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Related papers: Hanle effect for stellar dipoles and quadrupoles

200 papers

This paper addresses the modelling issue of the linearly-polarized solar limb spectrum, which is due to scattering processes and it offers a rich diagnostic potential for exploring solar magnetic fields via the Hanle effect. However, this…

Astrophysics · Physics 2007-10-30 J. Trujillo Bueno

The quantum theory of polarized light allows one to model scattering in the solar atmosphere for inferring its properties. This powerful approach has revealed two key long-standing problems in solar physics: the puzzling dilemmas between…

Solar and Stellar Astrophysics · Physics 2016-11-01 E. S. Carlin , M. Bianda

Probing the magnetism of the upper solar chromosphere requires measuring and modeling the scattering polarization produced by anisotropic radiation pumping in UV spectral lines. Here we apply PORTA (a novel radiative transfer code) to…

Solar and Stellar Astrophysics · Physics 2015-06-23 Jiri Stepan , Javier Trujillo Bueno , Jorrit Leenaarts , Mats Carlsson

In the canonical model of a pulsar, rotational energy is transmitted through the surrounding plasma via two electrical circuits, each connecting to the star over a small region known as a "polar cap." For a dipole-magnetized star, the polar…

High Energy Astrophysical Phenomena · Physics 2018-01-03 Samuel E. Gralla , Alexandru Lupsasca , Alexander Philippov

Hanle scattering is an important diagnostic tool to study weak solar magnetic fields. Partial frequency redistribution (PRD) is necessary to interpret the linear polarization observed in strong resonance lines. Usually angle-averaged PRD…

Solar and Stellar Astrophysics · Physics 2013-04-22 H. D. Supriya , M. Sampoorna , K. N. Nagendra , B. Ravindra , L. S. Anusha

Disk accretion to rotating stars with complex magnetic fields is investigated using full three-dimensional magnetohydrodynamic (MHD) simulations. The studied magnetic configurations include superpositions of misaligned dipole and quadrupole…

Astrophysics · Physics 2009-11-13 M. Long , M. M. Romanova , R. V. E. Lovelace

Quantum interference effects together with partial frequency redistribution (PFR) in line scattering produce subtle signatures in the so called Second Solar Spectrum (the linearly polarized spectrum of the Sun). These signatures are…

Solar and Stellar Astrophysics · Physics 2019-10-25 M. Sampoorna , K. N. Nagendra , K. Sowmya , J. O. Stenflo , L. S. Anusha

Given that dynamically significant magnetic fields in at least some massive stars have now been measured, our contribution addresses the question, to what extent can fields be directly detected in circumstellar gas? The question speaks…

Astrophysics · Physics 2007-08-20 Richard Ignace , Kenneth G. Gayley

The degree of linear polarization has recently been found to show wide random variations over the solar disk. These variations are presumably at least partly due to fluctuations in the flux density of turbulent photospheric magnetic fields…

Astrophysics · Physics 2007-05-23 K. Petrovay

It is generally assumed that magnetic fields play an important role in the formation and evolution of protoplanetary disks. One way of observationally constraining magnetic fields is to measure polarized emission and absorption produced by…

Solar and Stellar Astrophysics · Physics 2020-03-04 Stefan Heese , Sebastian Wolf

A spherical tensor expansion is carried out to express the resonant inelastic scattering cross-section as a sum of products of fundamental spectra with tensors involving wavevectors and polarization vectors of incident and scattered…

Strongly Correlated Electrons · Physics 2014-05-20 Amélie Juhin , Christian Brouder , Frank De Groot

Solar magnetic fields alter scattering polarization in spectral lines like Sr I at 4607 {\AA} via the Hanle effect, making it a potential diagnostic for small-scale mixed-polarity photospheric magnetic fields. Recently, observational…

Solar and Stellar Astrophysics · Physics 2024-02-08 Franziska Zeuner , Tanausú del Pino Alemán , Javier Trujillo Bueno , Sami K. Solanki

Photoluminescence polarization is experimentally studied for samples with (In,Ga)As/GaAs selfassembled quantum dots in transverse magnetic field (Hanle effect) under slow modulation of the excitation light polarization from fractions of Hz…

Mesoscale and Nanoscale Physics · Physics 2017-04-26 M. S. Kuznetsova , R. V. Cherbunin , I. Ya. Gerlovin , I. V. Ignatiev , S. Yu. Verbin , D. R. Yakovlev , D. Reuter , A. D. Wieck , M. Bayer

We predict polarimetric line profiles for scattering off rotating disks using a Monte Carlo technique. We have discovered that there is a marked difference between scattering of line emission by a disk that reaches the stellar surface, and…

Astrophysics · Physics 2009-11-10 Jorick S. Vink , Tim J. Harries , Janet E. Drew

Radiative polarization of electrons and positrons through the Sokolov-Ternov effect is important for applications in high-energy physics. Radiative spin-polarization is a manifestation of quantum radiation reaction affecting the…

High Energy Physics - Phenomenology · Physics 2018-08-29 D. Seipt , D. Del Sorbo , C. P. Ridgers , A. G. R. Thomas

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

External spiral galaxies seen edge-on exhibit X-shape magnetic fields in their halos. Whether the halo of our own Galaxy also hosts an X-shape magnetic field is still an open question. We would like to provide the necessary analytical tools…

Astrophysics of Galaxies · Physics 2015-06-18 Katia Ferriere , Philippe Terral

A new technique based on superposition of two speckle patterns is proposed and demonstrated for controlled modulation of the spatial polarization distribution of the resultant speckle. It is demonstrated both theoretically and…

Optics · Physics 2021-11-15 Abhijit Roy , Rakesh K. Singh , Maruthi M. Brundavanam

Multipole expansion methods have been primarily used for analyzing the electromagnetic scattering from non-magnetic isotropic dielectric scatterers, and studies about the scattering from magnetic objects seem to be lacking. In this work, we…

Light scattered off particles can become linearly polarized. Stars surrounded by oblique, co-rotating envelopes are therefore expected to manifest periodic linear polarimetric variations. The electron scattering magnetospheres of magnetic…

Solar and Stellar Astrophysics · Physics 2022-01-05 M. S. Munoz , G. A. Wade , D. M. Faes , A. C. Carciofi , J. Labadie-Bartz