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Related papers: Improved near optimal angular quadratures for pola…

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In three-dimensional (3D) radiative transfer (RT) problems, the tensor product quadratures are generally not optimal in terms of the number of discrete ray directions needed for a given accuracy of the angular integration of the radiation…

Solar and Stellar Astrophysics · Physics 2020-04-08 Jiri Stepan , Jaume Jaume Bestard , Javier Trujillo Bueno

A new, very fast method for 3D radiative transfer on fully threaded grids with arbitrarily high angular resolution is presented. The method uses completely cell-based discretization, and is ideally suited for problems with diffuse…

Astrophysics · Physics 2009-11-11 A. O. Razoumov , C. Y. Cardall

Context. Magnetic fields are important to the dynamics of many astrophysical processes and can typically be studied through polarization observations. Polarimetric interferometry capabilities of modern (sub)millimeter telescope facilities…

Instrumentation and Methods for Astrophysics · Physics 2020-04-08 Boy Lankhaar , Wouter Vlemmings

Aims. The main goal of this paper is to present an accurate and efficient numerical strategy for solving the radiative transfer problem for polarised radiation in strong resonance lines forming out of local thermodynamic equilibrium, taking…

We present two new accurate and efficient method to compute the formal solution of the polarized radiative transfer equation. In this work, the source function and the absorption matrix are approximated using quadratic and cubic Bezier…

Solar and Stellar Astrophysics · Physics 2015-06-12 J. de la Cruz Rodríguez , N. Piskunov

Higher resolution telescopes as well as 3D numerical simulations will require the development of detailed 3D radiative transfer calculations. Building upon our previous work we extend our method to include both continuum and line transfer.…

Astrophysics · Physics 2009-11-13 E. Baron , Peter H. Hauschildt

We consider the numerical approximation of boundary conditions in radiative transfer problems by a perfectly matched layer approach. The main idea is to extend the computational domain by an absorbing layer and to use an appropriate…

Numerical Analysis · Mathematics 2018-02-26 Herbert Egger , Matthias Schlottbom

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

The atmospheres of planets (including Earth) and the outer layers of stars have often been treated in radiative transfer as plane-parallel media, instead of spherical shells, which can lead to inaccuracy, e.g. limb darkening. We give an…

Statistical Mechanics · Physics 2009-11-11 Michael J. Caola

Context. The numerical modeling of the generation and transfer of polarized radiation is a key task in solar and stellar physics research and has led to a relevant class of discrete problems that can be reframed as linear systems. In order…

Solar and Stellar Astrophysics · Physics 2021-12-08 Gioele Janett , Pietro Benedusi , Luca Belluzzi , Rolf Krause

Solving the continuum radiative transfer equation in high opacity media requires sophisticated numerical tools. In order to test the reliability of such tools, we present a benchmark of radiative transfer codes in a 2D disc configuration.…

Solar and Stellar Astrophysics · Physics 2015-05-13 C. Pinte , T. J. Harries , M. Min , A. M. Watson , C. P. Dullemond , P. Woitke , F. Menard , M. C. Duran-Rojas

The sizable linear polarization signals produced by the scattering of anisotropic radiation in the core of the Ca I 4227 $\mathrm{\r{A}}$ line constitute an important observable for probing the inhomogeneous and dynamic plasma of the lower…

Solar and Stellar Astrophysics · Physics 2021-03-24 J. Jaume Bestard , J. Trujillo Bueno , J. Štěpán , T. del Pino Alemán

When integrating the radiative transfer equation for polarized light, the necessity of high-order numerical methods is well known. In fact, well-performing high-order formal solvers enable higher accuracy and the use of coarser spatial…

Solar and Stellar Astrophysics · Physics 2017-09-06 Gioele Janett , Oskar Steiner , Luca Belluzzi

We simulate convection near the solar surface, where the continuum optical depth is of order unity. Hence, to determine the radiative heating and cooling in the energy conservation equation, we must solve the radiative transfer equation…

Astrophysics · Physics 2007-05-23 Robert Stein , Aake Nordlund

Principal contributions to QED radiative effects for Moller scattering of polarized particles are investigated both on the Born level and taking into account radiative corrections (RC). Scattering on the case of longitudinal and transversal…

High Energy Physics - Phenomenology · Physics 2007-05-23 N. M. Shumeiko , J. G. Suarez

A method for the fast and accurate solution of the radiative transfer equation in plane-parallel media with coherent isotropic scattering is presented. This largely analytical approach uses the formalism of meromorphic functions in order to…

Astrophysics · Physics 2007-05-23 G. V. Efimov , N. V. Kryzhevoi , W. von Waldenfels , R. Wehrse

Context: State of the art quantitative spectroscopy of OB-stars compares synthetic spectra (calculated by means of 1D, spherically symmetric computer codes) with observations. Certain stellar atmospheres, however, show strong deviations…

Solar and Stellar Astrophysics · Physics 2018-09-12 L. Hennicker , J. Puls , N. D. Kee , J. O. Sundqvist

We describe a novel adaptive ray tracing scheme to solve the equation of radiative transfer around point sources in hydrodynamical simulations. The angular resolution adapts to the local hydrodynamical resolution and hence is of use for…

Astrophysics · Physics 2009-11-07 Tom Abel , Benjamin D. Wandelt

Scattering measurements with incident linearly polarized $\gamma$ rays provide information on spins, parities, and $\gamma$-ray multipolarity mixing coefficients, and, therefore, on the nuclear matrix elements involved in the transitions.…

Nuclear Experiment · Physics 2021-06-18 Christian Iliadis , Udo Friman-Gayer

Polarimetry is about to become a powerful tool for determining the atmospheric properties of exoplanets. To provide the basis for the interpretation of observational results and for predictive studies to guide future observations,…

Earth and Planetary Astrophysics · Physics 2021-02-03 Moritz Lietzow , Sebastian Wolf , Robert Brunngräber
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