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Apports de la sismologie des étoiles F et G à l'étude des cœurs convectifs.

Abstract : The high-quality seismic data obtained with the CoRoT satellite open new opportunities for the study of stellar interiors and evolution. My PhD thesis consisted of the analysis and the interpretation of the oscillation spectra of several solar-like pulsators observed from both the ground and space, in particular with the CoRoT satellite. When analyzing an oscillation spectrum, the goal is to determine the parameters of the star pulsation modes (the eigenfrequencies, amplitudes, lifetimes,...). Within the DAT (group responsible for the analysis of the solar-like pulsators observed with CoRoT), I contributed to adapt to the studied objects a method successfully used to extract the mode parameters of the Sun. I applied this method to the analysis of the first five solar-like pulsators observed with CoRoT. Particular care was given to the determination of the significance of the detected peaks, which strengthened the detection of mixed modes in the spectrum of the star HD 49385. In the framework of the interpretation of the oscillation spectra, I investigated the information which the seismic parameters convey about the structure of the core for several of the analyzed stars. These stars have (or have had) a convective core, whose characteristics depend on chemical transport processes (e.g. overshooting), which are currently ill-described by theoretical models. I modeled three solar-like pulsators which have different masses and evolutionary stages. Their seismic parameters make it possible to probe their cores and therefore to obtain observational constraints on the processes of transport. In particular, the detection of mixed modes in avoided crossing in the spectrum of the star HD 49385 has led me to study how this type of mode can contribute to the understanding of the structure of the core.
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https://tel.archives-ouvertes.fr/tel-00553197
Contributor : Sébastien Deheuvels <>
Submitted on : Thursday, January 6, 2011 - 4:57:19 PM
Last modification on : Monday, December 14, 2020 - 9:52:15 AM
Long-term archiving on: : Thursday, April 7, 2011 - 3:12:25 AM

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  • HAL Id : tel-00553197, version 1

Citation

Sébastien Deheuvels. Apports de la sismologie des étoiles F et G à l'étude des cœurs convectifs.. Astrophysique [astro-ph]. Observatoire de Paris, 2010. Français. ⟨tel-00553197⟩

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