| 灾变理论在太阳物理和天体物理其他研究领域中的应用 |
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| 引用本文： | 林隽,王修鹏,蒙盈.灾变理论在太阳物理和天体物理其他研究领域中的应用[J].天文学进展,2010,28(1). |
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| 作者姓名： | 林隽 王修鹏 蒙盈 |
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| 作者单位： | 1. 中国科学院,国家天文台/云南天文台,昆明,650011;Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
2. 中国科学院,国家天文台/云南天文台,昆明,650011;中国科学院,研究生院,北京,100039 |
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| 基金项目： | 国家自然科学基金资助项目，国家科技部973计划支持项目，中国科学院方向性创新项目，NASA项目 |
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| 摘 要： | 叙述和介绍了太阳爆发的磁通量绳灾变理论和模型的发展过程,强调了建立这样的模型所需要的观测基础。讨论了由模型所预言的爆发磁结构的几个重要特征以及观测结果对这种预言的证实。在此模型的基础上,讨论了一个典型的爆发过程中所出现的不同现象及它们之间的相互关系。最后,介绍了作者的一项最新尝试:将太阳爆发的灾变理论和模型应用到对黑洞吸积盘间歇性喷流的理论研究当中,以及研究所取得的初步结果。
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| 关 键 词： | 耀斑 爆发日珥 磁重联 电流片 MHD理论和模型 等离子体不稳定性 黑洞吸积盘喷流 |
The Catastrophe Theory and Applications to the Solar Eruption and Other Research Areas of Astrophysics |
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| LIN Jun,WANG Xiu-peng,MENG Ying.The Catastrophe Theory and Applications to the Solar Eruption and Other Research Areas of Astrophysics[J].Progress In Astronomy,2010,28(1). |
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| Authors: | LIN Jun WANG Xiu-peng MENG Ying |
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| Abstract: | This work introduced and discussed the development of the catastrophe theory and model of solar eruptions and the related works. Solar flares, eruptive prominences, and coronal mass ejections (CMEs) are three different manifestations resulted from a single energy release process during the solar eruption. Any theory that attempts to explain the solar eruption needs to account for the energy driving the eruption, production of solar flare, eruption of prominence, and propagation of CME including large amounts of mass and magnetic flux in the outermost corona and interplanetary space. The fundamental base of observations for establishing such a theory and the associated model was addressed in the present work.It is well accepted that the energy driving solar eruptions is stored in the coronal magnetic field beforehand. Unceasing mass motions in the photosphere continue to displace the footpoints of the coronal magnetic field rooted in the dense photospheric plasma, building stress and thus the energy in the corona until the stored energy reaches a threshold. In this stage, the system evolves through a series of equilibrium configurations in the quasi-steady state, and the motion of the photosphere could be either shearing, or converging, or twisting, or emerging of new flux from the photosphere, or interacting of one magnetic configuration with others nearby, or combining of all these processes.The evolution after the stored energy exceeds the threshold turns from quasi-steady to dy-namic, and the stored energy is released in a violent fashion as a result of the loss of equilibrium in the system. The transition of the evolution from gradual to violent constitutes the catastrophe according to the standard theory of the catastrophe.The loss of equilibrium stretches the closed magnetic field so severely that the field is effectively opened and produces a current sheet that separates the fields of opposite polarity. Magnetic re-connection invoked by various plasma instabilities inside the current sheet diffuses magnetic field and converts the magnetic energy into heat and kinetic energy of the plasma, and the fast-particle kinetic energy, and allows the catastrophe to develop smoothly to a plausible eruption. Part of the released energy accounts for solar flares that basically show as bright growing flare loops in the corona and bright separating flare ribbon on the solar disk, and another part is responsible for various mass flows, including propagations of CMEs and fast particles. Therefore, solar flares are intrinsically related to CMEs, and the more energetic the eruption is, the more apparent the relationship is, although the fashion of the energy partition is still an open question.Investigations of the loss of equilibrium and the catastrophe, as well as the consequent evo-lution in a magnetic structure indicate that magnetic reconnection is not a necessity for the triggering of the eruption; the loss of equilibrium itself could be a pure mechanical process with-out being involved in any dissipation of magnetic field. To allow the catastrophe to smoothly develop to a plausible eruption, on the other hand, magnetic reconnection is required to diffuse the magnetic field at a reasonably fast rate, otherwise the catastrophe is prevented from further developing and the evolution in the system will eventually be stopped. Fast reconnection dissi-pates the magnetic field quickly and sends the reconnected plasma and magnetic flux downwards to the Sun and upwards to the outermost corona and interplanetary space, which are responsi-ble for the growing flare loop system and the CME bubble that is observed to expand rapidly, respectively.Considering the fact that most of the universe is in the form of plasma threaded by a magnetic field, we realize that the process of energy transportation and conversion happening in the solar atmosphere may also occur in other places of similar environment, for instance, in the black hole and accretion disk system. In a thick disk, plasma motions due to the differential rotation and instabilities result in deformation of the magnetic field as taking place in the solar atmosphere, and the energy accumulation in the corona. The catastrophe occurring in the coronal magnetic field is very likely to account for the episodic jets that are usually observed in the black hole and accretion disk system. |
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| Keywords: | CME flares eruptive prominences CMEs magnetic reconnection MHD theories andmodels plasma instabilities Black hole accretion disk jets |
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