AO188
Introduction
Note: In S09B, Subaru new AO system (AO188) is available with IRCS only in the natural guide star (NGS) mode. Those who submit proposals using AO188+IRCS are encouraged to make contact with the AO188 development team in advance.
AO188 is equipped with a 188 element wavefront curvature sensor with photon counting APD modules and a 188 element bimorph mirror. AO188 is installed at the IR Nasmyth platform of Subaru telescope, whereas our previous AO36 system was operated at the Cassegrain focus. This can be used in either natural guide star (NGS) or laser guide star (LGS) mode.
The open-use instrument operated with AO188 is IRCS. HiCIAO and Kyoto-3DII will also be available with AO188 as PI type instruments. AO188 has successfully completed the first light observations with IRCS in late 2006 (see the press release). AO188 NGS mode has been offered for open use observations since 2008B. Currently, LGS mode is in commissioning phase.
For the NGS mode operation, a natural guide star is required. The guide star should be a bright star located within 30 arcsec of from your target. You can also use your target itself as the NGS. To obtain reasonable performance improvement, the NGS should be brighter than R magnitude of 16.5. Diffraction-limited spatial resolution can be achieved at KLM-band with a sufficiently bright guide star at good observing conditions. At shorter wavelength (zJH band), high spatial resolution comparable to or even higher than the K-band diffraction-limit resolution can be achieved. The maximum Strehl ratio so far achieved at K-band is 0.55 at a 0.5'' seeing condition.
Previous AO36 system has been decomissioned since S08B semester and no longer available. If you need the information of AO36, please see old AO page.
Further information
Questions regarding this page should be directed to Yosuke Minowa
(
). Please note
that all numbers on these pages are subject to change as the performance
of AO188 is better determined.
05 February 2009