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MLAMBDA/PI
images, commonly known as banana
plots, are improved by overruling the default y-range by checking the
withyranges
box and setting, e.g. yimagemin=0, yimagemax=2500.
Fig. 36 shows plots of the merged RGS1 events. These
plots are orthogonal projections of the all-important
MLAMBDA,XDSP_CORR,PI
3-D RGS data space of the merged list of
all the events detected in the observation, thus showing all the
features of RGS data. The edges are clear of the 9 CCDs, numbered
1-9 from right to left. In both plots, wavelength and dispersion angle
increase from left to right.
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The pointing coordinates were evidently chosen well enough to put this
bright source central in the aperture. The source was bright enough to
be seen up to 4th or even a weak 5th order in the characteristic
hyperbolic-shaped areas occupied by photons that have passed through the
gratings. There are plenty of hot pixels and columns and the so-called
fixed pattern noise shows as the herring-bone pattern in CCDs 1 and
2. Calibration sources of F K at PI
eV span CCDs
2&3 and 7&8 ; and Al K at PI
eV span CCDs 3&4
and 8&9.
The locations of the selection regions may be checked using the task rgsimplot
http://xmm-tools.cosmos.esa.int/external/sas/current/doc/rgsimplot
which plots them over MLAMBDA-XDSP
and MLAMBDA-PI
images
that are, in this case, most usefully generated from the screened events
files. Fig. 37 shows such an example.