LOW, MEDIUM, HIGH, EXTENDED ...
how do I get "the" EPIC PSF from calview?
The calibration file GUI task
calview supports the visualization
of the four basic representations of the X-ray
Point Spread Function (PSF) that are encoded in the
Calibration Access Layer (CAL) as part of the SAS. They can be selected by
setting the Accuracy Level parameter
calview window before
invoking View/PSF or
View/Encircled Energy/Encircled Energy (PSF):
As a baseline, the EXTENDED mode gives the best
results for 1-D PSFs. A summary of its applicability
is given in
EPIC Calibration Status Document.
There is no good general model for a 2-D PSF yet,
due principally to the lack of the necessary in-orbit measurements.
The MEDIUM model,
although based on simulations, and although it assumes
that all the mirror modules have the same response, may at
least give an idea of the off-axis PSF deformation.
For more detailed information on the LOW, MEDIUM and HIGH mode PSFs,
as well as the calibration files and the calibration SAS interface,
the user is referred to the Calibration Access and Data Handbook.
- LOW, corresponding to a single Gaussian parameterization.
It is both energy and off-axis angle dependent, but the same for each EPIC
- MEDIUM, corresponding to 2-D maps generated from
SciSim simulations. It is
energy and off-axis angle dependent, but the same for each EPIC telescope
- EXTENDED, corresponding to a King-profile model,
energy, off-axis and telescope dependent [details can be found in
EPIC Calibration Status Document. Further information can
be found in the following Technical Notes:
CAL-TN-0022-1.0, EPIC-MCT-TN-011 (MOS), and EPIC-MCT-TN-012 (pn)]
- HIGH, corresponding to a three-Gaussian model,
dependent on the off-axis angle only (over a limited validity range)
Pages maintained by SAS librarian.
Any question about SAS should be addressed to the
XMM-Newton help desk.
June 18, 2009