The 21 cm Power Spectrum from the Cosmic Dawn: First Results from the OVRO-LWA
The 21 cm Power Spectrum from the Cosmic Dawn: First Results from the OVRO-LWA
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DOI：
10.3847/1538-3881/ab2629
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发表时间：
2019-06
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影响因子：
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通讯作者：
M. Eastwood;M. Anderson;R. Monroe;G. Hallinan;M. Catha;J. Dowell;H. Garsden;L. Greenhill;B. Hicks;J. Kocz;D. Price;F. Schinzel;H. Vedantham;Yuankun Wang
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文献类型：
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作者：
M. Eastwood;M. Anderson;R. Monroe;G. Hallinan;M. Catha;J. Dowell;H. Garsden;L. Greenhill;B. Hicks;J. Kocz;D. Price;F. Schinzel;H. Vedantham;Yuankun Wang
中性氢的21厘米跃迁为宇宙的宇宙黎明--第一颗星星形成的时代--打开了一扇观测窗口。我们使用欧文斯谷射电天文台长波阵列的28小时数据，在z = 18.4（）处对21 cm发射的空间功率谱设置上限，并在EDGES实验报告的吸收特征范围内。在这个过程中，我们展示了双Karhunen-Loève变换的前景滤波的第一个应用程序，并诊断目前限制测量的系统误差。我们还提供了一个更新的模型，从北方半球测量的低频前景发射的角功率谱，它可以用来完善下一代实验的灵敏度预测。
The 21 cm transition of neutral hydrogen is opening an observational window into the Cosmic Dawn of the universe—the epoch of first star formation. We use 28 hr of data from the Owens Valley Radio Observatory Long Wavelength Array to place upper limits on the spatial power spectrum of 21 cm emission at z ≈ 18.4 ( ), and within the absorption feature reported by the EDGES experiment. In the process we demonstrate the first application of the double Karhunen–Loève transform for foreground filtering, and diagnose the systematic errors that are currently limiting the measurement. We also provide an updated model for the angular power spectrum of low-frequency foreground emission measured from the northern hemisphere, which can be used to refine sensitivity forecasts for next-generation experiments.