Characterization of the repeating FRB 20220912A with the Allen Telescope Array
Characterization of the repeating FRB 20220912A with the Allen Telescope Array
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DOI：
10.1093/mnras/stad3630
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发表时间：
2023-12
影响因子：
4.8
通讯作者：
Sofia Z. Sheikh;Wael Farah;Alexander W Pollak;Andrew Siemion;M. Chamma;Luigi F. Cruz;Roy H. Davis-Roy-H.
中科院分区：
文献类型：
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作者：
Sofia Z. Sheikh;Wael Farah;Alexander W Pollak;Andrew Siemion;M. Chamma;Luigi F. Cruz;Roy H. Davis-Roy-H.
FRB 20220912 A是一个重复的快速射电暴（FRB），于2022年秋季被发现，并在几个月内保持高度活跃。我们报告的35个FRB的检测从541小时的后续观察这个源使用最近翻新的艾伦望远镜阵列，覆盖1344 MHz的带宽主要集中在1572 MHz。所有35个FRB在带的下半部分被检测到，在上半部分未检测到，并且覆盖4-431 Jy-ms（中值= 48.27 Jy-ms）的能量密度。我们发现与以前的中继器研究的一系列的spectrotemporal功能，包括一致性：随着时间的推移，向下的频率漂移的突发;带宽和中心频率之间的正相关性;和随着时间的推移，在子突发持续时间减少。我们报告了在两个月的观测活动中，观测到的爆发中心频率明显下降（相当于每天下降6.21 ± 0.76 MHz）。我们预测FRB 20220912 A的截止通量为Fmax 104 Jy-ms，因为该源与全天速率一致，并且发现FRB 20220912 A对全天FRB速率的贡献显着，对于100 Jy-ms的通量，贡献率为百分之几。我们研究了特征时间尺度和子爆发周期性，发现（a）在多分量爆发中，子爆发间的中值时间尺度为5.82 ± 1.16 ms，（B）即使在样品中间隔最均匀的多组分爆发中也没有严格周期性的证据。我们的研究结果表明，宽带观测FRB的重要性，并提供了一套重要的观测参数，对FRB祖和发射机制模型进行比较。
FRB 20220912A is a repeating Fast Radio Burst (FRB) that was discovered in Fall 2022 and remained highly active for several months. We report the detection of 35 FRBs from 541 h of follow-up observations of this source using the recently refurbished Allen Telescope Array, covering 1344 MHz of bandwidth primarily centred at 1572 MHz. All 35 FRBs were detected in the lower half of the band with non-detections in the upper half and covered fluences from 4–431 Jy-ms (median = 48.27 Jy-ms). We find consistency with previous repeater studies for a range of spectrotemporal features including: bursts with downward frequency drifting over time; a positive correlation between bandwidth and centre frequency; and a decrease in sub-burst duration over time. We report an apparent decrease in the centre frequency of observed bursts over the two months of the observing campaign (corresponding to a drop of 6.21 ± 0.76 MHz per d). We predict a cut-off fluence for FRB 20220912A of Fmax ≲ 104 Jy-ms, for this source to be consistent with the all-sky rate, and find that FRB 20220912A significantly contributed to the all-sky FRB rate at a level of a few per cent for fluences of ∼100 Jy-ms. Finally, we investigate characteristic time-scales and sub-burst periodicities and find (a) a median inter-subburst time-scale of 5.82 ± 1.16 ms in the multi-component bursts and (b) no evidence of strict periodicity even in the most evenly spaced multi-component burst in the sample. Our results demonstrate the importance of wideband observations of FRBs, and provide an important set of observational parameters against which to compare FRB progenitor and emission mechanism models.