Far-infrared photometric observations of the outer planets and satellites withHerschel-PACS

Abstract

We present all Herschel-PACS photometer observations of Mars, Saturn, Uranus, Neptune, Callisto, Ganymede, and Titan. All measurements were carefully inspected for quality problems, were reduced in a (semi-)standard way, and were calibrated. The derived flux densities are tied to the standard PACS photometer response calibration, which is based on repeated measurements of five fiducial stars. The overall absolute flux uncertainty is dominated by the estimated 5% model uncertainty of the stellar models in the PACS wavelength range between 60 and 210 µm. A comparison with the corresponding planet and satellite models shows excellent agreement for Uranus, Neptune, and Titan, well within the specified 5%. Callisto is brighter than our model predictions by about 4−8%, Ganymede by about 14−21%. We discuss possible reasons for the model offsets. The measurements of these very bright point-like sources, together with observations of stars and asteroids, demonstrate the high reliability of the PACS photometer observations and the linear behavior of the PACS bolometer source fluxes over more than four orders of magnitude (from mJy levels up to more than 1000 Jy). Our results show the great potential of using the observed solar system targets for cross-calibration purposes with other ground-based, airborne, and space-based instruments and projects. At the same time, the PACS results will lead to improved model solutions for future calibration applications.

Calibration and performance of the NIKA2 camera at the IRAM 30-m Telescope

“…In summary, this study confirms that Uranus ESA V4 and Neptune ESA V5 models are accurate to 5% for predicting planet flux densities. This result also agrees with the accuracy estimated from Herschel SPIRE and PACS observations (Müller et al 2016;Swinyard et al 2014). Furthermore, the variations of Uranus and Neptune fluxes over the duration of a typical NIKA2 run are taken into account, although they are negligible compared to the model accuracy.…”

Fire in the Heart: A Characterization of the High Kinetic Temperatures and Heating Sources in the Nucleus of NGC 253

“…Band 7 flux calibrator uncertainties are estimated to be 10% for Neptune (Müller et al 2016) and 5% for Uranus (Orton et al 2014). As was done for our Band 6 measurements, for our absolute flux uncertainty estimate for Neptune we have increased the nominal 5% uncertainty quoted by Müller et al (2016) owing to the presence of a CO absorption transition at 345.796 GHz present in the atmosphere of Neptune. For unknown reasons the 12m Array measurements of NGC 253 at Band 7 employed a nonstandard flux calibrator (J2258−2758).…”

“…For Mars our estimate of the absolute flux uncertainty derives from the 1-50 GHz absolute flux (Perley & Butler 2013) and 23-93 GHz absolute brightness temperature (Weiland et al 2011) measurements of Mars. For our absolute flux uncertainty estimate for Neptune we have increased the nominal 5% uncertainty quoted by Müller et al (2016) owing to the presence of a CO absorption transition at 230.538 GHz present in the atmosphere of Neptune to 10%. At Band 7 flux calibration was effected using J2258−2758 (390 mJy), , and Uranus (63.8-66.6 Jy).…”

Planckintermediate results

“…The following papers discuss the brightness of the planet, either as an absolute measurement or one that is relative to another planet or a model Wright (1976); Rather et al (1974); Rudy et al (1987);Muhleman & Berge (1991); Goldin et al (1997); Sidher et al (2000); Runyan et al (2003); Swinyard et al (2010); Perley & Butler (2013); Müller et al (2016). The polarization properties of Mars are described in Perley & Butler (2013).…”