EDP Sciences
Free Access
Volume 421, Number 2, July II 2004
Page(s) 755 - 762
Section The Sun
DOI https://doi.org/10.1051/0004-6361:20047044

A&A 421, 755-762 (2004)
DOI: 10.1051/0004-6361:20047044

Effects of non-grey radiative transfer on 3D simulations of solar magneto-convection

A. Vögler

Max-Planck-Institut für Sonnensystemforschung (Formerly: Max-Planck-Institut für Aeronomie.) , Max-Planck-Strasse 2, 37191 Katlenburg-Lindau, Germany

(Received 9 January 2004 / Accepted 24 March 2004)

We compare 3D simulations of photospheric magneto-convection which include a multigroup modelling of the non-grey radiative transfer with simulations based on a grey radiative transfer using the Rosseland mean opacity. While the simulation properties in the solar surface layers around $\tau_{\rm Ross}=1$ are very similar both cases, pronounced differences occur both in the temperature structure of magnetic field concentrations in the upper photosphere and in the appearance of strong magnetic fields in brightness maps. The results show that a non-grey treatment of the radiative transfer is mandatory if magneto-convective simulations are to be compared with observational results by calculating synthetic spectra of temperature-sensitive lines originating in the middle and upper photosphere.

Key words: magnetohydrodynamics (MHD) -- Sun: magnetic fields -- Sun: photosphere

© ESO 2004