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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

We present some theoretical predictions concerning the amplitude and magnetic sensitivity of the linear polarization signals produced by scattering processes in the hydrogen Ly-alpha line of the solar transition region. To this end, we have…

Solar and Stellar Astrophysics · Physics 2015-05-28 Javier Trujillo Bueno , Jiri Stepan , Roberto Casini

The quantum interference between the fine structure states of an atom modifies the shapes of the emergent Stokes profiles in the Second Solar Spectrum. This phenomenon has been studied in great detail both in the presence and absence of…

Solar and Stellar Astrophysics · Physics 2015-06-22 K. Sowmya , K. N. Nagendra , M. Sampoorna , J. O. Stenflo

Context. Rigorous modeling of the \ion{Ba}{ii} ${\lambda}4554$ formation is potentially interesting since this strongly polarized line forms in the solar chromosphere where the magnetic field is rather poorly known. Aims. To investigate the…

Astrophysics · Physics 2009-11-13 M. Derouich

Spectral lines emitted by plasmas provide information about the thermodynamic conditions, the degree of randomness or the interactions prevailing in the medium. Collisions by plasma electrons penetrating the extent of bound-electron…

Atomic Physics · Physics 2019-05-22 Jean-Christophe Pain , Franck Gilleron

We report the first spectropolarimetric observations and modeling of CaH transitions in sunspots. We have detected strong polarization signals in many CaH lines from the A-X system, and we provide the first successful fit to the observed…

Astrophysics · Physics 2010-11-11 S. V. Berdyugina , D. M. Fluri , R. Ramelli , M. Bianda , D. Gisler , J. O. Stenflo

Here we formulate and solve the 3D radiative transfer problem of the polarization of the solar continuous radiation. Our approach takes into account not only the anisotropy of the continuum radiation, but also the symmetry-breaking effects…

Astrophysics · Physics 2011-02-11 J. Trujillo Bueno , N. Shchukina

We report novel spectropolarimetric observations of sunspots carried out with the Tenerife Infrared Polarimeter (TIP) in a near-IR spectral region around 15410 A, which is known to contain two groups of prominent OH lines that show circular…

Astrophysics · Physics 2009-11-11 A. Asensio Ramos , J. Trujillo Bueno , M. Collados

The main possibilities of investigation of leptons and bosons production in interaction of polarized photons are considered. The usage of $\gamma\gamma\to f\bar{f}[+\gamma]$ reactions for the luminosity measurement on linear photon collider…

High Energy Physics - Phenomenology · Physics 2007-08-21 T. V. Shishkina

$F$-state interference significantly modifies the polarization produced by scattering processes in the solar atmosphere. Its signature in the emergent Stokes spectrum in the absence of magnetic fields is depolarization in the line core. In…

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

The main goal of this thesis has been to investigate the effects that the macroscopic vertical velocity fields have on the scattering polarization signals formed in the solar chromosphere. Until now, the impact of macroscopic motions had…

Solar and Stellar Astrophysics · Physics 2014-02-10 Edgar S. Carlin Ramírez

This article presents an introduction to optical pumping, atomic polarization and the Hanle effect in weakly magnetized stellar atmospheres. Although the physical processes and the theoretical framework described here are of interest for…

Astrophysics · Physics 2007-05-23 Javier Trujillo-Bueno

The polarization observed in the spectral lines of the He I 10830 multiplet carries valuable information on the dynamical and magnetic properties of plasma structures in the solar chromosphere and corona, such as spicules, prominences,…

Astrophysics · Physics 2008-11-26 J. Trujillo Bueno , A. Asensio Ramos

We review the problem of proton beam bombardment of solar chromosphere considering the self-consistent NLTE polarized radiation transfer in hydrogen lines. Several observations indicate a linear polarization of the H-alpha line of the order…

Astrophysics · Physics 2008-11-26 Jiri Stepan

We highlight the main results of a three-dimensional (3D) multilevel radiative transfer investigation about the solar disk-center polarization of the Ca {\sc ii} 8542 \AA\ line. First, we investigate the linear polarization due to the…

Solar and Stellar Astrophysics · Physics 2016-07-27 Jiří Štěpán , Javier Trujillo Bueno

We employ the magnetic and velocity fields from turbulent dynamo simulations to synthesize the polarization of a typical photospheric line. The synthetic Stokes profiles have properties in common with those observed in the quiet Sun. The…

Astrophysics · Physics 2009-11-07 J. Sánchez Almeida , T. Emonet , F. Cattaneo

We present an analytic model of thermal state-to-state rotationally inelastic collisions of polar molecules in electric fields. The model is based on the Fraunhofer scattering of matter waves and requires Legendre moments characterizing the…

Chemical Physics · Physics 2008-07-09 Mikhail Lemeshko , Bretislav Friedrich

We theoretically study the influence of laser polarization in inelastic scattering of electrons by hydrogen atoms in the presence of a circularly polarized laser field in the domain of field strengths below $10^{7}$ V/cm and high projectile…

Atomic Physics · Physics 2023-06-16 Gabriela Buică

There is an ongoing debate about the origin and even the very existence of a high degree of linear polarization of some chromospheric spectral lines observed in solar flares. The standard explanation of these measurements is in terms of the…

Solar and Stellar Astrophysics · Physics 2015-06-17 Jiri Stepan , Petr Heinzel

This is a theoretical investigation on the formation of the linearly polarized line spectrum of ionized cerium in the sun. We calculate the scattering line polarization pattern emergent from a plane-parallel layer of Ce {\sc ii} atoms…

Astrophysics · Physics 2009-11-11 R. Manso Sainz , E. Landi Degl'Innocenti , J. Trujillo Bueno