Exploring the consequences of chromatic data excision in 21-cm epoch of reionization power spectrum observations
Exploring the consequences of chromatic data excision in 21-cm epoch of reionization power spectrum observations
复制标题
探索再电离功率谱观测的 21 厘米历元中彩色数据切除的后果
DOI：
10.1093/mnras/stab3456
复制
发表时间：
2021
影响因子：
4.8
通讯作者：
Morales, Miguel F.
中科院分区：
文献类型：
--
作者：
Wilensky, Michael J.;Hazelton, Bryna J.;Morales, Miguel F.
我们探讨如何彩色射频干扰（RFI）的旗帜影响21厘米功率谱测量。我们特别研究比分析分辨率更粗糙的标志。我们发现，这样的RFI标志产生多余的功率在EoR窗口中的剩余RFI的方式大致相同。我们使用快速全息反卷积（fhd）模拟来解释这是由于在阵列的干涉采样功能的色中断。我们还使用这些模拟与误差消除功率谱与交错观测噪声相结合，以表明如果不修改当前的标记策略或实施非常准确和完整的前景减法，21 cm EoR实验将无法进行显著检测。作为一种缓解策略，我们发现，通过在检测到RFI时标记整个分析波段来完全规避色结构，这是一种简单的实现方法，并且非常成功。这就需要一个低误报率的检测策略，以防止过多的数据丢失。
We explore how chromatic radio frequency interference (RFI) flags affect 21-cm power spectrum measurements. We particularly study flags that are coarser than the analysis resolution. We find that such RFI flags produce excess power in the EoR window in much the same way as residual RFI. We use Fast Holographic Deconvolution (fhd) simulations to explain this as a result of chromatic disruptions in the interferometric sampling function of the array. We also use these simulations in conjunction with Error Propagated Power Spectrum with InterLeaved Observed Noise to show that without modifying current flagging strategies or implementing extremely accurate and complete foreground subtraction, 21-cm EoR experiments will fail to make a significant detection. As a mitigation strategy, we find that circumventing the chromatic structure altogether by flagging the entire analysis band when RFI is detected is simple to implement and highly successful. This demands a detection strategy with a low false-positive rate in order to prevent excessive data loss.