XMM-Newton Science Analysis System
omsource (omsource-1.27) [xmmsas_20190531_1155-18.0.0]
Aperture photometry is conducted in a similar fashion to that for the Imaging mode.
Because of the very small window, an IMAGING mode window containing
the source can be used, through the parameter backgroundimageset, to obtain the
background. In this case the source counts will be extracted using the image, whilst
the background will be obtained using an annulus centred on the source in the background image.
The aperture radius can be changed between 6 and 12 pixels. The upper
limit corresponds to the cal calibration radius. Using a smaller radius than
the upper limit will result in the source counts being scaled to the
calibration radius using the point-spread function (this correction is the
tabulated psf1 corr value).
XMM-Newton SOC/SSC -- 2019-06-02
