Resonance line polarization and the Hanle effect in optically thick media. II - Case of a plane-parallel atmosphere

V. Bommier (1) , E. Landi Degl'Innocenti , S. Sahal-Bréchot (2)

1 LESIA (UMR_8109) - Laboratoire d'études spatiales et d'instrumentation en astrophysique
2 LERMA - Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique

The results of computations of resonance polarization and the Hanle effect (weak magnetic field) for a two-level atom in a plane-parallel optically thick atmosphere and numerical methods for solving them are presented. The findings are compared with results yielded by other methods, of the differential method type, in zero magnetic field and under the hypothesis of complete frequency redistribution, and a good agreement is obtained. The novel computation method, called the 'global' method, is applied to test the validity of the results obtained by the iterative method. The result of the computations are finally presented in the form of Hanle diagrams for some magnetic field and line-of-sight geometries.

Mots clés: H Alpha Line; Linear Polarization; Optical Thickness; Radiative Transfer; Solar Prominences; Atomic Energy Levels; Iterative Solution; Magnetic Fields; Resonance; Zeeman Effect

Domaines: Physique [physics]; Astrophysique [astro-ph]; Astrophysique stellaire et solaire [astro-ph.SR]

V. Bommier, E. Landi Degl'Innocenti, S. Sahal-Bréchot. Resonance line polarization and the Hanle effect in optically thick media. II - Case of a plane-parallel atmosphere. Astronomy and Astrophysics - A&A, 1991, 244, pp.383-390. ⟨hal-02393565⟩