The two faces of the METIS Adaptive Optics system Remko Stuik , Stefan Hippler, Andrea Stolte, Bernhard Brandl, Lars Venema, Miska Le Louarn, Matt Kenworthy, Rainer Lenzen, Eric Pantin, Joris Blommaert, Alistair Glasse, Michael Meyer, and the METIS consortium
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The two faces of the METIS Adaptive Optics system Remko Stuik, Stefan Hippler, Andrea Stolte, Bernhard Brandl, Lars Venema, Miska Le Louarn, Matt Kenworthy,
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The two faces of the METIS Adaptive Optics system
Remko Stuik, Stefan Hippler, Andrea Stolte, Bernhard Brandl, Lars
Venema, Miska Le Louarn, Matt Kenworthy, Rainer Lenzen, Eric Pantin, Joris
Blommaert, Alistair Glasse, Michael Meyer, and the
METIS consortium
Outline
The science & METIS AO SystemThe SCAO systemThe LTAO system
1. An imager at L/M & N band with an 18˝×18˝ wide FOV. The imager includes:
– Coronagraphy at L/M and N-band– Long slit, low-resolution (R ~ 5000) spectroscopy at
L/M & N– Polarimetry at N-band [TBC].
2. An IFU fed, high resolution spectrograph at L/M band
– [2.9 – 5.3μm] with a FoV of ≈0.4˝×1.5˝ and – a spectral resolution of R≈100,000.
All subsystems work at the diffraction limit– METIS requires AO correction
27 May 2013
Science versus AO Requirements
The Science•Discovery and Characterization of Exoplanets. •Circumstellar Disk Structure and Evolution•Formation and Evolution of Stars and Star Clusters. •Physics and Chemistry of the Solar System.•Formation and Evolution of Galaxies. •Unique Scientific Opportunities.
The AO SystemHigh Contrast/Low residual jitter
Correction over a larger field of viewEmbedded sources
Tracking on moving sourcesHigh sky coverage/Extended sourcesFlexible AO system
27 May 2013
The two faces
SCAO •Excellent on-axis•Integrated in METIS
– Minimize residual jitter
•‘simple’ first light AO
BUT:•Requires bright GS
– Low sky coverage
•No performance in field– Strong drop towards edge
LTAO•Wide(r) field performance•Accepts fainter GS(s)
– Increased sky coverage
BUT:•Decreased on-axis•Separate system
– Larger jitter
•Increased complexity
27 May 2013
Note: Both systems required to reach full potential of METIS
SCAO Implementation
• SCAO internal to METIS – Cold, low (M)IR background
• Dichroic first optic inside METIS– Cold!– Splits at ~2.5 micron– Full METIS field ~18x18”
• Large field selector– Full METIS field– Allows or field de-rotation
• ~40x40 sub-apertures– Reduced complexity
• IR WFS– Embedded sources– Selex experience Gravity
• Pyramid WFS– Detector available– But extended sources?
27 May 2013
ELT Focus
METIS Entrance Window
Dichroic
Field Selector
Pupil de-rotator
ADC?
SCAO Simulations
• Currently running YAO simulations– Specific science cases– Include spiders, segmentation,…– Investigate static speckles
• METIS requires an AO system to meet its science requirements– Requires both SCAO and LTAO [at first light]
• Reaching the diffraction limit (>60% @ N) relatively easy with a simple AO system– High Strehl, Stable PSF very likely– Can use standard components developed for other AO systems – >93% @ N requires more work/full end-to-end investigation
• Parallel development of an external LTAO system– Enhancing the sky coverage– Further improving PSF stability in field– Might use internal WFS for Lower Orders and/or NGS tomography
• Still much work to do– Full integrated modeling of all effects– Verifying input data atmospheric modeling – Cross-coupling of effects– Impact of telescope vibrations, etc..