Linear polarization of the O VI lambda 1031.92 coronal line. II. Constraints on the magnetic field and the solar wind velocity field vectors in the coronal polar holes

TitreLinear polarization of the O VI lambda 1031.92 coronal line. II. Constraints on the magnetic field and the solar wind velocity field vectors in the coronal polar holes
Type de publicationJournal Article
Year of Publication2002
AuteursRaouafi, N.-E., Sahal-Bréchot S., and Lemaire P.
JournalAstronomy and Astrophysics
Volume396
Pagination1019-1028
Date PublishedDec
Résumé

Numerical computation results of the linear polarization parameters of the O VI lambda1031 .92 coronal line are presented. They are based on theoretical results obtained by Raouafi (2002 and 2000), which give the Stokes parameters of a resonance scattering spectral line sensitive simultaneously to the Hanle effect and to the Doppler redistribution. In the present coronal case, the Hanle effect is due to the coronal magnetic field and the Doppler redistribution to the macroscopic motion of the scattering O$^{5+}$ coronal ions (solar wind velocity field vector). Constraints on the coronal magnetic field vector and on the solar wind velocity field vector are obtained by comparing the numerical results and the linear polarization measurements of the O VI lambda1031 .92 coronal line obtained through particular observations performed by SUMER/SoHO.

DOI10.1051/0004-6361:20021418