The Herschel PACS photometer calibration

摘要: We present a flux calibration scheme for the PACS chopped point-source photometry observing mode based on of five stellar standard sources. This was used science observations only early in mission. Later, it pointing and measurements. Its turns this type observation into fully validated data products Herschel Science Archive. Systematic differences with regard to principal photometer mode, scan map, are derived amount 5 − 6 %. An empirical method calibrate out an apparent response drift during first 300 Operational Days is presented. The relative photometric accuracy (repeatability) as good 1 % blue green band up red band. Like map inconsistencies among models become visible 2 stars used. absolute therefore mainly limited by model uncertainty, which all three bands.