Planck intermediate results LII. Planet flux densities
Planck intermediate results LII. Planet flux densities
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DOI：
10.1051/0004-6361/201630311
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发表时间：
2017-11-27
影响因子：
6.5
通讯作者：
Zacchei, A.
中科院分区：
文献类型：
--
作者：
Akrami, Y.;Ashdown, M.;Zacchei, A.
描述了火星、木星、土星、天王星和海王星这五个行星在六个普朗克高频仪器频段 (100-857 GHz) 的通量密度测量结果，然后将这些测量结果与模型和现有数据进行比较。在我们的分析中，我们还包括了对普朗克低频仪器的三个频率（30、44 和 70 GHz）下木星和土星亮度的估计。结果对这些行星的固有亮度和亮度随时间变化提供了限制。大多数行星通量密度估计都受到系统误差的限制，但在许多情况下仍能得出优于 1% 的测量结果。将普朗克 HFI、威尔金森微波各向异性探测器 (WMAP) 和阿塔卡马宇宙学望远镜 (ACT) 的数据应用到一个模型，该模型纳入了土星环对行星总通量密度的贡献，表明土星环系统的光谱指数在 30-1000 GHz 频率范围内的最佳拟合值为 beta(ring) = 2 : 30 +/- 0 : 03。还对具有偏振敏感探测器的四个频段（100-353 GHz）中的行星偏振幅度进行了估计；该分析提供了火星极化在 100、143、217 和 353 GHz 下分别为 1.8、1.7、1.2 和 1.7% 的 95% 置信度上限。对于所有五颗行星（不包括 353 GHz 的木星观测），Planck-HFI 测量值与采用的模型预测之间的平均比率对于 100、143、217 和 353 GHz 分别为 1.004、1.002、1.021 和 1.033。因此，行星热力学温度的模型预测与 Planck-HFI 探测器的绝对校准一致，约为百分之三的水平。我们将我们的测量结果与最近发表的宇宙微波背景实验的结果进行比较。特别是，我们观察到 Planck HFI 和 WMAP 测量的磁通密度在 2% 以内一致。这些结果使得在毫米波长范围内进行的实验能够针对普朗克进行交叉校准，并改进行星科学中使用的辐射传输模型。
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(ring) = 2 : 30 +/- 0 : 03 over the 30-1000 GHz frequency range. Estimates of the polarization amplitude of the planets have also been made in the four bands that have polarization-sensitive detectors (100-353 GHz); this analysis provides a 95% confidence level upper limit on Mars's polarization of 1.8, 1.7, 1.2, and 1.7% at 100, 143, 217, and 353 GHz, respectively. The average ratio between the Planck-HFI measurements and the adopted model predictions for all five planets (excluding Jupiter observations for 353 GHz) is 1.004, 1.002, 1.021, and 1.033 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.