XMM-Newton Science Analysis System: User Guide

6.3.2 Event selection & corrections

The following tasks are applied to each individual fast mode window,

• omprep (step4). The task omprep applied to the event list file will augment its header contents with house-keeping information. A modified intermediate event list file will be created.

• evselect (step5). The task evselect extracts the photon events from the event-list file and builds a pseudo image corresponding to the fast mode window.

• omfastshift (step6). The task omfastshift uses the tracking history file (as contained in the intermediate processing product of the tracking history task) to correct the position of the photon events for drifts of the spacecraft during the exposure. New columns are added to the event-list file with corrected coordinates.

• omfastflat (step7). The task omfastflat applies the tracking history file to the OM flatfield file (obtained from omflatgen) to build a shifted flat field corresponding to the fast mode pseudo image.

  It is pointed out again the peculiarity of the flat field for OM. As for image data, a unity flat field is applied to fast mode data as well.