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The FMOS Facility for the SUBARU telescope. Gavin Dalton Oxford/RAL. Overview of F ibre M ulti O bject S pectrograph project for the Subaru telescope. Masayuki Akiyama (Subaru Telescope, NAOJ) on behalf of FMOS team (P.I. Toshinori Maihara). FMOS: instrument overview.
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The FMOS Facility for the SUBARU telescope Gavin Dalton Oxford/RAL
Overview ofFibreMultiObjectSpectrographproject for the Subaru telescope Masayuki Akiyama (Subaru Telescope, NAOJ) on behalf of FMOS team (P.I. Toshinori Maihara)
FMOS: prime-focus corrector • Prime-focus corrector designed and fabricated by AAO • Three BSM51Y design with F/2.0 and 30arcmin diameter FoV. • Image quality optimized between 0.9-1.8micron
FMOS: fibre positioner • If we put 400 magnetic buttons with fibres (like 2dF) on the prime-focus of the Subaru telescope, it would be like,,, • So we need new fibre positioning method for FMOS… 145mm = 30arcmin
FMOS:Echidna: 1998 Birth of Echidna concept • Concept by Peter Gillingham (AAO) shown at SPIE@Kona • Tiling the focal plane with 400 of them = 7mm x 7mm each
FMOS:Echidna:Long-term development effort • 1998 Echidna with “Nano-motor” • 1999 Echidna with “inch-worm” design • 2000 Echidna with “ball-spine” design
FMOS:Echidna: 2001 Final design fixed “Stick-and-slip” motion with sawtooth voltage signal
FMOS:Echidna: Under testing in Hilo • Focal plane with 480 fibres.
FMOS:Echidna: Under testing in Hilo • Focal plane imager.
FMOS:Echidna: Under testing in Hilo • Positioner unit • SEE ECHIDNA THE MOVIE !!
FMOS:Echidna: test results so far • Focal plane imaging camera tested. Positions of 400 fibres in 154mm FoV can be measured with 2-3micron r.m.s. accuracy. • Configuration accuracy of 10micron (corresponds to 0.12 arcsec. Fibre core is 100micron, i.e. 1.2”) can be achieved for >95% of the 400 fibres with 7 iterations in 11minutes. • Fibre tip is 30micron r.m.s. from the focal plane.
FMOS: prime-focus unit (PIR) • New prime focus unit with • instrument focusing unit (Z-movement) • corrector lens adjustment mechanism (XY-movement) • cable wrapping unit • for FMOS is constructed by Kyoto Univ. and Mitsubishi.
FMOS: fibre train with connector • Fibre trains with • 120mm 200 fibres/slit • strain relief boxes • F2/F5 conversion air connector • fibre back illumination system • was designed and fabricated in Durham. • F5-side fibre • F2-side fibre
FMOS: fibre train with connector N.B. some of the tolerances on these lenses turn out to be difficult!
FMOS: fibre train with connector A lot of attention has been paid to cable management!
The FMOS Spectrographs Gavin Dalton Oxford/RAL
Spectrograph outline • 2 bench-mounted spectrographs (total slit length is ~700 arcseconds). • Optics cooled to ~200K, with articulated cryogenic cameras • OH suppression by masking lines at intermediate focus. • Full ZYJH wavelength coverage in 4 shots at suppression resolution • Full coverage in 1 shot through redispersing VPH grating
Why OH Suppression? Because the IR sky is rather nasty… Can work between the lines, but then we start to run out of pixels to do anything useful with this wonderful wide field!
Accomodation Issues • No space for systems of this size in any convenient location • Extra floor added to Subaru enclosure on IR side above the Nasmyth platform • Limited access (spectrogaphs must be assembled in situ) • Cost…
FMOS Commissioning Schedule • Near future mile-stones(first discussions on this project were 01/97!) • 2007/10 Transfer IR prime-focus unit (PIR) and Echidna fibre positioner to summit • 2007/12 Engineering observations of IR prime-focus unit • Check image quality • Check Auto-Guiding/Shack Hartmann system • 2008/01 Engineering observation of Echidna fibre positioner • Check positioning accuracy (spectrographs available) • 2008/02 Start engineering observation with two spectrographs • 2008/?? Open use observation with shared risk mode/GTO
So what can we do? • 20 nights GTO: Galaxy evolution survey, ~15000 ‘good’ spectra from e.g. UDS (Interesting possibility would be to cover the DEEP2 AEGIS area?). • Opportunity for a large programme (few x 105 redshifts). –See Totani’s talk. • Whatever else comes up?