MUSE+GALACSI: the First Years

The Multi-Unit Spectroscopic Explorer instrument (MUSE), is an integral-field spectrograph at one of the Nasmyth foci of the 8m-class Yepun telescope at Paranal observatory. MUSE's most powerful modes use the Adaptive Optics Facility consisting of a Deformable Secondary Mirror with over 1000 actuators commanded by a real-time computer up to 1000 times per second. At the core of the system are 4 laser guide stars monitored by GALACSI, the wave-front sensor system. MUSE functions with two modes: Wide-Field Mode (1'x1' field), making use of Ground Layer Adaptive Optics and Narrow-Field Mode (7.5"x7.5" field) using full laser tomography. In this work, we will present the results of a campaign to monitor the AO performance as measured by MUSE during the first years of operations. We will evaluate the dependence of this performance, as characterized by the point-spread function, on easily monitored environmental parameters such as ground-layer fraction, coherence time, seeing, and airmass.