XMM-Newton Data Files Handbook

4.1 Observation/Slew data science, non-science, and spacecraft files

This section gives a basic description of the ODF/SDF component files for pointed and slew observations, respectively. The full information and details can be found in the ODF/SDF Interface Control Document [6]. There are six categories of ODF/SDF component files:

• Instrument science files are all files directly related to the scheduled observation time period. No calibration of the science telemetry is performed before it is stored in the instrument science files. The science parameters are extracted from the telemetry packets and stored in their raw form with, in general, no further processing being performed. If additional processing is required in order to generate an instrument science file, additional descriptions can be found in the relevant sections.

• Diagnostics files created during calibration observations

• Instrument housekeeping files:
  • Instrument periodic housekeeping files contain the calibrated instrument periodic housekeeping parameters and instrument-related derived parameters. The periodic housekeeping parameters are extracted from the telemetry packets and the derived parameters calculated. The parameters are then calibrated using the applicable calibration curves (as defined in the XMM-Newton telemetry data base) and stored, with the corresponding time key, in the relevant instrument periodic housekeeping file.

  • Instrument non-periodic housekeeping files

• Spacecraft files containing information of spacecraft attitude, orbit, housekeeping, and time conversion.

• EPIC Radiation Monitor (ERM) observation/slew period files. These are ERM science files which correspond to observation and slew periods. The ERM data are partitioned to correspond to observation and slew periods (see Sect. 4.1.9).

• ASCII Summary files, which contain a summary of the information relating to the observation or slew.

All the above files, except the Summary files (Sect. 4.1.2), the raw attitude file (Sect. 4.1.11.2), and the reconstructed orbit file (Sect. 4.1.11.3), are in FITS format. They come in two flavors: binary table files or image files. There are three types of binary table files, event lists, auxiliary files, and housekeeping files. An event list contains all the events detected in a specific CCD (EPIC, RGS) or defined window (OM). One file per exposure is defined. An auxiliary file contains frame/cycle information, plus other general information, generated by the CCD that was active during an exposure/observation, or bookkeeping information generated by the on-board software. A housekeeping file contains the calibrated instrument housekeeping parameters and instrument-related derived parameters. An ODF/SDF image file consists of a primary header unit, a primary data unit of zero length and one image extension HDU (see Sect. 3).

All the ODF/SDF files share a common primary header. The headers of the binary or image extensions of the other ODF/SDF files differ from each other, although sharing a set of common keywords (see [6]). For each header value an explanation is given next to the value in the header.

The ODF/SDF constituent files are described in the following sections, most of which are self-explanatory. Short descriptions of a few files are given in Sect. 10.