Some Notes on Self-similar Axisymmetric Force-free Magnetic Fields and Rotating Magnetospheres

作者: Ian Lerche

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摘要: An axisymmetric force-free magnetic field in spherical coordinates has a relationship between its azimuthal component to poloidal flux-function. A power law dependence for the connection admits separable solutions but poses nonlinear eigenvalue boundary-value problem separation parameter (Low and Lou, Astrophys. J. 352, 343 (1990)).When atmosphere of star is rotating complexity increases. These Notes consider spectrum, providing an understanding eigen functions field's degree multi-polarity, rotation rate radial decay as illustrated through polytropic equation state. The are restricted uniform fields. Dominant effects presented changing spatial patterns from those without rotation. For differential nonaxisymmetric fields there may be even richer topological structure governing equations have remained intractable date. Perhaps methods discussion given here uniformly situation indicate possible procedure such problems that need solved urgently more complete stellar atmospheres.

参考文章(22)
Lile Wang, Yu-Qing Lou, Steady-state axisymmetric nonlinear magnetohydrodynamic solutions with various boundary conditions Monthly Notices of the Royal Astronomical Society. ,vol. 439, pp. 2323- 2341 ,(2014) , 10.1093/MNRAS/STU050
Shangbin Yang, Jörg Büchner, Jean Carlo Santos, Hongqi Zhang, Evolution of Relative Magnetic Helicity: Method of Computation and Its Application to a Simulated Solar Corona above an Active Region Solar Physics. ,vol. 283, pp. 369- 382 ,(2013) , 10.1007/S11207-013-0236-5
T. Wiegelmann, Nonlinear force-free modeling of the solar coronal magnetic field Journal of Geophysical Research: Space Physics. ,vol. 113, pp. n/a- n/a ,(2008) , 10.1029/2007JA012432
G. Valori, P. Démoulin, E. Pariat, S. Masson, Accuracy of magnetic energy computations Astronomy and Astrophysics. ,vol. 553, ,(2013) , 10.1051/0004-6361/201220982
A Mangalam, B Ravindra, Avijeet Prasad, Separable Solutions of Force-Free Spheres and Applications to Solar Active Regions The Astrophysical Journal. ,vol. 786, pp. 81- ,(2014) , 10.1088/0004-637X/786/2/81
T. Tadesse, T. Wiegelmann, S. Gosain, P. MacNeice, A. A. Pevtsov, First use of synoptic vector magnetograms for global nonlinear, force-free coronal magnetic field models Astronomy and Astrophysics. ,vol. 562, ,(2014) , 10.1051/0004-6361/201322418
B. C. Low, N. Flyer, The Topological Nature of Boundary Value Problems for Force-Free Magnetic Fields The Astrophysical Journal. ,vol. 668, pp. 557- 570 ,(2007) , 10.1086/520503
J. J. Aly, T. Amari, Structure and evolution of the solar coronal magnetic field Geophysical & Astrophysical Fluid Dynamics. ,vol. 101, pp. 249- 287 ,(2007) , 10.1080/03091920701495320
I. Lerche, B. C. Low, A nonlinear eigenvalue problem for self-similar spherical force-free magnetic fields Physics of Plasmas. ,vol. 21, pp. 102902- ,(2014) , 10.1063/1.4897366