Causal production of the electromagnetic energy flux and role of the negative energies in the Blindfold-Znajek process
Causal production of the electromagnetic energy flux and role of the negative energies in the Blindfold-Znajek process
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蒙眼-兹纳耶克过程中电磁能通量的因果产生和负能量的作用
DOI：
10.1093/ptep/ptw081
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发表时间：
2016
影响因子：
3.5
通讯作者：
Kenji Toma & Fumio Takahara
中科院分区：
文献类型：
--
作者：
Aswin Vishnuradhan;Y. Kozuka;M. Uchida;J. Falson;A. Tsukazaki;M. Kawasaki;Kenji Toma & Fumio Takahara
布兰福德-兹纳耶克过程，即从旋转黑洞（BH）中提取稳定的电磁能量，被广泛认为在活动星系核、伽马射线暴和星系微类星体中驱动相对论性喷流，尽管波印廷通量是如何产生的以及BH的旋转能量是如何减少的仍在争论中。我们一般地讨论了Kerr BH磁层充满无碰撞等离子体沿磁场屏蔽电场，扩展了Komissarov [S.]S. Komissarov，星期一。r·阿斯特朗。Soc。文献综述[j] .中国农业大学学报（自然科学版），2004(5)。Toma和F. Takahara, Mon，不。r·阿斯特朗。Soc。[j] .农业科学，442,2855(2014)]，并提出了解决问题的新思路。对于穿过大气层赤道面的磁力线，我们发现在坐标基上测量的负能量粒子流入在该平面附近产生，作为波印亭通量产生的反馈，这似乎是一个类似于机械彭罗斯过程的过程。对于穿过事件视界的场线，我们首先表明负电磁能量稳定流入的概念在物理上不是必需的，部分原因是电磁能量密度的符号取决于坐标。然后，我们在Boyer-Lindquist和Kerr-Schild坐标系下建立了连续注入的无力等离子体填充真空时依赖过程的解析玩具模型，并提出了稳定的向外坡印亭通量的结构是由等离子体与真空入口边界处的位移电流和交叉场电流因果关系构建的。在稳态下，坡印亭磁通在没有任何电磁源的情况下保持不变。
The Blandford–Znajek process, the steady electromagnetic energy extraction from a rotating black hole (BH), is widely believed to work for driving relativistic jets in active galactic nuclei, gamma-ray bursts, and Galactic microquasars, although it is still under debate how the Poynting flux is causally produced and how the rotational energy of the BH is reduced. We generically discuss the Kerr BH magnetosphere filled with a collisionless plasma screening the electric field along the magnetic field, extending the arguments of Komissarov [S. S. Komissarov, Mon. Not. R. Astron. Soc.,50, 427 (2004)] and our previous [K. Toma and F. Takahara, Mon. Not. R. Astron. Soc.,442, 2855 (2014)] paper, and propose a new picture for resolving the issues. For the magnetic field linesthreading the equatorial plane in the ergosphere, we find that the inflow of particles with negative energy as measured in the coordinate basis is generated near that plane as a feedback from the Poynting flux production, which appears to be a similar process to the mechanical Penrose process. For the field linesthreading the event horizon, we first show that the concept of the steady inflow of negative electromagnetic energy is not physically essential, partly because the sign of the electromagnetic energy density depends on the coordinates. Then we build an analytical toy model of a time-dependent process in both the Boyer–Lindquist and Kerr–Schild coordinate systems, in which the force-free plasma injected continuously fills a vacuum, and suggest that the structure of the steady outward Poynting flux is causally constructed by the displacement current and the cross-field current at the ingoing boundary between the plasma and the vacuum. In the steady state, the Poynting flux is maintained without any electromagnetic source.