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Paper: Stellar Atomic Opacities
Volume: 515, Workshop on Astrophysical Opacities
Page: 3
Authors: Turck-Chièze, S.
Abstract: Atomic opacities are fundamental ingredients of stellar evolution: they largely determine the energy transfer inside the stellar interiors and play crucial roles in the stellar ages and in any thermodynamic indicator. They are determined by complex atomic calculations performed for a large range of temperatures and densities and numerous ionic species. Therefore, their knowledge was for a long time purely theoretical, and the available tables were the result of different approaches often used as black boxes. Differences were observed among them but their origin was not so clear; their resolution has been stimulated by the development of stellar seismology that scrutinizes the stellar interiors, and by the hope of astrophysicists to validate the physics contained in the stellar evolution codes. In the 1990s the high quality of the measured solar neutrino fluxes and of the solar acoustic modes encouraged an update of these calculations. At the same time the first dedicated opacity measurements have also been performed. During the last decade the asteroseismic space probes (COROT, KEPLER) have encouraged new comparisons between the theoretical teams (mainly in France and the USA) and the generation of new tables. Opacity measurements at the Sandia Laboratory Z facility and promising ones on high-energy laser facilities (OMEGA, NIF, LMJ) present new challenges for accurate opacities. This review shows an astrophysicist's point of view with interesting comparisons and suggestions for new perspectives.
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