X-ray reverberation in 1H 0707−495 revisited
X-ray reverberation in 1H 0707−495 revisited
复制标题
重新审视 1H 0707−495 中的 X 射线混响
DOI：
10.1111/j.1365-2966.2010.17261.x
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发表时间：
2010
影响因子：
4.8
通讯作者：
V. Braito
中科院分区：
文献类型：
--
作者：
L. Miller;T. Turner;J.N.Reeves;V. Braito
窄线Seyfert 1星系1H0707-495在软能（0.3-1 keV）和中能（1-4 keV） x射线波段的通量变化之间显示出时间滞后，该波段在正值和负值之间振荡，作为变化模式频率的函数。在这里，我们使用现有的XMM-Newton数据测量和分析了硬x射线波段（4-7.5 keV）与软x射线波段和中x射线波段之间的滞后，并证明了整个滞后谱，考虑到全能量范围（0.3-7.5 keV）和全频率范围（10 -5≤ν≤10 -2 Hz），与先前声称的与内部吸积盘相关的回响不一致。相反，我们证明了一个简单的混响模型，其中散射或反射存在于所有x射线波段，解释了全套滞后，而不需要对滞后符号变化进行任何特别解释。解释观测到的滞后所需的时间延迟范围在硬带中扩展到大约1800秒。结果与x射线通过吸收介质散射引起的混响一致，吸收介质的不透明度随着能量的增加而降低，并且部分地覆盖了源。推断出了吸收和散射环核物质的高覆盖系数。
The narrow-line Seyfert 1 galaxy 1H0707-495 has previously been identified as showing time lags between flux variations in the soft-energy (0.3-1 keV) and medium-energy (1-4 keV) X-ray bands that oscillate between positive and negative values as a function of the frequency of the mode of variation. Here we measure and analyse the lags also between a harder X-ray band (4-7.5 keV) and the soft and medium bands, using existing XMM-Newton data, and demonstrate that the entire spectrum of lags, considering both the full energy range, 0.3-7.5 keV, and the full frequency range, 10 -5 ≲ ν ≲ 10 -2 Hz, are inconsistent with previous claims of arising as reverberation associated with the inner accretion disc. Instead we demonstrate that a simple reverberation model, in which scattering or reflection is present in all X-ray bands, explains the full set of lags without requiring any ad hoc explanation for the time lag sign changes. The range of time delays required to explain the observed lags extends up to about 1800 s in the hard band. The results are consistent with reverberation caused by scattering of X-rays passing through an absorbing medium whose opacity decreases with increasing energy and that partially covers the source. A high covering factor of absorbing and scattering circumnuclear material is inferred.