GIRAFFE

The SAAO Grating Instrument for Radiation Analysis with a Fibre Fed Échelle - GIRAFFE - consists of two components:

(i) The head which is mounted at the Cassegrain focus to collect light from the star and direct it into the fibre;

(ii) The spectrograph, constructed on an optical bench in the Coude room, in which the light emerging from the fibre is dispersed and recorded by a CCD camera.

The CCD camera is controlled by a PC in the observing room. The software, called QUARTZ, has the task of setting the exposure time, reading and displaying the CCD image and also controlling various components on the GIRAFFE head, such as the arc lamp and flatfield lamps. At the end of the exposure the FITS file is transferred to the server and can be displayed and reduced via the thin client.

There are four PCs that the observer will use:

1. A Linux PC called giraffe running QUARTZ.

2. A thin client system for data storage ltsp.suth.saao.ac.za.

3. A laptop running a LabView program to display the APD counts, i.e. monitor the light intensity emerging from the fibre.

4. The Linux TCS PC for acquisition and autoguiding.

The technicians would have set up the PC running QUARTZ in diagnostic mode. You need to exit from this and start the software in your own directory.

• Click Exit in the top right of the QUARTZ window, and answer No when it asks you to save a file.

• In a terminal, navigate to /data/ccd, create your own subdirectory, change to that directory and run QUARTZ from there:

cd mkdir xyz cd xyz new_quartz

When prompted, select MUS1 from the pulldown menu, then select Local Setups and giraffe.gir, Ready and OK.

Each GIRAFFE run is assigned a run number, QUARTZ will prompt you to enter. To determine your run number, look in the GIRAFFE log book located in the 1.9-m dome book rack and look for the last entry. Increase that run number by one. If you are a returning observer and wish to use the same directory, you will need to change your run number by deleting the file disk.file from your directory.

At this stage QUARTZ will spend some time initializing the CCD controller and checking the status of the GIRAFFE head. To check that things are working, you can read out the CCD by selecting the Read CCD item from the CCD drop-down menu. This will display information regarding the bias reading and the maximum CCD count.