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Related papers: Radiative transfer in stellar atmospheres

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The solar atmosphere is diagnosed by solving the polarized radiative transfer problem for plasmas in Non-Local Thermodynamic Equilibrium (NLTE). A key challenge in multidimensional NLTE diagnosis is to integrate efficiently the radiative…

Solar and Stellar Astrophysics · Physics 2025-03-31 E. S. Carlin , S. Blanes , F. Casas

We derive radiative transport equations for solutions of a Schr\"odinger equation in a periodic structure with small random inhomogeneities. We use systematically the Wigner transform and the Bloch wave expansion. The streaming part of the…

Statistical Mechanics · Physics 2015-06-25 Guillaume Bal , Albert Fannjiang , George Papanicolaou , Leonid Ryzhik

We develop a method of analyzing radio frequency spectral line observations to derive data on the temperature, density, velocity, and molecular abundance of the emitting gas. The method incorporates a radiative transfer code with a new…

Astrophysics · Physics 2009-11-10 Eric Keto , George B. Rybicki , Edwin A. Bergin , Rene Plume

Polarized NLTE radiative transfer in the presence of scattering in spectral lines and/or in continua may be cast in a so-called reduced form for six reduced components of the radiation field. In this formalism the six components of the…

Solar and Stellar Astrophysics · Physics 2015-06-17 Marianne Faurobert , Ivan Milic , Olga Atanackovic

We present a program suite for the radiative transfer problem solution in axi-symmetrical dusty galaxy disks, intended primarily for spectrophotometric analysis of stellar populations by means of integrated and differential photometry. The…

Astrophysics · Physics 2007-05-23 D. Semionov , V. Vansevicius

A finite element method for solving the resonance line transfer problem in moving media is presented. The algorithm works in three spatial dimensions on unstructured grids which are adaptively refined by means of an a posteriori error…

Astrophysics · Physics 2009-11-07 E. Meinkoehn , S. Richling

This paper presents an overview of the radiative transfer problem of calculating the spectral line intensity and polarization that emerges from a (generally magnetized) astrophysical plasma composed of atoms and molecules whose excitation…

Solar and Stellar Astrophysics · Physics 2015-05-14 J. Trujillo Bueno

Nuclear reaction rates are one of the most important ingredients in describing how stars evolve. The study of the nuclear reactions involved in different astrophysical sites is thus mandatory to address most questions in nuclear…

Nuclear Experiment · Physics 2021-07-29 Faïrouz Hammache , Nicolas de Séréville

New high-resolution spectropolarimetric observations of solar prominences require improved radiative modelling capabilities in order to take into account both multi-dimensional - at least 2D - geometry and complex atomic models. This makes…

Astrophysics · Physics 2009-11-13 L. Leger , L. Chevallier , F. Paletou

This review paper outlines background information and covers recent advances made via the analysis of spectra and images of prominence plasma and the increased sophistication of non-LTE (ie when there is a departure from Local Thermodynamic…

Solar and Stellar Astrophysics · Physics 2011-05-10 N. Labrosse , P. Heinzel , J. -C. Vial , T. Kucera , S. Parenti , S. Gunar , B. Schmieder , G. Kilper

In the present article, we discuss a numerical method of solution for the so-called "full non-LTE" radiation transfer problem, basic formalism of which was revisited by Paletou & Peymirat (2021; see also Oxenius 1986). More specifically,…

Instrumentation and Methods for Astrophysics · Physics 2023-03-15 F. Paletou , M. Sampoorna , C. Peymirat

I suggest a novel type of nuclear reactions in accreting neutron stars - neutron transfer, which is quantum tunneling of weakly bounded neutron from one nucleus to another. I estimate the rate of this process for fixed nuclei separation and…

Nuclear Theory · Physics 2018-12-07 Andrey I. Chugunov

The standard nonlocal thermodynamic equilibrium (non-LTE) multi-level radiative transfer problem only takes into account the deviation of the radiation field and atomic populations from their equilibrium distribution. We aim to show how to…

Solar and Stellar Astrophysics · Physics 2026-02-13 Tristan Lagache , Frédéric Paletou , Malali Sampoorna

The aim of this work is to draw attention to the processes of radiative charge exchange in non-symmetric ion-atom collisions as a factor of influence on the opacity of stellar atmospheres in VUV region. For that purpose calculations of the…

Solar and Stellar Astrophysics · Physics 2013-11-05 V. A. Sreckovic , A. A. Mihajlov , Lj. M. Ignjatovic , M. S. Dimitrijevic

Optical/UV photons and even harder radiation components in galaxies are absorbed and scattered by dust and re-emitted at infrared wavelengths. For a better understanding of the obscured regions of the galaxies detailed models of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Ralf Siebenmorgen , Frank Heymann

We present a new radiative transfer code for axi-symmetric stellar atmospheres and compare test results against 1D and 2D models with and without velocity fields. The code uses the short characteristic method with modifications to handle…

Astrophysics · Physics 2009-11-11 J. Zsargo , D. J. Hillier , L. N. Georgiev

Using the methods of general relativity Lindquist derived the radiative transfer equation that is correct to all orders in v/c. Mihalas developed a method of solution for the important case of monotonic velocity fields with spherically…

Solar and Stellar Astrophysics · Physics 2014-11-20 E. Baron , Bin Chen , P. H. Hauschildt

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

We study the Radiative Transfer equations coupled with the time dependent temperature equation of a fluid: existence, uniqueness, a maximum principle are established. A short numerical section illustrates the pros and cons of the method.

Analysis of PDEs · Mathematics 2021-12-30 Francois Golse , Olivier Pironneau

The radiative properties of most structures are intimately connected to the way in which their constituents are ordered on the nano-scale. We have proposed a new representation for radiative heat transfer formalism in many-body systems. In…

Mesoscale and Nanoscale Physics · Physics 2017-10-04 Moladad Nikbakht
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