천문학회지 (Journal of The Korean Astronomical Society)

  • 제52권4호
  • /
  • Pages.89-97
  • /
  • 2019
  • /
  • 1225-4614(pISSN)
  • /
  • 2288-890X(eISSN)
한국천문학회 (The Korean Astronomical Society)
권호 표지
DOI QR코드

DOI QR Code

MERGING AND FRAGMENTATION IN THE SOLAR ACTIVE REGION 10930 CAUSED BY AN EMERGING MAGNETIC FLUX TUBE WITH ASYMMETRIC FIELD-LINE TWIST DISTRIBUTION ALONG ITS AXIS

  • Magara, Tetsuya (Department of Astronomy and Space Science, Kyung Hee University)
  • 투고 : 2019.02.28
  • 심사 : 2019.06.10
  • 발행 : 2019.08.31
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

We demonstrate the subsurface origin of the observed evolution of the solar active region 10930 (AR10930) associated with merging and breakup of magnetic polarity regions at the solar surface. We performed a magnetohydrodynamic simulation of an emerging magnetic flux tube whose field-line twist is asymmetrically distributed along its axis, which is a key to merging and fragmentation in this active region. While emerging into the surface, the flux tube is subjected to partial splitting of its weakly twisted portion, forming separate polarity regions at the solar surface. As emergence proceeds, these separate polarity regions start to merge and then break up, while in the corona sigmoidal structures form and a solar eruption occurs. We discuss what physical processes could be involved in the characteristic evolution of an active region magnetic field that leads to the formation of a sunspot surrounded by satellite polarity regions.

