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Two magnetic components in sunspot penumbrae
The magnetic and kinematic configuration of sunspot penumbrae is investigated by performing an inversion of the Stokes profiles of three infrared lines at 1565 nm. We use a two-component model
The 1.5 meter solar telescope GREGOR
The 1.5 m telescope GREGOR opens a new window to the understanding of solar small-scale magnetism. The first light instrumentation includes the Gregor Fabry Perot Interferometer (GFPI), a filter
Selective absorption processes as the origin of puzzling spectral line polarization from the Sun
It is shown that the polarized light arises from selective absorption from the ground level of the triplet system of helium, and that the presence of magnetic fields of the order of a few gauss that are highly inclined with respect to the solar radius vector disproves the common belief that population imbalances in long-lived atomic levels are insignificant.
The Imaging Magnetograph eXperiment (IMaX) for the Sunrise Balloon-Borne Solar Observatory
The Imaging Magnetograph eXperiment (IMaX) is a spectropolarimeter built by four institutions in Spain that flew on board the Sunrise balloon-borne solar observatory in June 2009 for almost six days
On the validity of the 630 nm Fe I lines for magnetometry of the internetwork quiet Sun
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
Quiet-Sun inter-network magnetic fields observed in the infrared
This paper presents the results of an investigation of the quiet Sun's magnetic field based on high-resolution infrared spectropolarimetric observations obtained with the Tenerife Infrared
Spectropolarimetric Investigation of the Propagation of Magnetoacoustic Waves and Shock Formation in Sunspot Atmospheres
Velocity oscillations in sunspot umbrae have been measured simultaneously in two spectral lines: the photospheric Si I λ10827 line and the chromospheric He I λ10830 multiplet. From the full Stokes
Field-aligned Evershed flows in the photosphere of a sunspot penumbra
We determine the inclinations of the vector magnetic field and flow velocity in a sunspot penumbra by interpreting full Stokes profiles of three infrared lines observed with the Tenerife Infrared
Observation of Convective Collapse and Upward-moving Shocks in the Quiet Sun
We present spectropolarimetric evidence of convective collapse and destruction of magnetic flux by upward-moving fronts in the quiet Sun. The observational material consists of time series of the
Optimum modulation and demodulation matrices for solar polarimetry.
It is demonstrated, based on the definition of polarimetric efficiency, that the maximum efficiencies of an ideal polarimeter are unity for Stokes I and for (Q( 2) + U(2) + V(2))(1/2) and that this occurs if O(T)O is diagonal.