Program

Tutorial1: Imaging – photometry and astrometry

Goal: familiarize students with the notion of PSF. Illustrate different sort of high-angular PSFs, and introduce the different concepts of Adaptive Optics (SCAO, LTAO, MCAO, GLAO). Use standard photometry tools (e.g. DAOphot, StarFinder, SuperStar), and evaluate the impact of the PSF on the photometry accuracy. Define PSF models, and evaluate the PSF variations over the field and in time. Introduce astrometry standard tools (e.g. starfinder), and introduce systematics error in astrometry.

Tutorial2: Spectroscopy.

Open and understand a 3D data cube. Understand the transformations from the raw data to the 3D data cube. Extract spatial and spectral information from a cube. Introduce the Line Spread Function (LSF) concept. Illustrate the impact of Beam Smearing, and its impact on velocity dispersion measurements. Understand the impact of under sampling the PSF. Retrieve the velocity fields of a distant galaxy.

Tutorial3: High-Contrast imaging

Introduce the concept of coronagraphy, and the different sort of coronagraphs. Understand the impact of residual speckles on planet detection. Introduce the concepts of Angular Differential Imaging (ADI) and Spectral Differential Imaging (SDI). Compute the raw contrast, and post-processing contrast on real images. Compute the fundamental limit of photon noise. Derive the contrast limit needed to detect an exo-earth on a 40m telescope.

Ressources (python code) will be available for all the tutorials on a dedicated Wiki page.

Driving through an AO bench

We will take the opportunity to travel the main components of an AO bench, and try to understand the impact of different factors on the final PSF. By using an AO bench developped at LAM (and called LOOPS) we will see the impact of the seeing, or of some fundamental design choice on the expected performance. This will be done as an interactive exercice.

Virtual tour of Gemini & VLT control room

If conditions allow, we will organize a virtual tour of the VLT and Gemini control room, to better understand how large telescopes are operated, and what are the observation carried with these telescopes.