GALACSI--The Ground Layer AO system for MUSE


Remko Stuik, Roland Bacon, Ralf Conzelmann, Bernard Delabre, Enrico Fedrigo, Norbert Hubin, Miska Le Louarn, Stefan Stroebele


MUSE, the Multi-Unit Spectroscopic Explorer, is an AO assisted Integral Field Spectrograph, currently in the Preliminary Design Phase as a second generation instrument for the VLT. MUSE will feature two modes, each with an associated AO mode. The first mode is the Wide Field Mode, mainly aiming at the study of high redshift galaxies. For this mode, the AO system has to deliver an improvement of at least a factor of two over the full 1x1 arcminute Field of View. The second mode, the Narrow Field mode, aims at the high-resolution spectroscopy of nearby extended objects, for example galaxies and globular clusters. For this mode the AO system will have to deliver near-diffraction limited performance over a small field of view. In this paper we discuss the trade-offs in the current design of GALACSI--the MUSE AO system--and illustrate with a number of simulations the expected performance in the Wide- and Narrow Field Modes.