Internal shocks driven by accretion flow variability in the compact jet of the black hole binary GX 339-4
Internal shocks driven by accretion flow variability in the compact jet of the black hole binary GX 339-4
复制标题
黑洞双星 GX 339-4 紧凑射流中吸积流变化驱动的内部冲击
DOI：
10.1093/mnras/stu2711
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发表时间：
2014
影响因子：
4.8
通讯作者：
S. Corbel
中科院分区：
文献类型：
--
作者：
S. Drappeau;J. Malzac;J. Belmont;P. Gandhi;S. Corbel
近年来，紧凑型喷气机在理解吸积黑洞发动机方面发挥着越来越大的作用。在x射线双星系统中，致密射流通常与源爆发的硬态相联系在一起。最近对GX 339-4的观测表明，在中红外波段存在一个可变的同步加速器光谱断裂，这与它的紧凑喷流有关。在本研究使用的模型中，我们假设喷射发射是由喷射速度的快速波动驱动的内部激波中加速的电子产生的。所得的谱能分布（SED）和变异性对假设的射流洛伦兹因子波动的傅里叶功率谱密度（PSD）非常敏感。这些波动很可能是由吸积流的可变性引发的，而这种可变性最好由x射线发射来追踪。假设喷流洛伦兹因子波动的PSD与观测到的x射线PSD相同，我们的研究发现，内部激波模型成功地再现了观测时源的射电-红外SED以及报道的强中红外光谱变动性。
In recent years, compact jets have been playing a growing role in the understanding of accreting black hole engines. In the case of X-ray binary systems, compact jets are usually associated with the hard state phase of a source outburst. Recent observations of GX 339-4 have demonstrated the presence of a variable synchrotron spectral break in the mid-infrared band that was associated with its compact jet. In the model used in this study, we assume that the jet emission is produced by electrons accelerated in internal shocks driven by rapid fluctuations of the jet velocity. The resulting spectral energy distribution (SED) and variability properties are very sensitive to the Fourier power spectrum density (PSD) of the assumed fluctuations of the jet Lorentz factor. These fluctuations are likely to be triggered by the variability of the accretion flow which is best traced by the X-ray emission. Taking the PSD of the jet Lorentz factor fluctuations to be identical to the observed X-ray PSD, our study finds that the internal shock model successfully reproduces the radio to infrared SED of the source at the time of the observations as well as the reported strong mid-infrared spectral variability.