Theoretical study of the collisional depolarization and of the Hanle effect in the line Na I D2 observed on the solar limb

Details Theoretical study of the collisional depolarization and of the Hanle effect in the line Na I D2 observed on the solar limb Theoretical study of the collisional depolarization and of the Hanle effect in the line Na I D2 observed on the solar limb

Jun 2002

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002sf2a.conf..125b&link_type=abstract

SF2A-2002: Semaine de l'Astrophysique Francaise, meeting held in Paris, France, June 24-29, 2002, Eds.: F. Combes and D. Barret,

Astronomy and Astrophysics

Astrophysics

Scientific paper

Observations of the Na I D lines polarization in quiet regions near the solar limb have been recently achieved, in particular with THEMIS (Bommier V., Molodij G., 2002, AandA 381, 241). These observations are in very good agreement with a theoretical model developed by Landi Degl'Innocenti (1998, Nature 392, 256, and 1999, "Solar Polarization", K.N. Nagendra and J.O. Stenflo (eds.), ASSL 243, 61). However, this model, based on the existence of atomic polarization in the line lower level, leads to the so-called "Sodium paradox": the existence of this at omic polarization is incompatible with the existence of a magnetic field stronger than 5 mG (except vertical), and also with the existence of collisional depolarization. We have investigated this last point, by using the collisional coefficients recently computed by B. Kerkeni from a quantum chemistry model. We have solved the statistical equilibrium equations for the atomic density matrix in the last scattering approximation, in order to investigate the Na I D2 line polarization formation and destruction at the solar limb. We have obtained that the atomic polarization in the lower level is completely destroyed by the collisions with neutral hydrogen at the line formation depth, which results in a "paradox in the paradox".

Affiliated with

Also associated with

No associations

Rating

Theoretical study of the collisional depolarization and of the Hanle effect in the line Na I D2 observed on the solar limb 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 Theoretical study of the collisional depolarization and of the Hanle effect in the line Na I D2 observed on the solar limb, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Theoretical study of the collisional depolarization and of the Hanle effect in the line Na I D2 observed on the solar limb will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1200946