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

International audienceThe 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