Mapping the inner accretion disc of the Galactic black hole J1550–564 through its rise to outburst
Mapping the inner accretion disc of the Galactic black hole J1550–564 through its rise to outburst
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绘制银河系黑洞 J1550-564 内部吸积盘从上升到爆发的过程
DOI：
10.1046/j.1365-8711.2001.04406.x
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发表时间：
2001
影响因子：
4.8
通讯作者：
C. Done
中科院分区：
文献类型：
--
作者：
C. Done
摘要 我们研究了 X 射线瞬变 J1550-564 上升到爆发阶段的前 14 次观测的光谱特性。使用 PCA 和 HEXTE 仪器，我们发现 3-200 keV 光谱从标准低/硬状态平稳地传递到非常高的状态。从未遇到过经典的高态，这可能表明这不是上升阶段的现象。我们发现单个 PCA 光谱可以通过圆盘黑体和包含反射的热康普顿化模型充分拟合。一旦达到非常高的状态，连续谱就会出现明显的光谱曲率，这可能表明复合热/非热等离子体的存在。我们对反射参数的详细建模显示，在低态和极高态之间转变开始时，平均电离急剧增加。反射分数存在相关的变化，但其确切值取决于所使用的连续介质模型。反射分数在 V=2p 、 0:1 的值附近变化，并且永远与 V=2pa 1 一致。我们可以使用相对论涂抹来约束内半径，虽然存在很大的不确定性，但数据与在任一状态下延伸到最后稳定轨道 (6 Rg) 的盘不兼容。当系统处于爆发状态时，盘不稳定性模型（以及观察到的 QPO 频率增加）强烈暗示在观察到低状态谱时不存在标准内盘。这与截断的圆盘兼容，由 X 射线热、平流主导的吸积流填充。然而，一旦考虑了盘表面的流出和/或强光电离的影响，爆发盘上方的磁耀斑也可以与观察到的光谱相匹配。我们清楚地看到反射器在非常高的状态下发生强烈电离。这可能来自碰撞电离，因为圆盘表面温度为 0.7 keV。这可以强烈抑制来自内盘的反射。
ABSTRA C T We study the spectral properties of the first 14 observations of the rise to outburst phase of the X-ray transient J1550‐564. Using both the PCA and HEXTE instruments, we find that the 3‐200 keV spectra pass smoothly from a standard low/hard state to a very high state. The classic high state is never encountered, possibly indicating that it is not a phenomenon of the rise phase. We find that the individual PCA spectra can be fitted adequately by a disc blackbody and a thermal Comptonization model which includes reflection. Once the very high state is reached, there is clear spectral curvature of the continuum, which possibly indicates the presence of a composite thermal/non-thermal plasma. Our detailed modelling of the reflection parameters shows a sharp increase in mean ionization at the onset of the transition between the low state and very high state. There is a related variability in the reflected fraction, but its exact value depends on the continuum model used. The reflected fraction varies around values of V=2p , 0:1, and is never consistent with V=2pa 1. We can constrain the inner radius using relativistic smearing and, while there are large uncertainties, the data are incompatible with a disc extending to the last stable orbit (6 Rg) in either state. As the system is on the rise to outburst, the disc instability models (and observed increasing QPO frequency) strongly imply that there is no standard inner disc at the time the low-state spectrum is observed. This is compatible with a truncated disc, filled by an X-ray hot, advection-dominated accretion flow. However, magnetic flares above the outbursting disc can also match the observed spectra, once the effects of either outflow and/or strong photoionization of the surface of the disc are included. We clearly see strong ionization of the reflector in the very high state. This is probably from collisional ionization, as the disc surface temperature is ,0.7 keV. This can strongly suppress reflection from the inner disc.
天体物理等离子体发射的高能物理过程和机制：IAU 研讨会 195
影响因子：
3.5
作者：
S. Tsuruta
通讯作者：
S. Tsuruta