Photospheric modeling through spectral line inversion.
Temperature and radial velocity stratifications and fluctuations
J. Koza(1,2),
A. Kucera(2),
J. Rybak(2),
H. Wohl(3)
1 - Sterrekundig Instituut, Universiteit Utrecht, P.O.Box 80000, NL-3508
TA Utrecht, The Netherlands
2 - Astronomical Institute, Slovak Academy of Sciences, SK-05960 Tatranská
Lomnica, Slovakia
3 - Kiepenheuer-Institut fur Sonnenphysik, Schoneckstr. 6, 79104 Freiburg,
Germany
Aims. We aim to determine average radial stratifications of various
physical parameters throughout the solar photosphere at high angular
resolution for non-magnetic and magnetic areas and to compare these with
standard semiempirical 1D modeling and with 3D hydrodynamics (HD) and
magnetohydrodynamics (MHD) simulations.
Methods. We analyse a 15-min sequence of adaptive-optics spectrograms
of very high angular resolution taken at solar disk centre. We split the
data between a quiet area and a magnetic one and derive mean temperature
and velocity stratifications and fluctuations for these separately by
applying LTE inversion based on response functions.
Results. The mean temperature stratifications in the non-magnetic
region agree well with the classical 1D models and the 3D simulations at
all heights. However, the observed rms temperature is much lower than in
the simulations, the observed mean velocities indicate more upflows, and
the observed velocity fluctuations are smaller except in upper layers.
Some of the discrepancies are likely to result from remaining smearing
by atmospheric seeing and instrumental limitations. The magnetic area
shows conspicuous behaviour at large height. We also find evidence of
fast low-photosphere downflows in the magnetic area and of enhanced
temperature above a small pore.
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