AA and the AAO of the Future

1
AA? and the AAO of the Future

• Matthew Colless, UCL, 28 June 2004

2
AAO of the Future - UK Share

• New AAT Agreement runs from 2006 to 2010
• The UK share of time is determined by the share
  of AAO income from PPARC (contribution, grants
  etc.)
• UK contribution halves in 2006-7 again in 2007-8
• Min. UK share is 25 in 2006-7 12.5 thereafter
• If AAO obtains PPARC funds for instrumentation
  (e.g. Gemini WFMOS) then UK share could be larger
• Opportunity exists to buy unfunded AAT nights
  for specific projects (terms conditions t.b.d.)

3
AAO of the Future - Operations

• The AAO of the (near) future will have 4
  instruments UCLES/UHRF, IRIS2, WFI, AA?
  visitor instruments
• Instruments will be scheduled in at least 1-week
  blocks (and more likely bright/dark time blocks)
• Night assistant every night and support
  astronomer for at least the first night(s) of
  each run
• May be less night-time technical support, but
  goal is to achieve higher standards of
  reliability and user-friendliness for all
  instruments and telescope

4
The AA? Project

• AA? is the AAOs major upgrade of the 2dF
  facility
• existing 2dF field corrector and ADC
• upgraded positioner robot and new field plates
• 392 new fibres, 2.0? diameter, 30m long
• 8 guide bundles (cf. 4 with 2dF) plate
  rotation, for improved reliability precision of
  acquisition
• new spectrograph stable, bench-mounted,
  high-efficiency, dual-beam, 2k x 4k CCDs

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Goals for Upgraded System

• High spectral resolution R10,000 and ?v1-2
  km/s
• High throughput aim for 2-3x better throughput
  than 2dF
• High stability 1/20 pixel over several hours,
  to get best velocity precision and sky
  subtraction
• Excellent sky subtraction sky subtraction to 1
  or better in standard operation nod shuffle
  mode possible with all fibres for Poisson-limited
  sky subtraction performance
• Improved reliability and ease of use especially
  fibre positioner and configuration/data-reduction
  software

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AA? Key Performance Features

• Throughput peak is 15-20 (2-3x 2dFs
  throughput)
• Spectral resolution 8000 MOS, 13000 IFU (gt2x
  2dF)
• Wavelength coverage 370-950nm
• PSF spatially-invariant PSF for all setups
  wavelengths
• Stability bench-mounted spectrograph gives much
  better wavelength calibration and sky subtraction
  than 2dF
• CCDs 2k x 4k 15?m CCDs, each arm separately
  optimized
• Sampling better spatial sampling, wider fibre
  separation
• Nod Shuffle can NS all 392 fibres (also
  mini-shuffle)

7
AA? Survey Performance

• Instrument AA? 2dF 6dF Sloan FLAMES VIMOS WFMO
  S
• Telescope AAT AAT UKST
  VLT VLT Gemini
• Mirror diameter (m) 3.9 3.9 1.2 2.5 8 8 8
• Mirror area (m2) 11.9 11.9 1.1 4.9 50.3 50.3 50.3
• System efficiency 0.4 0.15 0.3 0.3 0.3 0.4 0.
  3
• FoV diameter (deg) 2 2 6 3 0.42 0.50 1.5
• FoV area (deg2) 3.1 3.1 28 7.1 0.14 0.20 1.75
• objects 392 400 150 640 132 560 4000
• photons/unit time 1900 700 50 900 2000 11000 600
  00
• Survey duration 0.07 0.18 0.11 0.10 0.47 0.25 0.04
  
• (time taken to cover
• fixed area of sky)

8
Conclusions

• Key features field of view, multiplex,
  throughput, spectral resolution, stability, sky
  subtraction, IFU
• Possible future upgrade multiple deployable IFUs
• Science programs high velocity precision or high
  S/N spectra of many faint objects over wide
  fields
• Key advantages
• fastest survey spectrograph in the world
• opportunity for ambitious large programs