XMM-Newton Science Analysis System


omdetect (omdetect-5.19.4) [xmmsas_20090615_1801-9.0.0]

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Source classification

A source is classified as either ``point-like'' or ``extended'' by comparing its computed semi-major axis with that of the point-spread function, both having been computed using moments. A source is ``extended'' if the difference between its semi-major axis and that of the PSF is greater than 3 times the error in the semi-major axis of the source, otherwise it is classified as ``point-like''.