1 Institut d’Astrophysique Spatiale (IAS), UMR 8617, CNRS, Université Paris Saclay, Université Paris Sud, 91405 Orsay, France
2 INAF–Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, 50125 Firenze, Italy
Received: 8 April 2016
Accepted: 11 May 2016
The knowledge of the point spread function (PSF) of imaging instruments represents a fundamental requirement for astronomical observations. The Herschel PACS PSFs delivered by the instrument control centre are obtained from observations of the Vesta asteroid, which provides a characterisation of the central part and, therefore, excludes fainter features. In many cases, however, information on both the core and wings of the PSFs is needed. With this aim, we combine Vesta and Mars dedicated observations and obtain PACS PSFs with an unprecedented dynamic range (~106) at slow and fast scan speeds for the three photometric bands.
Key words: instrumentation: photometers / techniques: image processing / techniques: photometric
Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.
FITS files of our PACS PSFs (Fig. 2) are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (220.127.116.11) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/591/A117
© ESO, 2016