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A&A 442, 1059-1078 (2005)
DOI: 10.1051/0004-6361:20052958
Stokes diagnostics of simulations of magnetoconvection of mixed-polarity quiet-Sun regions
E. V. Khomenko1, 2, S. Shelyag3, S. K. Solanki3 and A. Vögler31 Instituto de Astrofísica de Canarias, 38205, C/ Vía Láctea s/n, Tenerife, Spain
2 Main Astronomical Observatory, NAS, 03680 Kyiv, Zabolotnogo str. 27, Ukraine
e-mail: khomenko@iac.es
3 Max-Planck-Institut für Sonnensystemforschung, 37191 Katlenburg-Lindau, Germany,
e-mail: shelyag@mps.mpg.de,solanki@mps.mpg.de,avoegler@mps.mpg.de
(Received 1 March 2005 / Accepted 11 May 2005 )
Abstract
Realistic solar magneto-convection simulations including
the photospheric layers are used to study the polarization of the
Fe I Zeeman-sensitive spectral lines at 6301.5, 6302.5, 15 648 and
15 652 Å.
The Stokes spectra are synthesized in a series of snapshots with a
mixed-polarity magnetic field whose average unsigned strength
varies from
to 140 G.
The effects of spatial resolution and of the amount of magnetic
flux in the simulation box on the profiles shapes, amplitudes and
shifts are discussed.
The synthetic spectra show many properties in common with those
observed in quiet solar regions.
In particular, the simulations reproduce the width and depth of
spatially averaged Stokes I profiles, the basic classes of the
Stokes V profiles and their amplitude and area asymmetries, as
well as the abundance of the irregular-shaped Stokes V profiles.
It is demonstrated that the amplitudes of the 1.56 
m lines
observed in the inter-network are consistent with a "true"
average unsigned magnetic field strength of 20 G.
We show that observations using these and visible lines, carried
out under different seeing conditions (e.g., simultaneous
observations at different telescopes), may result in different
asymmetries and even opposite polarities of the profiles in the
two spectral regions observed at the same spatial point.
Key words: magnetohydrodynamics (MHD) -- Sun: magnetic fields -- Sun: infrared -- polarization -- Sun: photosphere
© ESO 2005