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Using a quantum electrodynamical approach, we derive the scattering phase matrices for polarized radiation involving forbidden line transitions and in the presence of an external magnetic field. The case of (J=0->2->0) scattering is…

Astrophysics · Physics 2008-05-27 Yee Yee Oo , Phyu Phyu San , M. Sampoorna , K. N. Nagendra , G. Ramachandran

We present the theoretical framework and numerical methods we have implemented to solve the problem of the generation and transfer of polarized radiation in spectral lines out of local thermodynamical equilibrium, while accounting for…

Solar and Stellar Astrophysics · Physics 2022-09-01 Ernest Alsina Ballester , Luca Belluzzi , Javier Trujillo Bueno

The existence of asymmetries in the circular polarization (Stokes V) profiles emerging from the solar photosphere is known since the 1970s. These profiles require the presence of a velocity gradient along the line of sight, possibly…

Solar and Stellar Astrophysics · Physics 2012-03-06 A. Sainz Dalda , J. Martinez-Sykora , L. Bellot Rubio , A. Title

With the recent advent of circular polarization capabilities at the Atacama Large Millimeter/submillimeter Array (ALMA), Zeeman effect measurements of spectral lines are now possible as a means to directly probe line-of-sight magnetic…

Solar and Stellar Astrophysics · Physics 2020-11-04 Renato Mazzei , L. Ilsedore Cleeves , Zhi-Yun Li

We present our analysis aimed at inferring average magnetic fields in slowly-rotating solar-like stars. Using the spectral line inversion code SPINOR, we perform high-accuracy line profile fitting and investigate whether Zeeman broadening…

Solar and Stellar Astrophysics · Physics 2010-12-15 Richard I. Anderson , Ansgar Reiners , Sami K. Solanki

Large-scale magnetic fields at the surface of massive stars do not only influence the outer-most layers of the star, but also have consequences for the deep interior, only observationally accessible through asteroseismology. We performed a…

Solar and Stellar Astrophysics · Physics 2017-09-20 B. Buysschaert , C. Neiner , M. Briquet , C. Aerts

We systematically study pulsar light curves, taking into account the special relativistic effect, i.e., the Doppler factor due to the fast spin of the neutron stars, together with the time delay, which comes from the difference of the…

High Energy Astrophysical Phenomena · Physics 2018-12-05 Hajime Sotani , Umpei Miyamoto

This study investigates the polarization characteristics of solitonic boson stars surrounded by a thin accretion disk. By comparing their polarization images with corresponding optical images, we find a positive correlation between the…

General Relativity and Quantum Cosmology · Physics 2025-08-19 Xiao-Xiong Zeng , Chen-Yu Yang , Hao Yu , Ke-Jian He

Basic scenarios and mechanisms for the formation and decay of small-scale magnetic elements and their manifestation in synthesized Stokes profiles of the Fe I 15648.5 A infrared line are considered in the context of two-dimensional modeling…

Solar and Stellar Astrophysics · Physics 2012-10-15 V. A. Sheminova , A. S. Gadun

This paper provides testable predictions about starlight polarizations to constrain the geometry of the Galactic magnetic field, in particular the nature of the poloidal component. Galactic dynamo simulations and Galactic dust distributions…

Astrophysics of Galaxies · Physics 2012-02-07 Michael D. Pavel

Throughout the last decades, Zeeman-Doppler Imaging (ZDI) has been intensively used to reconstruct large-scale magnetic topologies of active stars from time series of circularly polarized (Stokes $V$) profiles. ZDI being based on the…

Solar and Stellar Astrophysics · Physics 2022-09-28 Benjamin Finociety , Jean-François Donati

The intense magnetic fields of neutron stars naturally lead to strong anisotropy and polarization of radiation emanating from their surfaces, both being sensitive to the hot spot position on the surface. Accordingly, pulse phase-resolved…

High Energy Astrophysical Phenomena · Physics 2025-02-21 Matthew G. Baring , Hoa Dinh Thi , George A. Younes , Kun Hu

Mechanisms influencing absorption line profiles of fast rotating stars can be sorted into two groups; (i) intrinsic variations sensitive to temperature and pressure, and (ii) global effects common to all spectral lines. I present a detailed…

Astrophysics · Physics 2009-11-10 Ansgar Reiners

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

We initiate numerical studies of differentially rotating magnetised (proto) neutron stars by studying - through construction from first principles - the coupling between an assumed differential rotation and an impressed magnetic field. For…

Astrophysics · Physics 2007-05-23 A. V. Thampan

Response functions to perturbations in the temperature, pressure, microturbulent velocity, and magnetic intensity were calculated for the Stokes parameter profiles of the lines Fe I 525.06, 525.02 and Fe II 614.92 nm. The procedure proposed…

Solar and Stellar Astrophysics · Physics 2012-11-13 V. A. Sheminova

We have developed a relativistic model for pulsar radio emission and polarization by taking into account of detailed geometry of emission region, rotation and modulation. The sparks activity on the polar cap leads to plasma columns in the…

High Energy Astrophysical Phenomena · Physics 2015-06-03 D. Kumar , R. T. Gangadhara

Stars are changing entities in a constant evolution during their lives. At non-secular time scales (from seconds to years) the effect of dynamical processes such as convection, rotation, and magnetic fields can modify the stellar…

Solar and Stellar Astrophysics · Physics 2019-07-09 S. Mathur , J. Ballot , R. A. Garcia

Our current knowledge about the stellar magnetic fields relies almost entirely on the circular polarization observations. Very few objects have been observed so far in all four Stokes parameters. The magnetic Ap star HD24712 (DO Eri,…

Solar and Stellar Astrophysics · Physics 2015-06-17 N. Rusomarov , O. Kochukhov , N. Piskunov

The configuration and evolution of the magnetic field in star-forming cores are investigated in order to directly compare simulations and observations. We prepare four different initial clouds having different magnetic field strengths and…

Solar and Stellar Astrophysics · Physics 2015-06-11 Akimasa Kataoka , Masahiro N. Machida , Kohji Tomisaka
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