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XMM-Newton CCF Release Note
XMM-CCF-REL-172
Improving pn Window mode CTI correction and rening the long
term CTI correction for all pn Modes
M. Kirsch
July 19, 2004
1 CCF components
Name of CCF VALDATE List of Blocks
changed
CAL VERSION XSCS ag
EPN CTI 0013 2000-01-01T00:00:00 CTI-
HIGH ADD PAR
3.169 NO
EPN CTI 0013 2000-01-01T00:00:00 LONG TERM CTI 3.169 NO
2 Changes
The EPN CTI 0013.CCF improves an under-correction of the CTI of 2-3 % for the pn Small Window
mode at energies between 550 and 700 eV where O-lines are found in supernova remnants. In
addition, in this CCF the Large Window mode CTI was adjusted to the Small Window mode CTI
for energies below 500 eV.
In addition the long term CTI behaviour of all modes is now modeled with an additional quadratic
term in order to tail o the time dependence.
2.1 CTI-HIGH ADD PAR
The values of the column SW PAR that take special CTI behaviour in Small Window mode into ac-
count have been rened by determining the Oxygen line positions of 1E0102 and N132D observations
from the single and double pixel event spectra for dierent modes.
1

XMM-Newton CCF Release XMM-CCF-REL-172 Page: 2
The values of the column LW PAR have been rened adjusting the LW mode spectra of zeta
Puppis to the SW spectra.
2.2 LONG TERM CTI
The long term behaviour is now modeled with an additional quadratic term in order to tail of the
time dependence.
3 Scientic Impact of this Update
The change will reduce residuals around 500 eV for the Small Window mode. In addition the slightly
increasing over-correction with time for all modes has now disappeared.
4 Estimated Scientic Quality
Line energies measured for Oxygen lines in spectra from 1E0102 and N132D were found to be
systematically lower by 10-15 eV in SW mode as compared to other readout modes. The changed
CTI parameters of EPN CTI 0013.CCF remove this discrepancy.
5 Test procedures & results
MPE re-processed all the 1E0102 and N132D observations with the new EPN CTI 0013.CCF and
determined the Oxygen line positions again from the single and double pixel event spectra. Figure 1
shows the the positions (relative to the expected values for the He-like triplet and a pair of lines near
660 eV; i.e. two data points per spectrum). The upper panel is using the old EPN CTI 0012.CCF
and the lower the new EPN CTI 0013.CCF, in both cases derived from single-pixel event spectra.
For better comparison the same scale is used. There is now agreement between SW and the other
modes. A similar plot for the double spectra (not shown)demonstrates the same improvement.
Since the Large Window mode CTI correction is based on the Small Window mode CTI correction
every change in the Small Window mode requires also the adjustment of the Large Window mode
to that new situation. That does not mean that Large and Small Window mode data have been
in disagreement with the EPN CTI 0012.CCF. The Large Window mode CTI was adjusted to the
Small Window mode for energies below 0.5 keV using a zeta Puppis observation.
For the long term CTI renement all available CALCLOSED data have been processed and
the Al-K and Mn-K lines have been tted with Gaussians in order to determine the line positions.
Figure 3 shows the line positions of the internal calibration source for old EPN CTI 0012.CCF
(black) and new EPN CTI 0013.CCF (red) for Mn-K(alpha) and Al-K. The Al-K position is not

XMM-Newton CCF Release XMM-CCF-REL-172 Page: 3
Figure 1: Positions relative to the expected values for the He-like triplet and a pair of lines
near 660 eV. The upper panel is using the old EPN CTI 0012.CCF and the lower the new
EPN CTI 0013.CCF. For better comparison the same scale is used.

XMM-Newton CCF Release XMM-CCF-REL-172 Page: 4
expected to be at the reference value of 1486 eV, because the Partial Event Eect shifts the center
of the line position to lower energies. This is later corrected by the detector response matrix. For
Mn-K however the line should be spot on the 5896 eV, since the energy calibration after launch was
xed to that value with a reference measurement of revolution 23. The slight not time dependent
over-correction of the Mn-K line position should be improved.
6 Expected Updates
For Small Window mode further improvements may be possible in a next iteration after the line
shapes (redistribution below 500 eV) are adjusted.
For all modes the Mn-K energy position should be rened, since the absolute energy position
was probably dened for a non nominal operation temperature.

XMM-Newton CCF Release XMM-CCF-REL-172 Page: 5
Al­K position old and new LT CTI correction
200 400 600
revolution
290
292
294
296
298
300
energy
in
ADU
old
new
.
Mn­K position old and new LT CTI correction
200 400 600
revolution
1160
1170
1180
1190
1200
energy
in
ADU
old
new
Figure 2: Linepositions of the internal calibration source for old EPN CTI 0012.CCF (black) and
new EPN CTI 0013.CCF (red) for Mn-K(alpha) and Al-K.