Recherche de compagnons de faible masse par Optique Adaptative

Abstract : In the last decade, the field of the search and study of cold companions around solar neighborhood stars has greatly improved. The study of low mass stellar companions and brown dwarf companions brings important constraints in the understanding of stellar formation. The study of planetary systems allows us to understand the formation of our own solar system. Up to now, most systems were discovered with the radial velocities technique. This technique is an indirect method that prevents from analysing the photons of a cold companion. The next step consists in detecting and analysing the photons of such companions. Many projects of high contrast imaging instruments have been recently developed in order to fulfil this task. This thesis was inspired by the scientific preparation and the development of such a project: the SPHERE instrument that will be installed at the Very Large Telescope in Chile in 2012. In the first part, I introduce the astrophysical questions that motivate the search for star companions and describe the two observation techniques that I used during my PhD: high contrast imaging and radial velocities techniques. A state of art about the status of the search for low mass stellar companions, brown dwarf companions and planetary companions is also done. In the second part, I describe the observation, data reduction and analysis techniques I used. The third part presents a study on the brown dwarf desert around around solar type stars that were selected from a sample of stars with radial velocity drift. In the fourth part, I develop an observation work that consists in detecting the planetary or brown dwarf companions around red dwarfs. The last part is devoted to the description of the SPHERE instrument and to my own contribution into this instrumental project.


https://tel.archives-ouvertes.fr/tel-00714874
Contributor : Guillaume Montagnier <>
Submitted on : Thursday, July 5, 2012 - 7:56:11 PM
Last modification on : Friday, July 6, 2012 - 1:13:59 PM

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  • HAL Id : tel-00714874, version 1

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Guillaume Montagnier. Recherche de compagnons de faible masse par Optique Adaptative. Solar and Stellar Astrophysics [astro-ph.SR]. Université Joseph-Fourier - Grenoble I, 2008. French. <tel-00714874>

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