Jet Parameters in the Black Hole X-Ray Binary MAXI J1820+070
Jet Parameters in the Black Hole X-Ray Binary MAXI J1820+070
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DOI：
10.3847/1538-4357/ac38a9
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发表时间：
2021-08
期刊：
影响因子：
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通讯作者：
A. Zdziarski;A. Tetarenko;M. Sikora
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文献类型：
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作者：
A. Zdziarski;A. Tetarenko;M. Sikora
本文研究了吸积黑洞双星MAXI J1820+070硬态喷流。根据可用的无线电-光学光谱和变异性数据，我们对喷流参数施加了严格的约束。我们发现，虽然不可能仅从光谱和可变性特性来唯一地确定喷流洛伦兹因子，但我们可以估计喷流开口角（<$1.5 ° ± 1°），喷流开始发射同步辐射的距离（<$3 × 1010 cm），以及那里的磁场强度（<$104 G），具有相对较低的不确定性，因为它们对体洛伦兹因子的依赖性较弱。我们发现，从无线电到亚毫米波长的变异性功率谱的突破是一致的，在时间尺度上的变异性阻尼等于沿沿着射流在任何洛伦兹因子的旅行时间。这一因素仍然可以受到电子-正电子对生产率内的喷气基地，我们计算的基础上观察到的X射线/软伽马射线光谱，和喷气功率，需要小于吸积功率。最小（1.5）和最大（4.5）洛伦兹因子分别对应于对和离子的优势，以及最小和最大喷流功率。我们估计了穿过BH的磁通量，发现在磁制动流吸积流中，射流可以由Blandford-Znajek机制提供动力。我们指出，我们推导的形式主义的核心的变化，在河外射电源观察到的相似性。
We study the jet in the hard state of the accreting black hole (BH) binary MAXI J1820+070. From the available radio-to-optical spectral and variability data, we put strong constraints on the jet parameters. We find while it is not possible to uniquely determine the jet Lorentz factor from the spectral and variability properties alone, we can estimate the jet opening angle (≈1.°5 ± 1°), the distance at which the jet starts emitting synchrotron radiation (∼3 × 1010 cm), and the magnetic field strength there (∼104 G), with relatively low uncertainty, as they depend weakly on the bulk Lorentz factor. We find the breaks in the variability power spectra from radio to submillimeter wavelength are consistent with variability damping over the timescale equal to the travel time along the jet at any Lorentz factor. This factor can still be constrained by the electron–positron pair-production rate within the jet base, which we calculate based on the observed X-ray/soft-gamma-ray spectrum, and the jet power, required to be less than the accretion power. The minimum (∼1.5) and maximum (∼4.5) Lorentz factors correspond to the dominance of pairs and ions, and the minimum and maximum jet power, respectively. We estimate the magnetic flux threading the BH and find the jet can be powered by the Blandford–Znajek mechanism in a magnetically arrested flow accretion flow. We point out the similarity of our derived formalism to that of core shifts, observed in extragalactic radio sources.