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XMM-Newton CCF Release Note
XMM-CCF-REL-127
EPIC MOS CTI
B. Altieri
November 11, 2002
1 CCF components
Name of CCF VALDATE EVALDATE List of Blocks CAL XSCS
(start of val. period) (end of validity period) changed VERSION ag
EMOS1 CTI 0015 2002-11-07T05:00:00 CTI EXTENDED cal 3.147+ NO
EMOS1 CTI 0015 2002-11-07T05:00:00 CTI EXTENDED cal 3.147+ NO
2 Changes
A new set of MOS CTI parameters has been derived for the MOS cool operations that started
in revolution 533, when the operating temperature of MOS CCD was lowered from -100C (since
the launch) down to -120C, in order to mitigate the eects of the CTI degradation on the energy
resolution.
The parallel CTI is reduced by a factor 2 to 3 depending on the CCD, at this new operating
temperatureas can be seen in gures 1 and 2 for central CCDs only. The MOS CTI parameters have
been derived according to the latest algorithm that will be immplemented and available in SAS 5.4.
3 Scientic Impact of this Update
The use of this new CCF is mandatory for all observation acquired after revolution 533 for MOS,
otherwise the energy scale will be completely wrong, as the CTI was seriouly improved.
1

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4 Estimated Scientic Quality
With the same caveat as discussed in detail in the previous delivery note (XMM-CCF-REL-124) is
is assessed that the MOS energy scale with this new CCF shall be correct within 5eV at about 2
keV and within 10 eV at 6keV, for not too bright sources.
With this new operating temperature, the energy resolution of the MOS camera that degraded
by 20% since launch is improved, with a FWHM decreasing from 160eV to 140eV.
5 Test procedures & results
The new CTI CCFs have been tested with the Development Track (DT) version of the SAS at
VilSpa that includes the new CTI algorithm, called by the FITS header keyword ALGOID = 2.
The results have be shown in the previous section.
6 Expected Updates
The parameters of this CCF will have to be rened in the future as they are based only on the
measurements made with the internal calibration source in revolutions 533 and 534. Besides, as the
degradation rate of the CTI at this temperature is not yet known, it has been put to zero.

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Figure 1: MOS1 transfer losses since launch at Mn and Al energies, for the central CCD, overlayed
with the CTI model as parametrized in the new set of CCFs
Figure 2: MOS2 transfer losses since launch at Mn and Al energies, for the central CCD, overlayed
with the CTI model as parametrized in the new set of CCFs