[daip] Flux Question

[Cara Battersby]

HI there,

I've been getting some final numbers from VLA data that I reduced awhile ago
(Project AJ345), and have come up with some puzzling questions about the
flux.  I have been getting differences for point source fluxes of the order
of a factor of two.  My first method was somewhat standard (simple uv
clipping of very high points, simple cleaning) and achieved a point source
flux (for the central source) of about 0.35 mJy/beam.  My friend, who is
trying to learn CASA, also reduced the data and achieved a point source flux
(for the central source) of about 0.2 mJy/beam.  The main qualitative
difference in the images are the large scale ripples in my original map.
So, I went back and removed the short UV spacings (though there ARE extended
sources in the map, so I don't believe that this is a real solution).  This
achieved a point source flux (for the central soruce) of about 0.45
mJy/beam.  Both this map, and the CASA map appear qualitatively better, due
to the lack of ripples.  However, I don't want to just exclude data (because
there IS large scale structure), but I am very confused about the source of
the ripples, and more importantly, the wildly different point source fluxes
that these different methods achieve.

Do you have any idea why this might be happening, or have a suggestion for
something else to try?

Cheers,
   Cara
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