AAOmicron instrument design

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AAOmicron instrument design
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Strawman requirements
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System architecture
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2df corrector
Figure. Spot diagrams for field positions 0, 0.2,
0.4, 0.6, 0.8, and 1.0 degrees radii, wavelengths
0.93?m (dark blue), 1.2?m (light blue), 1.4?m
(green), 1.6?m (yellow), 1.75?m (red) and zenith
angle 0º.
Figure. Spot diagrams for field positions 0, 0.2,
0.4, 0.6, 0.8, and 1.0 degrees radii, wavelengths
0.37?m (dark blue), 0.4?m (light blue), 0.5?m
(green), 0.75?m (yellow), 0.95?m (red) and zenith
angle 0º
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2dF corrector cont..
Figure. Polychromatic point source encircled
energies for field positions 0, 0.2, 0.4, 0.6,
0.8, and 1.0 degrees radii, wavelengths 0.93?m
(dark blue), 1.2?m (light blue), 1.4?m (green),
1.6?m (yellow), 1.75?m (red) and a zenith angle
0º.
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Fibre aperture
Figure. The aperture losses in a 2 fibre as a
function of seeing for a point source offset from
the fibre centre by 0.3.
Figure. The SNR in a 2 fibre as a function of
seeing for a z1, E0 galaxy, with an re10kpc de
Vaucouleurs profile.
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Fibre throughput
Figure. Nominal near infrared internal fibre
transmission characteristics for a 38m length of
the FBP fibre used in the AAOmega fibre bundle.
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Spectrograph (fixed configuration)
Figure. Diagram of the AAOmicron
optical/mechanical concept design.
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Detector package

• Rockwell Hawaii 2 array
• Pixels 18?m 15?m for AAOmega
• 1.7um cut off device
• Reduce thermal background
• Higher operating temperature
• Identical camera design to AAOmega
• Effective width of 2.9 pixels (FWHM).
• Detector 1.67 times shorter (spatial direction)
  only 240 fibres.

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Spectral resolution and coverage
Table. Wavelength windows for AAOmicron 700
resolution elements.
Figure. Near infrared atmospheric transmission at
the siding spring observatory site measured with
CASPIR (UNSW).
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Total system throughput

• Estimated peak total system throughput of 20
  for the z and J bands and 15 for the H bands.
• Provisional throughput estimates for AAOmicron
  established by similar process as AAOmega.
• Includes - Atmospheric absorption, telescope
  optics, fibre losses (including aperture/seeing
  coupling losses), spectrograph and grating
  losses, and detector quantum efficiencies.

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Possible upgrades

• Variable configuration.
• 2 x Hawaii2 allows all 396 fibres (US250K each).
• Dual optical infrared observations (New fibre
  bundle).
• Dual beam AAOmega clone, but 200 fibres.
• OH Suppression fibres.
• ??

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Questions?