[daip] [!4953]: aips - Running XGAUS

[Eric Greisen]

Eric Greisen updated #4953
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       Staff (Owner): Eric Greisen (was: -- Unassigned --)
              Status: Closed (was: Open)
                 Due: - Cleared - (was: 27 May 2014 08:49 PM)

Running XGAUS
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           Ticket ID: 4953
                 URL: https://help.nrao.edu/staff/index.php?/Tickets/Ticket/View/4953
           Full Name: Chris De Pree
               Email: cdepree at agnesscott.edu
             Creator: User
          Department: AIPS Data Processing
       Staff (Owner): Eric Greisen
                Type: Issue
              Status: Closed
            Priority: Default
      Template Group: Default
             Created: 23 May 2014 08:49 PM
             Updated: 26 May 2014 09:10 PM



For spectral-line fitting you must use the TRANS image.
It fits Gaussians on the X axis.

The FLUX value MUST be set to a value.  Try 10*sigma or even 100*sigma.
Also try PIXVAL=0.  It is plotting only those pixels with peak value 0.585 mJy
and, at first, you want to plot everything to see what you are doing.  The 
error messages indicate that it is getting a very bad fit but does not get any
guidance from you due to PIXVAL.  It is trying hopeless pixels because FLUX
rather than a reasonable starting point for doing fitting.  (You can re-start
later with the same table and a lower FLUX.)

I attach the draft of my memo on such things, which is fairly complete for
XGAUS.

Eric Greisen





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