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Related papers: Radiation Transfer in Cloud Layers

200 papers

A cloud of cold N two-level atoms driven by a resonant laser beam shows cooperative effects both in the scattered radiation field and in the radiation pressure force acting on the cloud center-of-mass. The induced dipoles synchronize and…

Atomic Physics · Physics 2013-02-05 Tom Bienaime , Romain Bachelard , Nicola Piovella , Robin Kaiser

To describe the energy transport in the seismic coda, we introduce a system of radiative transfer equations for coupled surface and body waves in a scalar approximation. Our model is based on the Helmholtz equation in a half-space geometry…

Geophysics · Physics 2019-09-04 Ludovic Margerin , Andres Bajaras , Michel Campillo

A dense cloud of atoms with randomly changing positions exhibits coherent and incoherent scattering. We show that an atomic cloud of subwavelength dimensions can be modeled as a single scatterer where both coherent and incoherent components…

Quantum Physics · Physics 2021-06-30 Rasoul Alaee , Akbar Safari , Robert W. Boyd

We develop a scattering theory to investigate the multi-photon transmission in a one-dimensional waveguide in the presence of quantum emitters. It is based on a path integral formalism, uses displacement transformations, and does not…

Quantum Physics · Physics 2015-11-25 Tao Shi , Darrick E. Chang , J. Ignacio Cirac

We assume a distribution of clouds optically thick for electron scattering (OTCM) which are moderately optically thin for absorption and we consider them as a model of the mean quasar spectrum of Laor et al. (1997). We show that the model…

Astrophysics · Physics 2007-05-23 B. Czerny , A. -M. Dumont

We discuss the scattering of photons from a three-level emitter in a one-dimensional waveguide, where the transport is governed by the interference of spontaneously emitted and directly transmitted waves. The scattering problem is solved in…

Quantum Physics · Physics 2010-11-15 D. Witthaut , A. S. Sorensen

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 introduce a model for charge and heat transport based on the Landauer-Buttiker scattering approach. The system consists of a chain of $N$ quantum dots, each of them being coupled to a particle reservoir. Additionally, the left and right…

Mesoscale and Nanoscale Physics · Physics 2009-03-19 Philippe A. Jacquet

(abridged) We calculate near-infrared thermal emission spectra using a doubling-adding radiative transfer code, which includes scattering by clouds and haze. Initial temperature profiles and cloud optical depths are taken from the…

Earth and Planetary Astrophysics · Physics 2011-08-08 R. J. de Kok , Ch. Helling , D. M. Stam , P. Woitke , S. Witte

We discuss the different physical processes contributing to the infrared continuum of AGN, assuming that both photoionization from the active center and shocks ionize and heat the gas and dust contained in an ensemble of clouds surrounding…

Astrophysics · Physics 2009-11-10 M. Contini , S. M. Viegas , M. A. Prieto

The high resolution and sensitivity provided by proposed Atacama Large Millimeter Array will reveal new small scale structures in many sources, e.g. star forming regions. Such inhomogeneities may not have been considered in the analysis of…

Astrophysics · Physics 2007-05-23 M. Juvela , P. Padoan

Spectral lines of helium are commonly observed on the Sun. These observations contain important informations about physical conditions and He/H abundance variations within solar outer structures. The modeling of chromospheric and coronal…

Solar and Stellar Astrophysics · Physics 2011-05-19 Pierre Gouttebroze , Nicolas Labrosse

Mid and far infrared maps of many Galactic star forming regions show multiple peaks in close proximity, implying more than one embedded energy sources. With the aim of understanding such interstellar clouds better, the present study models…

Astrophysics · Physics 2009-10-31 A. D. Karnik , S. K. Ghosh

We study the effect of a weakly driven atomic cloud's polarization distribution on its photon scattering lineshape. In doing this, we find three distinct polarization regimes. First, for dilute clouds, the polarization magnitude is…

Atomic Physics · Physics 2020-01-15 F. Robicheaux , R. T. Sutherland

As the 3D spatial properties of exoplanet atmospheres are being observed in increasing detail by current and new generations of telescopes, the modelling of the 3D scattering effects of cloud forming atmospheres with inhomogeneous opacity…

Earth and Planetary Astrophysics · Physics 2021-06-04 Elspeth Lee , Kenneth Wood , Ian Dobbs-Dixon , Anna Rice , Christiane Helling

It is possible to fabricate mesoscopic structures where at least one of the dimensions is of the order of de Broglie wavelength for cold electrons. By using semiconductors, composed of more than one material combined with a metal slip-gate,…

Quantum Physics · Physics 2017-08-23 B. Nilsson

We present and discuss the results of new multiple-scattering radiative transfer calculations for three representative types of galactic environments, filled with either homogeneous or two-phase clumpy dust distributions. Extinction and…

Astrophysics · Physics 2009-10-05 Adolf N. Witt , Karl D. Gordon

We present the results of a series of calculations studying the collapse of molecular cloud cores performed using a three-dimensional smoothed particle hydr odynamics code with radiative transfer in the flux-limited diffusion approximation.…

Astrophysics · Physics 2009-11-13 Stuart C. Whitehouse , Matthew R. Bate

We present the implementation of a radiative transfer solver with coherent scattering in the new BIFROST code for radiative magneto-hydrodynamical (MHD) simulations of stellar surface convection. The code is fully parallelized using MPI…

Solar and Stellar Astrophysics · Physics 2017-11-08 W. Hayek , M. Asplund , M. Carlsson , R. Trampedach , R. Collet , B. V. Gudiksen , V. H. Hansteen , J. Leenaarts

We present a wide grid of models for the structure and transmission properties of warm absorbers in active galactic nuclei (AGN). Contrary to commonly used constant density models, our absorbing cloud is assumed to be under constant total…

Astrophysics · Physics 2007-05-23 A. Rozanska , R. Goosmann , A. -M. Dumont , B. Czerny