Measurements of flux density are described for five planets, Mars, Jupiter, Saturn, Uranus, and Neptune, across the six Planck High Frequency Instrument frequency bands (100-857 GHz) and these are ...then compared with models and existing data. In our analysis, we have also included estimates of the brightness of Jupiter and Saturn at the three frequencies of the Planck Low Frequency Instrument (30, 44, and 70 GHz). The results provide constraints on the intrinsic brightness and the brightness time-variability of these planets. The majority of the planet flux density estimates are limited by systematic errors, but still yield better than 1% measurements in many cases. Applying data from Planck HFI, the Wilkinson Microwave Anisotropy Probe (WMAP), and the Atacama Cosmology Telescope (ACT) to a model that incorporates contributions from Saturn's rings to the planet's total flux density suggests a best fit value for the spectral index of Saturn's ring system of \(\beta _\mathrm{ring} = 2.30\pm0.03\) over the 30-1000 GHz frequency range. The average ratio between the Planck-HFI measurements and the adopted model predictions for all five planets (excluding Jupiter observations for 353 GHz) is 0.997, 0.997, 1.018, and 1.032 for 100, 143, 217, and 353 GHz, respectively. Model predictions for planet thermodynamic temperatures are therefore consistent with the absolute calibration of Planck-HFI detectors at about the three-percent-level. We compare our measurements with published results from recent cosmic microwave background experiments. In particular, we observe that the flux densities measured by Planck HFI and WMAP agree to within 2%. These results allow experiments operating in the mm-wavelength range to cross-calibrate against Planck and improve models of radiative transport used in planetary science.
Parity violating extensions of the standard electromagnetic theory cause in vacuo rotation of the plane of polarization of propagating photons. This effect, also known as cosmic birefringence, ...impacts the cosmic microwave background (CMB) anisotropy angular power spectra, producing non-vanishing \(T\)--\(B\) and \(E\)--\(B\) correlations that are otherwise null when parity is a symmetry. Here we present new constraints on an isotropic rotation, parametrized by the angle \(\alpha\), derived from Planck 2015 CMB polarization data. To increase the robustness of our analyses, we employ two complementary approaches, in harmonic space and in map space, the latter based on a peak stacking technique. The two approaches provide estimates for \(\alpha\) that are in agreement within statistical uncertainties and very stable against several consistency tests. Considering the \(T\)--\(B\) and \(E\)--\(B\) information jointly, we find \(\alpha = 0.31^{\circ} \pm 0.05^{\circ} \, ({\rm stat.})\, \pm 0.28^{\circ} \, ({\rm syst.})\) from the harmonic analysis and \(\alpha = 0.35^{\circ} \pm 0.05^{\circ} \, ({\rm stat.})\, \pm 0.28^{\circ} \, ({\rm syst.})\) from the stacking approach. These constraints are compatible with no parity violation and are dominated by the systematic uncertainty in the orientation of Planck's polarization-sensitive bolometers.
The sizes, temperatures, and free neutron-to-proton ratios of the initial interaction zones produced in the collisions of 40 MeV/nucleon {sup 40}Ar+{sup 112}Sn and 55 MeV/nucleon {sup 27}Al+{sup ...124}Sn are derived using total detected neutron plus charged particle multiplicity as a measure of the impact parameter range and number of participant nucleons. The size of the initial interaction zone, determined from a coalescence model analysis, increases significantly with decreasing impact parameter. The temperatures and free neutron-to-proton ratios in the interaction zones are relatively similar for different impact parameter ranges and evolve in a similar fashion.
PDF
