Improving the Epoch of Reionization Power Spectrum Results from Murchison Widefield Array Season 1 Observations
Improving the Epoch of Reionization Power Spectrum Results from Murchison Widefield Array Season 1 Observations
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DOI：
10.3847/1538-4357/ab40a8
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发表时间：
2019-09
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通讯作者：
N. Barry;M. Wilensky;C. Trott;B. Pindor;A. Beardsley;B. Hazelton;I. Sullivan;M. Morales;J. Pober;J. Line;B. Greig;R. Byrne;A. Lanman;W. Li;C. Jordan;R. Joseph;B. McKinley;M. Rahimi;S. Yoshiura;J. Bowman;B. Gaensler;J. Hewitt;D. Jacobs;D. Mitchell;N. Udaya Shankar;S. Sethi;R. Subrahmanyan;S. Tingay;R. Webster;J. Wyithe
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作者：
N. Barry;M. Wilensky;C. Trott;B. Pindor;A. Beardsley;B. Hazelton;I. Sullivan;M. Morales;J. Pober;J. Line;B. Greig;R. Byrne;A. Lanman;W. Li;C. Jordan;R. Joseph;B. McKinley;M. Rahimi;S. Yoshiura;J. Bowman;B. Gaensler;J. Hewitt;D. Jacobs;D. Mitchell;N. Udaya Shankar;S. Sethi;R. Subrahmanyan;S. Tingay;R. Webster;J. Wyithe
21厘米的再电离时代（EoR）结构的测量受到来自分析和观测条件的系统学。使用Murchison Widefield Array（MWA）2013年的数据，我们展示了减轻这两种污染源的重要性。Beardsley等人的结果与我们更新的分析结果之间的直接比较证明了新的精确技术，将分析系统性降低了2.8倍。然后，我们进一步降低系统切除观察污染的超微弱RFI，减少了额外的因素3.8的权力天顶指向。通过这种增强的分析精度和新开发的RFI缓解，我们使用21小时的数据计算出在k = 0.20 h Mpc−1和z = 7时EoR结构的噪声主导上限Δ2 ≤ 3.9 × 103 mK2，将以前的MWA限制提高了近一个数量级。
Measurements of 21 cm Epoch of Reionization (EoR) structure are subject to systematics originating from both the analysis and the observation conditions. Using 2013 data from the Murchison Widefield Array (MWA), we show the importance of mitigating both sources of contamination. A direct comparison between results from Beardsley et al. and our updated analysis demonstrates new precision techniques, lowering analysis systematics by a factor of 2.8 in power. We then further lower systematics by excising observations contaminated by ultra-faint RFI, reducing by an additional factor of 3.8 in power for the zenith pointing. With this enhanced analysis precision and newly developed RFI mitigation, we calculate a noise-dominated upper limit on the EoR structure of Δ2 ≤ 3.9 × 103 mK2 at k = 0.20 h Mpc−1 and z = 7 using 21 hr of data, improving previous MWA limits by almost an order of magnitude.