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Scattering polarization signals in the Sr I 4607 \AA\ spectral line are among the strongest originating from the solar photosphere, offering a powerful diagnostic of tangled magnetic fields in the 3--300 G range via the Hanle effect.…

Planets reflect and linearly polarize the radiation that they receive from their host stars. The emergent polarization is sensitive to aspects of the planet atmosphere such as the gas composition and the occurrence of condensates and their…

Earth and Planetary Astrophysics · Physics 2018-02-28 Antonio García Muñoz

Magnetic field topology, thermal structure and plasma motions are the three main factors affecting the polarization signals used to understand our star. In this theoretical investigation, we focus on the effect that gradients in the…

Solar and Stellar Astrophysics · Physics 2012-10-12 E. S. Carlin , R. Manso Sainz , A. Asensio Ramos , J. Trujillo Bueno

Weak entangled magnetic fields with mixed polarity occupy the main part of the quiet Sun. The Zeeman effect diagnostics fails to measure such fields because of cancellation in circular polarization. However, the Hanle effect diagnostics,…

Astrophysics · Physics 2009-11-13 A. I. Shapiro , S. V. Berdyugina , D. M. Fluri , J. O. Stenflo

The topic of magnetic field diagnostics with the Zeeman effect is currently vividly discussed. There are some testable inversion codes available to the spectropolarimetry community and their application allowed for a better understanding of…

Solar and Stellar Astrophysics · Physics 2016-11-29 M. Derouich

Aims: This paper extends previous studies in modeling time varying linear polarization due to axisymmetric magnetic fields in rotating stars. We use the Hanle effect to predict variations in net line polarization, and use geometric…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 R. Ignace , K. T. Hole , J. P. Cassinelli , G. D. Henson

We determine magnetic fields from the photosphere to the upper chromosphere combining data from the Hinode satellite and the CLASP2.1 sounding rocket experiment. CLASP2.1 provided polarization profiles of the Mg~{|sc ii} $h$ and $k$ lines,…

Full Stokes spectropolarimetric data (in the 10830 A region) of an active region filament were obtained in July 2005 using the Tenerife Infrared Polarimeter instrument. The polarization profiles in the filament show Zeeman-like signatures.…

Solar and Stellar Astrophysics · Physics 2010-01-15 C. Kuckein , R. Centeno , V. Martinez Pillet

Two of the most attractive spectral windows for spectropolarimetric investigations of the physical properties of the plasma structures in the solar chromosphere and corona are the ones provided by the spectral lines of the He I 10830 A and…

Astrophysics · Physics 2009-11-13 R. Centeno , J. Trujillo Bueno , H. Uitenbroek , M. Collados

Context. The scattering polarization signal observed in the photospheric Sr i 4607 {\AA} line is expected to vary at granular spatial scales. This variation can be due to changes in the magnetic field intensity and orientation (Hanle…

Solar and Stellar Astrophysics · Physics 2018-06-20 M. Bianda , S. Berdyugina , D. Gisler , R. Ramelli , L. Belluzzi , E. S. Carlin , J. O. Stenflo , T. Berkefeld

The near-Earth space weather is driven by the quick release of magnetic free energy in the solar corona. Probing this extremely hot and rarified region of the extended solar atmosphere requires modeling the polarization of forbidden and…

Solar and Stellar Astrophysics · Physics 2021-11-03 Supriya Hebbur Dayananda , Javier Trujillo Bueno , Ángel de Vicente , Tanausú del Pino Alemán

Interference between magnetic substates of the hyperfine structure states belonging to different fine structure states of the same term influences the polarization for some of the diagnostically important lines of the Sun's spectrum, like…

Solar and Stellar Astrophysics · Physics 2015-12-25 K. Sowmya , K. N. Nagendra , M. Sampoorna , J. O. Stenflo

The next generation of solar observatories aim to understand the magnetism of the solar chromosphere. Therefore, it is crucial to understand the polarimetric signatures of chromospheric spectral lines. For this purpose, we here examine the…

Basic aspects of the relationship between the magnetic field and polarized maser radiation are described with the emphasis on interpreting the observed spectra. Special attention is given to three issues--the limitations on the…

Astrophysics · Physics 2008-11-11 William D. Watson

Anisotropy of atomic states is characterized by population differences and coherences between Zeeman sublevels. It can be efficiently created and probed via resonant interactions with light, the technique which is at the heart of modern…

The Hanle effect has been proposed as a new diagnostic of circumstellar magnetic fields for early-type stars, for which it is sensitive to field strengths in the 1-300 G range. In this paper we compute the polarized P-Cygni line profiles…

Astrophysics · Physics 2009-11-10 R. Ignace , K. H. Nordsieck , J. P. Cassinelli

This paper considers the problem of modeling the light polarization that emerges from an astrophysical plasma composed of atoms whose excitation state is significantly influenced by the anisotropy of the incident radiation field. In…

Solar and Stellar Astrophysics · Physics 2011-05-03 Javier Trujillo Bueno

Sr I 4607\AA spectral line shows one of the strongest scattering polarization signals in the visible solar spectrum. The amplitudes of these signals are expected to vary at granular spatial scales. This variation can be due to changes in…

Ca {\sc i} 4227 \AA\, line is a strong resonance line formed in the Solar chromosphere. At the limb, it produces the largest scattering polarization signal. So far, modeling the linear polarization in this line has been limited to the use…

Solar and Stellar Astrophysics · Physics 2025-03-11 Harsh Mathur , L. S. Anusha , Devang Agnihotri

Theoretical investigations predicted that high spatio-temporal resolution observations in the Sr I 4607 A line must show a conspicuous scattering polarization pattern at the solar disk-center, which encodes information on the unresolved…

Solar and Stellar Astrophysics · Physics 2021-04-21 T. del Pino Alemán , J. Trujillo Bueno