[alma-config] CLEAN and difference results for B arrays

[mel wright 456]

A disk model can easily be subtracted analytically from the uv-data
removing any doubts about pixelation. The goal of deconvolution is
to subtract the most reasonable models (consistent with our a-priori
information) which leave a residual image which is consistent with
the noise. Clean components are not a good approximation to smooth
distributions and maxen is not so good for point sources,
so it seems more reasonable to me to 1st subtract
any a-priori distribution from the uv-data, and then
deconvolve the remaining structure. The goal for Cygnus A, for
example, is probably to compare with well determined lower
frequency images to find spectral index differences, so one
could 1st subtract the lower frequency image, scaled by the
null hypothesis spectral indices, and then deconvolve what is
left, if anything, until the residual is consistent with the
noise.
		My 2 cents worth,

			Melvyn