标题： 超软窄线赛弗特1型星系的盘反射模型 显示英文标题

标题： A Disc Reflection Model for Ultra-Soft Narrow-Line Seyfert 1 Galaxies

摘要： 我们对五个窄线赛弗特1型星系（NLS1s）的XMM-Newton观测结果进行了详细分析。它们在X射线波段都显示出非常软的连续辐射发射，光子指数为$\Gamma\gtrsim 2.5$。因此，本文将它们称为“超软”NLS1s。通过使用基于反射模型来拟合它们的光学/紫外-X射线能谱分布（SED），我们发现这些超软NLS1s中的盘表面处于比其他典型赛弗特1 AGN更高的电离状态。我们的最佳拟合SED模型表明，假设可用黑洞质量测量值，这五个超软NLS1s具有$\lambda_{\rm Edd}=1-20$的爱丁顿比。此外，我们的模型推断，在这些超软NLS1s中，盘能量的很大一部分是以非热辐射的形式辐射出去的，而不是从盘发出的热辐射。由于它们的极端性质，在铁带上的X射线观测特别具有挑战性。未来的观测，例如来自Athena的任务，将使我们能够更清楚地了解铁带上的光谱形状，从而区分反射模型与其他宽带光谱解释。 显示英文摘要

摘要： We present a detailed analysis of the XMM-Newton observations of five narrow-line Seyfert 1 galaxies (NLS1s). They all show very soft continuum emission in the X-ray band with a photon index of $\Gamma\gtrsim 2.5$. Therefore, they are referred to as `ultra-soft' NLS1s in this paper. By modeling their optical/UV-X-ray spectral energy distribution (SED) with a reflection-based model, we find indications that the disc surface in these ultra-soft NLS1s is in a higher ionisation state than other typical Seyfert 1 AGN. Our best-fit SED models suggest that these five ultra-soft NLS1s have an Eddington ratio of $\lambda_{\rm Edd}=1-20$ assuming available black hole mass measurements. In addition, our models infer that a significant fraction of the disc energy in these ultra-soft NLS1s is radiated away in the form of non-thermal emission instead of the thermal emission from the disc. Due to their extreme properties, X-ray observations of these sources in the iron band are particularly challenging. Future observations, e.g. from Athena, will enable us to have a clearer view of the spectral shape in the iron band and thus distinguish the reflection model from other interpretations of their broadband spectra.