Ringberg Conference
Oct 29 - Nov 2, 2007

Astronomy with Laser Guide Star
Adaptive Optics

The field of Adaptive Optics (AO) for astronomy has matured in recent years, and diffraction-limited image resolution in the near-infrared spectral range is now routinely achieved by most 8-10m class tele-scopes. In order to work, adaptive optics needs a nearby reference star that has to be relatively bright, thereby limiting the area of the sky that can be surveyed. To overcome this limitation, astronomers use a powerful laser that creates an artificial star – a so called laser guide star (LGS) – where and when they need it. The combination of both techniques, LGS and AO, has opened new research windows to galactic and extragalactic astronomy. Research topics range from the study of binary brown dwarf systems, search for exo-planets, observations of young, massive stars, starburst clus-ters, galactic black holes and active galactic nuclei, galaxy clusters as well as high redshift galaxies, including those magnified by gravi-tational lensing effects.

This workshop is intented to bring together scientists and engineers working in the field of Laser Guide Star Adaptive Optics.

The aims of this meeting can be summarised in the following points:
The purpose of LGS-AO is to widen the range and increase the impact of astrophysics that is possible with adaptive optics. Therefore, we ask: for what science are LGS-AO systems being used?

Evaluation and discussion of the first science results obtained from LGS-AO systems. In particular:
Galactic center and AGN, galactic and extra-galactic star formation, solar system objects, brown dwarfs, galaxies and cosmology.

LGS-AO systems are designed to produce high strehl ratios and diffrac-tion limited observations over most of the sky. Are the systems living up to these expectations?

The first generation of LGS systems on 3-m class telescopes (at the Lick Observatory, and at Calar Alto, the MPIA/MPE system) were difficult to use; the new generation on 8- to 10-m class telescopes

are significantly better. Are we now confident that LGS-AO could become part of the standard observing procedure, as is envisaged for the next generation of extremely large telescopes?

Have LGS-AO systems been employed in novel methods of observing (e.g. if there is no natural star for tip-tilt compensation)? Have these been successful?

Knowledge of the Point Spread Function is of crucial importance for extracting the most information from the data. What progress has been made in determining this for LGS-AO (either empirically through additional observations or via modelling)?

What lessons have been learned either in the design or operation of the LGS-AO systems that should be borne in mind when designing future systems for ELTs?

last update: 16 November 2007
editor of this page: Stefan Hippler