키워드

참고문헌

  1. Abbett, W. P., Fisher, G. H., & Fan, Y. 2000, The Three-Dimensional Evolution of Rising, Twisted Magnetic Flux Tubes in a Gravitationally Stratified Model Convection Zone, ApJ, 540, 548 https://doi.org/10.1086/309316
  2. Abramenko, V., Yurchyshyn, V., & Wang, H. 2008, Intermittency in the Photosphere and Corona above an Active Region, ApJ, 681, 1669 https://doi.org/10.1086/588426
  3. An, J. M., & Magara, T. 2013, Stability and Dynamics of a Flux Rope Formed via Flux Emergence into the Solar Atmosphere, ApJ, 773, 21 https://doi.org/10.1088/0004-637X/773/1/21
  4. Aschwanden, M. J. 2005, Physics of the Solar Corona. An Introduction with Problems and Solutions, 2nd edn. (Chichester: Praxis Publishing Ltd.)
  5. Bharti, L., Joshi, C., & Jaaffrey, S. N. A. 2007, Observations of Dark Lanes in Umbral Fine Structure from the Hinode Solar Optical Telescope: Evidence for Magneto-convection, ApJ, 669, L57 https://doi.org/10.1086/523352
  6. Biskamp, D., & Welter, H. 1980, Coalescence of Magnetic Islands, Phys. Rev. Lett., 44, 1069 https://doi.org/10.1103/PhysRevLett.44.1069
  7. Clyne, J., & Rast, M. 2005, A Prototype Discovery Environment for Analyzing and Visualizing Terascale Turbulent Fluid Flow Simulations, Proc. SPIE, 5669, 284
  8. Clyne, J., Mininni, P., Norton, A., & Rast, M. 2007, Interactive Desktop Analysis of High Resolution Simulations: Application to Turbulent Plume Dynamics and Current Sheet Formation, New J. Phys., 9, 301 https://doi.org/10.1088/1367-2630/9/8/301
  9. Dorch, S. B. F., & Nordlund, A. 1998, Numerical 3D Simulations of Buoyant Magnetic Flux Tube, A&A, 338, 329
  10. Emonet, T., & Moreno-Insertis, F. 1998, The Physics of Twisted Magnetic Tubes Rising in a Stratified Medium: Two-Dimensional Results, ApJ, 492, 804 https://doi.org/10.1086/305074
  11. Fan, Y. 2009, Magnetic Fields in the Solar Convection Zone, Living Rev. Sol. Phys., 6, 4
  12. Fan, Y. 2016, Modeling the Initiation of the 2006 December 13 Coronal Mass Ejection in AR 10930: The Structure and Dynamics of the Erupting Flux Rope, ApJ, 824, 93 https://doi.org/10.3847/0004-637X/824/2/93
  13. Finn, J. M., & Kaw, P. K. 1977, Coalescence Instability of Magnetic Islands, Phys. Fluids, 20, 72 https://doi.org/10.1063/1.861709
  14. Gold, T., & Hoyle, F. 1960, On the Origin of Solar Flares, MNRAS, 120, 89 https://doi.org/10.1093/mnras/120.2.89
  15. Golub, L., Deluca, E., Austin, G., et al. 2007, The X-Ray Telescope (XRT) for the Hinode Mission, Sol. Phys., 243, 63 https://doi.org/10.1007/s11207-007-0182-1
  16. Guo, Y., Ding, M. D., Wiegelmann, T., & Li, H. 2008, 3D Magnetic Field Configuration of the 2006 December 13 Flare Extrapolated with the Optimization Method, ApJ, 679, 1629 https://doi.org/10.1086/587684
  17. Harra, L. K., Williams, D. R., Wallace, A. J., Magara, T., Hara, H., Tsuneta, S., Sterling, A. C., & Doschek, G. A. 2009, Coronal Nonthermal Velocity Following Helicity Injection Before an X-Class Flare, ApJ, 691, L99 https://doi.org/10.1088/0004-637X/691/2/L99
  18. Hayashi, T. 1981, Numerical Simulations of Forced Coalescence of Magnetic Islands Generated by a Tearing Mode Instability, J. Phys. Soc. Japan, 50, 3124 https://doi.org/10.1143/JPSJ.50.3124
  19. Inoue, S., Magara, T., Watari, S., & Choe, G. S. 2012, Nonlinear Force-Free Modeling of a Three-Dimensional Sigmoid Observed on the Sun, ApJ, 747, 65 https://doi.org/10.1088/0004-637X/747/1/65
  20. Isobe, H., et al. 2007, Flare Ribbons Observed with G-Band and FeI 6302? Filters of the Solar Optical Telescope on Board Hinode, PASJ, 59, 807 https://doi.org/10.1093/pasj/59.sp3.S807
  21. Knizhnik, K. J., Linton, M. G., & DeVore, C. R. 2018, The Role of Twist in Kinked Flux Rope Emergence and Delta-Spot Formation, ApJ, 864, 89 https://doi.org/10.3847/1538-4357/aad68c
  22. Kosugi, T., et al. 2007, The Hinode (Solar-B) Mission: An Overview, Sol. Phys., 243, 3 https://doi.org/10.1007/s11207-007-9014-6
  23. Kubo, M., et al. 2007, Hinode Observations of a Vector Magnetic Field Change Associated with a Flare on 2006 December 13, PASJ, 59, 607 https://doi.org/10.1093/pasj/59.3.607
  24. Liu, Y., et al. 2008, A Comprehensive View of the 2006 December 13 CME: From the Sun to Interplanetary Space, ApJ, 689, 563 https://doi.org/10.1086/592031
