Colloquium: Arcier Benjamin (Space Flight)

13 december 2018 13:00 - Locatie: Lecture Hall C, Faculty of Aerospace Engineering, Kluyverweg 1, Delft.

Simulation and Feasibility study of the Single Laser Adaptive Optics system for the ELT/METIS

Mid-infrared observations are crucial in astrophysics, for example to probe the star formation at the earliest epoch of the Universe. The METIS instrument (Mid-Infrared ELT-based Imager and Spectrograph), based on the 39-meter aperture Extremely Large Telescope, will take advantage of the giant mirror to achieve an unrivaled resolution in mid-infrared. However, to achieve this limit, the perturbations created by the temperature fluctuations in the atmosphere need to be removed by a system called Adaptive Optics.

METIS will already have an AO system, called SCAO for Single Conjugate Adaptive Optics. However, this system will require a guide star with a K-band magnitude of 11, which considerably limits where the atmospheric compensation (thus high-resolution observations) could be done. The idea is to use an artificial guide star, called Laser Guide Star, to get rid of this constraint. For a telescope with the size of the ELT, several lasers are recommended in a configuration called Laser Tomography AO or Multi-Conjugate AO. However, because of the complexity and cost of such a solution, the only available solution for the ELT/METIS is a Single Laser AO system (SLAO), which will be less complex and expensive at the expense of a decrease in performance. The question is: What is the actual performance of such a SLAO system, and how could it be implemented on the existing instrument METIS?