活动星系核中的初级X射线辐射被广泛认为是由于来自热电子日冕中吸积盘的热辐射的康普顿化。由此产生的光谱可以，在第一近似，与截止功率定律，光子指数和高能量翻转编码信息的X射线发射区域的物理性质建模。自从10 keV以上的X射线卫星发射以来，人们对活动星系核（$Γ$，E $_c$）的光子指数和高能曲率进行了大量的研究。然而，由于NuSTAR前所未有的高达79 keV的灵敏度，这两个可观测量的高精度测量仅在近年来才获得。我们的目的是推导之间的关系的唯象参数（$Γ$和E $_c$）和X射线发射区域（热日冕）的固有属性，即光学深度和温度。我们使用MoCA（Monte Carlo code for Comptonisation in Astrophysics）产生的合成光谱的情况下，活动星系核的M $_{BH}$ =1.5 $\times$ 10 $^8$ M $_{sun}$和吸积率为10%，然后比较它们与广泛使用的幂律模型与指数高能截止。我们提供了有关$Γ$和E $_c$与冠状电子的不透明度和温度的球形和板状冠的情况下的唯象关系。这些关系给出了一个定义良好的参数空间，其中完全包含观测值的起源。利用文献中引用的越来越多的高能量截止值，我们报告使用MoCA获得的物理量与使用通常采用的光谱康普顿化模型估计的物理量的比较。最后，我们讨论了不同的黑洞质量和吸积率对推导关系的影响。
英文摘要：
The primary X-ray emission in active galactic nuclei (AGNs) is widely believed to be due to Comptonisation of the thermal radiation from the accretion disc in a corona of hot electrons. The resulting spectra can, in first approximation, be modelled with a cut-off power law, the photon index and the high-energy roll-over encoding information on the physical properties of the X-ray-emitting region. The photon index and the high-energy curvature of AGNs ($Γ$, E$_c$) have been largely studied since the launch of X-ray satellites operating above 10 keV. However, high-precision measurements of these two observables have only been obtained in recent years thanks to the unprecedented sensitivity of NuSTAR up to 79 keV. We aim at deriving relations between phenomenological parameters ($Γ$ and E$_c$) and the intrinsic properties of the X-ray-emitting region (the hot corona), namely the optical depth and temperature. We use MoCA (Monte Carlo code for Comptonisation in Astrophysics) to produce synthetic spectra for the case of an AGN with M$_{BH}$=1.5$\times$10$^8$ M$_{sun}$ and accretion rate of 10% and then compared them with the widely used power-law model with an exponential high-energy cutoff. We provide phenomenological relations relating $Γ$ and E$_c$ with the opacity and temperature of the coronal electrons for the case of spherical and slab-like coronae. These relations give origin to a well defined parameter space which fully contains the observed values. Exploiting the increasing number of high-energy cut-offs quoted in the literature, we report on the comparison of physical quantities obtained using MoCA with those estimated using commonly adopted spectral Comptonisation models. Finally, we discuss the negligible impact of different black hole masses and accretion rates on the inferred relations.
Turbulent AGN coronae as the origin of diffuse neutrinos up to PeV energies
School of Astronomy and Space Science, Nanjing University（南京大学天文与空间科学学院）；Key laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education（现代天文学和天体物理学教育部重点实验室（南京大学））；Tianfu Cosmic Ray Research Center（天府宇宙线研究中心）
On high-energy particles in accretion disk coronae of supermassive black holes: implications for MeV gamma rays and high-energy neutrinos from AGN cores
AGN X-ray coronae at high luminosity: A broadband study of RBS 229 and PG 1407+265
Università degli Studi Roma Tre（罗马三大学）；ASI – Agenzia Spaziale Italiana（意大利航天局）；INAF – Osservatorio Astronomico di Roma（罗马天文台）；INAF – Osservatorio Astrofisico di Arcetri（阿切尔菲天文台）；INAF – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna（博洛尼亚天体物理与空间科学天文台）；Univ. Grenoble Alpes, CNRS, IPAG（格勒诺布尔阿尔卑斯大学）；Jet Propulsion Laboratory, California Institute of Technology（加州理工学院喷气推进实验室）；Alma Mater Studiorum, Università degli Studi di Bologna（博洛尼亚大学）
