标题： 高度遮蔽活动星系核检测：射电与X射线的挑战 显示英文标题

标题： Heavily Obscured AGN detection: a Radio vs X-ray challenge

摘要： 在本工作中，我们研究了在主要的深空星系外调查中，不同AGN遮蔽水平、红移和AGN总光度下的AGN射电检测效果。我们特别关注比较它们的射电和X射线可检测性，并对当前和未来的射电调查做出预测。我们通过推导未遮蔽（即氢柱密度$\log N_{H} <22$）的AGN、遮蔽（$22<\log N_{H}<24$）和康普顿厚（CTK，$\log N_{H} >24$）AGN的1.4 GHz光度函数，将宇宙X射线背景（CXB）的AGN人口合成模型的预测外推到射电波段。然后，我们使用这些函数根据给定射电调查的面积、流量极限和完整性来预测可检测的AGN数量，并将其与X射线预测得到的AGN数量进行比较。当应用于同时覆盖射电和X射线观测的深空星系外区域时，我们表明，虽然X射线选择通常在检测未遮蔽AGN方面更有效，但考虑到当前调查和设施，在平均情况下，CTK AGN的射电表面密度是X射线的$\sim 10$倍，且在高红移时甚至更大。我们的结果表明，目前的射电目录中已经存在数千个CTK AGN，但其中大多数在相应的X射线观测中未被检测到。我们还提出了平方千米阵列天文台（SKAO）在其未来深空和宽视场射电连续谱调查中预期检测到的AGN数量，发现它能够在$z>6$检测到超过2000个AGN，并在$z>10$检测到数十个，其中一半以上预计为CTK。 显示英文摘要

摘要： In this work, we study the AGN radio detection effectiveness in the major deep extragalactic surveys, considering different AGN obscuration levels, redshift, and AGN bolometric luminosities. We particularly focus on comparing their radio and X-ray detectability, making predictions for present and future radio surveys. We extrapolate the predictions of AGN population synthesis model of cosmic X-ray background (CXB) to the radio band, by deriving the 1.4 GHz luminosity functions of unobscured (i.e. with hydrogen column densities $\log N_{H} <22$), obscured ($22<\log N_{H}<24$) and Compton-thick (CTK, $\log N_{H} >24$) AGN. We then use these functions to forecast the number of detectable AGN based on the area, flux limit, and completeness of a given radio survey and compare it with the AGN number resulting from X-ray predictions. When applied to deep extragalactic fields covered both by radio and X-ray observations, we show that, while X-ray selection is generally more effective in detecting unobscured AGN, the surface density of CTK AGN radio detected is on average $\sim 10$ times larger than the X-ray one, and even greater at high redshifts, considering the current surveys and facilities. Our results suggest that thousands of CTK AGN are already present in current radio catalogs, but most of them escaped any detection in the corresponding X-ray observations. We also present expectations for the number of AGN to be detected by the Square Kilometer Array Observatory (SKAO) in its future deep and wide radio continuum surveys, finding that it will be able to detect more than 2000 AGN at $z>6$ and some tens at $z>10$, more than half of which are expected to be CTK.