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The goal of this work is to develop a simple analytic description of the emission properties (spectrum and polarization) of the condensed, strongly magnetized surface of neutron stars. We have improved the method of van Adelsberg et al.…

High Energy Astrophysical Phenomena · Physics 2016-02-16 A. Y. Potekhin , V. F. Suleimanov , M. van Adelsberg , K. Werner

We present a general radiative transfer model which allows the Zeeman diagnostics of complex and unresolved solar magnetic fields. Present modeling techniques still rely to a large extent on a-priori assumptions about the geometry of the…

Astrophysics · Physics 2009-11-13 T. A. Carroll , M. Kopf

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

The rotating vector model and radius-to-frequency mapping in the presence of multipole magnetic field in pulsars and magnetars are considered. An axisymmetric potential field is assumed. It is found that: (1) The radiation beam in the case…

High Energy Astrophysical Phenomena · Physics 2023-10-12 J. L. Qiu , H. Tong , H. G. Wang

Because of the unquestionable presence of magnetic fields in stars, their role in the structure of stellar atmospheres has for a long time been a subject of speculation. In our contribution to this discussion we present spectropolarimetric…

Solar and Stellar Astrophysics · Physics 2022-02-02 Marina Giarrusso

We introduce methods for estimating the spectral density of a random field on a $d$-dimensional lattice from incomplete gridded data. Data are iteratively imputed onto an expanded lattice according to a model with a periodic covariance…

Methodology · Statistics 2019-08-12 Joseph Guinness

Insights on stellar surface large-scale magnetic field topologies are usually drawn by applying Zeeman-Doppler-Imaging (ZDI) to the observed spectropolarimetric time series. However, ZDI requires experience for reliable results to be…

Solar and Stellar Astrophysics · Physics 2022-06-02 L. T. Lehmann , J. -F. Donati

In this work, we simulate the evolution of the solar wind along its main sequence lifetime and compute its thermal radio emission. To study the evolution of the solar wind, we use a sample of solar mass stars at different ages. All these…

Solar and Stellar Astrophysics · Physics 2019-06-17 D. Ó Fionnagáin , A. A. Vidotto , P. Petit , C. P. Folsom , S. V. Jeffers , S. C. Marsden , J. Morin , J. -D. do Nascimento

We introduce a method to quantify the quality-of-fit between data and observables depending on the large scale Galactic magnetic field. We combine WMAP5 polarized synchrotron data and Rotation Measures of extragalactic sources in a joint…

Astrophysics of Galaxies · Physics 2009-07-22 Ronnie Jansson , Glennys R. Farrar , Andre H. Waelkens , Torsten A. Ensslin

We propose and demonstrate an experimental implementation for the observation of magnetic fields from spatial features of absorption profiles in a warm atomic vapor. A radially polarized vector beam that traverses an atomic vapor will…

We have developed a complete theory for the calculation of the observed Stokes parameters for radiation emitted from the surface of a rapidly rotating neutron star (NS) using the oblate Schwarzschild approximation. We accounted for the…

High Energy Astrophysical Phenomena · Physics 2020-11-11 Vladislav Loktev , Tuomo Salmi , Joonas Nättilä , Juri Poutanen

The method of solar magnetic field calibration for the filter-based magnetograph is normally the linear calibration method under weak-field approximation that cannot generate the strong magnetic field region well due to the magnetic…

Solar and Stellar Astrophysics · Physics 2021-02-10 Jingjing Guo , Xianyong Bai , Yuanyong Deng , Hui Liu , Jiaben Lin , Jiangtao Su , Xiao Yang , Kaifan Ji

Accounting for stellar activity is a crucial component of the search for ever-smaller planets orbiting stars of all spectral types. We use Doppler imaging methods to demonstrate that starspot induced radial velocity variability can be…

Solar and Stellar Astrophysics · Physics 2017-01-18 J. R. Barnes , S. V. Jeffers , G. Anglada-Escude , C. A. Haswell , H. R. A. Jones , M. Tuomi , F. Feng , J. S. Jenkins , P. Petit

A method was presented of profiling the magnetic field, with a zero vector of magnetic flux density $B_{r}$ and strong gradient G, enabling conditions for the Stern-Gerlach spectroscopy to be accomplished in condensed matter (the method has…

Instrumentation and Detectors · Physics 2009-10-31 C. J. Lewa

Context. Recent high angular resolution polarimetric continuum observations of circumstellar disks provide new insights into their magnetic field. However, direct constraints are limited to the plane of sky component of the magnetic field.…

Solar and Stellar Astrophysics · Physics 2017-11-22 R. Brauer , S. Wolf , M. Flock

Our earlier work [J. Opt. 19. (2017) 0905603] showed that, in contrast to the four parameters of the traditional Stokes vector description of the statistics of the partially polarized light, the complete second-order statistics of the…

Optics · Physics 2023-03-07 Mikhail Charnotskii

In this paper we present a three-dimensional numerical model for the radio emission of Magnetic Chemically Peculiar stars, on the hypothesis that energetic electrons emit by the gyrosynchrotron mechanism. For this class of radio stars,…

Astrophysics · Physics 2009-11-10 C. Trigilio , P. Leto , G. Umana , F. Leone , C. S. Buemi

With application to inner stellar radiative zones, a linear theory is used to analyze the instability of a dipole-parity toroidal background field, in the presence of density stratification, differential rotation, and realistically small…

Solar and Stellar Astrophysics · Physics 2015-03-25 G. Ruediger , M. Schultz , L. L. Kitchatinov

Current knowledge about stellar magnetic fields relies almost entirely on circular polarization observations. Few objects have been observed in all four Stokes parameters. The magnetic Ap star HD 24712 (DO Eri, HR 1217) was recently…

Solar and Stellar Astrophysics · Physics 2013-10-03 N. Rusomarov , O. Kochukhov , N. Piskunov

A method for the determination of integrated longitudinal stellar fields from low-resolution spectra is the so-called slope method, which is based on the regression of the Stokes V signal against the first derivative of Stokes I. Here we…

Solar and Stellar Astrophysics · Physics 2017-08-18 C. Scalia , F. Leone , M. Gangi , M. Giarrusso , M. J. Stift