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XMM-Newton CCF Release Note
XMM-CCF-REL-115
EPIC Filter Transmission (Regions)
D Lumb
April 18, 2002
1 CCF components
Name of CCF VALDATE List of Blocks
changed
CAL VERSION XSCS ag
EMOS1 FILTRANSX 0010 2000 01 01T00:00:00 FILTER-THICK,
THIN ,MEDIUM,
OPEN
NO
EMOS2 FILTRANSX 0010 2000 01 01T00:00:00 FILTER-THICK
,THIN ,MEDIUM,
OPEN
NO
EPN FILTRANSX 0013 2000 01 01T00:00:00 FILTER-THICK
,THIN ,MEDIUM,
OPEN
NO
2 Changes
The spatial region selection expression has been expanded from 1000 arcsec to 1100 arcsec, so that
future changes of greater than 1 arcminute in telescope axis location will be accommodated in the
lter location. An editorial change also to anchor the low energy point at 0eV instead of 40eV
prevents a small negative excursion in lter transmission, albeit at energies below the nominal range
of EPIC.
3 Scientic Impact of this Update
Editorial change, necessary to make tasks such as eexpmap and evigweight work (and possibly other
tasks) in the case where the opticsx,opticsy keywords would be modied to account for possible oset
of the telescope axis from the detetcor centre.
1

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4 Estimated Scientic Quality
See previous version
5 Expected Updates
Whenever we have suфcient data to map the spatial variation of transmission (the THICK lters
in particular), then spatial region expressions will be introduced to describe the variation projected
at the detector.
There may be improvements in existing transmission vs. E curves as we analyse more calibration
data.
6 Test Procedures
Using calview the transmission curves on-axis for the lters were compared with the existing sets.
The application of the existing and new data les to the vignetting weighting maps was compared,
and the validity of the improved spatial region demonstrated by nding a complete image map.
7 Test Results
All lter data les were identically modied by changing only the radius of the selection region, and
the addition of a 0eV anchor point. The concerns for verifying changes then are that the transmission
vs. energy values are not modied, and that the new spatial region correctly accounts for shifts in
opticsx,opticsy.
7.1 Transmisison
Figure 1 shows a comparison of transmission for the case of MOS1 THICK lter. The curves are
identical, with the expected exception of the range 0 - 40eV, where the addition of an anchor point
removes aphysical -ve transmisison values seen in the old data sets.
7.2 Spatial selection
A test CCF was built using OPT ICSX;OPT ICSY keywords arbitrarily moved about 1 arcminute
from the existing centre. A typical event list set was processed through SAS v5.3 evigweight, and

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Figure 1: Comparison of transmission curves
the image displayed with weighting. Due to the lack of valid data points at the greatest extreme, a
NULL value of weighting produces an incorrect truncation of the image to lower left (Figure 2).
Application of the new F ILTRANSX les was made to the test CCF and the procedure re-
peated. The image recovered the whole valid range as expected (Figure 3).

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Figure 2: Vignetting weighted image - due to shift in telescope axis w.r.t. lter, the lack of valid
data points at the extreme edge reuls in loss of data towards the southwest
Figure 3: Vignetting weighted image - the improved data le with larger selection region recovers
the data at the edge of eld