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Related papers: Detailed Opacity Calculations for Stellar Models

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The broadening of lines by Stark effect is widely used for inferring electron density and temperature in plasmas. Stark-effect calculations often rely on atomic data (transition rates, energy levels,...) not always exhaustive and/or valid…

Atomic Physics · Physics 2017-04-05 Jean-Christophe Pain , Franck Gilleron , Maxime Comet , Dominique Gilles

Calculating opacities for a wide range of plasma conditions (i.e. temperature, density, element) requires detailed knowledge of the plasma configuration space and electronic structure. For plasmas composed of heavier elements, relativistic…

Plasma Physics · Physics 2023-05-02 Nathanael Gill , Christopher Fontes , Charles Starrett

We describe the Cool Opacity-sampling Dynamic EXtended (CODEX) atmosphere models of Mira variable stars, and examine in detail the physical and numerical approximations that go in to the model creation. The CODEX atmospheric models are…

Astrophysics · Physics 2009-11-13 M. J. Ireland , M. Scholz , P. R. Wood

We present what constraints on opacities can be derived from the analysis of stellar pulsations of BA-type main-sequence stars. This analysis consists of the construction of complex seismic models which reproduce the observed frequencies as…

Solar and Stellar Astrophysics · Physics 2019-12-03 Jadwiga Daszynska-Daszkiewicz , Przemyslaw Walczak , Alosha Pamyatnykh , Wojciech Szewczuk

Laboratory (laser and Z-pinch) opacity measurements of well-characterized plasmas provide data to assist inertial confinement fusion, astrophysics and atomic-physics research. In order to test the atomic-physics codes devoted to the…

Plasma Physics · Physics 2020-02-19 Jean-Christophe Pain , Franck Gilleron

Pulsating stars are universally recognized as precise distance indicators and tracers of stellar populations. Their variability, combined with well-defined relationships between pulsation properties and intrinsic evolutionary parameters…

Solar and Stellar Astrophysics · Physics 2024-11-05 Giulia De Somma , Marcella Marconi , Santi Cassisi , Roberto Molinaro

Spectral energy distributions for models of arbitrarily rotating stars are computed using two dimensional rotating stellar models, NLTE plane parallel model atmospheres, and a code to integrate the appropriately weighted intensities over…

Astrophysics · Physics 2008-05-09 A. Gillich , R. Deupree , C. Lovekin , I. Short , N. Toque

An overview of selected topical problems on modelling oscillation properties in solar-like stars is presented. High-quality oscillation data from both space-borne intensity observations and ground-based spectroscopic measurements provide…

Solar and Stellar Astrophysics · Physics 2011-03-28 Gunter Houdek

The calculation of line widths constitutes theoretical and computational challenges in the calculation of opacities of hot dense plasmas. Opacity models use line broadening approximations that are untested at stellar interior conditions.…

Solar and Stellar Astrophysics · Physics 2016-06-22 M. Krief , A. Feigel , D. Gazit

In this review given at the Hot and Cool: Bridging Gaps in Massive Star Evolution conference, I present the state of the art in red supergiant star atmosphere modelling. The last generation of hydrostatic 1D LTE MARCS models publicly…

Solar and Stellar Astrophysics · Physics 2009-03-23 Bertrand Plez

For high temperatures and densities, stellar opacities obtained from the Opacity Project (OP) were smaller than those obtained from the OPAL project. Iglesias and Rogers [Ap.J. v443, 469 (1995)] suggested that the discrepancy was due to the…

Astrophysics · Physics 2009-11-10 N. R. Badnell , M. J. Seaton

Stars play a decisive role in our Universe, from its beginning throughout its complete evolution. For a thorough understanding of their properties, evolution, and physics of their outer envelopes, stellar spectra need to be analyzed by…

Solar and Stellar Astrophysics · Physics 2024-09-06 Joachim Puls , Artemio Herrero , Carlos Allende Prieto

We have included opacity tables in our stellar evolution code that enable us to accurately model the structure of stars composed of mixtures with carbon and oxygen independently enhanced relative to solar. We present tests to demonstrate…

Astrophysics · Physics 2009-11-10 J. J. Eldridge , C. A. Tout

We examine the role of opacities in stellar pulsation with reference to Cepheids and RR Lyraes, and examine the effect of augmented opacities on the theoretical pulsation light curves in key temperature ranges. The temperature ranges are…

Solar and Stellar Astrophysics · Physics 2018-06-11 S. M. Kanbur , M. Marconi , A. Bhardwaj , R. Kundu , H. P. Singh

Stellar seismology appears more and more as a powerful tool for a better determination of the fundamental properties of solar-type stars. However the particular case of Sun is still challenging. The helioseismic sound speed determination…

The excitation of pulsation modes in beta Cephei and Slowly Pulsating B stars is known to be very sensitive to opacity changes in the stellar interior where T~2 10^5 K. In this region differences in opacity up to ~50% can be induced by the…

Astrophysics · Physics 2009-11-13 Andrea Miglio , Josefina Montalban , Marc-Antoine Dupret

Codes to compute mean opacities and radiative accelerations for arbitrary chemical mixtures using the Opacity Project recently revised data have been restructured in a client--server architecture and transcribed as a subroutine library.…

We review the main results obtained from our seismic studies of B-type main sequence pulsators, based on the ground-based, MOST, Kepler and BRITE observations. Important constraints on stellar opacities, convective overshooting and rotation…

Solar and Stellar Astrophysics · Physics 2018-12-04 Jadwiga Daszynska-Daszkiewicz , Przemysław Walczak , Wojciech Szewczuk , Alosha Pamyatnykh

Analysis of high-resolution stellar spectra relies heavily upon atomic data. These include energy levels, wavelengths, cross-sections for various types of interactions between particles and photons, such as photoionization and collision…

Solar and Stellar Astrophysics · Physics 2011-04-12 Maria Bergemann

Models of radiation transport in stellar atmospheres are the hinge of modern astrophysics. Our knowledge of stars, stellar populations, and galaxies is only as good as the theoretical models, which are used for the interpretation of their…

Solar and Stellar Astrophysics · Physics 2016-07-27 Maria Bergemann