Community Release Note for PACS Calibration Set v26

PACS calibration file set v26 incorporates the following differences from the previous community
release, v16:

The PACS photometer flux calibration has been re-derived, changes are implemented in the
new response calibration file "FM, 6". Absolute fluxes of point-sources will change by
less than 5%, extended sources will change by 10-20%.
Aperture photometry of point-sources requires from now on the application of new aperture
correction factors, taking into account that there is still significant flux beyond 60 arcsec.
These new correction factors (together with the old ones, applicable for PACS photometer observations
calibrated with the old version of the Response calibration file in PACS calibration file set v16 or
older) are stored in: "PCalPhotometer_ApertureCorrection_FM_v2.fits" and can be retrieved via the
new task "photApertureCorrectionPointSource" to be applied after "annularSkyAperturePhotometry"
(available in hipe version 7.0 and later, users of earlier hipe versions can refer to aperture corrections
listed in the "PACS photometer Point-source flux calibration" note on the PACS instrument page at the HSC:
http://herschel.esac.esa.int/
Invntt calibration files, used in the madmap map making, updated to v4.
Version 4 of Invntt contains the values of version 1, but in a new format needed by a software update.
New calibration product: DetectorReadoutTimeShift. Currently not used in the pipeline processing.
New calibration product: CoolerRecyclingTimes. Currently not used in the pipeline processing.

Capacitance Ratios updated based on in-orbit measurement. Will change signals of very bright sources
(observed with non-standard capacitance) by a few percent.

PACS Photometer observations - all PACS Spectrometer - very bright sources observed in the largest capacitance.

The following calibration products have been updated: