论文标题
核/FRB实验的注射系统
An Injection System for the CHIME/FRB Experiment
论文作者
论文摘要
搜索快速无线电爆发（FRB）的专用调查受到选择效应的影响，这些效应偏向于观察到的事件人群。软件注入系统是一种通过将合成FRB的模拟人群直接注入实时搜索管道中来纠正这些偏见的一种方法。然后，只要正确考虑了望远镜特征（例如梁模型和校准因子），就可以使用注射的种群将固有的爆发特性映射到预期的信噪比（SNR）上。本文介绍了为加拿大氢强度映射实验（Chime/FRB）开发的注射系统。测试了该系统以确保高检测效率，并验证了脉冲校准方法。使用〜85,000个合成FRB的注射群，我们发现注射FRB的通量与SNR之间的相关性与第一个Chime/FRB目录中的Chime/FRB检测结果一致。我们还注意到，望远镜的灵敏度随着宽阔的爆发宽度的函数而差异很大，但不是分散度度量的函数。我们得出的结论是，可以使用注射数据重新训练Chime/FRB使用的一些基于机器学习的射频干扰（RFI）缓解方法，以提高对广泛事件的敏感性，并且计划对提出的注射系统的升级将允许确定更准确的Chime/FR BRB选择在不久的将来的功能。
Dedicated surveys searching for Fast Radio Bursts (FRBs) are subject to selection effects which bias the observed population of events. Software injection systems are one method of correcting for these biases by injecting a mock population of synthetic FRBs directly into the realtime search pipeline. The injected population may then be used to map intrinsic burst properties onto an expected signal-to-noise ratio (SNR), so long as telescope characteristics such as the beam model and calibration factors are properly accounted for. This paper presents an injection system developed for the Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst project (CHIME/FRB). The system was tested to ensure high detection efficiency, and the pulse calibration method was verified. Using an injection population of ~85,000 synthetic FRBs, we found that the correlation between fluence and SNR for injected FRBs was consistent with that of CHIME/FRB detections in the first CHIME/FRB catalog. We also noted that the sensitivity of the telescope varied strongly as a function of the broadened burst width, but not as a function of the dispersion measure. We conclude that some of the machine-learning based Radio Frequency Interference (RFI) mitigation methods used by CHIME/FRB can be re-trained using injection data to increase sensitivity to wide events, and that planned upgrades to the presented injection system will allow for determining a more accurate CHIME/FRB selection function in the near future.
