[daip] task MOMNT

[Violette Impellizzeri]

Hello,
 I have a question concerning the right use of momnt on an absorption 
map. I tried different options to set the parameters FLUX and ICUT in 
the task momnt (and xmom).
 From my understanding FLUX cuts the flux below a certain threshold, 
whereas ICUT will cut the flux below if > 0, and above if < 0. Since I 
would like to create a moment map of an absorption I set the flux to be 
very low (-1 Jy/beam) and I tried setting icut to -0.001 Jy, all this 
smoothing over 5 pixels. With these parameters all the flux was "cut", 
which made me think that icut is still cutting the flux below 0.001 Jy, 
i.e. the absorption I am trying to make a map of.
When I set icut to something very small (-0.02 Jy), I see the absorption 
in the moment map, but it is also very noisy, because all the flux below 
-20 mJy is still being 'cut', but it is still mapping everything above 
including the noise.
Is this a bug in the task or am I doing something wrong? I guess there 
must be a way to set a lower limit, i.e. cut everything above a certain 
value?
Thank you,
   Violette


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Violette Impellizzeri         National-Radio-Astronomy Observatory
      * * * *                                    520 Edgemont Road
Tel: +01-434-244-6811                    Charlottesville, VA 22903
Fax: +01-343-   -                        mailto: violette at nrao.edu
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