Assessing the tilt of the solar magnetic field axis through Faraday rotation observations

dc.creatorMancuso, S.
dc.creatorGarzelli, M. V.
dc.date2007-02-27
dc.date.accessioned2026-07-07T10:21:52Z
dc.date.available2026-07-07T10:21:52Z
dc.descriptionContext: Faraday rotation measurements of extragalactic radio sources during coronal occultation allow assessment of both the electron density distribution and the three-dimensional magnetic field topology in the outer solar corona. Aims: We simulate the three-dimensional structure of both the coronal magnetic field and the electron density distribution in order to reproduce the excess Faraday rotation measures (RMs) of the occulted radio sources observed during solar activity minimum. In particular, we infer the tilt of the solar magnetic axis with respect to the rotation axis. Methods: We compare the output of the model with Very Large Array (VLA) radio polarimetric measurements of a sample of extragalactic sources observed in May 1997. Information on the magnetic field geometry can be retrieved by fine-tuning the set of model free parameters that best describe the observations. Results: We find that predicted and observed Faraday rotation measures are in excellent agreement, thus supporting the model. Our best-fitting model yields a tilt angle $θ_{RB}=3.3^{\circ}$ of the solar magnetic axis with respect to the solar rotation axis around Carrington Rotation 1923. This result is consistent with analogous but independent estimates computed from the expansion coefficients of the photospheric field observed at the Wilcox Solar Observatory (WSO).
dc.description8 pages, 5 figures, accepted for publication in A&A
dc.identifierhttps://arxiv.org/abs/astro-ph/0702719
dc.identifierhttp://arxiv.org/abs/astro-ph/0702719
dc.identifierAstron.Astrophys.466:L5-L8,2007
dc.identifierdoi:10.1051/0004-6361:20066917
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/175318
dc.subjectAstrophysics
dc.titleAssessing the tilt of the solar magnetic field axis through Faraday rotation observations
dc.typetext

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