Speaker
Dr
Sylvaine TURCK-CHIÈZE
(CEA)
Description
Stellar opacities are fundamental ingredients of stellar evolution. They contribute to the age of stars and determine the transfer of energy in stellar interiors for a great variety of stars. This transfer of energy results from complex and difficult atomic calculations that must be performed for a large number of species and for specific mixtures through a large range of temperature and density.
These ingredients for astrophysics have been known only theoretically for several decades, and the calculations have been developed by a small amount of groups mainly located in the United States even through international teams.
Nevertheless, different approaches (OPAL and OP) have been considered a long time with well-known differences. Such effort has been stimulated by the development of more and more precise measurements of the stellar interiors and the desire to validate the hypotheses contained in stellar evolution codes.
Solar neutrinos and helioseismology have constrained in the nineties new insights, and first experimental opacity measurements have been performed to validate the existing or new calculations.
More recently the development of asteroseismology and the dedicated spatial probes (SoHO, COROT, KEPLER…) have encouraged new comparisons between theoretical teams in different countries (mainly USA and France).
In parallel the realization of measurements on Z pinch in Sandia and promising ones on high-energy laser facilities (OMEGA, NIF, LMJ) represent new opportunities to progress on accurate opacities for stellar evolution.
This introduction will rapidly describes the history of the last 3 decades, the present situation and the perspectives in this field.
Primary author
Dr
Sylvaine TURCK-CHIÈZE
(CEA)
