A Numerical Simulation of Twodimensional Radiative Equilibrium in Magnetostatic Flux Tubes. I. The Model
Abstract
We describe an efficient numerical procedure for obtaining selfconsistent radiative and mechanical equilibria of solar magnetostatic flux tubes. The flux tube is treated as a localized but continuous concentration of magnetic flux in a twodimensional slab geometry. Starting from some given initial atmosphere, we compute a preliminary magnetostatic equilibrium state by a nonlinear iterative technique, subject to certain boundary conditions on the magnetic field. Given the resulting spatial distribution of opacities (derived from the initial run of temperature and density along each field line), and with knowledge of a distant radiation field incident upon the magnetic region, the radiative state of the atmosphere is computed by the shortcharacteristics method assuming gray, LTE conditions. The new temperature derived from the angleaveraged radiation field is used to update the hydrostatic atmosphere for the magnetostatic calculation, and so on, until both mechanical and radiative balance is attained.
 Publication:

The Astrophysical Journal
 Pub Date:
 February 1993
 DOI:
 10.1086/172333
 Bibcode:
 1993ApJ...404..788P
 Keywords:

 Magnetohydrostatics;
 Solar Atmosphere;
 Solar Magnetic Field;
 Stellar Models;
 Radiative Transfer;
 Sunspots;
 Solar Physics;
 MAGNETOHYDRODYNAMICS: MHD;
 RADIATIVE TRANSFER;
 SUN: ATMOSPHERE;
 SUN: SUNSPOTS