LGS AO at W. M. Keck Observatory: routine operations and remaining challenges

The Laser Guide Star Adaptive Optics (LGS AO) at the W.M. Keck Observatory is the first system of its kind being used to conduct routine science on a ten-meter telescope. In 2005, more than fifty nights of LGSAO science and engineering were carried out using the NIRC2 and OSIRIS science instruments. In this paper, we report on the typical performance and operations of its LGS AO-specific sub-systems (laser, tip-tilt sensor, low-bandwidth wavefront sensor) as well as the overall scientific performance and observing efficiency. We conclude the paper by describing our main performance limitations and present possible developments to overcome them.