XMM-Newton Data Files Handbook

6.7 Event list structure in the OM Fast Mode

The output files from the OM reduction chains have the extension `.FIT'. The names of the files start with `P' for the products and with `F' for the intermediate images and time series. The PPS products (Sect. 8) consist only of the products, while the omfchain and omichain tasks preserve the intermediate files. Event files are only produced in Fast mode, and one file is created for each exposures. The names of the event files are:

FIIIIIIIIIIOMSEEEEVLIST1000.FIT

with IIIIIIIIII the 10-digit observation ID and EEE the exposure number. An event file of this kind has the following extensions:

• 1 PRIMARY extension, which contains no data

• 1 OMFAE1 extension, which contains the raw and corrected information for each event. The first columns are a copy of the ODF *FAE* files.

• 1 MODES extension, which contains the physical coordinates of the Fast Window in unbinned pixels. Their meaning are:
  • MODE: observation mode, which could be either imaging (0) or event (1). For the Fast data it is always 1.

  • WINDOWX0: the X-coordinate (in pixels) of the lower left corner of the OM window;
  • WINDOWY0: the Y-coordinate (in pixels) of the lower left corner of the OM window;

  • WINDOWDX: width of the OM window in the horizontal direction (in pixels);

  • WINDOWDY: width of the OM window in the vertical direction (in pixels)

An overview of the columns in each of the above extensions is given in Table 34.

Table 34: OM Fast Mode event list column

Name	Units	Description
BINTABLE EVENT
FRAME	COUNTER	Frame count number
FTCOARSE	SECONDS	Coarse Time from the beginning of exposure
FTFINE	MILLISECONDS	Fine Frame Time
PHA		Dummy for compatibility with SAS evselect task
RAWX	PIXELS	Event X coordinate as measured by the detector
RAWY	PIXELS	Event Y coordinate as measured by the detector
TIME	SECONDS	Time relative to TIMEZERO
CORR_X	PIXELS	X coordinate corrected for spacecraft drift
CORR_Y	PIXELS	Y coordinate corrected for spacecraft drift
WIN_FLAG		(0/1) outside window after drift correction
FACTOR	PIXELS	bin factor
BADPIX		Bad Pixel Flag (0/1)
BINTABLE MODES
MODE		0=Image; 1=Fast
WINDOWX0	PIXELS	chip x-coordinates of lower left corner of Fast Window
WINDOWY0	PIXELS	chip y-coordinates of lower left corner of Fast Window
WINDOWDX	PIXELS	size of Fast Window in x
WINDOWDY	PIXELS	size of Fast Window in y