Constraining jet/disc geometry and radiative processes in stellar black holes XTE J1118+480 and GX 339−4
Constraining jet/disc geometry and radiative processes in stellar black holes XTE J1118+480 and GX 339−4
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DOI：
10.1111/j.1365-2966.2009.14896.x
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发表时间：
2009-04
影响因子：
4.8
通讯作者：
D. Maitra;S. Markoff;C. Brocksopp;Michael S. Noble;M. A. Nowak;J. Wilms
中科院分区：
文献类型：
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作者：
D. Maitra;S. Markoff;C. Brocksopp;Michael S. Noble;M. A. Nowak;J. Wilms
我们提出了银河系恒星黑洞（BH）瞬态X射线双星（XRB）系统XTE J1118+480和GX 339−4的准同步宽带（通过X射线的无线电）观测的模拟结果，使用辐照盘+致密喷流模型。除了量化的射流的物理特性，我们已经开发出一种新的照射盘模型，它也约束了外部吸积盘的几何形状和温度，通过假设一个盘加热粘性能量释放和X射线照射从内部区域。对于源XTE J1118+480，它具有更好的光谱覆盖范围的两个在光学和近红外（OIR）波长，我们表明，整个宽带连续可以很好地描述由流出为主的模型+照射光盘。盘外缘的最佳拟合半径与系统的罗氏瓣几何形状一致，吸积盘外缘的温度与其他XRB的温度相似。对这个源来说，射流对圆盘的辐照可以忽略不计。对于GX 339−4，整个连续体仅由喷流主导模型很好地描述，不需要圆盘分量。对于两个XRB，这两个XRB具有非常不同的物理和轨道参数，并且在观测期间处于不同的吸积状态，喷流底部的大小相似，并且两者似乎都更喜欢加速/冲击区域中的高比例的非热电子和喷流中的磁主导等离子体。这些结果，沿着最近从模拟其他星系XRB和活动星系核的类似结果，可能表明一个内在的统一性，在多样性的几何和辐射特性的致密喷流吸积黑洞。
We present results from modelling of quasi-simultaneous broad-band (radio through X-ray) observations of the Galactic stellar black hole (BH) transient X-ray binary (XRB) systems XTE J1118+480 and GX 339−4 using an irradiated disc + compact jet model. In addition to quantifying the physical properties of the jet, we have developed a new irradiated disc model which also constrains the geometry and temperature of the outer accretion disc by assuming a disc heated by viscous energy release and X-ray irradiation from the inner regions. For the source XTE J1118+480, which has better spectral coverage of the two in optical and near-infrared (OIR) wavelengths, we show that the entire broad-band continuum can be well described by an outflow-dominated model + an irradiated disc. The best-fitting radius of the outer edge of the disc is consistent with the Roche lobe geometry of the system, and the temperature of the outer edge of the accretion disc is similar to those found for other XRBs. Irradiation of the disc by the jet is found to be negligible for this source. For GX 339−4, the entire continuum is well described by the jet-dominated model only, with no disc component required. For the two XRBs, which have very different physical and orbital parameters and were in different accretion states during the observations, the sizes of the jet base are similar and both seem to prefer a high fraction of non-thermal electrons in the acceleration/shock region and a magnetically dominated plasma in the jet. These results, along with recent similar results from modelling other galactic XRBs and AGNs, may suggest an inherent unity in diversity in the geometric and radiative properties of compact jets from accreting black holes.