6dF (for 6-degree field) is an AAO-built instrument consisting of an
automated fibre positioner and multi-object spectroscopic observing facility
for the UK Schmidt Telescope. The positioner, like the FLAIR
facility that it replaced (and unlike 2dF on the AAT) operates remotely
from the telescope in a special enclosure in the dome. It is shown here
under the watchful eye of UKST observer Kristin Fiegert.
Note: because of fibre breakages and limited access for repairs, the operational number of available spectroscopic fibres is usually less than 150. Please contact UK Schmidt Telescope staff for latest information.
The two interchangeable field plate units, each with 150 spectroscopic
fibres (shown parked above), allow one of them to be configured while the
other is on the telescope. Each unit is loaded into the telescope in a
similar way to the photographic plateholders. The 5-metre-long fiducial
bundles are cabled separately from the spectroscopic fibres, and feed an
intensified CCD camera for field acquisition and guidance.
A range of 5 gratings is available, and they are used in standard configurations giving the fixed wavelength ranges detailed below. Note that grating changes can only be carried out during daytime. Gratings 425R and 580V (the 6dF Galaxy Survey gratings) are conventionally mounted together in a remotely-controlled slide mechanism that allows rapid interchange between them. Grating 1700I is the RAVE survey grating.
Grating Reciprocal Instrumental CCD Spectral dispersion resolution resolution range
(Å/mm) (Å) (Å/pixel) (Å)
425R 169 6.6 2.20 5300-7600 580V 126 4.9 1.64 3900-5600 1201B 60 2.1 0.78 3600-4400 1516R 46 1.5 0.6 6200-6800 1700I 30 1.0 0.4 8415-8800
(All in 1st order)
Page maintained by: Fred Watson, AAO
Last revision: 19 December 2008