Numerical modeling of solar faculae close to the limb
Abstract
A numerical simulation was performed to interpret high-resolution spectropolarimetric observations of polar faculae on the Sun. A semi-empirical three-dimensional model of facula structures, controlled by several free parameters, was constructed. It consists of two components, the atmosphere within small-scale magnetic flux tubes and the exterior atmosphere. Multi-ray 1.5D radiative transfer calculations were performed along oblique rays passing through a highly inhomogeneous atmosphere of the simulation box. By the comparison of the properties of the calculated Stokes profiles from the synthetic faculae with the observed properties, a set of free parameters of the model (such as: size, number density of flux tubes, internal temperature stratification and magnetic field strength) was deduced, which satisfies the observational constraints. The hypothesis about solar faculae as a conglomerate of small-scale magnetic flux tubes is verified. The model reproduces all observed properties: the continuum contrast and its center-to-limb variation, the Stokes I and V profiles of Fe I and Fe II lines, the apparent magnetic field strengths, and the displacement towards the limb of the continuum intensity against the line-of-sight magnetograms.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- August 2005
- DOI:
- 10.1051/0004-6361:20052879
- Bibcode:
- 2005A&A...439..323O
- Keywords:
-
- Sun: faculae;
- plages;
- Sun: magnetic fields;
- methods: numerical;
- radiative transfer