The Adaptive Optics (AO) system is used at the Cassegrain focus of the Shane 3-meter Telescope. It can be used in either natural guide star (NGS) or laser guide star (LGS) mode. The AO system routinely reaches the diffraction limit (0.15") at 2.2 microns.
NGS mode requires a natural guide star brighter than 13th magnitude under normal conditions, within 55" of the science target.
LGS mode requires a natural guide star brighter than 16th magnitude for tip/tilt correction, within 55" of the science target. Laser operations are also restricted to elevations greater than 45 degrees and from 10pm to 5am local time due to air traffic from the regional airports.
The AO system feeds IRCAL, an AO-optimized IR camera that uses a 256x256 Rockwell PICNIC array which is sensitive from 0.9 - 2.5 microns and provides Nyquist sampled imaging at 2.2 microns (0.076 arcsec/pix). The internal image quality is excellent over the entire 19.4 arcsecond field of view. IRCAL is equipped with standard near-IR photometric filters and some narrow-band filters. User supplied filters can be installed in a warm external filter wheel. IRCAL also has grisms for medium resolution (R=500) H and K spectroscopy.
AO has been in operation since 1996 as an LLNL R&D project, under Claire Max and Scot Olivier. A major redesign of the optics by Brian Bauman and Don Gavel occurred from 1999-2001. The system became available for use as a science instrument by the UC community in Fall 2001. Further upgrades to the AO system (particularly for LGS mode) continue through the present to improve performance, reliability, and efficiency.
The AO system is now a Lick Observatory facility instrument, available to the University of California astronomical community by subscription. Follow these links to:
It is recommended that new AO users contact Elinor Gates firstname.lastname@example.org prior to proposal submission so that we can be sure you have enough information to assess whether adaptive optics is feasible for your observations.Please direct questions to a Mount Hamilton support astronomer
Contributors to manual: