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首页> 外文期刊>The Astrophysical journal >Observational Strategies of Cosmic Microwave Background Temperature and Polarization Interferometry Experiments
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Observational Strategies of Cosmic Microwave Background Temperature and Polarization Interferometry Experiments

机译:宇宙微波背景温度和偏振干涉测量实验的观测策略

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We have simulated the interferometric observation of the cosmic microwave background (CMB) temperature and polarization fluctuations. We have constructed data pipelines from the time-ordered raw visibility samples to the CMB power spectra that utilize the methods of data compression, maximum likelihood analysis, and optimal subspace filtering. They are customized for three observational strategies: the single pointing, the mosaicking, and the drift-scanning. For each strategy, derived are the optimal strategy parameters that yield band power estimates with minimum uncertainty. The results are general and can be applied to any close-packed array on a single platform such as the CBI and the forthcoming AMiBA experiments. We have also studied the effect of rotation of the array platform on the band power correlation by simulating the CBI single-pointing observation. It is found that the band power anticorrelations can be reduced by rotating the platform and thus densely sampling the visibility plane. This enables us to increase the resolution of the power spectrum in the l-space down to the limit of the sampling theorem (Δl = 226 ≈ π/θ), which is narrower by a factor of about than the resolution limit (Δl ≈ 300) used in the recent CBI single-pointing observation. The validity of this idea is demonstrated for a two-element interferometer that samples visibilities uniformly in the uv-annulus. From the fact that the visibilities are the Fourier modes of the CMB field convolved with the beam, a fast unbiased estimator (FUE) of the CMB power spectra is developed and tested. It is shown that the FUE gives results very close to those from the quadratic estimator method without requiring large computer resources even though uncertainties in the results increase.
机译:我们已经模拟了宇宙微波背景(CMB)温度和极化波动的干涉观测。我们已经构建了从时间顺序的原始可见性样本到CMB功率谱的数据管道,这些数据管道利用了数据压缩,最大似然分析和最佳子空间滤波的方法。它们针对三种观察策略进行了定制:单点指向,镶嵌和漂移扫描。对于每种策略,得出的是最优策略参数,这些参数可以在最小不确定性的情况下产生带功率估计。结果是通用的,可以应用于单个平台上的任何密排阵列,例如CBI和即将进行的AMiBA实验。我们还通过模拟CBI单点观测研究了阵列平台旋转对频带功率相关性的影响。已经发现,可以通过旋转平台并因此对可见性平面进行密集采样来减少带功率反相关。这使我们能够将L空间中功率谱的分辨率降低到采样定理的极限(Δl= 226≈π/θ),该定理比分辨率极限(Δl≈300)缩小约一个因子。 )用于最近的CBI单点观察。用两元素干涉仪在uv环上均匀地采样可见性,证明了这种想法的有效性。基于可见性是CMB场与光束卷积的傅里叶模式这一事实,开发并测试了CMB功率谱的快速无偏估计器(FUE)。结果表明,即使不确定性增加,FUE所提供的结果也非常接近于二次估计器方法,而无需大量的计算机资源。

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