First you need to switch off the gui, by editing the setup parameter file. In iraf this is doing by typing
which takes you into the iraf parameter file editor. Move up and down using the arrow keys and change entries by typing the new entries on the appropriate line. In this case, you will wish to move to the line that says gui and type no and then the return key -- the yes will change to a no. To exit type:
Now define the parameters for the RGO spectrograph by typing:
Now edit the rgoaat parameter file in the same fashion as above by typing:
to change the reduction par-meters e.g. name of file to be reduced, name of associated arc file etc. Note that if you are working at low resolution (e.g. with the 250B grating) you are advised to use the arc linelist (the arclist parameter) in rgo$linelists/cuar_lowres.
A number of the parameters controlling the reduction e.g. the number ofspectra to find, the grating etc. used can only be accessed through the `rpars' entry in the rgoaat parameter file. Move the cursor to the rpars entry and type:
to access these parameters - there are lots of them! The grating parameters are right at the end. :q gets you out of the rpars file and another :q get you out of the rgoaat file. You might also wish to change the noise parameters of the chip, which control the cosmic ray rejection.
Most of the parameters used by the rgoaat routine are those that appear in the standard iraf routines (e.g apall, identify used in the reduction of slit spectroscopy, and on which this reduction package is largely based. To get some idea of the required responses (the default parameters may not suit your particular observation), you are strongly recommended to read the excellent manual A Users' Guide to Reducing Slit Spectra with Iraf by Jeanette Barnes et al., a copy of which is located in the control room with the other manuals. It provides a comprehensive and easy-to-read guide to all the routines required to carry out long-slit reduction in iraf, and was largely the guide used to package together the various iraf scripts used to create this pipeline reduction system.
Once you are happy with the desired parameter values, you reduce the data by typing:
and, after prompting you for the file to be reduced (you can just hit return if the filename is already there), the procedure will automatically do your data-reduction with the parameters that you edited into the parameter files. Note that the routine also leaves you in the plot mode - so type q to get out. If you want a hard-copy plot of the spectrum type:
before quitting and it will send a hard-copy output to whatever printer previously set in the setenv PRINTER hppost_6 command.
Other useful plot manipulation commands e.g. Gaussian fitting ( k key), over-plotting ( o key, followed by g key), are available -- type ? for a full list. If you have reduced more than one spectrum from the data-frame type:
to move to the next spectrum, or:
to move back to the previous spectrum.
To obtain a log of the reduction you can type:
to look as the most recent portion of the iraf logfile.
If you are happy with retaining the same reduction parameters throughout the night (e.g number of spectra to find stays the same, you are using the same background region for sky subtraction), then you can run the procedure directly from the iraf command line thus:
rgoaat 05jan0062 arclist=05jan0063 redo=yes
which means reduce run number 62 using the arc in run 63, and over-write the previous reduction.
If you do make a mistake and/or the program `bombs out' for any reason, you are advised to type
a couple of times. This should remove any rogue processes hanging around. flpr stands for `flush process' and is one of those incantations that iraf gurus become all too familiar with.