EDP Sciences
Free access
Volume 431, Number 2, February IV 2005
Page(s) 687 - 692
Section The Sun
DOI http://dx.doi.org/10.1051/0004-6361:20041714

A&A 431, 687-692 (2005)
DOI: 10.1051/0004-6361:20041714

DOT tomography of the solar atmosphere

III. Observations and simulations of reversed granulation
J. Leenaarts1 and S. Wedemeyer-Böhm2

1  Sterrekundig Instituut, Utrecht University, Postbus 80 000, 3508 TA Utrecht, The Netherlands
    e-mail: j.leenaarts@astro.uu.nl
2  Kiepenheuer-Institut für Sonnenphysik, Schöneckstrasse 6, 79104 Freiburg, Germany
    e-mail: wedemeyer@kis.uni-freiburg.de

(Received 22 July 2004 / Accepted 5 October 2004 )

We compare high-quality image sequences from the Dutch Open Telescope (DOT) with synthetic image sequences obtained from 3D radiation-hydrodynamics simulations of the solar granulation. In particular, we study the subsonic brightness pattern observed in the wings of $\ion{Ca}{ii}$ H & K. The simulations reproduce the observed intensity contrast, time scales, and Fourier behaviour rather well. Most differences can be attributed to the resolution difference between the observations and the simulation and the small geometrical extent of the simulation. We conclude that magnetic fields play no major role in the formation of reversed granulation.

Key words: Sun: photosphere -- Sun: chromosphere -- Sun: magnetic fields

© ESO 2005