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What is the best way to do photometry on slightly extended objects (size a few arcsec to about 5-6 arcsec)?
Posted by Seppo Laine on 29 January 2009 12:16 PM

You could use the SExtractor and the Kron flux from its output. This was done by the SWIRE Legacy team. Or, you could take a circular aperture, with a size just larger than the outermost isophote of your target, and do aperture photometry and apply the appropriate aperture correction to get a flux density measurement. This should get you to within 5%-10%. The most accurate flux estimates would theoretically come from fitting a source model convolved with a PSF to compare to the measured fluxes. Unfortunately, there is no publicly available software for performing such estimations.