The AAOmega Spectrograph

The AAOmega spectrograph (credit: Barnaby Norris)

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 can be fed by several front-ends, either the Two Degree Field ("2dF") multi-object system, or the KOALA integral field unit. These pages focus on the 2dF/AAOmega system with KOALA described in its own pages.
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.