论文标题
使用球形谐波与工程开发阵列2在159MHz的南部天空中成像2
Imaging the Southern Sky at 159MHz using Spherical Harmonics with the Engineering Development Array 2
论文作者
论文摘要
国际射电天文学的主要优先事项之一是通过发现21 cm HI线的回报时期(EOR)来研究早期宇宙。由于21 cm信号的弱性质,因此检测EOR的重要部分是从我们的观察值中去除污染的前景,因为它们是多个数量级更明亮的数量级。为了实现这一目标,需要跨越各种频率的天空图来校准和前景减法。与现有的低频天空图相辅相成,我们利用工程开发阵列2(EDA2)(平方公里阵列(SKA)低频原型阵列系统系统的工程开发阵列2(EDA2)构建了一个南部天空图。我们使用M模式形式主义在159MHz的角度分辨率为3度,并在(EDA2)的数据中提供超过+60度至-90度的信息,以159MHz的形式创建全天空地图。我们还引入了一种新方法,以可视化和量化干涉仪映射的基线分布向球形谐波的基线分布,并讨论如何使用先前的信息来约束干涉仪对干涉仪不敏感的球形谐波组件。
One of the major priorities of international radio astronomy is to study the early universe through the detection of the 21 cm HI line from the epoch of reionisation (EoR). Due to the weak nature of the 21 cm signal, an important part in the detection of the EoR is removing contaminating foregrounds from our observations as they are multiple orders of magnitude brighter. In order to achieve this, sky maps spanning a wide range of frequencies and angular scales are required for calibration and foreground subtraction. Complementing the existing low-frequency sky maps, we have constructed a Southern Sky map through spherical harmonic transit interferometry utilising the engineering development array 2 (EDA2), a square kilometre array (SKA) low-frequency array prototype system. We use the m-mode formalism to create an all-sky map at 159MHz with an angular resolution of 3 degrees, with data from the (EDA2) providing information over +60 degrees to -90 degrees in declination. We also introduce a new method for visualising and quantifying how the baseline distribution of an interferometer maps to the spherical harmonics, and discuss how prior information can be used to constrain spherical harmonic components that the interferometer is not sensitive to.