined 50 $deg^2$ observed for more than 6Ms with XMM-Newton, occupying the parameter space between deep surveys and very wide area surveys; at the same time it benefits from a wealth of ancillary data. This paper marks the first release of the XXL point source catalogue selected in the 2-10 keV energy band with limiting flux $F_{2-10keV}=4.8\cdot10^{-14}\rm{erg\,s^{-1}\,cm^{-2}}$. We use both public and proprietary data sets to identify the counterparts of the X-ray point-like sources and improved upon the photometric redshift determination for AGN by applying a Random Forest classification trained to identify for each object the optimal photometric redshift model library. We also assign a probability to each source to be a star or an outlier. We model with Bayesian analysis the X-ray spectra assuming a power-law model with the presence of an absorbing medium. We find an average unabsorbed photon index of $\Gamma=1.85$ and average hydrogen column density $\log{N_{H}}=21.07 cm^{-2}$. We find no trend of $\Gamma$ or $N_H$ with redshift and a fraction of 26% absorbed sources ($\log N_{H}>22$). We show that the XXL-1000-AGN number counts extended the number counts of the COSMOS survey to higher fluxes and are fully consistent with the Euclidean expectation. We constrain the intrinsic luminosity function of AGN in the 2-10 keV energy band where the unabsorbed X-ray flux is estimated from the X-ray spectral fit up to z=3. Finally, we demonstrate the presence of a supercluster size structure at redshift 0.14, identified by means of percolation analysis of the XXL-1000-AGN sample. The XXL survey, reaching a medium flux limit and covering a wide area is a stepping stone between current deep fields and planned wide area surveys.