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Last modified: 2 August 2010

URL: http://cxc-newtest.cfa.harvard.edu/ciao4.2/bugs/psextract.html

Bugs: psextract


psextract is not a CIAO tool; it is a script which is available for download from the Scripts page.


Caveats

  1. Source and background region(s) must each be confined to a single chip. (03 Feb 2009)

Bugs

  1. Unable to run acis_fef_lookup

    (02 Aug 2010)


Caveats

  1. Source and background region(s) must each be confined to a single chip. (03 Feb 2009)

    psextract cannot correctly handle the case where a region contains events from two different chips. A problem will be evident in the output event statistics:

    Source Event statistics: CHIP 3 644.44444444 956.97037037 SKY 2676.9863516 4554.0813151
    Background Event statistics: CHIP 2.953125 638.609375 953.140625 SKY 2673.1927109 4553.2426224 
    

    The chip number - 2.953 - is not an integer because it's calculated over two chips. The same problem would appear if the source region spanned multiple chips.

    The script will hang indefinitely if this occurs.


Bugs

  1. Unable to run acis_fef_lookup

    (02 Aug 2010)

    This message usually indicates that the input event file is missing the CTI_APP header keyword. acis_fef_lookup requires this header keyword in order to select the FEF file from the CALDB.

    The CTI_APP header keyword was added to standard data processing at version DS 7.6.10. If your dataset is old enough that it doesn't have a CTI_APP keyword, consider running the Reprocessing Data to Create a New Level=2 Event File thread to be sure that the newest calibration has been applied to the file.

    If you don't wish to reprocess, run CIAO contributed script, check_ctiapp.sh:

    unix% chmod +w acis_evt2.fits
    
    unix% check_ctiapp.sh acis_evt2.fits
    Setting CTI_APP value to PPPPPNPNPP 
    

Last modified: 2 August 2010