The AAOmega Spectrograph
The Instrument
The AAOmega spectrograph was successfully commissioned in January 2006. The spectrograph is a dual-beam system, with Blue and Red arms that cover the full wavelength range, 370nm to 850nm, or 470nm to 950nm using a redder dichroic, at low resolution and are tunable over these ranges at higher resolutions.
The AAOmega spectrograph is fed by one of two front-ends, either the Two Degree Field ("2dF") multi-object system or the SPIRAL integral field unit. These are described below: The Two Degree Field system ("2dF") is the AAT's most complex astronomical instrument. It is designed to allow the acquisition of up to 392 simultaneous spectra of objects anywhere within a two degree field on the sky. It consists of a wide-field corrector, an atmospheric dispersion compensator and a robot gantry which positions optical fibres to 0.3 arcseconds on the sky. A tumbling mechanism with two field plates allows the next field to be configured while the current field is being observed.
SPIRAL is a 512 element fibre-lenslet integral field unit (IFU). It has a field of view of 22.4 x 11.2 arcsec at a spatial resolution of 0.7 arcsec.
- Contact persons at the AAO.
- Image gallery - A selection of images of the AAT, 2dF and the fibre buttons
- CCD details
- On-line manuals and information
- Dedicated AAOmega software
- Instrumentation papers associated with AAOmega and its software:
- "AAOmega: a scientific and optical overview" : Saunders et al. 2004 SPIE 5492 389
- "AAOmega: a multipurpose fiber-fed spectrograph for the AAT" : Smith et al. 2004 SPIE 5492 410
- "Performance of AAOmega: the AAT multi-purpose fiber-fed spectrograph" : Sharp et al. 2006 SPIE 6269E 14, arXiv:astro-ph/0606137
- "Multi-object spectroscopy field configuration by simulated annealing": Miszalski et al. 2006 MNRAS 371 1537
- "Optimal Tiling of Dense Surveys with a Multi-Object Spectrograph" : Robotham et al. 2010 PASA 27 76, arXiv:0910.5121
- "Optimal Extraction of Fibre Optic Spectroscopy" : Sharp & Birchall 2010 PASA 27(1) 91, arXiv:0912.0558
- "Sky subtraction at the Poisson limit with fibre-optic multi-object spectroscopy" : Sharp & Parkinson, MNRAS, 2010, 408, 2495
Proposal Preparation Tools
- The list of available AAOmega gratings and the AAOmega Grating calculator
- AAOmega MOS S/N Calculator
- AAOmega SPIRAL (IFU) S/N Calculator
Observing preparation Tools
The Configure page provides all necessary links and information for the target allocation software including information about complex configurations and Nod and Shuffle mode.
- AAOmega Frequently Asked Questions
- AAOmega Frequently Made Mistakes
Reducing your data
The 2dfdr page provides all necessary links and information for the data reduction task including information about the file format and fixing the wavelength solution if necessary.
Information for Support Astronomers and expert users
- Support News lists changes in support procedure with date added.
- Operations manuals and technical documentation
- First night check list
- How to change AAOmega Gratings
- AAOmega Focus
- How to support Nod and Shuffle observations
- How to support SPIRAL and the SPIRAL control and calibration system
Resources for Instrument Astronomers
- AAOmega fibre analysis, code and data used for October 2012 New Fibre Analysis
- How to do model the gripper distortion pairs
The original 2dF observing system on which AAOmega is based was responsible for two large survey programs. The data for these are available from 2dF survey data.
Sarah Brough (sb@aao.gov.au)