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The heating mechanism of a corona above an accretion disk in active galactic nuclei (AGNs) is still unknown. One possible mechanism is magnetic reconnection heating requiring energy equipartition between magnetic energy and gas energy in…

High Energy Astrophysical Phenomena · Physics 2014-11-11 Yoshiyuki Inoue , Akihiro Doi

Compton scattering is involved in many astrophysical situations. It is well known and has been studied in detail for the past fifty years. Exact formulae for the different cross sections are often complex, and essentially asymptotic…

High Energy Astrophysical Phenomena · Physics 2015-05-13 R. Belmont

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

Thermal conduction between a cool accretion disk and a hot inner corona can result in either evaporation of the disk or condensation of the hot corona. At low mass accretion rates, evaporation dominates and can completely remove the inner…

High Energy Astrophysical Phenomena · Physics 2015-05-20 B. F. Liu , C. Done , Ronald E. Taam

The emission from galactic black holes and Seyfert galaxies is generally understood in term of two-phase models (Haardt and Maraschi 1991, 1993). Such models postulate that a hot plasma coexists with relatively colder material in the inner…

Astrophysics · Physics 2009-11-10 Julien Malzac , Anne-Marie Dumont , Martine Mouchet

Several galactic black holes show transitions between spectral states. In this paper we present a unifying radiation transfer model that can fit the spectral data in both states. We fit individual broad-band (from 1 keV up to 4 MeV)…

Astrophysics · Physics 2007-05-23 Juri Poutanen , Paolo Coppi

Sheets of slab waveguides with sharp corners are investigated. By means of rigorous numerical experiments, we look at oblique incidence of semi-guided plane waves. Radiation losses vanish beyond a certain critical angle of incidence. One…

Optics · Physics 2016-04-20 Manfred Hammer , Andre Hildebrandt , Jens Förstner

Compton scattering plays an important role in various astrophysical objects such as accreting black holes and neutron stars, pulsars, and relativistic jets, clusters of galaxies as well as the early Universe. In most of the calculations it…

High Energy Astrophysical Phenomena · Physics 2010-07-22 Juri Poutanen , Indrek Vurm

Compton scattering by the proton has been measured using the tagged-photon facility at MAMI (Mainz) and the large-acceptance arrangement LARA. The new data are interpreted in terms of dispersion theory based on the SAID-SM99K…

In this paper we present two efficient implementations of the diffusion approximation to be employed in Monte Carlo computations of radiative transfer in dusty media of massive circumstellar disks. The aim is to improve the accuracy of the…

Instrumentation and Methods for Astrophysics · Physics 2009-11-13 M. Min , C. P. Dullemond , C. Dominik , A. de Koter , J. W. Hovenier

Accreting black holes show a complex and diverse behaviour in their soft spectral states. Although these spectra are dominated by a soft, thermal component which almost certainly arises from an accretion disc, there is also a hard X-ray…

Astrophysics · Physics 2016-01-13 P. T. Zycki , C. Done , D. A. Smith

By taking into account photon absorption, we investigate the vertical structure of accretion flows with comparable radiation and gas pressures. We consider two separate energy equations for matter and radiation in the diffusion limit. In…

High Energy Astrophysical Phenomena · Physics 2019-08-10 Maryam Samadi , Shahram Abbassi , Wei-Min Gu

We present detailed calculations of the electron thermalization by synchrotron self-absorption accounting for cooling by Compton scattering. For the first time, we solve coupled kinetic equations for electrons and photons without any…

Astrophysics · Physics 2009-06-23 Indrek Vurm , Juri Poutanen

Compton scattering is the dominant opacity source in hot neutron stars, accretion disks around black holes and hot coronae. We collected here a set of numerical expressions of the Compton scattering redistribution functions for unpolarized…

High Energy Astrophysical Phenomena · Physics 2019-01-03 J. Madej , A. Różańska , A. Majczyna , M. Należyty

X-ray observations can be used to effectively probe the galactic ecosystem, particularly its hot and energetic components. However, existing X-ray studies of nearby star-forming galaxies are limited by insufficient data statistics and a…

High Energy Astrophysical Phenomena · Physics 2025-04-23 Luan Luan , Q. Daniel Wang

Two semi-analytical approaches to solve the problem of light scattering on nanowire antennas are developed and compared. The derivation is based on the exact solution of the plane wave scattering problem in case of an infinite cylinder. The…

Optics · Physics 2015-05-27 Christian Kremers , Dmitry N. Chigrin

The inverse radiative transfer problem finds broad applications in medical imaging, atmospheric science, astronomy, and many other areas. This problem intends to recover the optical properties, denoted as absorption and scattering…

Numerical Analysis · Mathematics 2017-08-08 Qin Li , Ruiwen Shu , Li Wang

The relevance of resonant scattering (absorption by photo-excitation and re-emission out of the line of sight) in the solar corona has always been discussed controversially. Ratios of emission lines from identical ions but different…

Astrophysics · Physics 2009-11-07 J. -U. Ness , J. H. M. M. Schmitt , M. Audard , M. Guedel , R. Mewe

Accurate synchrotron transfer coefficients are essential for modeling radiation processes in astrophysics. However, their current calculation methods face significant challenges. Analytical approximations of the synchrotron emissivity,…

Instrumentation and Methods for Astrophysics · Physics 2025-06-23 David van Duren , Monika Mościbrodzka

We deduce the equations that describe how polarized radiation is Comptonized by a hot electron gas. Low frequencies are considered, and the equations are expanded to second order in electron velocities. Induced scattering terms are included…

Astrophysics · Physics 2009-10-31 Frode K. Hansen , Per B. Lilje
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