NFIRAOS: TMT narrow field near-infrared facility adaptive optics
Abstract
Although many of the instruments planned for the TMT (Thirty Meter Telescope) have their own closely-coupled adaptive optics systems, TMT will also have a facility Adaptive Optics (AO) system, NFIRAOS, feeding three instruments on the Nasmyth platform. This Narrow-Field Infrared Adaptive Optics System, employs conventional deformable mirrors with large diameters of about 300 mm. The requirements for NFIRAOS include 1.0-2.5 microns wavelength range, 30 arcsecond diameter science field of view (FOV), excellent sky coverage, and diffraction-limited atmospheric turbulence compensation (specified at 133 nm RMS including residual telescope and science instrument errors.) The reference design for NFIRAOS includes six sodium laser guide stars over a 70 arcsecond FOV, and multiple infrared tip/tilt sensors and a natural guide star focus sensor within instruments. Larger telescopes require greater deformable mirror (DM) stroke. Although initially NFIRAOS will correct a 10 arcsecond science field, it uses two deformable mirrors in series, partly to provide sufficient stroke for atmospheric correction over the 30 m telescope aperture, but mainly to improve sky coverage by sharpening near-IR natural guide stars over a 2 arcminute diameter "technical" field. The planned upgrade to full performance includes replacing the ground-conjugated DM with a higher actuator density, and using a deformable telescope secondary mirror as a "woofer." NFIRAOS feeds three live instruments: a near-Infrared integral field Imaging spectrograph, a near-infrared echelle spectrograph, and after upgrading NFIRAOS to full multi-conjugation, a wide field (30 arcsecond) infrared camera.
Additional Information
© 2006 Society of Photo-Optical Instrumentation Engineers (SPIE). The authors gratefully acknowledge the support of the TMT partner institutions. They are the Association of Canadian Universities for Research in Astronomy (ACURA), the Association of Universities for Research in Astronomy (AURA), the California Institute of Technology and the University of California. This work was supported, as well, by the Canada Foundation for Innovation, the Gordon and Betty Moore Foundation, the National Optical Astronomy Observatory, which is operated by AURA under cooperative agreement with the National Science Foundation, the Ontario Ministry of Research and Innovation, and the National Research Council of Canada.Attached Files
Published - 62720Q.pdf
Files
Name | Size | Download all |
---|---|---|
md5:d97fbdb338739e23c9b92de8c6330041
|
917.3 kB | Preview Download |
Additional details
- Eprint ID
- 95619
- Resolver ID
- CaltechAUTHORS:20190520-152727204
- Association of Canadian Universities for Research in Astronomy (ACURA)
- Association of Universities for Research in Astronomy (AURA)
- Caltech
- University of California
- Canada Foundation for Innovation
- Gordon and Betty Moore Foundation
- National Optical Astronomy Observatory (NOAO)
- NSF
- Ontario Ministry of Research and Innovation
- National Research Council of Canada
- Created
-
2019-05-20Created from EPrint's datestamp field
- Updated
-
2021-11-16Created from EPrint's last_modified field
- Caltech groups
- Thirty Meter Telescope
- Series Name
- Proceedings of SPIE
- Series Volume or Issue Number
- 6272