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A Substantial Amount of Hidden Magnetic Energy in the Quiet Sun
Author/s: Javier Trujillo Bueno, Nataliya Shchukina y Andrés Asensio Ramos
Reference: letters to nature - NATURE |VOL 430 | 15 JULY 2004 - www.nature.com/nature | Link
Center-to-limb variation of the Q/I scattering amplitudes of the photospheric line of Sr I at 4607 Angstroms. The symbols correspond to various observations taken during a minimum and a maximum of the solar activity cycle. The colored lines show scattering polarization calculations in a three-dimensional hydrodynamical model of the solar photosphere, assuming a volume-filling, single-value microturbulent field. The best fit to the observations is obtained for 60 gauss. With a more realistic exponential Probability Distribution Function (black, dashed-dotted line), the best fit is obtained for <B>=130 gauss. This indicates that there is a vast amount of "hidden" magnetic energy in the "quiet" solar photosphere, carried by a tangled magnetic field at subresolution scales. This "hidden" magnetic field is practically invisible to the traditional diagnostic tools based on the Zeeman effect.
An investigation carried out at the IAC has demonstrated that the apparently non-magnetic regions of the solar photosphere (the innermost region of the atmosphere of the Sun) are instead permeated by a "chaotic" magnetic field of very significant intensity, which implies the presence of a vast amount of "hidden" magnetic energy in the quiet solar photosphere. This investigation required to develop first a novel diagnostic technique of magnetic fields, which is based on three-dimensional numerical simulations of the Hanle effect in atomic and molecular lines.
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