XMM-Newton Science Analysis System: User Guide


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4.3.2 Running the EPIC pn processing meta-task

The EPIC pn meta task epproc concatenate all first-level pn tasks to produce calibrated event lists. The pn processing is sketched out in figure 8. The main subroutine (epframes, badpixfind, badpix, epevents and attcalc) creates one event list for a single exposure and for all selected CCDs from all the relevant ODF material and bad pixel lists calling in sequence:

  1. epframes to process a CCD, exposure and datamode specific ODF file, creating the output raw event list and GTI data set,
  2. badpixfind to find new bad pixels,
  3. badpix to process the raw event list, adding the BADPIX extension,
  4. epevents to process the event list file, flagging trailing events, performing split events pattern recognition, CTI and gain correction to create the calibrated event list and fill the PHA and PI columns,
  5. attcalc to calculate the X and Y sky coordinates.

Finally, making use of the task evlistcomb, the CCD specific data sets are merged into a single event list. evselect selects all those events arriving in good time intervals, applies (by default) the destructive filter selection (#XMMEA_EP) && (PI $>$ 150 $\vert\vert$ PI $<$ -150) and writes the output file. For a description of the event attribute based selection, refer to the documentation of the SAS package evatt.

In the EPIC pn imaging mode, the EVENTS binary table of the calibrated event list file contains 14 columns i.e TIME, RAWX, RAWY, DETX, DETY, X, Y, PHA, PI, FLAG, PATTERN, PAT_ID, PAT_SEQ and CCDNR. For a description of the PAT* columns, refer to the documentation of the task epevents. The definition of the PATTERN values is also visualized in figure 13.

In the EPIC pn timing mode, the EVENTS binary table of the calibrated event list file contains only 9 columns: the spatial coordinates DETX, DETY, X, Y are not present as (in this mode) only one axis (RAWX) contains spatial information whereas the other axis is a measure of the arrival time of the event.

Figure 8: Pipeline processing of the EPIC pn observation data.
\begin{figure}\centerline{\psfig{figure=EPIC/epchain_chart.ps,width=12cm}}\end{figure}



Subsections
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Next: 4.3.2.1 Improving the quality of EPIC pn data: epreject Up: 4.3 Running the EPIC pipeline processing Previous: 4.3.1 Running the EPIC MOS processing meta-task
European Space Agency - XMM-Newton Science Operations Centre