XMM-Newton Science Analysis System
psfgen (psfgen-1.7) [xmmsas_20211130_0941-20.0.0]
There are several implementations of the PSF which can be selected
with the level parameter.
PSF accuracy levels
- ELLBETA This is the most complex PSF implementation and
is used in the processing pipeline for source searching and by
default in the task arfgen
to calculate the effective area.
See  for more details.
- EXTENDED A model based on the King function which was
the forerunner of the ELLBETA model.
- MEDIUM Based on images generated by the XMM-Newton event
- HIGH An early simple PSF which isn't recommended for
- LOW An early even simpler model which is also not recommended for general use.
XMM-Newton SOC -- 2021-11-30