Oscillations in Sunspots observed in the Near Infrared

被引：0
作者：
H. Balthasar
机构：
[1] Astrophysikalisches Institut Potsdam,
[2] Telegrafenberg,undefined
来源：
Solar Physics | 2003年 / 218卷
关键词：
Azimuth; Angle Inclination; Magnetic Field Strength; Periodic Variation; Fast Mode;
D O I：
暂无
中图分类号：
学科分类号：
摘要：
Spectropolarimetric time series of two sunspots are investigated to search for magnetic field oscillations. While the existence of velocity oscillations in the five-minute band is clearly confirmed, periodic variations of the magnetic field strength or the magnetic angles inclination and azimuth are small and restricted to very narrow areas. They occur in single frequency bins, but different for magnetic field strength and angles. Small dark structures embedded in one penumbra or in the near surroundings of the other spot exhibit enhanced power for the magnetic variations at all frequencies. Phase differences are rather unsure. The obtained values are in agreement with intrinsic magnetic field variations produced by slow magnetoacoustic modes as well as with an opacity mechanism connected with fast modes.
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页码：85 / 97
页数：12
相关论文
共 58 条
  • [11] Rodríguez Hidalgo I.(1998)undefined Astrophys. J. 497 464-undefined
  • [12] Groth E. J.(2003)undefined Astron. Astrophys. 403 297-undefined
  • [13] Horn T.(2003)undefined Astron. Astrophys. 401 685-undefined
  • [14] Staude J.(2001)undefined Astrophys. J. 561 435-undefined
  • [15] Landgraf V.(1998)undefined Astron. Astrophys. 335 L97-undefined
  • [16] Horne J. H.(1992)undefined Astrophys. J. 398 375-undefined
  • [17] Baliunas S. L.(2002)undefined Astron. Astrophys. 392 1095-undefined
  • [18] Khomenko E. V.(2002)undefined Astron. Astrophys. 386 1123-undefined
  • [19] Collados M.(1982)undefined Proc. IEEE 70 1055-undefined
  • [20] Bellot Rubio L.R.(1996)undefined Astrophys. J. 465 436-undefined
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