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Last modified: 29 March 2018


Bugs: fullgarf

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PHAFRAC column values

The grating ARF files created by mkgarf contain a PHAFRAC column. It is not used by any analysis tools nor is it used when modeling and fitting. It is contains diagnostic information used by the developers.

When the grating ARFs for individual CCDs are combined the dmarfadd tool simply copies the PHAFRAC column from one of the input files to the output. It does not try to combine the values in any way. This is also the case when combining positive and negative orders, and when combining responses from multiple observations.

Therefore, the PHAFRAC values may be different based on the order the files are input tool. Again, since the values are not used, this has user-visable effect.

*** ERROR: aspect histogram acisf00459_ah4.fits[ASPHIST] contains no rows

This error is from mkgarf and occurs when a chip wasn't on for the observation. The fullgarf script attempts to calculate gARFs for ACIS chips S0-S3 if the order is less than zero or chips S3-S5 if the order is greater than zero, regardless of whether or not the chip was actually used in the observation. This error can be ignored, as it does not adversely affect the script output.

WARNING: OSIP file contains invalid data for the region
512<=CHIPX<=768 608<=CHIPY<=640 at 0.1 keV.
WARNING: OSIP file contains invalid data for the region
512<=CHIPX<=768 608<=CHIPY<=640 at 0.277 keV.

This warning is innocuous. Events at energies < 0.3 keV are outside the supported range of wavelength by HETG/ACIS-S (the events would fall off the chips). The gARFs should be fine for use in the analysis.

Last modified: 29 March 2018
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