The MSSSO Wide Field CCD H Imaging Survey

Instrumentation

The survey is being conducted in the 16 inch telescope dome at the Siding Spring Observatory. The 16 inch telescope tube has been replaced with the camera and CCD as shown in Figure 1.

  
Figure 1: Wide-field camera and CCD as set up at 16 inch telescope, Siding Spring Observatory.

The Nikkor-Q lens has a focal length of 400 mm f/4.5 and a diameter of 122 mm. Each filter is secured in a PVC holder which slides into the casing beneath the lens. The focus changes for the different filters and adjustment for this is made by rotating a knurled ring on which the lens is mounted.

A suite of 75-90 mm diameter interference filters and 75 mm coloured glass filters was available from the ANU 2.3 m telescope. Initial observations were made with a 15 Å wide H filter but this was changed to a 55 Å filter (centred on 6563 Å) to ensure uniform transmission of the H line across the field. It will also be a better match to the UK Schmidt H survey (Parker & Phillipps 1998).

We have calculated a maximum blue-shift in the H 55Å filter of 13 Å (Ealing Optics Catalog 1981). This corresponds to incident light being at the maximum off-axis angle of .

To record the data we use a SITe thinned CCD which has 2048 2048 pixels, with a pixel size of 24 m. The resolution is 12'' per pixel, producing a field of view of .

© Copyright Astronomical Society of Australia 1997