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Method
The background box may be either a circle away from the source box,
in which case the user is asked to enter a background centre and
radius, or it may be an annulus around the source box. To avoid the
possibility of contaminating a background annulus with counts from
the extended wings of the point spread function, the box is defined
by an inner and outer radius. The user should ensure that the inner
radius is beyond the point where the PSF of the source has decayed to
~ zero.
Next: Procedure Up: XRTBCKBOX Prev: XRTBCKBOX