NGC 5548：VII中AGN的解剖结构。遮蔽和宽带连续谱变率的快速研究
Anatomy of the AGN in NGC 5548: VII. Swift study of obscuration and broadband continuum variability
摘要：
我们提出了我们的调查，在塞弗特1星系NGC 5548的X射线遮蔽和光学紫外X射线连续的长期变化。在2013年和2014年，斯威夫特天文台平均每隔一两天就对NGC 5548进行一次监测，记录的观测数据可以追溯到2005年，总计观测时间约为670 k。这两个宽带谱建模和时间均方根变异性分析适用于雨燕数据。我们解开的变化所造成的吸收，由于一个模糊的弱电离外流附近的磁盘，从可变性的内在连续分量（软X射线过剩和幂律）起源于磁盘及其相关的日冕。我们应用于这一广泛的雨燕数据的光谱模型是我们从2013年夏季多卫星活动（包括XMM-牛顿，NuSTAR和HST）的堆叠光谱分析中推导出的NGC 5548的全球模型。我们的雨燕研究结果表明，在10天到5个月的时间尺度上，遮蔽物覆盖率的变化是软X射线波段变化的主要原因。X射线源的遮蔽覆盖分数的范围在0.7和近1.0之间。软过剩分量对X射线变化的贡献通常比遮蔽物小得多，但当光学紫外连续谱爆发时，它变得相当。我们发现，软过剩是一致的，是高能量的尾巴的光学紫外线连续，并可以解释为温暖的康普顿化：向上散射的磁盘种子光子在一个温暖的，光学厚的日冕的一部分，内部磁盘。到目前为止，雨燕对NGC 5548的监测显示，这个模糊物已经连续出现在我们的视线中至少4年了（至少从2012年2月开始）。
英文摘要：
We present our investigation into the long-term variability of the X-ray obscuration and optical-UV-X-ray continuum in the Seyfert 1 galaxy NGC 5548. In 2013 and 2014, the Swift observatory monitored NGC 5548 on average every day or two, with archival observations reaching back to 2005, totalling about 670 ks of observing time. Both broadband spectral modelling and temporal rms variability analysis are applied to the Swift data. We disentangle the variability caused by absorption, due to an obscuring weakly-ionised outflow near the disk, from variability of the intrinsic continuum components (the soft X-ray excess and the power-law) originating from the disk and its associated coronae. The spectral model that we apply to this extensive Swift data is the global model that we derived for NGC 5548 from analysis of the stacked spectra from our multi-satellite campaign of summer 2013 (including XMM-Newton, NuSTAR and HST). The results of our Swift study show that changes in the covering fraction of the obscurer is the primary and dominant cause of variability in the soft X-ray band on timescales of 10 days to ~ 5 months. The obscuring covering fraction of the X-ray source is found to range between 0.7 and nearly 1.0. The contribution of the soft excess component to the X-ray variability is often much less than that of the obscurer, but it becomes comparable when the optical-UV continuum flares up. We find that the soft excess is consistent with being the high-energy tail of the optical-UV continuum and can be explained by warm Comptonisation: up-scattering of the disk seed photons in a warm, optically thick corona as part of the inner disk. To this date, the Swift monitoring of NGC 5548 shows that the obscurer has been continuously present in our line of sight for at least 4 years (since at least February 2012).
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
