论文标题
测量HERA的主要光束原位：方法论和第一个结果
Measuring HERA's primary beam in-situ: methodology and first results
论文作者
论文摘要
21 cm宇宙学中的核心挑战是从明亮的前景中隔离宇宙学信号。许多分离技术都依赖于天空的准确知识和仪器响应，包括天线一束光束。 For drift-scan telescopes such as the Hydrogen Epoch of Reionization Array \citep[HERA, ][]{DeBoer2017} that do not move, primary beam characterization is particularly challenging because standard beam-calibration routines do not apply \citep{Cornwell2005} and current techniques require accurate source catalogs at the telescope resolution.我们从\ citet {pober2012}中提出了该方法的扩展，其中他们使用梁对称性建立了一个重叠源轨道网络，该网络破坏了源通量密度和梁响应之间的脱落性并允许同时估计。我们使用早期的HERA观察结果拟合仪器的光束响应，发现我们的结果与电磁模拟相对于具有高信噪比的峰值增益的电磁模拟非常吻合。此外，我们在151〜MHz时构建了一个具有90个源的源目录，至1.4〜JY的通量密度。
The central challenge in 21~cm cosmology is isolating the cosmological signal from bright foregrounds. Many separation techniques rely on the accurate knowledge of the sky and the instrumental response, including the antenna primary beam. For drift-scan telescopes such as the Hydrogen Epoch of Reionization Array \citep[HERA, ][]{DeBoer2017} that do not move, primary beam characterization is particularly challenging because standard beam-calibration routines do not apply \citep{Cornwell2005} and current techniques require accurate source catalogs at the telescope resolution. We present an extension of the method from \citet{Pober2012} where they use beam symmetries to create a network of overlapping source tracks that break the degeneracy between source flux density and beam response and allow their simultaneous estimation. We fit the beam response of our instrument using early HERA observations and find that our results agree well with electromagnetic simulations down to a -20~dB level in power relative to peak gain for sources with high signal-to-noise ratio. In addition, we construct a source catalog with 90 sources down to a flux density of 1.4~Jy at 151~MHz.
