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- I implemented the "efficiency factor" that accounts for the trigger rate and energy dependent effects of ghost events on the effective area. The implementation is based on the parameterization of the trigger rate as a function of livetime fraction and of the linear fits to the relative efficiency as a function of trigger rate for different energy bands as described on slides 1 and 29 of David Paneque's presentation to C&A on April 20.
The code reads in a text file that contains the required six parameters. Currently, the location of that file is specified by an environment variable, EFFICIENCY_PAR_FILE, but eventually, this information would probably be added as an extension in the effective area FITS files in CALDB.
I tested and updated the new P6_V\[345] IRFs that Riccardo provided after having fixed the energy dispersion bug he reported at C&A last Thursday. It is in irfs/caldb v0r9p1.Wiki Markup
Using the efficiency factor information will require another extension to the tabulation of accumulated livetimes in gtltcube, to include tabulation of livetime-weighted deadtime fractions. David and Eric's studies indicate that residual backgrounds (which to first order increase with deadtime fraction and so counter the efficiency factors) may also be an important consideration in applying efficiency factors to analyses of diffuse emission.
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