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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

Linearly polarized emission is described, in general, in terms of the Stokes parameters $Q$ and $U$, from which the polarization intensity and polarization angle can be determined. Although the polarization intensity and polarization angle…

Astrophysics of Galaxies · Physics 2018-01-31 C. A. Herron , B. M. Gaensler , G. F. Lewis , N. M. McClure-Griffiths

The observation of the polarization emerging from a rotating star at different phases opens up the possibility to map the magnetic field in the stellar surface thanks to the well-known Zeeman Doppler Imaging. When the magnetic field is…

Solar and Stellar Astrophysics · Physics 2015-06-05 M. J. Martínez González , A. Asensio Ramos

The STOKES Monte Carlo radiative transfer code has been extended to model the velocity dependence of the polarization of emission lines. We use STOKES to present improved modelling of the velocity-dependent polarization of broad emission…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Rene W. Goosmann , C. Martin Gaskell , Frederic Marin

Disk polarization at (sub)millimeter wavelengths is being revolutionized by ALMA observationally, but its origin remains uncertain. Dust scattering was recently recognized as a potential contributor to polarization, although its basic…

Solar and Stellar Astrophysics · Physics 2017-11-08 Haifeng Yang , Zhi-Yun Li , Leslie W. Looney , Josep M. Girart , Ian W. Stephens

Direct imaging has paved the way for atmospheric characterization of young and self-luminous gas giants. Scattering in a horizontally-inhomogeneous atmosphere causes the disk-integrated polarization of the thermal radiation to be linearly…

Earth and Planetary Astrophysics · Physics 2018-11-09 Tomas Stolker , Michiel Min , Daphne M. Stam , Paul Mollière , Carsten Dominik , Rens Waters

We present the results of a Monte Carlo radiative transfer code that calculates the polarization produced by multiple Thomson scattering and variable absorptive opacity in a circumstellar disk around one component of a close detached binary…

Astrophysics · Physics 2009-11-10 Jennifer L. Hoffman , Barbara A. Whitney , Kenneth H. Nordsieck

Many active stars are covered in spots, much more so than the Sun, as indicated by spectroscopic and photometric observations. It has been predicted that star spots induce non-zero intrinsic linear polarization by breaking the visible…

Solar and Stellar Astrophysics · Physics 2018-05-16 T. M. Yakobchuk , S. V. Berdyugina

Several studies discussing imaging polarimetry observations of protoplanetary disks use the so-called radial Stokes parameters Q_phi and U_phi to discuss the results. This approach has the advantage of providing a direct measure of the…

Solar and Stellar Astrophysics · Physics 2015-10-14 H. Canovas , F. Ménard , J. de Boer , C. Pinte , H. Avenhaus , M. R. Schreiber

A general theoretical framework is developed for interpreting spectropolarimetric observations of optically thin emission line scattering from small dust particles. Spatially integrated and spatially resolved line profiles of both scattered…

Astrophysics · Physics 2009-10-22 W. J. Henney

Line scattering polarization can be strongly affected by Rayleigh scattering by neutral hydrogen and Thompson scattering by free electrons. Often a continuum depolarization results, but the Doppler redistribution produced by the continuum…

Solar and Stellar Astrophysics · Physics 2015-06-18 T. del Pino Alemán , R. Manso Sainz , J. Trujillo Bueno

Double-peaked line profiles are commonly considered a hallmark of rotating disks, with the distance between the peaks a measure of the rotation velocity. However, double-peaks can arise also from radiative transfer effects in optically…

Astrophysics of Galaxies · Physics 2015-06-04 Moshe Elitzur , Andres Asensio Ramos , Cecilia Ceccarelli

A line photon incident in an electron-scattering medium is transferred in a diffusive way both in real space and in frequency space, and the mean number of scatterings changes as the wavelength shifts from the line center. This leads to the…

Astrophysics · Physics 2009-10-31 Hee-Won Lee

Scattering of re-emitted flux is considered to be at least partially responsible for the observed polarisation in the (sub-)millimetre wavelength range of several protoplanetary disks. Although the degree of polarisation produced by…

Solar and Stellar Astrophysics · Physics 2020-08-26 Robert Brunngräber , Sebastian Wolf

Similar to the case of solar system planets, reflected starlight from exoplanets is expected to be polarized due to atmospheric scattering and the net disk integrated polarization should be non-zero owing to the asymmetrical illumination of…

Earth and Planetary Astrophysics · Physics 2021-09-01 Aritra Chakrabarty , Sujan Sengupta

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

High-contrast scattered light observations have revealed the surface morphology of several dozens of protoplanetary disks at optical and near-infrared wavelengths. Inclined disks offer the opportunity to measure part of the phase function…

Earth and Planetary Astrophysics · Physics 2016-12-07 T. Stolker , C. Dominik , M. Min , A. Garufi , G. D. Mulders , H. Avenhaus

We calculate the polarization of radiation from thick accretion disks with vertically averaged global magnetic field. The polarization arises as a result of the radiation scattering by free electrons in magnetized plasma of a disk. We…

Astrophysics · Physics 2007-05-23 Yu. N. Gnedin , N. A. Silant'ev , P. S. Shternin

Techniques of calculation of emission line profiles formed in a non--uniform accretion disk is presented. Change of the profile shape as a function of phase turn of the disk with a bright spot on the surface is analysed. A possibility of a…

Astrophysics · Physics 2007-05-23 N. V. Borisov , V. V. Neustroev

[abridged] We investigate the effects of various AGN scattering region geometries on the polarized flux. We introduce a new, publicly available Monte Carlo radiative transfer code, Stokes, which models polarization induced by scattering off…

Astrophysics · Physics 2011-01-31 Rene W. Goosmann , C. Martin Gaskell
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