Fe I 1565nm Instrumental Polarization paper



Most recent draft is here.
Jaeggli, Penn
Penn, Jaeggli, Henney, Walton, Ceja

Things to do:


(1) Next draft: matrix element time variations
(2) Velocity plot of Evershed flows using CN line.
(3) Check for linear polarization in CN line
(4) Maps of Stokes V in CN, OH - OH is done
(5) Line strength of CO lines vs CN line? - done: CO strong where CN weak
(6) Sample magnetic line fits - Carl found way to constrain damping term.
(7) Time sequence of magnetic parameters: penumbral inclination vs MMF Here is movie of inclination

Things done:


(1) Matrix elements are understood: sign errors from other references have been removed. Best fit gives low n, high k values (n=1, k=13).
Conclusions:
  • (a) most elements show small difference from model predictions, probably due to simplicity of model (i.e. just one value of n,k for all mirrors) and

  • (b) large Q => V term is likely from errors in the polarimeter calibration.



  • (c) Corrected spectra look good


    • (2) Fit line profiles using Milne-Eddington (Carl Henney) Latest results show problems with the Doppler line width in the fits, the magnetic field strength is too high, and some problems with normalization.

    (3) Map OH polarization vectors and compare with Fe
    (4) Map CN Evershed velocity
  • Maps show CN drops away in center of umbra


  • Line strength vs Temp


  • Line shift vs Temp


  • Is there an unknown photospheric line near CN? Looks like it




    • Context map


    Continuum map


    Vector map

    Instrumental Polarization References

  • Stenflo, Solar Magnetic Fields, 13.3.6, p320

  • Collados, SPIE, 2003, v4843, p55 "Stokes polarimeters in the near infrared"

  • Capitani et al, Solar Physics, 1989, v120, p173 "Polarization Properties of a Zeiss-type Coelostat: The Case of the Solar Tower in Arcetri"

  • Makita, Funakoshi and Hanaoka, Sac Peak Workshop 11, 1991, ed. November p.198 "Polarization of the Domeless Solar Telescope of the Hida Observatory"

  • November, Sac Peak Workshop 11, 1991, ed. November p.149 "Using the Zeeman Spectral-Polarization Symmetry for Telescope Calibration"

  • Foukal, Solar Astrophysics, Chap 2

  • Unno PASJ, 1956, v8 p108 "Line Formation of a Normal Zeeman Triplet"

  • Berdyugina and Solanki, AA, 2002, v385, p701 "The molecular Zeeman effect and diagnostics of solar and stellar magnetic fields I. Theorectical spectral patterns in the Zeeman regime"

    • Summer 2003 Reading

  • Foukal, Solar Astrophysics, Chap 3

  • Kitchin, Astrophysical Techniques, Chap 5.3-5.4

  • McPherson, Lin, Kuhn, Solar Physics 1992, v139, p255 "Infrared Array Measurements of Sunspot Magnetic Fields"

  • Kuhn et al Solar Physics 1994, v153, p143 "Removing instrumental polarization from Infrared solar Polarimetric Observations"

  • Bernasconi, ETHZ Thesis 1997, Chap 4