Document 
A&A 456, 1159-1164 (2006)
DOI: 10.1051/0004-6361:20065008
On the validity of the 630 nm Fe I lines for magnetometry of the internetwork quiet Sun
M. J. Martínez González, M. Collados and B. Ruiz CoboInstituto de Astrofísica de Canarias, 38205, La Laguna, Tenerife, Spain
e-mail: marian@iac.es
(Received 28 November 2005 / Accepted 16 May 2006)
Abstract
Aims.The purpose of this work is to analyze the reliability of the magnetic field strengths inferred from
the 630 nm pair of Fe I lines in internetwork quiet Sun regions.
Methods.Some numerical experiments have been performed that demonstrate
the inability of these lines to recover the magnetic field strength
in such low flux solar regions.
Results.It is shown how different model
atmospheres, with magnetic field strengths ranging from a few hundred Gauss
to kiloGauss, give rise to Stokes profiles that cannot be distinguished.
The reasons for this degeneracy are discussed.
Key words: Sun: magnetic fields -- Sun: atmosphere
© ESO 2006