First set-up the data-reduction parameters specific to the RGO spectrograph by typing:
and begin the reduction by typing:
You will then be returned with a gui (graphical-user interface) which will allow you to edit the parameters of the reduction. Most answers which require a yes/no (e.g. perform wavelength calibration, redo previous reduction etc.) are controlled by `radio-buttons' which toggle on and off when you click on them. Other entries require text input (e.g. name of associated arc file). If you are working at low resolution with the CuAr Arc (e.g with the 250B grating), you are advised to use the arc linelist in rgo$linelists/cuar_lowres.
ALL ENTRIES WHICH ARE TYPED IN MUST BE TERMINATED WITH THE RETURN KEY.
Other parameters which do not appear directly on the gui are hidden under the buttons at the top of the gui. Click on the relevant button to access these parameters (click on the same button to close the window. The parameters which control the dispersion (`Disp Cor' button) are particularly important, because the spectrograph grating, blaze direction, order and camera MUST be set in here, since they do not (as yet) appear in the header. These parameters are used to obtain an approximate first guess of the start wavelength and dispersion, as input to the automated arc line identification and calibration.
Under the `Ap Defs' button, you will find the number of spectra the routine is instructed to find. The default is for an auto search - it will give you back all the bright (and not-so-bright!) spectra in the image.
If you click on the Log button, you open a window which will give you a listing of the iraf logfile as the reduction progresses (i.e. where the spectrum/spectra are found in the image, the rms of the arc lines fits).
Most of the other buttons allow access to the parameters used by the iraf apall and identify routines (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 manual A Users' Guide to Reducing Slit Spectra with Iraf by 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.
When you are ready - click on the reduce button.
In a few seconds time a plot of the spectrum/spectra should appear in the lower window. The routine leaves you in cursor mode, in case you want to do some basic investigation of the data (C for cursor position etc ? for a list). In order to get out of cursor mode (required to do any further reduction) type Q
The gui system is flaky - a problem with iraf version 2.10.4. If you get into a mess, its best to logout of iraf, kill the xgterm window and go back in.
This is one of the reasons why you may wish to try....