  25. Longcope, D. W., Fisher, G. H., & Arendt, S. 1996, The Evolution and Fragmentation of Rising Magnetic Flux Tube, ApJ, 464, 999 https://doi.org/10.1086/177387
  26. Low, B. C. 1996, Solar Activity and the Corona, Sol. Phys., 167, 217 https://doi.org/10.1007/BF00146338
  27. Magara, T. 2001, Dynamics of Emerging Flux Tubes in the Sun, ApJ, 549, 608 https://doi.org/10.1086/319073
  28. Magara, T., & Tsuneta, S. 2008, Hinode's Observational Result on the Saturation of Magnetic Helicity Injected into the Solar Atmosphere and Its Relation to the Occurrence of a Solar Flare, PASJ, 60, 1181 https://doi.org/10.1093/pasj/60.5.1181
  29. Magara, T. 2008, Emergence of a Partially Split Flux Tube into the Solar Atmosphere, PASJ, 60, 809 https://doi.org/10.1093/pasj/60.4.809
  30. Magara, T. 2009, Characteristic Development of Magnetic Shear in a Flare-Producing Sunspot Obtained from Vector Magnetic Field Measurements by Hinode, ApJ, 702, 386 https://doi.org/10.1088/0004-637X/702/1/386
  31. Magara, T. 2015, MHD Simulation for Investigating the Evolutionary Path of a Solar Magnetic Field That Emerges, Structures Itself, Erupts, and Produces a Flare, PASJ, 67, L6 https://doi.org/10.1093/pasj/psv091
  32. Magara, T. 2017, Structural Properties of the Solar Flare-Producing Coronal Current System Developed in an Emerging Magnetic Flux Tube, PASJ, 69, 5 https://doi.org/10.1093/pasj/psw109
  33. Moon, Y.-J., et al. 2007, Hinode SP Vector Magnetogram of AR10930 and Its Cross-Comparison with MDI, PASJ, 59, 62
  34. Parker, E. N. 1955, The Formation of Sunspots from the Solar Toroidal Field, ApJ, 121, 491 https://doi.org/10.1086/146010
  35. Priest, E. R., & Forbes, T. G. 2002, The Magnetic Nature of Solar Flares, A&AR, 10, 313 https://doi.org/10.1007/s001590100013
  36. Pritchett, P. L., & Wu, C. C. 1979, Coalescence of Magnetic Islands, Phys. Fluids, 22, 2140 https://doi.org/10.1063/1.862507
  37. Schussler, M. 1979, Non-Linear Dynamo Theory - Finite Amplitude Magnetic Fields with Large Scale Circulation in a Compressible Stratified Medium, A&A, 71, 79
  38. Shibata, K., & Magara, T. 2011, Solar Flares: Magnetohy-drodynamic Processes, Living Rev. Sol. Phys., 8, 6 https://doi.org/10.12942/lrr-2011-6
  39. Schrijver, C. J., et al. 2008, Nonlinear Force-Free Field Modeling of a Solar Active Region around the Time of a Major Flare and Coronal Mass Ejection, ApJ, 675, 1637 https://doi.org/10.1086/527413
  40. Spruit, H. C. 1981, Motion of Magnetic Flux Tubes in the Solar Convection Zone and Chromosphere, A&A, 98, 155
  41. Stix, M. 1991, The Sun. An Introduction (Berlin: Springer-Verlag), 192
  42. Su, Y., et al. 2007, Evolution of the Sheared Magnetic Fields of Two X-Class Flares Observed by Hinode/XRT, PASJ, 59, 785 https://doi.org/10.1093/pasj/59.sp3.S785
  43. Tan, C., Chen, P. F., Abramenko, V., & Wang, H. 2009, Evolution of Optical Penumbral and Shear Flows Associated with the X3.4 Flare of 2006 December 13, ApJ, 690, 1820 https://doi.org/10.1088/0004-637X/690/2/1820
  44. Tsuneta, S., et al. 2008, The Solar Optical Telescope for the Hinode Mission: An Overview, Sol. Phys., 249, 167 https://doi.org/10.1007/s11207-008-9174-z
  45. Wang, H., Jing, J., Tan, C., Wiegelmann, T., & Kubo, M. 2008, Study of Magnetic Channel Structure in Active Region 10930, ApJ, 687, 658 https://doi.org/10.1086/592082
  46. Wang, S. J., Yan, Y. H., Liu, Y. Y., Fu, Q. J., Tan, B. L., & Zhang, Y. 2008, Solar Radio Spikes in 2.6 - 3.8 GHz during the 13 December 2006 Event, Sol. Phys., 253, 133 https://doi.org/10.1007/s11207-008-9278-5
  47. Williams, D. R., Harra, L. K., Brooks, D. H., Imada, S., & Hansteen, V. H. 2009, Evidence from the Extreme-Ultraviolet Imaging Spectrometer for Axial Filament Rotation before a Large Flare, PASJ, 61, 493 https://doi.org/10.1093/pasj/61.3.493
  48. Yan, Y., Huang, J., Chen, B., & Sakurai, T. 2007, Diagnostics of Radio Fine Structures around 3 GHz with Hinode Data in the Impulsive Phase of an X3.4/4B Flare Event on 2006 December 13, PASJ, 59, 815 https://doi.org/10.1093/pasj/59.sp3.S815
  49. Zhang, J., Li, L., & Song, Q. 2007, Interaction between a Fast Rotating Sunspot and Ephemeral Regions as the Origin of the Major Solar Event on 2006 December 13, ApJ, 662, L35 https://doi.org/10.1086/519280
  50. Zwaan, C. 1985, The Emergence of Magnetic Flux, Sol. Phys., 100, 397 https://doi.org/10.1007/BF00158438