...
- Acceptance cone cut centered at RA, Dec = 166.1138, 38.2088 J2000 degrees with a 15 deg radius:
Code Block DSTYP1 = 'POS(RA,DEC)' DSUNI1 = 'deg ' DSVAL1 = 'CIRCLE(166.1138,38.2088,15)'
- Time range cuts. These are encoded in the GTI extension.
Code Block DSTYP2 = 'TIME ' DSUNI2 = 's ' DSVAL2 = 'TABLE ' DSREF2 = ':GTI '
- Event class selection. The bit-mask selection is defined using this "BIT_MASK" function that has three arguments:
- FT1 column name
- Bit to set in the mask
- Pass version as given in the PASS_VER keyword in the FT1 EVENTS extension. This needs to be encoded in the BIT_MASK function designation so that it is propagated to downstream files (such as exposure maps) so that the IRF handling code can determine the IRFs to use based on the event selection and the
information in CALDB.Code Block DSTYP3 = 'BIT_MASK(EVENT_CLASS,2,P7V6)' DSUNI3 = 'DIMENSIONLESS' DSVAL3 = '1:1 '
- Energy range selection.
Code Block DSTYP4 = 'ENERGY ' DSUNI4 = 'MeV ' DSVAL4 = '100:300000'
- Zenith angle cut. This is needed by gtmktime to determine the time intervals in the FT2 file for which the the acceptance cone is completely contained within the maximum zenith angle. The accepted intervals are then expressed as GTIs. This cut is not strictly required by the likelihood tools (aside from gtmktime), but it is generally needed to remove Earth limb contamination.
Code Block DSTYP5 = 'ZENITH_ANGLE'
DSUNI5 = 'deg '
DSVAL5 = '0:105 'code
DSUNI5 = 'deg ' DSVAL5 = '0:105 '