AGN are among the most energetic phenomena in the Universe and in the last two decades INTEGRAL's contribution in their study has had a significant impact. Thanks to the INTEGRAL extragalactic sky surveys, all classes of soft X-ray detected (in the 2-10 keV band) AGN have been observed at higher energies as well. Up to now, around 450 AGN have been catalogued and a conspicuous part of them are either objects observed at high-energies for the first time or newly discovered AGN. The high-energy domain (20-200 keV) represents an important window for spectral studies of AGN and it is also the most appropriate for AGN population studies, since it is almost unbiased against obscuration and therefore free of the limitations which affect surveys at other frequencies. Over the years, INTEGRAL data have allowed to characterise AGN spectra at high energies, to investigate their absorption properties, to test the AGN unification scheme and to perform population studies. In this review the main results are reported and INTEGRAL's contribution to AGN science is highlighted for each class of AGN. Finally, new perspectives are provided, connecting INTEGRAL's science with that at other wavelengths and in particular to the GeV/TeV regime which is still poorly explored.

中文翻译：

---

AGN 的整体视图

AGN 是宇宙中能量最高的现象之一，在过去的二十年中，INTEGRAL 在他们的研究中的贡献产生了重大影响。由于 INTEGRAL 河外天空巡天，在更高能量下也观测到了所有类型的软 X 射线（在 2-10 keV 波段）AGN。截至目前，已编录的AGN约有450个，其中比较突出的部分是首次在高能下观测到的天体，或者是新发现的AGN。高能域 (20-200 keV) 是 AGN 光谱研究的一个重要窗口，也是 AGN 群体研究最合适的窗口，因为它几乎不受遮蔽的影响，因此不受其他影响调查的限制。频率。这些年来，INTEGRAL 数据允许在高能下表征 AGN 光谱，研究它们的吸收特性，测试 AGN 统一方案并进行群体研究。在这篇评论中，报告了主要结果，并针对每一类 AGN 突出了 INTEGRAL 对 AGN 科学的贡献。最后，提供了新的观点，将 INTEGRAL 的科学与其他波长的科学联系起来，特别是与仍然缺乏探索的 GeV/TeV 机制相联系。