AO188

News: Information for S13B applicants

  • In S13B, both NGS and LGS modes will be available in normal operation mode. Those who intend to use the LGS mode for the first time are encouraged to make contact with the support astronomer in advance.
  • Kyoto-3DII is available with AO188 as a PI-type instrument since S13A (please see call for proposal for more detail).
  • Applicants who intend to use the LGS mode with PI type instruments (such as HiCIAO, Kyoto-3DII), please make contact with the PI of the instrument and AO188 support astronomer.
  • There are some restrictions for the following operation.
    • Observation that reuquires to use the atmospheric dispersion corrector for non-sidereal objects.
    • Observation that reuquires to track the parallactic angle change (ADI mode) for non-sidereal objects.
    Those who want to observe with these kind of operation mode should make contact with the support astronomer in advance.
  • The AO188 development team have started the guaranteed time observations (GTOs) since S11A semester. In S13B, AO188 team will use 0.5 night for the GTO.

Introduction

Note: Please read Planning Observations carefully before submitting proposals.

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 is also available with AO188 as a PI type instrument. AO188 has successfully completed the first light observations with IRCS in late 2006 (see the press release).

AO188 in the NGS mode has been offered for open use observations since S08B. For the NGS mode operation, a natural guide star is required. The guide star should be a bright star located within 30 arcsec of the science 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.

As of the latter half of S11A semester, the LGS mode that uses an artificial sodium laser guide star for high-order wavefront correction will become available. The LGS can be propagated into the sky close to or on top of the science target. The brightness of the LGS is around 10.5 mag in R-band in best case. This brightness might become faint depending on the sodium layer condition and telescope elevation. A natural guide star is still required for the LGS mode operation to correct for the tip-tilt motion that cannot be sensed by the LGS. The tip-tilt guide star (TTGS) is expected to be brighter than 18 mag in R-band and located within around 90 arcsec from the science target. You might be able to get small correction with the guide star as faint as R~19 (only in dark night). The performance of the LGS mode is summarized in the performance page listed in below.

Previous AO36 system has been decommissioned since S08B semester and no longer available. If you need the information of AO36, please see old AO page.

Candidate targets for AO188 Guaranteed Time Observation (GTO)

The members of AO188 developing team have guaranteed time (GT), and intend to execute GT Observation (GTO) of following targets or fields. It should be mentioned, however, that this declaration does not prohibit observing of these targets by open-use users.
  • Imaging/Spectropolarimetry of NGC 1068
    • NGC 1068 (02h42m40.771s, -00d00m47.84s)

Instrument citation

Please cite the following paper when you refer AO188 in your publication.

"Commisioning status of Subaru laser guide sta adaptive optics system"
Hayano et al. 2010, Proc. SPIE in press.
"Current status of the laser guide star adaptive optics system for Subaru Telescope"
Hayano et al. 2008, Proc. SPIE, vol. 7015

Further information

Questions regarding this page should be directed to Yosuke Minowa (minoways_at_naoj.org). Please note that all numbers on these pages are subject to change as the performance of AO188 is better determined.

08 February 2013



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