论文标题
在45和150 MHz处的扩散无线电调查的绝对校准
Absolute Calibration of Diffuse Radio Surveys at 45 and 150 MHz
论文作者
论文摘要
我们使用边缘测量结果来确定Guzmán等人对漫射无线电调查的尺度和零级校正。 $ 45 $ MHz和Landecker＆Wielebinski的价格为$ 150 $ MHz。我们发现Guzmán等人。地图需要$ 1.076 \ pm 0.034 $（$2σ$）和零级校正为$ -160 \ pm 78 $ k（$2σ$），以最好地拟合边缘数据。对于Landecker＆Wielebinski地图，比例校正为$ 1.112 \ pm 0.023 $（$2σ$），零级校正为$ 0.7 \ pm 6.0 $ k（$2σ$）。校正不确定性由系统效应支配，其中最显着的是边缘接收器，天线指向以及对流层和电离层效应的不确定性。我们传播了校正不确定性，以估计校正地图本身中的不确定性，并发现Guzmán等人的MAP亮度温度中的$2σ$不确定性在$ 3.2-7.5 \％$中。 Landecker＆Wielebinski地图的地图和$ 2.1-9.0 \％$，其中最大的不确定性发生在高银河纬度。校正后的地图可用于改善现有的弥漫性低频无线电天空模型，这是分析宇宙学$ 21 $ cm观测的必不可少的工具，并研究了宇宙微波背景高于宇宙微波背景和已知银河系和外层面贡献的无线电单极过量的存在。
We use EDGES measurements to determine scale and zero-level corrections to the diffuse radio surveys by Guzmán et al. at $45$ MHz and Landecker & Wielebinski at $150$ MHz. We find that the Guzmán et al. map requires a scale correction of $1.076 \pm 0.034$ ($2σ$) and a zero-level correction of $-160 \pm 78$ K ($2σ$) to best-fit the EDGES data. For the Landecker & Wielebinski map, the scale correction is $1.112 \pm 0.023$ ($2σ$) and the zero-level correction is $0.7 \pm 6.0$ K ($2σ$). The correction uncertainties are dominated by systematic effects, of which the most significant are uncertainty in the calibration of the EDGES receivers, antenna pointing, and tropospheric and ionospheric effects. We propagate the correction uncertainties to estimate the uncertainties in the corrected maps themselves and find that the $2σ$ uncertainty in the map brightness temperature is in the range $3.2-7.5\%$ for the Guzmán et al. map and $2.1-9.0\%$ for the Landecker & Wielebinski map, with the largest percent uncertainties occurring at high Galactic latitudes. The corrected maps could be used to improve existing diffuse low-frequency radio sky models, which are essential tools in analyses of cosmological $21$ cm observations, as well as to investigate the existence of a radio monopole excess above the cosmic microwave background and known Galactic and extragalactic contributions.
