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Related papers: General Relativistic Radiative Transfer

200 papers

We derive new equations using the mixed-frame approach for one- and two-dimensional (axisymmetric) time-dependent radiation transport and the associated couplings with matter. Our formulation is multi-group and multi-angle and includes…

Astrophysics · Physics 2011-02-11 Ivan Hubeny , Adam Burrows

In this paper, we discuss the influence of the gravitational darkening effect on the emergent spectrum of a fast-rotating, flattened neutron star. Model atmosphere codes always calculate spectra of emergent intensities and fluxes emitted…

High Energy Astrophysical Phenomena · Physics 2022-02-16 A. Majczyna , J. Madej , A. Różańska , M. Należyty

The linear polarization signals produced by scattering processes in strong resonance lines are rich in information on the magnetic and thermal structure of the chromosphere and transition region of the Sun and of other stars. A correct…

Solar and Stellar Astrophysics · Physics 2015-06-19 Luca Belluzzi , Javier Trujillo Bueno

Simple yet accurate results for radiative transfer in layered media with discontinuous refractive index are obtained by the method of K-integrals, originally developed for neutron transport analysis. These are certain weighted integrals…

Optics · Physics 2016-01-05 Adrian C Selden

The effect of scattering processes in the continuum on the formation of spectral lines in a static atmosphere with an arbitrary distribution of the internal energy sources is investigated using Ambartsumian's principle of invariance.…

Astrophysics · Physics 2009-10-31 G. Israelian

We discuss the problem of polarized radiative transfer in general relativity. We present a set of equations suitable for solving the problem numerically for the case of an arbitrary space-time metric, and show numerical solutions to example…

Instrumentation and Methods for Astrophysics · Physics 2017-06-28 Pauli Pihajoki , Antti Rantala , Peter H. Johansson

We introduce and test a new and highly efficient method for treating the thermal and radiative effects influencing the energy equation in SPH simulations of star formation. The method uses the density, temperature and gravitational…

Astrophysics · Physics 2009-11-13 D. Stamatellos , A. P. Whitworth , T. Bisbas , S. Goodwin

We present recent developments on numerical algorithms for computing photon and particle trajectories in the surrounding of compact objects. Strong gravity around neutron stars or black holes causes relativistic effects on the motion of…

High Energy Astrophysical Phenomena · Physics 2020-04-08 Fabio Bacchini , Bart Ripperda , Lorenzo Sironi

We present a novel numerical implementation of radiative transfer in the cosmological smoothed particle hydrodynamics (SPH) simulation code {\small GADGET}. It is based on a fast, robust and photon-conserving integration scheme where the…

Astrophysics · Physics 2009-06-23 M. Petkova , V. Springel

General relativistic spectra from accretion disks around rotating neutron stars in the appropriate space-time geometry for several different equation of state, spin rates and mass of the compact object have been computed. The analysis…

Astrophysics · Physics 2009-10-31 S. Bhattacharyya , R. Misra , A. V. Thampan

In non-classical linear transport the chord length distribution between collisions is non-exponential and attenuation does not respect Beer's law. Generalized radiative transfer (GRT) extends the classical theory to account for such…

Statistical Mechanics · Physics 2020-02-19 Eugene d'Eon

To derive physical properties of the neutron star surface with observed spectra, a realistic model spectrum of neutron star surface emission is essential. Limited by computing resources, a full computation of the radiative transfer…

Astrophysics · Physics 2007-05-23 L. W. Yeh , G. T. Chen , H. K. Chang

When a laser beam passes through a rotating ground glass (RGG), the scattered light exhibits thermal statistics. This is extensively used in speckle imaging. This scattering process has not been addressed in photon picture and is especially…

Quantum Physics · Physics 2020-07-01 Sheng-Wen Li , Fu Li , Tao Peng , G. S. Agarwal

The improvement in observational facilities requires refining the modelling of the geometrical structures of astrophysical objects. Nevertheless, for complex problems such as line overlap in molecules showing hyperfine structure, a detailed…

Astrophysics · Physics 2015-03-13 F. Daniel , J. Cernicharo

We have calculated gamma-ray radiative transport in regions of high energy density, such as gamma-ray burst source regions, using a discrete ordinate, discrete energy group method. The calculations include two-photon pair production and…

Astrophysics · Physics 2009-10-22 B. J. Carrigan , J. I. Katz

We present a new formal solution of the Lagrangian equation of radiative transfer that is useful in solving the equation of radiative transfer in the presence of arbitrary velocity fields. Normally a term due to the inclusion of the…

Solar and Stellar Astrophysics · Physics 2009-11-13 S. Knop , P. H. Hauschildt , E. Baron

We have studied the impact of cosmic-ray acceleration in SNR on the spectra of cosmic-ray nuclei in the Galaxy using a series expansion of the propagation equation, which allows us to use analytical solutions for part of the problem and an…

Astrophysics · Physics 2009-11-10 I. Buesching , A. Kopp , M. Pohl , R. Schlickeiser , C. Perrot , I. Grenier

Within the framework of macroscopic quantum electrodynamics and scattering theory, we derive the general expressions for the variance of radiative heat transfer between two arbitrarily shaped objects placed in an arbitrary environment in…

Mesoscale and Nanoscale Physics · Physics 2020-07-29 F. Herz , C. Kathmann , S. -A. Biehs

Giant resonances (GRs) provide crucial insights into nuclear physics and astrophysics. Exciting GRs using particles like electrons is effective, yet the angular momentum (AM) transfer of electrons, including both intrinsic spin and orbital…

Context: Knowledge about hot, massive stars is usually inferred from quantitative spectroscopy. To analyse non-spherical phenomena, the existing 1D codes must be extended to higher dimensions, and corresponding tools need to be developed.…

Solar and Stellar Astrophysics · Physics 2019-12-25 L. Hennicker , J. Puls , N. D. Kee , J. O. Sundqvist