1. Markus Nielbock (MPIA) – PACS Photometer Flux Calibration EPOS Meeting PACS Photometer Flux Calibration Current Plans Markus Nielbock MPIA, 22 th February 2011

2. PACS Photometer Flux Calibration Target selection Markus Nielbock (MPIA) – PACS Photometer Flux Calibration 4 classes:

3. PACS Photometer Flux Calibration Transition to scan maps Markus Nielbock (MPIA) – PACS Photometer Flux Calibration ● scan maps now only supported science observing mode ● photometry on scan maps and chopped observations systematically different ● scan map calibration observations will be reference for flux calibration ● scan map photometry depends on data processing ● clear and detailed instructions

4. PACS Photometer Flux Calibration Flux extraction Markus Nielbock (MPIA) – PACS Photometer Flux Calibration ● aperture photometry

5. PACS Photometer Flux Calibration Flux extraction Markus Nielbock (MPIA) – PACS Photometer Flux Calibration ● aperture photometry ● highpass filter width scaled with PSF ● aperture correction taken from EEF, ● to be updated (see PICC-ME-TN-033)

6. PACS Photometer Flux Calibration Flux extraction Markus Nielbock (MPIA) – PACS Photometer Flux Calibration ● aperture photometry ● highpass filter width scaled with PSF ● aperture correction taken from EEF, ● to be updated (see PICC-ME-TN-033) ● colour correction

7. PACS Photometer Flux Calibration PSF and Encircled Energy Fraction Markus Nielbock (MPIA) – PACS Photometer Flux Calibration ● derived from scan map observations ● PSF core: (nearly) point sources Vesta and α Tau ● PSF wings: unsaturated areas of Mars

8. PACS Photometer Flux Calibration PSF and Encircled Energy Fraction Markus Nielbock (MPIA) – PACS Photometer Flux Calibration ● derived from scan map observations ● PSF core: (nearly) point sources Vesta and α Tau ● PSF wings: unsaturated areas of Mars

9. PACS Photometer Flux Calibration PSF and Encircled Energy Fraction Markus Nielbock (MPIA) – PACS Photometer Flux Calibration ● derived from scan map observations ● PSF core: (nearly) point sources Vesta and α Tau ● PSF wings: unsaturated areas of Mars WARNING! There is no single general PSF! A PSF is influenced by: ● fast scan PSF smearing ● reduction methods: ● highpass filtering, map pixel size, drizzling ● source SED ● straylight and ghost effects ● pointing quality

10. PACS Photometer Flux Calibration PSF and Encircled Energy Fraction Markus Nielbock (MPIA) – PACS Photometer Flux Calibration ● measured from Vesta ● sky set to zero at r = 60” ● basis of current flux calibration ● combination of Vesta and Mars ● adds ~10% flux at large radii ● affects extended source calibration ● to be inserted into flux calibration

11. PACS Photometer Flux Calibration Results Markus Nielbock (MPIA) – PACS Photometer Flux Calibration ● individual stellar models have an uncertainty of 5% ● estimate of total flux calibration uncertainty: ● 2.6% (70 µm), 2.8% (100 µm), 4.2% (160 µm) ● to be updated soon ● EEF to be added as calibration entry ● will include a method to determine suitable aperture correction ● non-linearity under investigation ● correction method not yet available