An operator perturbation method for polarized line transfer. III. Applications to the Hanle effect in 1D media

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

31

Polarization, Magnetic Fields, Radiative Transfer, Scattering, Stars: Atmospheres, Methods: Numerical

Scientific paper

In this paper we present an Approximate Lambda Iteration method to treat the Hanle effect (resonance scattering in the presence of a weak magnetic field) for lines formed with complete frequency redistribution. The Hanle effect is maximum in the line core and goes to zero in the line wings. Referred to as PALI-H, this method is an extension to non-axisymmetric radiative transfer problems of the PALI method presented in Faurobert-Scholl et al. (1997), hereafter referred to as Paper I. It makes use of a Fourier decomposition of the radiation field with respect to the azimuthal angle which is somewhat more general than the decomposition introduced in Faurobert-Scholl (1991, hereafter referred to as FS91). The starting point of the method is a vector integral equation for a six-component source vector representing the non-axisymmetric polarized radiation field. As in Paper I, the Approximate Lambda operator is a block diagonal matrix. The convergence rate of the PALI-H method is independent of the polarization rate and hence of the strength and direction of the magnetic field. Also this method is more reliable than the perturbation method used in FS91. The PALI-H method can handle any type of depth-dependent magnetic field. Here it is used to examine the dependence of the six-component source vector on the co-latitude, azimuthal angle and strength of the magnetic field. The dependence of the surface polarization on the direction of the line-of-sight and on the magnetic field is illustrated with polarization diagrams showing Q/I versus U/I at line center. The analysis of the results show that the full six-dimension problem can be approximated by a two-component modified resonance polarization problem, producing errors of at most 20% on the surface polarization at line center.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

An operator perturbation method for polarized line transfer. III. Applications to the Hanle effect in 1D media does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with An operator perturbation method for polarized line transfer. III. Applications to the Hanle effect in 1D media, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and An operator perturbation method for polarized line transfer. III. Applications to the Hanle effect in 1D media will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1601419

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.