The three spectral regimes found in the stellar black hole XTE J1550-564 in its high/soft state
The three spectral regimes found in the stellar black hole XTE J1550-564 in its high/soft state
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DOI：
10.1086/380433
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发表时间：
2004-01-20
影响因子：
4.9
通讯作者：
Makishima, K
中科院分区：
文献类型：
--
作者：
Kubota, A;Makishima, K
本文介绍了分析的多个RXTE PCA数据的黑洞双星超光速喷流，XTE J1550 - 564，在其1998 - 1999年爆发期间获得的。X射线光谱显示出典型的高/软光谱状态的功能，可以近似地描述由光学厚盘光谱加上幂律尾。三个不同的光谱区，我们称之为“标准区”，“异常区”和“明显的标准区”，已经从整个观测光谱中发现。当X射线光度远低于6 x 10（38）ergs s（-1）（假设距离为5 kpc）时，XTE J1550 - 564处于标准状态，其中软光谱分量占主导地位，幂律分量和观察到的圆盘内径保持不变。当光度超过临界光度时，实现了明显的标准制度，其中光学厚盘的光度随温度的上升不太陡峭，并且光谱形状与标准吸积盘的光谱形状适度失真。在这个制度中，已被发现的径向温度梯度的磁盘是平坦的比标准的吸积盘。显然标准制度的结果表明，一个苗条的磁盘，这是一个解决方案预测的高质量吸积率。在中间异常制度（或在文献中的非常高的状态），光谱变得更加困难，和磁盘的内半径推导出一个简单的磁盘模型谱明显随时间变化显着。这些性质可以解释为盘光子的显着热逆康普顿化的结果，正如久保田及其同事在GRO J1655 - 40的异常区域中发现的那样。
The present paper describes the analysis of multiple RXTE PCA data of the black hole binary with superluminal jet, XTE J1550 - 564, acquired during its 1998 - 1999 outburst. The X-ray spectra show features typical of the high/soft spectral state and can approximately be described by an optically thick disk spectrum plus a power-law tail. Three distinct spectral regimes, which we call the "standard regime,'' the "anomalous regime,'' and the "apparently standard regime,'' have been found from the entire set of the observed spectra. When the X-ray luminosity is well below similar to 6 x 10(38) ergs s(-1) (assuming a distance of 5 kpc), XTE J1550 - 564 resides in the standard regime, in which the soft spectral component dominates the power-law component and the observed disk inner radius is kept constant. When the luminosity exceeds the critical luminosity, the apparently standard regime is realized, in which the luminosity of the optically thick disk rises less steeply with the temperature, and the spectral shape is moderately distorted from that of the standard accretion disk. In this regime, the radial temperature gradient of the disk has been found to be flatter than that of the standard accretion disk. The results of the apparently standard regime suggest a slim disk, which is a solution predicted for a high mass accretion rate. In the intermediate anomalous regime ( or very high state in the literature), the spectrum becomes much harder, and the disk inner radius derived using a simple disk model spectrum apparently varies significantly with time. These properties can be explained as a result of significant thermal inverse Comptonization of the disk photons, as was found from GRO J1655 - 40 in its anomalous regime by Kubota and coworkers.