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nametext
deVaucouleursAlso know as the r1/4 law, it describes the radial light profile of a typical elliptical galaxy. Defined as
I(r) = I0exp{-7.67[(r/re)1/4]}. An elliptical version of this profile is fit to every detected object, yielding the deV parameters.
exponential modelThe radial light distribution of a disk galaxy can often be fit by an exponential profile:
I(r) = I0exp(-1.68r/re)
The number 1.68 is chosen so that the model radius is a half-light radius. An elliptical version of this profile is fit to every detected object, yielding the exp parameters.
magnitude, modelJust as the PSF magnitudes are optimal measures of the fluxes of stars, the optimal measure of the flux of a galaxy would use a matched galaxy model. With this in mind, the code fits two models to the two-dimensional image of each object in each band:
1. a pure deVaucouleurs profile, and
2. a pure exponential profile.
The best-fit model in the r-band is fit to the other four bands; the results are stored as the model magnitudes. Details, including a very important warning, can be found here.
modelMagThe model magnitude. See magnitude, model.