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Resonance spectral lines such as H I Ly {\alpha}, Mg II h&k, and Ca II H&K that form in the solar chromosphere are influenced by the effects of 3D radiative transfer as well as partial redistribution (PRD). So far no one has modeled these…

Solar and Stellar Astrophysics · Physics 2016-12-28 Andrii V. Sukhorukov , Jorrit Leenaarts

Partial frequency redistribution (PRD), describing the formation of the line profile, has negligible observational effects for optical depths smaller than ~10^3, at the resolving power of most current instruments. However, when the spectral…

Earth and Planetary Astrophysics · Physics 2015-05-27 Roxana E. Lupu , Paul D. Feldman , Stephan R. McCandliss , Darrell F. Strobel

This paper presents a detailed study of the scattering polarization profiles formed under partial frequency redistribution (PRD) in two thermal models of the solar atmosphere. Particular attention is given to understanding the influence of…

Solar and Stellar Astrophysics · Physics 2010-10-12 M. Sampoorna , J. Trujillo Bueno , E. Landi Degl'Innocenti

The long-standing paradox of the linear polarization signal of the Na i D1 line was recently resolved by accounting for the atom's hyperfine structure and the detailed spectral structure of the incident radiation field. That modeling relied…

Solar and Stellar Astrophysics · Physics 2023-09-25 Gioele Janett , Ernest Alsina Ballester , Luca Belluzzi , Tanausú del Pino Alemán , Javier Trujillo Bueno

Angle-frequency coupling in scattering of polarized light on atoms is represented by the angle-dependent (AD) partial frequency redistribution (PRD) matrices. There are several lines in the linearly polarized solar spectrum, for which PRD…

Solar and Stellar Astrophysics · Physics 2020-07-29 K. N. Nagendra , K. Sowmya , M. Sampoorna , J. O. Stenflo , L. S. Anusha

Modeling spectral line profiles taking frequency redistribution effects into account is a notoriously challenging problem from the computational point of view, especially when polarization phenomena (atomic polarization and polarized…

Solar and Stellar Astrophysics · Physics 2021-01-04 A. Paganini , B. Hashemi , E. Alsina Ballester , L. Belluzzi

Approximated forms of the RII and RIII redistribution matrices are frequently applied to simplify the numerical solution of the radiative transfer problem for polarized radiation, taking partial frequency redistribution (PRD) effects into…

Solar and Stellar Astrophysics · Physics 2023-11-29 Simone Riva , Nuno Guerreiro , Gioele Janett , Diego Rossinelli , Pietro Benedusi , Rolf Krause , Luca Belluzzi

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…

Radiative transfer calculations are essential for modeling planetary atmospheres. However, standard methods are computationally demanding and impose accuracy-speed trade-offs. High computational costs force numerical simplifications in…

Earth and Planetary Astrophysics · Physics 2025-11-03 Isaac Malsky , Tiffany Kataria , Natasha E. Batalha , Matthew Graham

Context. The correct modeling of the scattering polarization signals observed in several strong resonance lines requires taking partial frequency redistribution (PRD) phenomena into account. Aims. This work aims at assessing the impact and…

Hanle scattering is an important diagnostic tool to study weak solar magnetic fields. Partial frequency redistribution (PRD) is necessary to interpret the linear polarization observed in strong resonance lines. Usually angle-averaged PRD…

Solar and Stellar Astrophysics · Physics 2013-04-22 H. D. Supriya , M. Sampoorna , K. N. Nagendra , B. Ravindra , L. S. Anusha

The Ba II D2 line at 4554 A is a good example, where the F-state interference effects due to the odd isotopes produce polarization profiles, which are very different from those of the even isotopes that do not exhibit F-state interference.…

Solar and Stellar Astrophysics · Physics 2014-09-02 H. N. Smitha , K. N. Nagendra , J. O. Stenflo , M. Sampoorna

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 present a general method to calculate radiative transfer including scattering in the continuum as well as in lines in spherically symmetric systems that are influenced by the effects of general relativity (GR). We utilize a comoving…

Astrophysics · Physics 2009-11-11 S. Knop , P. H. Hauschildt , E. Baron

An angular distribution of received signals has a significant impact on their spectral and correlational properties. Most of angular dispersion models do not consider antenna patterns. The developed procedure for determining the propagation…

Information Theory · Computer Science 2025-03-25 Cezary Ziolkowski , Jan M. Kelner , Leszek Nowosielski , Marian Wnuk

Several strong solar resonance lines show observable linear scattering polarization signals, holding a great potential for investigating the magnetism of the outer solar atmosphere. Accurately modeling these signals requires solving the…

NASA's Interface Region Imaging Spectrograph (IRIS) space mission will study how the solar atmosphere is energized. IRIS contains an imaging spectrograph that covers the Mg II h&k lines as well as a slit-jaw imager centered at Mg II k.…

Solar and Stellar Astrophysics · Physics 2015-06-16 J. Leenaarts , T. M. D. Pereira , M. Carlsson , H. Uitenbroek , B. de Pontieu

Atmospheric escape is crucial to understand the evolution of planets in and out of the Solar system and to interpret atmospheric observations. While hydrodynamic escape simulations have been actively developed incorporating detailed…

Earth and Planetary Astrophysics · Physics 2024-02-27 Yuichi Ito , Tatsuya Yoshida , Akifumi Nakayama

The last decade has seen applications of Adaptive Mesh Refinement (AMR) methods for a wide range of problems from space physics to cosmology. With the advent of these methods, in which space is discretized into a mesh of many individual…

Astrophysics · Physics 2010-11-11 Argyro Tasitsiomi

Computation of propagation effects in the neutral atmosphere, namely path delay, extinction, and bending angle is a trivial task provided the 4D state of the atmosphere is known. Unfortunately, the mixing ratio of water vapor is highly…

Instrumentation and Methods for Astrophysics · Physics 2015-02-25 Leonid Petrov
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