143 research outputs found
Diagnostics of Coronal Magnetic Fields Through the Hanle Effect in UV and IR Lines
The plasma thermodynamics in the solar upper atmosphere, particularly in the
corona, are dominated by the magnetic field, which controls the flow and
dissipation of energy. The relative lack of knowledge of the coronal vector
magnetic field is a major handicap for progress in coronal physics. This makes
the development of measurement methods of coronal magnetic fields a high
priority in solar physics. The Hanle effect in the UV and IR spectral lines is
a largely unexplored diagnostic. We use magnetohydrodynamic (MHD) simulations
to study the magnitude of the signal to be expected for typical coronal
magnetic fields for selected spectral lines in the UV and IR wavelength ranges,
namely the H I Ly- and the He I 10830 {\AA} lines. We show that the
selected lines are useful for reliable diagnosis of coronal magnetic fields.
The results show that the combination of polarization measurements of spectral
lines with different sensitivities to the Hanle effect may be most appropriate
for deducing coronal magnetic properties from future observations.Comment: 15 pages, 5 figures, Frontiers in Astronomy and Space Sciences, 201
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