Research on Black Hole Magnetosphere

黑洞磁层研究

• 批准号: 04640268
• 负责人: TOMIMATSU Akira
• 金额: $ 0.77万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04640268/
• 关键词: Rotating Black Hole; Active Galaxies; Plasma Flows; MHD Waves; X-ray Radiation

Observational studies of active galactic nuclei suggest the existence of a massive black hole in the central region. In this research the astrophysical activities, such as jet formation and X-ray radiation, have been investigated in terms of a model of the black hole magnetosphere, by using the general ralativistic magnetohydrodynamic (MHD) equations. The approach is to consider the following three magnetospheric regions and to analyze plasma flows and magnetic field-line configurations.1. The inner ingoing-wind region with accretion onto black hole : For magnetically dominated winds near the black hole, the interaction between magnetic field and plasma particles transporting energy and angular momentum is found to work very effectively. Then it is shown that the generation of MHD waves highly disturbs the ingoing motion of plasma, and the collimated propagation towards therotation axis occurs as a trigger of jet-like outgoing winds.2. The outer outgoing-wind region extending to large distances : The magnetic self-collimating action of field lines is studied to estimate characteristicscales of the jet structure of relativistic outgoing winds and to give a boundary condition on the equatorial plane. The conclusion is that any observed jets should not have too high Lorentz factors.3. The particle creation region which is a boundary layr between ingoingand outgoing winds : The Joule dissipation in a thin shell with a large current density is proposed as a mechanism of steady supply of plasma particles into the magnetosphere. This idea is verified, by showing the production of ingoing and outgoing mass fluxes with a heat flux which is converted into X-ray radiation. Anunified treatment of the three different regions to relate the inner magnetospheric structure to the outer one through the particle creation mechanism remains in future works.

对活动星系核的观测研究表明，在中心区域存在一个巨大的黑洞。在这项研究中，天体物理活动，如射流的形成和x射线辐射，已经研究了黑洞磁层模型的条件下，使用广义相对论磁流体动力学（MHD）方程。方法是考虑以下三个磁层区域，并分析等离子体流和磁力线结构。吸积到黑洞的内部入风区：对于黑洞附近的磁主导风，发现磁场与传递能量和角动量的等离子体粒子之间的相互作用非常有效。结果表明，MHD波的产生极大地干扰了等离子体的入射运动，并导致了等离子体向自转轴的准直传播，从而引发了射流状的出射风。外出风区向远处延伸：研究了磁场线的磁自准直作用，估计了相对论性出风射流结构的特征尺度，并给出了赤道面上的边界条件。结论是，任何观测到的喷流都不应该有太高的洛伦兹因子。粒子产生区是入风和出风之间的边界层：提出了具有大电流密度的薄壳中的焦耳耗散作为等离子体粒子稳定供应到磁层的机制。这个想法被证实，通过显示生产的入口和出口的质量通量与热流转化为x射线辐射。对这三个不同区域进行统一处理，通过粒子产生机制将内磁层结构与外磁层结构联系起来，仍有待于今后的工作。

项目成果

A.Tomimatsu: "Asymptotic Collimation of Magnetized Winds far outside the Light Cylinder" Publ. Astron. Soc. Japan. Vol.46, No.2 (in press). (1994)

A.Tomimatsu：“远在光柱外的磁化风的渐近准直”Publ。

K.Hirotani: "Proc.4th Int.Toki Conf.on Plasma Physics and Controlled Nuclear Fusion" European Space Agency, 4 (1993)

K.Hirotani：“Proc.4th Int.Toki Conf.on 等离子体物理和受控核聚变”欧洲航天局，4 (1993)

K.Hirotani: "Proceedings of the 4th International Toki Conference on Plasma Physics and Controlled Nuclear Fusion" European Space Agency, 4 (1993)

K.Hirotani：“第四届国际 Toki 等离子体物理和受控核聚变会议记录”欧洲航天局，4 (1993)

K.Hirotani: "Accretion in a Kerr Black Hole Magnetosphere : Energy and Angular MomentumTransport between the Magnetic Field and the Matter" Astrophysical J.Vol.386, No.2. 455-463 (1992)

K.Hirotani：“克尔黑洞磁层中的吸积：磁场与物质之间的能量和角动量传输”《天体物理学杂志》第 386 卷，第 2 期。

A.Tomimatsu: "Asymptotic Collimation of Magnetized Winds far outside the Light Cylinder" Publ.Astron.Soc.Japan. 46(発表予定). (1994)

A.Tomimatsu：“光柱外磁化风的渐近准直”Publ.Astron.Soc.Japan 46（待出版）。