Journal of The Korean Astronomical Society (천문학회지)

The Korean Astronomical Society (한국천문학회)
권호 표지

CALIBRATION OF VECTOR MAGNETOGRAMS BY SOLAR FLARE TELESCOPE OF BOAO

  • MOON YONG-JAE (Bohyunsan Optical Astronomical Observatory, Korea Astronomy Observatory, Department of Astronomy, Seoul National University) ;
  • PARK YOUNG DEUK (Bohyunsan Optical Astronomical Observatory, Korea Astronomy Observatory) ;
  • YUN HONG SIK (Department of Astronomy, Seoul National University)
  • Published : 1999.04.01
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Abstract

In this study we present a new improved nonlinear calibration method for vector magnetograms made by the Solar Flare Telescope of BOAO. To identify Fe I 6302.5 line, we have scanned monochromatic images of the line integrated over filter passband, changing the location of the central transmission wavelength of a Lyot filter. Then we obtained a filter-convolved line profile, which is in good agreement with spectral atlas data provided by the Sacramento Peak Solar Observatory. The line profile has been used to derive calibration coefficients of longitudinal and transverse fields, employing the conventional line slope method under the weak field approximation. Our improved nonlinear calibration method has also been used to calculate theoretical Stokes polarization signals with various angles of inclination of magnetic fields. For its numerical test, we have compared input magnetic fields with the calibrated ones, which have been derived from the new improved non-linear method and the conventional method respectively. The numerical test shows that the calibrated fields obtained from the improved method are consistent with the input fields, but not with those from the conventional method. Finally, we applied our new improved method to a dipole model which characterizes a typical field configuration of a single, round sunspot. It is noted that the conventional method remarkably underestimates the transverse field component near the inner penumbra.

Keywords

References

  1. A High Resolution Altas of the Solar Irradiance from 380 to 700 Nanometers Beckers, J. M.;Bridges, C. A.;Gilliam, L. B.
  2. Ph. D. dissertation, Seoul National University Chae, J. C.
  3. Pub. Kor. Astron. Soc. v.10 Cho, K. S.;Kim, K. S.
  4. ApJ v.314 Gary, G. A.;Moore, R. L.;Hagyard, M. J.
  5. Sol. Phys. v.91 Hagyard, M. J.;Smith, Jr, J.B.;Teuber, D.;West, E. A.
  6. NASA Technical Memorandom 4048 The SAMEX Vector Magnetograph Hagyard, M. J.;Gary, G. A.;West, E. A.
  7. Sol. Phys. v.158 Hagyard, M. J.;Kineke
  8. Sol. Phys. v.39 Holweger, H.;Muller, E. A.
  9. ASP Series 46 The Magnetic and Velocity Fields of Solar Active Regions Ichimoto, K.;Sakurai, T.;Nishino, Y.;Shinoda, K.;Noguchi, M.;Kumagai, K.;Imai, H.;Irie, M.;Miyashita, M.;Tanaka, N.;Sano, I.;Suematsu, Y.;Hiei, E.;H. Zirin(ed.);G. Ai(ed.);H. Wang(ed.)
  10. Ichimoto, K.
  11. ApJ v.372 Jefferies, J. T.;Mickey, D. L.
  12. Pub. Kor. Astron. Soc. v.12 Kim, K. S.
  13. Solar Observations: Techniques and interpretation Landi Degl'Innocenti, E. L.;Sanchez, F.(ed.);Collados, M.(ed.);Vazquez, M.(ed.)
  14. ApJ v.373 Lites, B. W.;Thomas, A. B.;Johannesson, A.;Sharmer, G. B.
  15. ApJ v.418 Lites, B. W.;Elmore, D. F.;Seagraves, P.;Skumanich, A.
  16. Sol. Phys. v.155 Lites, B. W;Martinez, Pillet, V;Skumanich, A
  17. Pub. Kor. Astron. Soc. v.11 Moon, Y.-J.;Park, Y.D.;Jang, B.H.;Sim, K. J.;Yun, H. S.;Kim, J. H.
  18. Pub. Kor. Astron. Soc. v.12 Moon, Y. J.;Yoon, S.-Y.;Park, Y.D.;Jang, B.H.
  19. ApJ v.494 Moon, Y. J.;Yun, H. S.;Park, J.-S.
  20. Pub. Kor. Astron. Soc. v.12 Park, Y.D.;Moon, Y.-J.;Jang, B.-H.;Sim, K. J.
  21. PASJ v.47 Sakurai, T.;Ichimoto, K.;Nishino, Y.;Shinoda, K.;Noguchi, M.;Hiei, E.;Li, T.;He, F.;Mao, W.;Lu, H.;Ai, G.;Zhao, Z.;Kawakami, S.;Chae, J.
  22. Sol. Phys. v.161 Varsik, J. R.
  23. Sunspots : Theory and Observations Skumanich, A.;J. H. Thomas(ed.);N. O. Weiss(ed.)
  24. Sol. Phys. v.159 Zirin, H.