Transcript Laser Guide Star System at Subaru Telescope

AO188/LGS status
AO188 development group(Subaru Telescope, NAOJ)
2009.1.16 (JST)
Outline
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Current status
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Risk shared open use
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Commissioning schedule
Current stats on SR.
Sky background Oct 2008
9.1 mag
15.7 mag
16.6 mag
Aug 2008
Sep 2008
Oct 2008
Simulation 0.4”@0.5mm
Simulation 0.7”@0.5mm
Current status
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AO performance using natural guide stars (NGS)
 Observed SR matched with simulation results at faint end.
 Mismatch at bright end needs to be investigated.
 Need more statistics at various seeing condition.
 Detail analysis to compare the performance between simulation
and observation is required.
 Improvement on performance is planning.
Current status
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Risk shared open use for AO188 with NGS
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Imaging/Spectroscopy/Grism modes of IRCS are available.
AO acquisition time is about 10 to 15 minutes.
AO parameter tuning takes about 5 minutes.
9-points dithering
On slit dithering
Field rotation correction and PA selection by AO image
rotator.
Current status
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Engineering items.
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Non sidereal object. (Jan 15, 16)
Field distortion. (Analysis is on going)
Laser projection. (Jan 15, 16)
F-conversion optics for IRCS. (on going)
Isoplanatic angle. (Analysis is going on)
Extended guide star performance. (on going)
And so on……
Upcoming work
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Performance improvement.
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Laser guide star (LGS) mode.
 LGS upgrade at wavefront sensor.
 Tip-tilt and focus guide star acquisition unit.
 Tip-tilt and focus wavefront sensor.
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Additional components.
 ADC.
 BS exchange system. (NGS mode <-> LGS mode)
Schedule and milestone
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Laser projection resumed on Jan 15.
 9.5 engineering nights from Jan. to July.
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S09A open use of NGS mode. (10 nights)
 Some observing modes have a risk.
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Fabrication, test and install for new
components start around April, 2009.
Schedule and milestone
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S09B open use of NGS mode.
 Fully functional.
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Engineering observation of LGS mode starts
around autumn of 2009.
Risk shared open use of LGS mode from S10A.
Summary
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Strehl Ratio at bright end is lower than
that of simulation result.
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Mostly operational in NGS mode.
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Start testing on LGS mode this autumn.
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Risk-shared open use of LGS mode will
start from S10A.