论文标题
从Plaplanck到Cosmoglobe:初步
From BeyondPlanck to Cosmoglobe: Preliminary $\mathit{WMAP}$ $\mathit Q$-band analysis
论文作者
论文摘要
我们通过分析9年$ \ mathit {wmap} $时间订购的观测值,使用与Planck使用的类似机械使用$ \ MATHIT {PLANCK} $ LFI,介绍了Cosmoglobe分析框架的第一个应用。我们仅分析$ \ Mathit Q $ -band(41 GHz)数据,并报告从未启用的时间订购数据到校准图的低级分析过程。大多数现有的BeyondPlanck管道可以重复使用$ \ Mathit {wmap} $分析,对现有代码库的更改最小。主要修改是实现$ \ Mathit {Wmap} $ Team使用的相同预处理的Biconjugate梯度MAPMAKER。生产单个$ \ mathit {wmap} $ $ $ $ $ \ MATHIT Q $ 1频段样品需要22个CPU-HRS,略高于$ \ Mathit {Planck} $ 44 GHz样本的17 CPU-HRS的成本;这表明,$ \ mathit {wmap} $数据的完整端到端贝叶斯处理在计算上是可行的。通常,我们恢复的地图与$ \ Mathit {Wmap} $团队发布的地图非常相似,尽管有两个显着的区别。在温度下,我们发现$ \ sim2 \,\ mathrm {μk} $ quadrupole差异很可能是由不同的增益建模引起的,而在两极分化中,我们发现$ 2.5 \,\ mathrm {μk} $先前被称为$ \ simber vy Mathit} $ Teams} $。在Cosmoglobe处理中,这种模式是由于CMB太阳偶极子,透射失衡和旁观者之间的耦合而引起的。在频率图或TOD剩余图中均未找到这种模式的痕迹,这表明当前的处理已成功地在假定的参数模型中建模了这些较差的模式,该模式通过使用$ \ Mathit {planck} $信息来破坏Sky-Synchronchronous demeneracies breake obles-synchronous demeneracies固有的$ \ \ \ Mathit {wmap {wmap {wmap {
We present the first application of the Cosmoglobe analysis framework by analyzing 9-year $\mathit{WMAP}$ time-ordered observations using similar machinery as BeyondPlanck utilizes for $\mathit{Planck}$ LFI. We analyze only the $\mathit Q$-band (41 GHz) data and report on the low-level analysis process from uncalibrated time-ordered data to calibrated maps. Most of the existing BeyondPlanck pipeline may be reused for $\mathit{WMAP}$ analysis with minimal changes to the existing codebase. The main modification is the implementation of the same preconditioned biconjugate gradient mapmaker used by the $\mathit{WMAP}$ team. Producing a single $\mathit{WMAP}$ $\mathit Q$1-band sample requires 22 CPU-hrs, which is slightly more than the cost of a $\mathit{Planck}$ 44 GHz sample of 17 CPU-hrs; this demonstrates that full end-to-end Bayesian processing of the $\mathit{WMAP}$ data is computationally feasible. In general, our recovered maps are very similar to the maps released by the $\mathit{WMAP}$ team, although with two notable differences. In temperature we find a $\sim2\,\mathrm{μK}$ quadrupole difference that most likely is caused by different gain modeling, while in polarization we find a distinct $2.5\,\mathrm{μK}$ signal that has been previously called poorly-measured modes by the $\mathit{WMAP}$ team. In the Cosmoglobe processing, this pattern arises from temperature-to-polarization leakage from the coupling between the CMB Solar dipole, transmission imbalance, and sidelobes. No traces of this pattern are found in either the frequency map or TOD residual map, suggesting that the current processing has succeeded in modelling these poorly measured modes within the assumed parametric model by using $\mathit{Planck}$ information to break the sky-synchronous degeneracies inherent in the $\mathit{WMAP}$ scanning strategy.