spectra (version 2.1)

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This routine extracts spectra for sources, generates response matricies, extracts blank sky background spectra, and plots the spectra.

Spectra are extracted in sky coordinates from the filtered event files. Event files are combined if the spectra extracted from them would have the same response matrix and if they can be extracted using the same region filter. Specifically, SIS data with different CCD modes (1, 2 or 4) are kept separate, and GIS data with different numbers of PHA bins are kept separate. Also, data from different instruments or in different modes (BRIGHT BRIGHT2 FAST PH MPC), and data with different image resolutions are kept separate. The spectra are grouped to have a minimum of 40 counts per group.

GIS RMFs are static and can are just retrieved from a collection of pre-generated files. SIS RMFs depend on epoch and location on the chip so they must be generated using the FTOOL sisrmg. The following proceedure is used to generate SIS RMFs in 2 or 4 CCD mode:

  1. Extract both a spectrum and an event list from the extraction region.
  2. Divide the event list into an event list for each chip and determine the number of counts on each chip. on each chip.
  3. If the source is only on one chip, generate an RMF using the spectrum generated above.
  4. If the source is spread over more than chip, extract a spectrum from the event file for each chip and then generate an RMF for each spectrum.
  5. sum the individual RMFs, weighting by the number of events on each chip.

An ARF is generated for each spectrum using "extended source mode".

Blank sky spectra are extracted for each instrument and source region file. The blank sky event files have been previously selected to have COR (cut-off rigidity) consistent with the selection criteria used to generate filtered event files. The GIS blank sky event files have been gisclean-ed. The spectra extracted from these blank sky event files may be used for background subtraction (with caution) in high galactic latitude sources.

Finally, each spectrum is plotted using xspec.

FTOOLS called:

  1. addrmf
  2. ascaarf
  3. deadtime
  4. fmemsort
  5. fmerge
  6. grppha
  7. setup_parfile
  8. sisrmg
  9. xselect
STOOLS called:
  1. discrim_mask
  2. equals
  3. group_event_files
Utilities called:
  1. add_fits_keyword
  2. any_filename
  3. dump_table
  4. exception
  5. fetch_file
  6. file_to_log
  7. ftool_test
  8. generate_filename
  9. log_entry
  10. milestone
  11. parse_filename
  12. read_bintable
  13. read_fits_keyword
  14. read_parfile
  15. setup_parfile
  16. stool_test
  17. xselect_test