[daip] [!7774]: AIPS - Continuum subtraction in spectral line data cube.

[Yogesh Chandola]

Yogesh Chandola updated #7774
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Continuum subtraction in spectral line data cube.
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           Ticket ID: 7774
                 URL: https://help.nrao.edu/staff/index.php?/Tickets/Ticket/View/7774
           Full Name: Yogesh Chandola
               Email: yogesh.chandola at gmail.com
             Creator: User
          Department: AIPS Data Reduction
       Staff (Owner): Eric Greisen
                Type: Issue
              Status: Open
            Priority: Default
                 SLA: NRAO E2E
      Template Group: Default
             Created: 30 December 2015 09:06 AM
             Updated: 31 December 2015 06:24 AM
      Resolution Due: 08 January 2016 09:06 AM (8d 2h 41m)



 > It would appear that the continuum model that you UVSUBed
 > did not contain (correctly) all of the continuum flux. Is this at
 > L band? Did you use multiple facets to do your continuum imaging?
 > A large field, especially at P or L or even S band, will require multiple
 > facets to get the geometry correct. If the geometry is not 
 > correct sources will not subtract properly.
 > 
 > If the remaining continuum looks simple (not all sorts of spokes
 > and clutter), then you could simply subtract the residual continuum
 > with IMLIN or XBASL.
 > 
 > Eric Greisen
 > 
 > 
Yes, it is L band data and I have used multiple facets to do continuum imaging  as well as for making spectral line cubes. Should I use IMLIN on each facet cube separately and then FLATN or first FLATN and then IMLIN? IMLIN is also known to have problems while subtracting continuum off from the phase center.    

Yogesh

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