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XMM­Newton CCF Release Note
XMM­CCF­REL­246
Correction to the long­term CTI for pn Large Window, Small
Window and Fast Modes
M. Guainazzi, K. Dennerl
July 4, 2008
1 CCF components
Name of CCF VALDATE List of Blocks
changed
Change in CAL HB
EPN CTI 0019 2000­01­01T00:00:00 LONG TERM CTI NO
2 Changes
2.1 Reasons for this update
Issue#17 of the EPN CTI CCF included a refinement of the long­term CTI correction for Full Frame
and Extended Full Frame modes. However, the value of the 3rd element of the vector column T COEFF
of the extension LONG TERM CTI was accidentally (and erroneously) changed from -1.4 â 10 -6 to
-1.4 â 10 -7 in Rows#25 to #39. These rows correspond to the following modes: Large Window,
Small Window, Timing, Burst, which should not have been a#ected by this CCF update.
The CCF described in this Release Note corrects this error.
3 Scientific Impact of this Update
The error can have a significant impact on the determination of line energies in exposures taken in
one of the aforementioned modes, if pn data are reduced with CTI CCF Issues#17 and #18. Shifts
by #60 eV in the determination of the centroid energy have been reported for the Fe K # line in
1

XMM­Newton CCF Release XMM­CCF­REL­246 Page: 2
NGC 4151 (Obs.#0402660201; Small Window Mode) with respect to the measurements yielded by
the MOS cameras in the same observation, or to historical measurements of the same observable.
4 Estimated Scientific Quality
This CCF update will allow to recover the nominal accuracy in the energy reconstruction for pn
Imaging Modes observations: ±10 eV (cf. the EPIC Calibration Status Document).
5 Test procedures & results
The new CCF component has been visually inspected with the FTOOLS fv and ftdiff to ensure
that:
. the values of Row#25 to Rows#39 in the 3rd component of the vector column T COEFF in the
extension LONG TERM CTI are all -1.4 â 10 -6
. that the only di#erence between Issue#18 and Issue#19 is related to the values mentioned in
the bullet above
Moreover, it has been checked that Issue#19 yields the same long­term CTI correction for Full
Frame and Extended Full Frame Modes as Issue#17.
In Fig. 1 the Fe K # line measured by the pn camera in Obs.#0402660201 is compared for three
versions of the EPN CTI CCF: a) Issue#16 (black); b) Issue#17 (red); Issue#19 (green). The
comparison shows that this update recovers the proper CTI correction.
6 Expected Updates
A strategy to improve the long­term CTI correction for Large Window, Small Window and Fast
Modes is under study.

XMM­Newton CCF Release XMM­CCF­REL­246 Page: 3
6 6.2 6.4 6.6 6.8
1
1.5
Cts
s
-1
keV
-1
Energy (keV)
Black: EPN_CTI_16; Red: EPN_CTI_17; Green: EPN_CTI_19
NGC4151 - Obs.#0402660201 - Rev.#1277
MOS1
MOS2
Figure 1: Iron K # fluorescent line measured in the pn spectrum of NGC 4151 (Obs.#0402660201,
Small Window), when the data were reduced with three di#erent versions of the CTI CCF: a)
Issue#16 (black); b) Issue#17 (red); Issue#19 (green). The dotted lines indicate the 90% confidence
intervals for the measurement of the line centroid by the MOS cameras in the same observation:
blue: MOS 1; purple: MOS 2