The Current Status of the MISMA Hypothesis

  • J. Sánchez Almeida
Part of the Astrophysics and Space Science Library book series (ASSL, volume 243)


This work gathers new evidences which support the MISMA hypothesis, i.e., this conjecture on the highly irregular nature of most photospheric magnetic fields. It is discussed how the magnetic flux conservation in sunspots demands penumbrae pervaded by kilometer-wide irregularities. The diagnosis of this type of tiny scales requires special tools. One of such tools is briefly described here, namely, an inversion code which allows for optically thin irregularities when fitting the Zeeman induced polarization (i.e., when fitting the so-called Stokes profiles) . This technique has been systematically applied to observed quiet Sun magnetic elements. As a first result, all observed Stokes profiles can be reproduced with a single physical scenario. The scenario includes two magnetic components embedded in a non-magnetic medium, and it is actually the same needed to account for the asymmetries of the Stokes profiles in plage regions. Mixed polarities in the resolution element are frequently required for a proper inversion. All in all, MISMAs seem to provide a fairly consistent picture of the quiet Sun magnetic fields.

Key words

Line: profiles Polarization Methods: data analysis Sun: magnetic fields Sun: photosphere 


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Copyright information

© Springer Science+Business Media Dordrecht 1999

Authors and Affiliations

  • J. Sánchez Almeida
    • 1
  1. 1.Instituto de Astrofísica de CanariasLa Laguna, TenerifeSpain

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