arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2011.05609astro-ph.CO
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BeyondPlanck I. Planck低频仪器数据的全局贝叶斯分析

BeyondPlanck I. Global Bayesian analysis of the Planck Low Frequency Instrument data

BeyondPlanck Collaboration, K. J. Andersen, R. Aurlien, R. Banerji, A. Basyrov, M. Bersanelli, S. Bertocco, M. Brilenkov, M. Carbone, L. P. L. Colombo, H. K. Er… 展开作者

BeyondPlanck Collaboration, K. J. Andersen, R. Aurlien, R. Banerji, A. Basyrov, M. Bersanelli, S. Bertocco, M. Brilenkov, M. Carbone, L. P. L. Colombo, H. K. Eriksen, J. R. Eskilt, M. K. Foss, C. Franceschet, U. Fuskeland, S. Galeotta, M. Galloway, S. Gerakakis, E. Gjerløw, B. Hensley, D. Herman, M. Iacobellis, M. Ieronymaki, H. T. Ihle, J. B. Jewell, A. Karakci, E. Keihänen, R. Keskitalo, J. G. S. Lunde, G. Maggio, D. Maino, M. Maris, A. Mennella, S. Paradiso, B. Partridge, M. Reinecke, M. San, N. -O. Stutzer, A. -S. Suur-Uski, T. L. Svalheim, D. Tavagnacco, H. Thommesen, D. J. Watts, I. K. Wehus, A. Zacchei

AI总结:

BeyondPlanck项目提出Planck LFI数据的端到端贝叶斯分析框架,识别出增益过度平滑等新效应,约束再电离光学深度τ=0.066±0.013,并首次充分利用44 GHz通道。

摘要:

我们从动机、方法论和主要产品的角度描述了BeyondPlanck项目,并提供了一组配套论文的指南,这些论文更详细地描述了每个结果。我们为Planck LFI观测实现了一个完整的端到端贝叶斯分析框架。主要产品是完整的联合后验分布P(ω|d),其中ω代表所有自由仪器、天体物理和宇宙学参数的集合。这种方法的显著优点是:无缝的端到端不确定性传播;在每个不确定量最自然的基中精确建模天体物理和仪器效应;优化计算成本,各分析步骤之间几乎不需要人工干预;以及在单一框架内全面概述整个分析过程。我们特别关注利用Planck LFI进行低ℓ CMB偏振重建。我们识别出几个以前流程中未考虑的重要新效应,包括增益过度平滑以及30和44 GHz通道中的时变和非-1/f相关噪声。我们发现所有结果均与ΛCDM模型一致,我们将再电离光学深度约束为τ=0.066±0.013,低分辨率χ²超越概率为32%。由于考虑了更完整的仪器模型,该不确定性比官方流程大约30%。边缘CMB太阳偶极振幅为3362.7±1.4μK,其误差棒直接源自后验分布,无需任何临时仪器校正。我们目前未察觉Planck LFI数据中残留任何显著未建模系统效应,并且首次充分利用了44 GHz通道。(节选)

英文摘要:

We describe the BeyondPlanck project in terms of motivation, methodology and main products, and provide a guide to a set of companion papers that describe each result in fuller detail. We implement a complete end-to-end Bayesian analysis framework for the Planck LFI observations. The primary product is a full joint posterior distribution $P(ω|d)$, where $ω$ represents the set of all free instrumental, astrophysical, and cosmological parameters. Notable advantages of this approach are seamless end-to-end propagation of uncertainties; accurate modeling of both astrophysical and instrumental effects in the most natural basis for each uncertain quantity; optimized computational costs with little or no need for intermediate human interaction between various analysis steps; and a complete overview of the entire analysis process within one single framework. We focus in particular on low-$\ell$ CMB polarization reconstruction with Planck LFI. We identify several important new effects that have not been accounted for in previous pipelines, including gain over-smoothing and time-variable and non-$1/f$ correlated noise in the 30 and 44 GHz channels. We find that all results are consistent with the $Λ$CDM model, and we constrain the reionization optical depth to $τ=0.066\pm0.013$, with a low-resolution $χ^2$ probability-to-exceed of 32%. This uncertainty is about 30% larger than the official pipelines, arising from taking into account a more complete instrumental model. The marginal CMB Solar dipole amplitude is $3362.7\pm1.4μ\mathrm{K}$, where the error bar is derived directly from the posterior distribution without the need of any ad-hoc instrumental corrections. We are currently not aware of any significant unmodelled systematic effects remaining in the Planck LFI data, and, for the first time, the 44 GHz channel is fully exploited. (Abridged.)

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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