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The study of polarized radiation transfer in the highly-magnetized surface locales of neutron stars is of great interest to the understanding of accreting X-ray pulsars, rotation-powered pulsars and magnetars. This paper explores scattering…

High Energy Astrophysical Phenomena · Physics 2020-11-25 Joseph A. Barchas , Kun Hu , Matthew G. Baring

One of the greatest challenges in solar and stellar physics in coming years will be to observe the Second Solar Spectrum with a spatial resolution significantly better than 1 arcsec. This type of scattering polarization observations would…

Astrophysics · Physics 2009-11-13 Javier Trujillo Bueno , Nataliya Shchukina

This work aims to identify the relevant physical processes in shaping the intensity and polarization patterns of the solar K I D lines through spectral syntheses, placing particular emphasis on the D2 line. The theoretical Stokes profiles…

Solar and Stellar Astrophysics · Physics 2022-08-26 Ernest Alsina Ballester

Exposing the polarization signatures of the solar chromosphere requires studying its temporal variations, which is rarely done when modelling and interpreting scattering and Hanle signals. The present contribution sketches the scientific…

Solar and Stellar Astrophysics · Physics 2016-12-19 E. S. Carlin

Chromospheric magnetic fields are notoriously diffcult to measure. The chromospheric lines are broad, while the fields are producing a minuscule Zeeman-effect polarization. A promising diagnostic alternative is provided by the…

Solar and Stellar Astrophysics · Physics 2015-05-28 M. Bianda , R. Ramelli , L. S. Anusha , J. O. Stenflo , K. N. Nagendra , R. Holzreuter , M. Sampoorna , H. Frisch , H. N. Smitha

The intensity and the linear scattering polarization profiles of the hydrogen Ly-alpha line encode valuable information on the thermodynamic and magnetic structure of the upper layers of the solar chromosphere. The Chromospheric Lyman-Alpha…

Solar and Stellar Astrophysics · Physics 2023-05-03 Ernest Alsina Ballester , Luca Belluzzi , Javier Trujillo Bueno

Diagnostic techniques for stellar magnetic fields based upon spectropolarimetry. We propose and explore a new technique based upon the linear polarization emitted in Hanle-sensitive lines in disk-integrated stars where a dipolar magnetic…

Solar and Stellar Astrophysics · Physics 2015-05-20 A. López Ariste , A. Asensio Ramos , C. González Fernández

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

We present a formalism that incorporates hydrogen Lyman-alpha (Ly$\alpha$) polarization arising from the scattering of radiation in galaxy halos into the intensity mapping approach. Using the halo model, and emission profiles based on…

Astrophysics of Galaxies · Physics 2020-05-06 Lluís Mas-Ribas , Tzu-Ching Chang

A major challenge in solar physics is to obtain empirical information on the magnetic field of the million-degree plasma of the solar corona. To this end, we need observables of the solar radiation sensitive to the coronal magnetic field.…

The solar surface magnetic field is connected with and even controls most of the solar activity phenomena. Zeeman effect diagnostics allow for measuring only a small fraction of the fractal-like structured magnetic field. The remaining…

Solar and Stellar Astrophysics · Physics 2015-05-27 A. I. Shapiro , D. M. Fluri , S. V. Berdyugina , M. Bianda , R. Ramelli

A big challenge in solar and stellar physics in the coming years will be to decipher the magnetism of the solar outer atmosphere (chromosphere and corona) along with its dynamic coupling with the magnetic fields of the underlying…

Astrophysics · Physics 2009-11-13 A. Asensio Ramos , J. Trujillo Bueno , E. Landi Degl'Innocenti

The impact of the optical field polarization on the spectrum of magnetically-induced transitions, a class of transitions forbidden at zero magnetic field, is studied with a weak-probe sub-Doppler technique. The high spectral resolution of…

Atomic Physics · Physics 2025-02-19 A. Sargsyan , E. Klinger , A. Amiryan , D. Sarkisyan

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

We carry out a theoretical study of the polarization of the solar Mg II h-k doublet (including its extended wings) and the subordinate UV triplet around 280 nm. These lines are of great diagnostic interest, as they encode information on the…

Solar and Stellar Astrophysics · Physics 2020-04-21 T. del Pino Alemán , J. Trujillo Bueno , R. Casini , R. Manso Sainz

Non-local thermodynamic equilibrium (NLTE) effects in diagnostically important solar Fe I lines are important due to the strong sensitivity of Fe I to ionizing UV radiation, which may lead to a considerable under-population of the Fe I…

Solar and Stellar Astrophysics · Physics 2015-10-21 René Holzreuter , Sami K. Solanki

The physical interpretation of the spectral line polarization produced by the joint action of the Hanle and Zeeman effects offers a unique opportunity to obtain empirical information about hidden aspects of solar and stellar magnetism. To…

Astrophysics · Physics 2009-06-23 Luca Belluzzi , Javier Trujillo Bueno , Egidio Landi Degl'Innocenti

We demonstrate that the Hanle effect can be tuned between magnetically induced absorption (MIA) and magnetically induced transmission (MIT) simply by changing the polarization of the input laser beam. The experiments are done using closed…

Atomic Physics · Physics 2017-06-30 Harish Ravi , Mangesh Bhattarai , Vineet Bharti , Vasant Natarajan

Aims. The main goal of this paper is to present an accurate and efficient numerical strategy for solving the radiative transfer problem for polarised radiation in strong resonance lines forming out of local thermodynamic equilibrium, taking…

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…

Solar and Stellar Astrophysics · Physics 2016-06-29 N. E. Raouafi , P. Riley , S. Gibson , S. Fineschi , S. K. Solanki