CONTRIBUTION TO THE ASTRONOMICAL SITES STUDY BY MODELING AND in situ EXPERIMENTATION : APPLICATION TO THE SITES OF LA SILLA AND DOME C FOR FUTURE GIANT TELESCOPES

• Main Author: Sadibekova, Tatiana
• Other Authors: Laboratoire Universitaire d'Astrophysique de Nice (LUAN), Université Nice Sophia Antipolis (1965 - 2019) (UNS)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), European Southern Observatory (ESO), Université Nice Sophia Antipolis, Eric Fossat et Jean Vernin([e-mail]; [e-mail])
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2007
• Subjects: site characterization; atmospheric turbulence; turbulence profiles; adaptive optics parameters; charactérisation de site pour l'astronomie; turbulence atmosphérique; profils de turbulence; paramètres de l'optique adaptative; [SDU]Sciences of the Universe [physics]; [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph]; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; Antarctic; Géants; The Antarctic; Antarc*
• Online Access: https://theses.hal.science/tel-00271689; https://theses.hal.science/tel-00271689/document; https://theses.hal.science/tel-00271689/file/these_Sadibekova.pdf

This thesis was undertaken within the framework of the E-ELT project (European Extremely Large Telescope) where the site characterization for the future large telescopes is the paramount goal. The very important factor for astronomical observations is the atmospheric turbulence. Several techniques exist to measure the various integral parameters and the vertical profiles of optical turbulence. In this context I analyzed the various atmospheric profiling techniques applied to two astronomical sites : La Silla one ESO site in Chile and also the Antarctic site of the Dome C, which has been of great interest for the astronomers during the past few years. Therefore, the feasibility must be extensively studied, and proceed through an objective analysis of pros and cons. In the first part of my thesis, I review some important properties of Antarctic plateau. Then, I consider its geographical position and natural conditions that bring important advantages for astronomical observations at different wavelengths, and especially in the IR. Later, for understanding the seasonal behavior of the atmosphere above Dome C, the climatological situation, using the year-round data from the ECMWF (European Center for Medium-range Weather Forecasts) model for 2003-2004, is then presented. The results from the model are finally compared to the results already obtained from site testing campaigns at Concordia. In the second part of my thesis, I present vertical profiles of refractive index structure constant Cn2(h) measurements made at the 1-m telescope at La Silla Observatory (ESO, Chile) using the Generalized SCIDAR. Observations took place from July 2002 up to February 2003. I performed the data processing of 600Gb scintillation images to retrieve Cn2(h) and V(h) profiles using Maximum Entropy and Tikhonov Regularization inversion methods. Seeing values derived from C2n(h) profiles are successfully compared to the simultaneous seeing measurements taken with a DIMM. Five months statistics of the turbulent situation at La Silla ...