Interferometric observations of δVelorum

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Table of contents

1 Introduction: Our screen towards the Universe, the turbulent atmosphere
1.1 Looking through the screen
1.2 Characterizing the screen
1.2.1 The notion of turbulence
1.2.2 Is there a theory of turbulence?
1.2.3 Parameters for the viewing condition and their dependence on turbulence
1.2.4 Statistical description of atmospheric turbulence
1.2.5 Coherence-time measurements
1.3 Constituents of this thesis
1.3.1 Assessing time scales of turbulence at Dome C, Antarctica
1.3.2 A new instrument to measure the coherence time
1.3.3 Astrophysical application: interferometric observations of δVelorum
2 A method of estimating time scales of atmospheric piston and its application at DomeC (Antarctica) 
2.1 Introduction
2.2 Measurements
2.2.1 Observational setup
2.2.2 Data description
2.3 Quantifying the motion of the fringe pattern and the Airy discs
2.4 Coherence time
2.4.1 Estimating coherence time through Fourier analysis
2.4.2 Estimating coherence time through the evolution of correlation
2.4.3 Optimal setup for coherence time measurements
2.5 Conclusion
3 A method of estimating time scales of atmospheric piston and its application at DomeC (Antarctica) 
3.1 Introduction
3.2 Formalism
3.3 Measurements at Paranal
3.3.1 Observational set-up
3.3.2 Derivation of atmospheric parameters
3.3.3 Performance of the piston scope
3.4 Measurements at DomeC
3.5 Conclusions
4 Atmospheric coherence times in interferometry: definition and measurement
4.1 Introduction
4.2 Atmospheric coherence time in interferometry
4.2.1 Atmospheric coherence time τ0
4.2.2 Piston time constant
4.2.3 Piston power spectrum and structure function
4.2.4 Error of a fringe tracking servo
4.2.5 Summary of definitions and discussion
4.3 Measuring the atmospheric time constant
4.3.1 Existing methods of τ0 measurement
4.3.2 The new method: FADE
4.4 Conclusions
4.5 Appendix A – Derivation of the piston structure function
4.6 Appendix B – Fast focus variation
5 FADE, an instrument to measure the atmospheric coherence time 
5.1 Introduction
5.2 The instrument
5.2.1 Operational principle
5.2.2 Hardware
5.2.3 Optics
5.2.4 Acquisition software
5.2.5 Observations
5.3 Data analysis
5.3.1 Estimating the ring radius
5.3.2 Noise and limiting stellar magnitude
5.3.3 The response coefficient of FADE
5.3.4 Derivation of the seeing and coherence time
5.4 Analysis of observations
5.4.1 Influence of instrumental parameters
5.4.2 Comparison with MASS and DIMM
5.5 Conclusions and perspectives
5.6 Appendix A – Estimator of the ring radius and center
5.7 Appendix B – Structure function of atmospheric defocus
5.8 Appendix C – Simulations
5.8.1 Simulation tool
6 Interferometric observations of the multiple stellar system δVelorum 
6.1 Introductory remarks to the article
6.2 Introduction
6.3 Characteristics of δ Vel A derived from previous measurements .
6.3.1 Orbit orientation and eccentricity
6.3.2 Semi-major axis and stellar parameters
6.4 VLT Interferometer/VINCI observations
6.4.1 Data description
6.4.2 Comparison to a model
6.5 Results and discussion
6.5.1 The close eclipsing binary δVel (Aa-Ab)
6.5.2 The physical association of δVel C and D
6.6 Summary
7 Conclusion 
Bibliography