用球谐中天望远镜进行全天干涉测量
All-Sky Interferometry with Spherical Harmonic Transit Telescopes
摘要：
在本文中，我们描述了球谐过境望远镜，一种新的形式主义过境射电望远镜的分析。这种全天空方法绕过了传统干涉测量的弯曲天空复杂性，因此特别适合于宽场无线电干涉仪的分析。它可以实现数据及其统计数据的紧凑和计算效率的表示，从而可以采用新的方法来处理重要问题，如地图制作和前景删除。特别是，我们展示了它如何使使用的Karhunen-Loeve变换作为一个非常有效的前景过滤器，抑制现实的前景残差为我们的基准的例子，至少有一个因素低于21厘米的信号，即使在高度污染的地区的天空。这是尽管存在的角度频率模式混合固有的现实世界的仪器与频率相关的光束。我们表明，使用Fisher预测，前景清洗功率谱约束的影响不大相比，假设的前景自由测量。除了提供一个自然的现实世界的数据分析框架，目前正在建设中的21厘米望远镜和未来的实验，这种形式主义允许准确的功率谱预测，包括相互作用的设计约束和现实的实验系统与21世纪的21厘米科学。
英文摘要：
In this paper we describe the spherical harmonic transit telescope, a novel formalism for the analysis of transit radio telescopes. This all-sky approach bypasses the curved sky complications of traditional interferometry and so is particularly well suited to the analysis of wide-field radio interferometers. It enables compact and computationally efficient representations of the data and its statistics that allow new ways of approaching important problems like map-making and foreground removal. In particular, we show how it enables the use of the Karhunen-Loeve transform as a highly effective foreground filter, suppressing realistic foreground residuals for our fiducial example by at least a factor twenty below the 21cm signal even in highly contaminated regions of the sky. This is despite the presence of the angle-frequency mode mixing inherent in real-world instruments with frequency-dependent beams. We show, using Fisher forecasting, that foreground cleaning has little effect on power spectrum constraints compared to hypothetical foreground-free measurements. Beyond providing a natural real-world data analysis framework for 21cm telescopes now under construction and future experiments, this formalism allows accurate power spectrum forecasts to be made that include the interplay of design constraints and realistic experimental systematics with twenty-first century 21cm science.
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。
