Fourier-resolved energy spectra of the Narrow-Line Seyfert 1 Mkn 766
Fourier-resolved energy spectra of the Narrow-Line Seyfert 1 Mkn 766
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DOI：
10.1111/j.1365-2966.2008.13216.x
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发表时间：
2008-03
影响因子：
4.8
通讯作者：
P. Arévalo;I. McHardy;A. Markowitz;I. Papadakis;I. Papadakis;T. Turner;T. Turner;L. Miller;J. Reeves
中科院分区：
文献类型：
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作者：
P. Arévalo;I. McHardy;A. Markowitz;I. Papadakis;I. Papadakis;T. Turner;T. Turner;L. Miller;J. Reeves
我们计算傅立叶分辨的X射线光谱的Seyfert 1 Markarian 766研究的形状的变量组件有助于0.3-10 keV的能谱和它们的时间尺度依赖性。分数变异光谱峰值在1-3千电子伏，在其他塞弗特1星系，无论是一个恒定的贡献，从软多余的组件低于1千电子伏和康普顿反射组件高于2千电子伏或可变的暖吸收增强1-3千电子伏范围内的可变性一致。的均方根谱，它只显示的形状的可变组件，以及描述了一个单一的幂律与吸收功能约0.7千电子伏，这给它一个明显的软过剩。这种光谱形状可以由归一化变化的幂律产生，受到近似恒定（在每个轨道内）的暖吸收体的影响，其参数类似于Turner等人发现的覆盖散射场景中所有光谱分量的暖吸收体层的参数[NH_3 × 1021 cm-2，log（log）_1]。因此，平均光谱中的总软过量可以通过幂律上的恒定热吸收加上附加的较小可变分量的组合来产生。在较短的时间尺度上，均方根频谱变硬，这种演变是很好地描述了幂律斜率的变化，而吸收参数保持不变。均方根频谱的频率依赖性可以解释为通过扩展发射区域传播波动所产生的变化，其发射频谱是向中心硬化的幂律。这种情况下，降低了较低的能量带的短时间尺度的变化，使可变频谱更难在较短的时间尺度上，并在同一时间解释了硬滞后发现这些数据由Markowitz等人。
We compute Fourier-resolved X-ray spectra of the Seyfert 1 Markarian 766 to study the shape of the variable components contributing to the 0.3-10 keV energy spectrum and their time-scale dependence. The fractional variability spectra peak at 1-3 keV, as in other Seyfert 1 galaxies, consistent with either a constant contribution from a soft excess component below 1 keV and Compton reflection component above 2 keV or variable warm absorption enhancing the variability in the 1-3 keV range. The rms spectra, which show the shape of the variable components only, are well described by a single power law with an absorption feature around 0.7 keV, which gives it an apparent soft excess. This spectral shape can be produced by a power law varying in normalization, affected by an approximately constant (within each orbit) warm absorber, with parameters similar to those found by Turner et al. for the warm-absorber layer covering all spectral components in their scattering scenario [N H ∼ 3 × 10 21 cm -2 , log(ξ) ∼ 1]. The total soft excess in the average spectrum can therefore be produced by a combination of constant warm absorption on the power-law plus an additional less variable component. On shorter time-scales, the rms spectrum hardens and this evolution is well described by a change in power-law slope, while the absorption parameters remain the same. The frequency dependence of the rms spectra can be interpreted as variability arising from propagating fluctuations through an extended emitting region, whose emitted spectrum is a power law that hardens towards the centre. This scenario reduces the short time-scale variability of lower energy bands making the variable spectrum harder on shorter time-scales and at the same time explains the hard lags found in these data by Markowitz et al.