Evidence for a Cool Disk and Inhomogeneous Coronae from Wide-band Temporal Spectroscopy of CygX-1 with Suzaku
Evidence for a Cool Disk and Inhomogeneous Coronae from Wide-band Temporal Spectroscopy of CygX-1 with Suzaku
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带有朱雀的 CygX-1 宽带时域光谱证明冷盘和不均匀日冕的证据
DOI：
10.1093/pasj/65.4.80
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
S
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文献类型：
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作者：
Yamada;S.;Makishima;K.;Done;C.;Torii;S.;Noda;H. & Sakurai;S
利用2005年至2009年25次获取的宽带朱雀数据，以模型无关的方式对天鹅座X-1在低/硬和硬中间状态下的统一X射线能谱和定时研究进行了研究，总曝光量为450 ks。对于 14.8 个太阳质量，未吸收的 0.1–500 keV 源光度变化超过爱丁顿极限的 0.8%–2.8%。短（1-2秒）和长（天到月）时间尺度的变化需要至少三个独立的分量：局部低于2 keV的恒定分量，在2-10 keV范围内占主导地位的宽软分量，以及主要在10-300 keV范围内出现的硬分量。鉴于截断盘/热内流图，这些分别被解释为来自截断冷盘、软康普顿分量和硬康普顿分量的发射。随着截断半径的减小，圆盘的温度和光度不断增加，可以产生长期光谱演化。软康普顿分量同样增加，但硬康普顿分量没有增加，因此硬中间态的光谱以软康普顿分量为主；另一方面，硬康普顿成分在昏暗的低/硬状态下主导光谱，可能与为康普顿化提供种子光子的可变软发射有关。
Unified X-ray spectral and timing studies of Cygnus X-1 in the low/hard and hard intermediate state were conducted in a model-independent manner, using broadband Suzaku data acquired on 25 occasions from 2005 to 2009 with a total exposure of450 ks. The unabsorbed 0.1–500 keV source luminosity changed over 0.8%–2.8% of the Eddington limit for 14.8 solar masses. Variations on short (1–2 seconds) and long (days to months) time scales require at least three separate components: a constant component localized below2 keV, a broad soft one dominating in the 2–10 keV range, and a hard one mostly seen in the 10–300 keV range. In view of the truncated disk/hot inner-flow picture, these are respectively interpreted as emission from the truncated cool disk, a soft Compton component, and a hard Compton component. Long-term spectral evolution can be produced by the constant disk increasing in temperature and luminosity as the truncation radius decreases. The soft Compton component likewise increases, but the hard Compton does not, so that the spectrum in the hard intermediate state is dominated by the soft Compton component; on the other hand, the hard Compton component dominates the spectrum in the dim low/hard state, probably associated with a variable soft emission providing seed photons for the Comptonization.