We carried out a uniform and systematic analysis of a sample of 112 nearby bright Seyfert 1 type active galactic nuclei, the observations of which were carried out by the Nuclear Spectroscopic Telescope Array between 2013 August and 2022 May. The main goal of this analysis is to investigate the nature of the X-ray corona in Seyfert 1 galaxies. By fitting a physical model to the NuSTAR spectra, we could constrain the high-energy cutoff (Ecut) for 73 sources in our sample. To estimate the temperature of the corona (kTe) in our sample of 112 sources, we used the Comptonization model to fit their spectra. We could constrain kTe in 42 sources. We found a strong positive correlation between Ecut and kTe, with most of the sources lying above the empirical approximation of Ecut = 2−3 kTe. We investigated for possible correlations between various properties of the corona obtained from physical model fits to the observed spectra and between various coronal parameters and physical properties of the sources such as Eddington ratio and black hole mass. We found (a) a strong correlation between Ecut and the photon index and (b) a significant negative correlation between kTe and the optical depth. From detailed statistical analysis of the correlation of coronal parameters with the Eddington ratio and black hole mass, we found no significant correlation. The correlations observed in this study indicate that an optically thin corona is needed to sustain a hotter corona with a steeper spectrum.

中文翻译：

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关于 X 射线日冕在 Seyfert 1 星系中的特性


我们对附近 112 个明亮的 Seyfert 1 型活跃星系核的样本进行了统一和系统的分析，这些样本是在 2013 年 8 月至 2022 年 5 月期间由核光谱望远镜阵列进行的。这项分析的主要目标是研究 Seyfert 1 星系中 X 射线日冕的性质。通过将物理模型拟合到 NuSTAR 光谱中，我们可以限制样品中 73 个源的高能截止值 （Ecut）。为了估计我们 112 个源样本中的日冕温度 （kTe），我们使用了 Comptonization 模型来拟合它们的光谱。我们可以将 kTe 限制在 42 个源中。我们发现 Ecut 和 kTe 之间存在很强的正相关关系，大多数来源位于 Ecut = 2−3 kTe 的经验近似值之上。我们研究了从物理模型拟合中获得的日冕的各种特性与观察到的光谱之间以及各种日冕参数与光源的物理特性（如爱丁顿比和黑洞质量）之间的可能相关性。我们发现 （a） Ecut 与光子指数之间存在很强的相关性，以及 （b） kTe 与光学深度之间存在显著的负相关。通过对日冕参数与 Eddington 比率和黑洞质量相关性的详细统计分析，我们发现没有显着的相关性。本研究中观察到的相关性表明，需要一个光学薄的日冕来维持光谱更陡峭的更热的日冕。